Understanding the Interaction of Deficit Irrigation and ...

UNDERSTANDING THE INTERACTION OF DEFICIT IRRIGATION

AND MULCHING IN RAISED-BED IRRIGATION SYSTEM FOR

EFFICIENT WATER USE

By:

ABDUL MALIK

(2009-Ph.D-WRM-01)

FOR THE DEGREE OF

DOCTOR OF PHILOSOPHY

IN

WATER RESOURCES MANAGEMENT

FACULTY OF CIVIL ENGINEERING

CENTRE OF EXCELLENCE IN WATER RESOURCES ENGINEERING

University of Engineering and Technology, Lahore, Pakistan

2017

3

ABSTRACT

Deficit irrigation, mulching and planting methods are important factors that influence

the sugar beet yield and water use efficiency. A two years (2011/12 and 2012/13) field

study was conducted at Sugar Crops Research Institute, Mardan, Pakistan to investigate

the interactive effects of regulated deficit irrigation regimes, mulching and planting

methods on sugar beet yield components and water use efficiency under semi-arid

environment. The experimental setup consisted of three factors (irrigation, mulching

and planting methods) replicated three times. Thirty six treatments comprising of four

levels of irrigation regimes designated as (i) no deficit i.e. full irrigation (FI) , (ii) 20%

deficit irrigation (DI20), (iii) 40% deficit irrigation (DI40) and (iv) 60% deficit irrigation

(DI60); three levels of mulching (i) No Mulch (NM), (ii) Black Film Mulch (BFM) and

(iii) Straw Mulch (SM) and three planting methods (i) Conventional Ridge-Furrow

(CRF) planting (ii) medium raised bed (MRB) planting and (iii) Wide Raised-Bed

(WRB) planting. Soil moisture, irrigation water applied, and crop growth was

monitored through the growing season. Seasonal water used was determined by soil

moisture depletion studies. At maturity stage the crop was harvested. Sugar beet roots

yield and biomass were recorded in field, and sugar content in laboratory. Accordingly

from the collected data, Root Irrigation Water Use Efficiency (RIWUE), Sugar

Irrigation Water Use Efficiency (SIWUE), Root Crop Water Use Efficiency (RCWUE)

and Sugar Crop Water Use Efficiency (SCWUE) were determined. The effect of

treatments on sugar beet root yield, sugar content and sugar yield, RIWUE, SIWUE,

RCWUE and SCWUE were statistically evaluated. The sugar beet yield response

factors under different management practices were determined by Stewart‘s model.

AquaCrop model was used to predict the sugar beet canopy cover (CC), root yield and

biomass under different irrigation and soil management strategies.

Results of the study indicated that irrigation regimes significantly affected (at p < 0.05)

all the yield components and water use efficiency. Compared to full irrigation (FI), the

20%, 40% and 60% deficit irrigation regimes (DI20, DI40 and DI60), reduced the sugar

beet root yield that amounts 6.97, 20.03 and 35 %, respectively. Sugar yield was

significantly decreased (at p < 0.05) beyond DI20 with maximum decrease of 24.25%

was observed for DI60. Both the irrigation and crop water use efficiency were increased

with increasing level of irrigation deficit. The highest RIWUE with 17.06, SIWUE with

4

2.94, RCWUE with 9.72 and SCWUE with 1.67 kg m

-3 were obtained from DI60,

respectively. Mulching practices also significantly affected all the yield components

and water use efficiency. Maximum root yield (61.67 tons ha-1

) and sugar yield (9.96

tons ha-1

) were obtained in BFM. This was followed by SM with 58.18 tons ha-1

root

yield and 9.29 tons ha-1

sugar yield. RIWUE, SIWUE, RCWUE and SCWUE obtained

from BFM were 50.28, 19.58, 39.14 and 19.50% higher compared to that produced by

NM. Among the planting methods, highest root yield (61.04 tons ha-1

), sugar yield

(9.73 tons ha-1

), RIWUE (14.89 kg m-3

), SIWUE, (2.42 kg m-3

), RCWUE (10.63 kg m-

3) and SCWUE (1.74 kg m

-3) were recorded from MRB.

The interactions of irrigation regimes, mulching and planting methods significantly

affected sugar beet yield and water use efficiency components. The interaction of

FIBFMMRB produced significantly higher root yield (74.57 tons ha-1

) among all the

interactions. However, significantly higher sugar yield was obtained from

DI20BFMMRB. Comparing the results of DI40BFMMRB with conventional

practices (FINMCRF), it was observed that the root yield, sugar yield, RIWUE,

SIWUE, RCWUE and SCWUE obtained from the former were 10.32, 32.07, 135.55,

180.87, 91.28 and 127.96% higher from the later.

The seasonal crop yield response factors (Ky)root obtained under different planting

methods was ranged from 0.93 to 0.99 for NM, 0.53 to 0.61 for BFM and 0.65 to 0.71

for SM, respectively. Similarly (Ky)sugar obtained was ranged from 0.69 to 0.81 for NM,

0.31 to 0.50 for BFM and 0.43 to 0.47 for SM, respectively.

The relationships between sugar beet root yield and seasonal evapotranspiration (ET)

was curvilinear for mulch conditions and linear for No Mulch. However, the

relationship between sugar yield and ET was curvilinear irrespective of the mulching

condition.

The Food and Agricultural Organization (FAO) AquaCrop model was used to predict

the sugar beet CC, root yield and biomass under different in-field water management

practices. On the basis of different statistical indicators, such as Root Mean Square

Error (RMSE), Normalized Root Mean Square Error (NRMSE), index of agreement

5

(dindex), Nash–Sutcliffe Efficiency Factor (EF) and the Mean Bias Error (MBE), it was

observed that the AquaCrop model was in an excellent agreement between the observed

and simulated values of CC for all the calibrated fields irrespective of the mulching

condition and planting methods. The model also accurately simulated both the biomass

and root yield for all the calibrated fields. Validation results for conventional ridge

furrow planting (CRF) indicated good agreement between the simulated biomass and

root yield with their observed values. In medium raised bed planting, no significant

deviations of the simulated biomass and root yield from the measured values were

found for MRBNMDI20 . However deviation observed was significant for increased

stress level. In wide raised bed planting, good agreement between simulated and

measured biomass and root yield was found for all stress levels applied under SM

treatments. Under BFM treatment, the model performed very well for DI20 and DI40

treatments. For NM treatments, the model performance was good only under DI20. For

DI60, the model highly overestimated both the biomass and root yield for

NM and BFM treatment.

6

ACKNOWLEDGEMENTS

The author wishes to express his deepest gratitude to his thesis supervisor Prof.

Dr. Abdul Sattar Shakir, Dean Faculty of Civil Engineering, University of Engineering

& Technology, Lahore, for his valuable suggestion, best supervision, affectionate

behavior, keen interest and encouragement throughout the course of my studies.

I would like to express my gratitude and special thanks to my first advisor Prof.

Dr. Muhammad Latif for his valuable guidance and incredible encouragement during

my experimental works.

I also express deep gratitude to Dr. Muhammad Jamal, Professor Department of

Water Management, Agricultural University, Peshawar, for his helpful suggestions and

incredible encouragement throughout my research period.

I am thankful to Dr. Habeeb-ur-Rahman, Director, Centre of Excellence in

Water Resources Engineering, University of Engineering & Technology, Lahore, and

his staff for time to time help.

I express my indebtedness to the Director Sugar Crop Research Institute,

Mardan, Pakistan for providing the research facilities for conducting field experiments.

Special thanks to Mr Ismaeel, Agricultural Research Officer at SCRI for his technical

help during laboratory work.

I wish to acknowledge my external examiners; Prof. Dr. Abdul Razzaq

Gummen, Dean Faculty of Civil Engineering, University of Engineering & Technology,

Taxila, and Prof. Dr. Hashim Nisar Hashmi, Chairman, Department of Civil

Engineering, University of Engineering & Technology, Taxila, Dr. T.P. Curtis,

Professor of Environmental Engineering, School of Civil Engineering & Geosciences,

Newcastle University and Prof. DAWEI HAN.

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Special Thanks to Prof. Dr. Taj Ali Khan, Chairman Department of Agricultural

Engineering, University of Engineering & Technology, Peshawar for his valuable

support throughout my Ph. D research period.

Special thanks to Dr. Aftab, Senior Engineer WAPDA, Faisalabad, and all the

staff of Agricultural Engineering Department, University of Engineering & Technology,

Peshawar, for their valuable comments and guidance.

I have no words to express my feelings of affectionate gratitude for my beloved

uncle Dr. Mahmood Khan, who help me morally and financially throughout my

educational career.

Last but not least, I express my gratitude to my beloved parents, wife, children,

brothers and sisters for their continuous support, prayers and love throughout my career.

Engr. Abdul Malik

[email protected]

8

TABLE OF CONTENTS

Chapter No. Description Page #

ABSTRACT ........................................................................................................ iii

ACKNOWLEDGEMENT ................................................................................................. vi

TABLE OF CONTENTS ................................................................................................... viii

LIST OF TABLES ........................................................................................................ xi

LIST OF FIGURES ........................................................................................................ xiv

I INTRODUCTION .................................................................................................. 1

1.1 GENERAL ........................................................................................................ 1

1.2 PROBLEM STATEMENT .................................................................................... 5

1.3. OBJECTIVES ........................................................................................................ 7

II REVIEW OF LITERATURE ................................................................................. 8

2.1 DEFICIT IRRIGATION ....................................................................................... 8

2.1.1 Deficit irrigation practices in Pakistan ....................................................... 8

2.1.2 Effect of deficit irrigation practices on sugar beet yield and

water use efficiency .................................................................................... 9

2.3 MULCHING EFFECTS ......................................................................................... 14

2.3.1 Effect of plastic film mulching on crop yield and water use

efficiency .................................................................................................... 15

2.3.2 Effect of straw mulch on crop yield and water use efficiency ................... 17

2.4 FURROW IRRIGATED RAISED BED PLANTING METHODS ...................... 20

2.5 CROP GROWTH SIMULATION MODELS ........................................................ 22

2.5.1 AquaCrop model ........................................................................................ 24

III MATERIALS AND METHODS ........................................................................... 26

3.1 EXPERIMENTAL SITE AND CLIMATIC CONDITIONS ................................ 26

3.2 EXPERIMENTAL TREATMENTS AND DESIGN ............................................ 29

3.3 EXPERIMENTAL FIELD PREPARATION ........................................................ 33

3.4 CROP MANAGEMENT PRACTICES ................................................................ 33

3.5 SOIL DATA ........................................................................................................ 35

3.5.1 Soil texture ................................................................................................ 35

3.5.2 Soil bulk density ..................................................................................... 35

3.5.3 Soil pH and electrical conductivity (EC) .................................................. 36

3.5.4 Determination of soil moisture content ...................................................... 36

3.5.5 Soil available water capacity ...................................................................... 37

9

Table of Contents (Continued)

3.6 IRRIGATION APPLICATION ............................................................................. 37

3.7 EXPERIMENTAL RECORDINGS AND CALCULATIONS ............................ 38

3.7.1 Seed germination data ................................................................................ 38

3.7.2 Percent ground cover measurement ........................................................... 39

3.7.3 Harvesting .................................................................................................. 39

3.8 ROOT AND SUGAR IRRIGATION WATER USE EFFICIENCY .................... 39

3.9. ROOT AND SUGAR IRRIGATION CROP WATER USE EFFICIENCY ........ 40

3.10 CROP YIELD RESPONSE FACTOR (KY) ......................................................... 40

3.11 STATISTICAL ANALYSIS .................................................................................. 40

3.12 THE AQUACROP MODEL INPUT DATA ......................................................... 41

3.13 MODEL CALIBRATION, VALIDATION AND EVALUATION ...................... 43

3.14 MODEL PERFORMANCE ASSESSMENT ......................................................... 44

IV RESULTS AND DISCUSSIONS .......................................................................... 45

4.1 EFFECT OF IRRIGATION REGIMES ON SUGAR BEET YIELD

COMPONENTS ..................................................................................................... 45

4.2 EFFECT OF MULCHING ON SUGAR BEET YIELD COMPONENTS ........... 48

4.3 EFFECT OF PLANTING METHODS ON SUGAR BEET YIELD

COMPONENTS ..................................................................................................... 53

4.4 INTERACTION EFFECT OF IRRIGATION REGIMES AND MULCHING

ON SUGAR BEET YIELD COMPONENTS ....................................................... 54

4.5 INTERACTION EFFECT OF IRRIGATION REGIMES AND PLANTING

METHODS ON SUGAR BEET YIELD COMPONENTS ................................... 60

4.6 INTERACTION EFFECT OF MULCHING AND PLANTING METHODS ON

SUGAR BEET YIELD COMPONENTS .............................................................. 64

4.7 INTERACTION EFFECT OF IRRIGATION REGIMES, MULCHING

PRACTICES AND PLANTING METHODS ON SUGAR BEET

YIELD COMPONENTS ........................................................................................ 67

4.8 EFFECT OF IRRIGATION REGIMES, MULCHING PRACTICES AND

PLANTING METHODS ON THE AMOUNT OF APPLIED

IRRIGATION ........................................................................................................ 74

4.8.1 Main Effects ............................................................................................... 74

4.8.2 Interaction Effect of Irrigation Regimes and Mulching on Irrigation

Application Depth ..................................................................................... 75

4.8.3 Interaction Effect of Irrigation Regimes and planting methods on

Irrigation Application Depth ..................................................................... 77

4.8.4 Interaction Effect of Mulching and Planting methods on Irrigation

Application Depth ..................................................................................... 80


PLANTING METHODS ON THE AMOUNT OF SEASONAL

WATER USED ..................................................................................................... 82

10

Table of Contents (Continued)

4.9.1 Main Effects ............................................................................................... 82

4.9.2 Interaction Effect of Irrigation Regimes and Mulching on Sugar

Beet Seasonal Water Used ......................................................................... 84

4.9.3 Interaction Effect of Irrigation Regimes and Planting methods on

Sugar Beet Seasonal Water Used ............................................................... 86

4.9.4 Interaction Effect of Mulching and Planting methods on Sugar

Beet Seasonal Water Used ......................................................................... 88


PLANTING METHODS ON IRRIGATION WATER USE EFFICIENCY ........ 90

4.10.1 Main Effects ............................................................................................. 90

4.10.2 Interaction Effects ................................................................................... 96


PLANTING METHODS ON CROP WATER USE EFFICIENCY .................... 107

4.11.1 Main Effects ............................................................................................... 107

4.11.2 Interaction Effects ...................................................................................... 112

4.12 RELATIONSHIP BETWEEN SEASONAL EVAPOTRANSPIRATION AND

YIELD COMPONENTS OF SUGAR BEET ....................................................... 128

4.13 SUGAR BEET YIELD RESPONSE FACTOR (Ky) ............................................. 131

V AQUACROP MODEL CALIBRATION, VALIDATION

AND EVALUATION ............................................................................................ 137

5.1 MODEL PARAMETERS ...................................................................................... 137

5.2 CALIBRATION RESULTS FOR CANOPY COVER (CC) ................................. 139

5.3 VALIDATED RESULTS FOR CANOPY COVER (CC) ..................................... 140

5.4 CALIBRATED RESULTS FOR SUGAR BEET BIOMASS AND

ROOT YIELD ........................................................................................................ 145

5.5 SUGAR BEET BIOMASS AND ROOT YIELD VALIDATION ........................ 147

5.5.1 Validation Results for Conventional ridge-furrow (CRF) Planting ........... 147

5.5.2 Validation Results for Medium Raised-Bed (MRB) planting ................... 149

5.5.3 Validation Results for Wide Raised-Bed (WRB) Planting ........................ 151

VI SUMMERY, CONCLUSION and RECOMMENDATIONS ............................... 153

6.1 SUMMERY ........................................................................................................ 153

6.2. CONCLUSION ...................................................................................................... 162

6.3 RECOMMENDATIONS ....................................................................................... 165

REFRENCES ........................................................................................................ 167

11

LIST OF TABLES

Table No. Description Page No.

3.1 Main plots: Irrigation treatments ........................................................................... 30

3.2 Sub plots: Type of Mulching practices .................................................................. 30

3.3 Sub-sub plots: Furrow irrigated raised-bed planting methods ............................... 30

3.4 Details of treatments ............................................................................................... 31

3.5 Physical and chemical properties of the experimental site..................................... 35

4.1 Effect of irrigation regimes on sugar beet root yield, sugar content and

sugar yield during 2011/2012 and 2012/2013 cropping seasons ........................... 47

4.2 Mulching effect on sugar beet root yield, sugar content and sugar yield

during 2011/2012 and 2012/2013 cropping seasons .............................................. 49

4.3 Effect of different planting methods on sugar beet root yield, sugar content

and sugar yield during 2011/2012 and 2012/2013 cropping seasons ..................... 55

4.4 Interaction effect of irrigation regimes and mulching on yield components of

sugar beet. ........................................................................................................ 58

4.5 Interaction effect of irrigation regimes and planting methods on

yield components of sugar beet .............................................................................. 62

4.6 Interaction effect of Mulch and planting methods on yield components of

Sugar beet ........................................................................................................ 66

4.7 Interaction effect of irrigation regimes, mulching and cropping methods

on yield components of Sugar beet ....................................................................... 70

4.8 Mean depths of irrigation water applied (mm) to different treatments .................. 75

4.9 Interaction effects of irrigation regimes and mulch types on amount of

irrigation water applied .......................................................................................... 76

4.10 Interaction effects of irrigation regimes and planting methods on amount

of irrigation water applied ...................................................................................... 77

4.11 Interaction effects of mulching and planting methods on amount of irrigation

water applied to sugar beet crop in year 2011/2012 and 2012/2013 ..................... 80

4.12 Mean amount of seasonal water used (mm) by main treatments ........................... 83

12

4.13 Interaction effects of irrigation regimes and mulch types on amount of

sugar beet seasonal water used during 2011/2012 and 2012/2013

cropping seasons .................................................................................................... 86

4.14 Interaction effects of irrigation regimes and planting methods on amount

of sugar beet seasonal water used in year 2011/2012 and 2012/2013 ................... 87

4.15 Interaction effects of Mulching and planting methods on amount of sugar

beet seasonal water used in year 2011/2012 and 2012/2013 ................................. 88

4.16 Effect of irrigation regimes on root and sugar irrigation water use efficiencies .... 92

4.17 Effect of different types of mulching on root and sugar irrigation water

use efficiencies ....................................................................................................... 93

4.18 Effect of different planting methods on root and sugar irrigation water

use efficiencies ....................................................................................................... 93

4.19 Interaction effect of irrigation regimes and mulching on root and

sugar irrigation water use efficiencies .................................................................... 98

4.20 Interaction effects of irrigation regimes and planting methods on root and

sugar irrigation water use efficiencies .................................................................... 100

4.21 Interaction effect of mulching and planting methods on root and sugar irrigation

water use efficiencies ............................................................................................. 102

4.22 Interaction effects of irrigations regimes, mulching and planting methods

on root and sugar irrigation water use efficiencies ................................................ 105

4.23 Effect of irrigation regimes on root and sugar crop water use efficiencies ............ 108

4.24 Effect of different types of mulching on root and sugar crop water use

Efficiencies ........................................................................................................ 110

4.25 Effect of different planting methods on root and sugar crop water use

Efficiencies ........................................................................................................ 112

4.2 Interaction effect of irrigation regimes and mulching on root and sugar

crop water use efficiencies ..................................................................................... 114

4.27 Interaction effects of irrigation regimes and planting methods on root and

sugar crop water use efficiencies ........................................................................... 117

4.28 Interaction effect of mulching and furrow irrigated raised bed planting methods

on root and sugar crop water use efficiencies ........................................................ 119

4.29 Interaction effects of irrigations, mulching and planting methods on root

and sugar crop water use efficiencies ..................................................................... 126

13

4.30 Effect of deficit irrigation regimes (applied under different planting systems

and mulching conditions) on sugar beet yield response factor (ky) ....................... 132

5.1 Main parameters in the AquaCrop model calibrated for Sugar beet. ..................... 138

5.2 Statistical values based on the simulated and measured canopy cover for

the calibration fields (FI) during the 2011/2012 cropping season.......................... 139

5.3 Statistical values based on the simulated and the measured canopy cover

for validated fields (DI) during the 2011/2012 cropping season ........................... 141

5.4 Observed and simulated results of calibrated biomass and root yield of

sugar beet during the 2011/2012 cropping season ................................................. 146

5.5 Statistical results between the simulated and observed biomass and root

yield for the calibration fields during the 2011/12 irrigation season ..................... 146

5.6 Observed and simulated results of validated biomass (tons ha-1

) and root

yield (tons ha-1

) of sugar beet under conventional Ridge-Furrow planting .......... 148

5.7 Statistical results of the validated fields under conventional ridge-furrow

planting for different irrigation regimes and mulching types ................................ 148


) and root yield

(tons ha-1

) of sugar beet under Medium Raised-Bed planting ............................... 150

5.9 Statistical results of the validated fields under Medium Raised-bed

(MRB) planting pattern for different irrigation regimes and mulching ................. 150


) and root yield

(tons ha-1

) of sugar beet under Wide Raised-Bed planting .................................... 152

5.11 Statistical results of the validated fields under Wide Raised-bed planting

pattern for different irrigation regimes and mulching types................................... 152

14

LIST OF FIGURES

Figure No. Title Page No.

3.1 Location of the study area ...................................................................................... 27

3.2 Mean monthly maximum and minimum temperature for 66 years in

Peshawar valley (1947 - 2013). .............................................................................. 27

3.3 Mean monthly rainfall for 66 years (1947 - 2013) in Peshawar valley .................. 28

3.4 Comparison made between mean monthly rainfall for the years 1947 - 2000

and 2001 - 2013 in Peshawar valley ....................................................................... 28

3.5 Mean monthly maximum and minimum (a) air temperature and (b) Soil

temperature for the study site during 2011/2012 and 2012/2013 cropping

seasons ........................................................................................................ 29

3.6 Experimental Layout Plan ...................................................................................... 34

3.7 Diagram of AquaCrop input data (adapted from Raes et al., 2009) .......................

3.8 (a) Daily rainfall data for experimental site during 2011/2012 crop growing

season (b) Daily sunshine, wind speed, maximum and minimum relative

humidity data for experimental site during 2011/2012 crop growing season

(c)Daily maximum and minimum air temperature data at experimental site

during 2011/2012 crop growing season ................................................................ 43

4.1 (a, b, c). Relative increase/decrease in sugar beet (a) root yield (b) sugar

content and (c) sugar yield due to deficit irrigation regimes .................................. 49

4.2 (a, b, c). Relative increase/decrease in sugar beet (a) root yield (b) sugar

content and (c) sugar yield due to deficit mulching practices ................................ 52

4.3 (a, b, c). Relative increase/decrease in sugar beet (a) root yield (b)

sugar content and (c) sugar yield due to different planting methods. .................... 56

4.4 (a, b, c). Relative increase/decrease in (a) root yield (b) sugar content

and (c) sugar yield of sugar beet caused by the interaction effect of

different irrigation regimes and mulching practices. ............................................. 59

4.5 (a, b, c). Relative increase/decrease in (a) root yield (b) sugar content

and (c) sugar yield of sugar beet caused by the interaction effect of

different irrigation regimes and planting methods. ................................................ 63

4.6 (a, b, c). Relative increase in sugar beet (a) root yield (b) sugar content

and (c) sugar yield caused by the interaction effect of different mulching

and raised-bed planting methods ............................................................................ 67

15

4.7 % increase/decrease in root yield of sugar beet caused by interaction effect

of different irrigation regimes, mulching practices and planting methods

relative to FI-NM-CRF treatment .......................................................................... 71

4.8 % increase in sugar contents of sugar beet caused by interaction effect

of different irrigation regimes, mulching practices and planting methods

relative to FI-NM-CRF treatment .......................................................................... 72

4.9 % increase/decrease in sugar yield of sugar beet caused by interaction

effect of different irrigation regimes, mulching practices and planting

methods relative to FI-NM-CRF treatment ............................................................ 73

4.10 Effect of irrigation regimes, Mulch type and planting method pattern on

amount of irrigation water applied (mm) to sugar beet crop during 2011/2012

and 2012/2013 cropping ......................................................................................... 75

4.11 Interaction effect of Irrigation regimes and mulching on the amount of

irrigation water applied to sugar beet during 2011/2012 and 2012/2013

cropping season .................................................................................................... 78

4.12 Relative irrigation water saving by the interaction effects of irrigation

regimes and mulching practices ............................................................................. 78

4.13 Interaction effect of Irrigation regimes and planting methods on the amount

of irrigation water applied to sugar beet during 2011/2012 and

2012/2013 cropping season .................................................................................. 79

4.14 Relative irrigation water saving by the interaction effects of irrigation

regimes and planting pattern .................................................................................. 79

4.15 Interaction effect of mulch types and planting methods on the amount of


cropping season ...................................................................................................... 81

4.16 Relative irrigation water saving by the interaction effects of different

mulching and planting methods ............................................................................. 81

4.16 Effect of irrigation regimes, Mulch type and planting method on amount

of irrigation water used (mm) by sugar beet crop during 2011/2012

and 2012/2013 cropping ......................................................................................... 83

4.18 % decrease in seasonal water used of sugar beet under different irrigation

regimes, mulch types and planting methods for 2011/2012 and

2012/2013 cropping year ......................................................................................... 84

4.19 Relative decrease in seasonal water used of sugar beet under

different combination of irrigation regimes and mulch types ................................ 85

4.20 Relative decrease in seasonal water used of sugar beet under

different combination of irrigation regimes and planting methods ......................... 87

16

4.21 Interaction effects of mulching and planting methods on amount of

seasonal water used (mm) by sugar beet crop during 2011/2012 and

2012/2013 cropping ................................................................................................. 89

4.22 % decrease in seasonal water used of sugar beet under different combination

of mulching and planting methods for 2011/2012 and 2012/2013

cropping year ........................................................................................................ 89

4.23 Effect of irrigation regimes on root and sugar irrigation water use efficiency

of sugar beet for 2011/2012 and 2012/2013 cropping seasons ............................... 93

4.24 % increase in average root and sugar irrigation water use efficiency by

deficit irrigation treatments in comparison to full irrigation .................................. 94

4.25 Mulching effect on root and sugar irrigation water use efficiency of sugar

beet for 2011/2012 and 2012/2013 cropping seasons ............................................. 94


Black polyethylene film mulch and straw mulch treatments in comparison

to no-mulch treatment ............................................................................................ 95

4.27 Effect of planting methods on root and sugar irrigation water use efficiency

of sugar beet for 2011/2012 and 2012/2013 cropping Seasons ............................. 95


medium and wide raised bed furrow irrigated planting in

comparison to conventional ridge-furrow planting ................................................ 96

4.29 Relative increase in root and sugar irrigation water use efficiencies caused

by interaction effect of irrigation regimes and mulching practices ........................ 98

4.30 % increase in average root and sugar water use efficiency by interaction

effect of different irrigation regimes and planting methods over

FI CRF treatment .................................................................................................... 101

4.31 Relative increase in root and sugar irrigation water use efficiencies

by interaction effect of different mulching and cropping methods ........................ 103

4.32 Relative increase in average root and sugar irrigation water use efficiency

by interaction effect of different irrigation regimes, mulching and

planting methods .................................................................................................... 106

4.33 Relative increase in root and sugar crop water use efficiency by

irrigation regimes ................................................................................................... 108

4.34 Relative increase in root and sugar water use efficiency caused by black

film and straw mulches treatments ......................................................................... 110

4.35 Relative increase in root and sugar water use efficiency caused by medium

and wide planting methods ..................................................................................... 112

17


interaction effect of different irrigation regimes and mulches practices ................ 115


interaction effect of irrigation regimes and planting methods ............................... 117


interaction effect of mulching practices and planting methods .............................. 119


interaction effect of different irrigation regimes, mulching practices

and furrow irrigated raised-bed planting methods ................................................. 127

4.40 Relationship between sugar beet root yield and evapotranspiration (ET)

under straw and Black polyethylene film mulch situation in Semi-arid area

of Pakistan ........................................................................................................ 129

4.41 Relationship between sugar beet root yield and evapotranspiration (ET) under

no-mulch situation in Semi-arid area of Pakistan ................................................. 129

4.42 Relationship between sugar beet sugar yield and evapotranspiration (ET)

for under straw and Black Film Mulch under straw and

Black Film Mulch situation in Semi-arid area of Pakistan .................................... 130

4.43 Relationship between sugar beet sugar yield and evapotranspiration (ET) for

no-mulch situation in Semi-arid area of Pakistan .................................................. 130

4.44 Sugar beet yield response factor for different furrow irrigation/planting

systems with out application of any kinds of mulches ........................................... 134


systems with application of black film mulch (BFM) ............................................ 135


systems with application of straw mulch (SM) ...................................................... 136

5.1 Days after sowing of four phonological stages obtained from the calibration

fields during 2011/2012 cropping season ............................................................... 137

5.2 (a, b, c). Observed versus simulated canopy cover of sugar beet for the nine

calibration fields during the 2011/12 crop season. ................................................. 140

5.3 (a, b, c, d, e, f, g, h and i). Observed versus simulated canopy cover of sugar

beet for the twenty seven validation fields with three different deficit irrigation

regimes (DI20, DI40, DI60), three mulching systems (NM, BFM, SM) and three

planting methods (CRF, MRB, WRB). .................................................................. 145

18

CHAPTER I

INTRODUCTION

1.1 GENERAL

Water plays crucial role in all aspects of earth life systems and it is a significant

component of sustainable agricultural development in arid and semi-arid areas where

water is becoming increasingly a scarce resource and the water scarcity has become the

single greatest threat to life sustenance and natural ecosystem (FAO, 2007). Currently

about 4.0 billion people facing severe water scarcity (Mekonnen and Hoekstra, 2016).

By the end of third decade of the current century, almost half of the global population

will be living under severely high water stress conditions (OECD, 2008). The situation

is exacerbated by population explosion and land use change in developing countries

(Gebretsadik, 2016).

Very limited fresh water will be available for agricultural use in the near future,

mainly due to the rising living standard and increased competition from industrial,

environmental and domestic sectors (UNESCO-WWAP, 2012). Adequate and

sustainable agricultural water management is therefore crucial at all levels; from

catchment, to irrigated district, to farm and field scale. Managing water resources at

macro-level is relatively difficult, time consuming and expensive, even though it is

unavoidable. By comparison, the field level water management is relatively of low cost,

more practicable and easily workable that can be managed in short period of time.

Improving field scale level water management through adoption of more efficient and

effective irrigation methods is therefore crucial so that to release more water for

domestic, industrial and recreational uses (Syial, 2016 ; Tagar et al., 2012).

About 80 to 90 % of the irrigated land in arid and semi arid regions of the world

is irrigated using relatively inefficient traditional flood irrigation technique (Tiercelin

and Vidal 2006). As a result, more than 20% of the global irrigated lands are seriously

damaged by the salinity build-up (Qadir et al., 2014). It is because of these sorts of

problems that the use of modern, high-tech and efficient micro irrigation methods (drip,

bubbler, sprinkler etc.) are advocated worldwide. However, in most of the developing

countries, farmers are often reluctant to adopt this high-tech technology due to their

high installation, operation and maintenance costs (Syial, 2016). As a result these

methods have not yet been widely adopted by farming communities in developing

countries. Under these circumstances, new on-farm irrigation strategies must be

19

established that are more effective and efficient for sustainable utilization of the

available scarce water resources. At the same time it should also be economical, easy to

install and operate, and which are readily acceptable to the farming community.

In recent years the water resources planners, managers and researchers have

diverted their attention towards deficit irrigation which is considered as valuable and

sustainable production strategy in dry regions (Geerts and Raes, 2009; Chartzonlakis

and Bertaki, 2015). It is the optimization strategy where the crop is exposed to a certain

level of water stress by irrigating deliberately below their water requirements either

during a particular growth stage or throughout the whole growing season with

expectation that any loss of yield will be compensated by increased production from the

additional irrigated area with the water saved by deficit irrigation (English and Raja,

1996; Kirda, 2002). It is considered as a new on-farm irrigation management strategy,

which is not only productive but also efficient and sustainable for water limiting areas

(Nagaz et al., 2012). The aim of this practice is to maximize water use efficiency and to

stabilize – rather than maximize – yields (Geerts and Raes, 2009). It is a valuable

technique that can be effectively utilized for expanding irrigable land with the same

amount of water in a given irrigation scheme and thus will help to increase over all

production. This practice has been recognized as an important water-saving approach

for the production of many field and horticultural crops (Chai, 2016). Research has

shown that, adopting suitable management strategies, yield under full irrigation is quite

comparable to the yield under moderate deficit irrigation (Arshad et al., 2014).

Therefore, in water limited areas, deficit irrigation can be considered as a useful tool for

optimizing yield. It is also considered as a novel water-saving irrigation technique that

can be used as an effective tool for mitigating drought effects on irrigated crops and for

ensuring sustainable use of available water resources (Stikić, 2014). ). In arid areas,

where water is a scarce resource, DI strategies have a significant advantage in terms of

yield and water use efficiency and for reduction of salinity buildup. However, before

adopting this strategy, one must have prior knowledge of the crop yield responses to

deficit irrigation (Nagaz et al., 2012).

Sugarbeet (Beta vulgaris L.), a member of Chenopodiaceae family, is an important

sugar crop containing about 13 to 22 percent sugar levels when harvested (Karamer, 2016). It is

one of the major sources of the world‘s sugar and ranked second only to sugarcane (Al Jbawi

and Al Zubi, 2016). Currently thirty percent of the world‗s supply of sugar is derived from

sugar beet, the major portion of which is produced in industrialized countries leading by

20

European Union, the United States and Russia (Rozman, 2015). Beet pulps and molasses are its

important by products used as a source of high quality animal feed (Park et. al., 2001;

Senthilkumar et. al., 2016). Sugar beet molasses could be successfully used as a hypertonic

solution in osmotic dehydration of fruits and vegetables, owing to its high content of dry matter

(Šarić et. al., 2016). Beet lime is another by-product of sugar beet used for counteracting soil

acidity (Olego et. al., 2016). Thus considering the high economic value of sugar beet and its

byproducts, integrating this crop into crop rotation system in arid and semi-arid areas of

Pakistan may provide potential benefits to growers.

Sugar beet in Pakistan is the second most important sugar crop after sugar cane.

According to W. R. Brown, a British agricultural scientist in North West Frontier Province of

the United India (now Khyber Pakhtunkhwa, Pakistan) stated in 1912 that Peshawar valley of

the province offers one of the best lands for sugar beet in the whole sub-continent (cited in

Alizai, 1975). In 1920, the Indian Sugar Committee declared that the future of the sugar beet in

India (that time United India) if lies any where is the NWFP and this region is more favorable

for cultivating sugar beet instead of sugar cane Furthermore, this crop has the ability to fit in

the cropping pattern of this area in such a way that it would not only be more economical and

profitable but it is such a crop in which Pakistan can compete with the most important

producers in the worlds Alizi (1975). Despite these facts, sugar beet yield in Pakistan is

one of the World‘s lowest and is continuously declining from 43 tons ha-1

in 2004/2005

to 22 tons ha-1

in 2013/2014, which is almost three to four times less than the potential

yield of 70 to 90 tons ha-1

in the area (Iqbal and Saleem, 2015). The non availability of

improved inputs, weed infestation, poor soil preparation, inefficient planting method,

late sowing due to delay harvesting of the previous crop and water scarcity are some of

the main reason of low yield in Pakistan.

In order to achieve higher water use efficiency and to make the water saving

irrigation techniques practicable for the farming community in Pakistan, sugar beet

should be cultivated under a certain level of deficit irrigation. This is because every

crop has a critical limit up to which it can tolerate water deficit beyond which it starts

losses in yield (Chai et al., 2016). Yonts (2011) reported no significance decrease in

sugar beet root and sugar yield for mild (25%) to moderate (50%) deficit irrigation.

However, significant loss in both the yield components was observed when severe

(75%) deficit irrigation was applied. Topak et al., (2011) and Taleghani et al. (1998)

noted that sugar beet root and sugar yield at mild stress (up to 25% deficit) was not

statistically different than that obtained at full irrigation, however, significant decreases

in the yield was noted for moderate (50% deficit irrigation) and severe water stresses

21

(75% deficit irrigation). Similar results were also reported by Mahmoodi et al., (2008)

and Sahin et al., (2014). In other studies, Ghamarnia et al., (2012) and Marsi et al.,

(2015), observed a significant decrease in sugar beet root and sugar yield even at mild

(25%) deficit irrigation. The loss in root and sugar yield by the application of deficit

irrigation regimes to the sugar beet crop may be covered by raising the crop on raised-

bed and adopting proper moisture conservation practices (mulching).

Against the background of the low water use efficiency in conventional ridge-

furrow planting (Burt et al., 1997), raised bed planting has been introduced in many

developing countries of the world. This planting method is a new paradigm that is

consider as an alternative to the conventional flood irrigation for improving farm level

water management in water scarcity regions (Ozberk et al., 2009). Naresh et al., (2012),

reported that the raised bed planting increased the Cabbage yield by 13.38 to 24.6%,

Okra yield by 27.84 to 32.14% and Brinjal yield by 0.86 to 11.25%, respectively,

compared to conventional ridge-furrow planting. The increase observed in water use

efficiency was 26.39 to 36.62% for Cabbage, 45.83 to 49.17% for Okra and 21.86 to

24.89% for Brinjal, respectively, compared to conventional ridge furrow planting.

Zahoor et al., (2010) reported significant increase (up to 36%) in sugar yield when

sugar beet was grown in the form of two rows raised planting compared to conventional

ridge-furrow planting. Halim and Abd El-Razek, (2013), reported 47% higher water use

efficiency when crop was grown in the form of bed planting compared to the

conventional ridge-furrow planting. The excellent performance of furrow irrigated

raised bed planting might be due to the better fertilize use efficiency (Hossain et al.,

2009), higher radiation use efficiency (Quanqi et al., 2007), reduced weed infestation

and better water distribution efficiency (Zahoor et al., (2010).

In arid and semi-arid regions of the world, huge amount of soil moisture is loss

every year through unproductive evaporation. (Khamraev and Bezborodov, 2016). As a

result, crops face stress conditions and thus require more water for their survival.

Therefore, reducing this large amount of unrecoverable water losses are very crucial,

and if minimized will strongly contribute to soil moisture conservation for crop

production in water scarcity areas (Mellouli et al., 2000). In order to minimize the rate

of evaporation, the effect of the factors responsible for evaporation such as capillary

rise, heat of evaporation and vapor pressure gradient (Budagovsky , 1964), should be

diminished. Modifying the soil surface conditions by adopting suitable soil

management technique such as mulching can be prove very effective to reduce the

22

effects of the above mentioned factors responsible for evaporation (Rahman et. al,

2016; Mellouli et al., 2000). Conserving soil moisture is one of the chief advantages of

mulch application and thus it is considered as a valuable tool to reduce the negative

effects of deficit irrigation on crop yield Chukalla et al., (2015). Apart from soil

moisture conservation, it also protects the top soil surface from the effect of rain drop

erosion and solar radiation (Iqbal et al., 2003). According to Jalota (1993), in arid and

semi-arid areas, 40 to 70 percent of water loss by evaporation from soil surface can be

prevented by mulching. Arash (2013) obtained 33% higher yield of Bean for mulched

treatment than the No Mulched treatment. Kabir et al., (2016) reported that mulch have

profound effects on the yield and yield contributing parameters. It also controls weed

infestation (Matković et al., 2015), improve soil texture (Nawaz t. al., 2016), improve

aeration (Mahmood et al., 2015) and modify soil temperature (Bristo, 2015).

The field experimental results are generally site specific that may not be

applicable to other sites with different soil and climatic conditions. Furthermore, field

experiments are expensive, laborious; require large number of field trials and

treatments. Also, the obtained results are influenced by the weather condition that

generally varies from year to year that makes it difficult to assess the amount of

irrigation from the field experiments (Iqbal et al., 2014). In solving these problems,

crop growth simulation models such as AquaCrop is a helpful tool for refining field

tests and lower their overall costs and risk uncertainties (Whisler et al., 1986).

1.2 PROBLEM STATEMENT

Agriculture has pivotal impact on socio-economic set-up of Pakistan. It is

currently contributing more than 20% share to the national GDP (Usman, 2016) and

employs about half of the country labor force (GOP, 2014-2015). About 66% of the

country population living in rural areas is either directly or indirectly involved in

agriculture for their lively hood (Khoso et al., 2015). Despite of the fact that agriculture

plays a pivotal role in Pakistan economy, it is hampered by various constraints that

created unfavorable atmosphere for favorable crop growth and improved yields.

Among these, water scarcity remains the most critical (WWF, 2012). The Asian

Development Bank has already declared the Pakistan as one of the world most water-

stressed countries, not far from being classified as ―water scarce,‖ with less than 1,000

cubic meters of water availability per capita per year. The current water storage

capacity in Pakistan is limited to only 30-days supply, much below the recommended

23

1,000 days for countries having similar climatic conditions (ADB, 2013). Furthermore,

the existing canal irrigation system in Pakistan has not the capacity to fulfill the

requirement of the current agriculture system with 200% cropping intensity instead of

70% on the basis of which the original irrigation system was designed. This situation

will be further deteriorated due to the global warming with the predicted decline in

water resources and increase in crop consumptive use as indicated by the climate

change studies by different researchers in the country (Naheed and Rasul, 2010; Awan

et al., 2016).

It means that best use of water must be made for efficient crop production so

that to obtain sustainable yields. The current planting methods and irrigation water

application practices being followed by the farmers in the study area have not the

capacity for sustainable sugar beet production. They are well experienced in using the

conventional surface irrigation methods and traditional agronomic practices. They have

however no attraction for adopting the modern irrigation technologies because of

having relatively higher initial and operating costs, higher technical skill requirements

for their operation and maintainers, unavailability of cheap indigenous components of

efficient planting methods, poor economical conditions of the farmers, low land

holdings, and uncertain electric supplies. In this context, field-scale irrigation water

management through novel irrigation techniques such as deficit irrigation (DI) and raised-bed

planting along with some soil management practice such as mulching looks to be one of the

promising water saving strategies (Chukalla et al., 2015). Individually, the effect of these

techniques on sugar beet yield and water use efficiency have been tested by different

researchers, irrigation engineers and water resources managers in different parts of the world;

however the interactive effect of different irrigation regimes and mulching practices in raised

bed irrigation system with different planting methods have not been thoroughly investigated.

Therefore, this research study was conducted with the over all objective to determine the

optimum and efficient amount of irrigation water application, suitable mulching and

better planting methods so that to ensure the sustainable utilization of available scarce

water resources in arid and semi-arid regions, and consequently to optimize water

productivity of sugar beet under limited water supply and existing environmental and

socio-economic constraints. The specific objectives are as fallow:

24

1.3 OBJECTIVES

1. To study the effects of deficit irrigation regimes on yield and water use

efficiency of sugar beet in raised-bed irrigation system.

2. To assess the effect of mulching practices on yield and water use efficiency of

sugar beet.

3. To determine optimal water use efficiency under different planting methods in

raised-bed irrigation system.

4. To evaluate the interaction effect of deficit irrigation regimes, mulching and

planting methods on yield components, water use efficiency and yield response

factor of sugar beet.

5. Simulate the sugar beet yield for optimum irrigation management strategies

under deficit irrigation regimes using AquaCrop model

25

CHAPTER II

REVIEW OF LITERATURE

2.1 DEFICIT IRRIGATION

Deficit irrigation (DI) is a practice through which crops are exposed to a certain

degree of water stress by irrigating deliberately below their water requirements. While

adopting this practice, the farmer may loss certain degree of yield; however, visible

amount of irrigation water can be saved. The saved irrigation water can thus be used for

bringing additional area under irrigation which can increase overall production.

Research has shown that, adopting suitable management strategies, yield under full

irrigation is quite comparable to the yield under moderate deficit irrigation

[(Mulubrehan and Gebretsadikan, (2016); Bozkurt et al., (2015); Alenazi et al., (2016)).

Therefore, in water limited areas, deficit irrigation can be considered as a useful tool for

optimizing yield.

2.1.1 Deficit Irrigation Practices in Pakistan

Tariq, J.A. and K. Usman, (2009) investigated the impact regulated deficit

irrigation on maize yield at Jamra Agriculture Farm at Takht-i-Bhai, Pakistan. Five

irrigation depths at the rate of 0.50, 0.75, 1.00 and 1.25 of pan-evaporation, and the

depth as per farmer‘s practices were applied, accordingly. Treatment that received

water in accordance to 0.75 of pan evaporation produced the highest average maize

yield (2993 kg ha-1

) and highest water use efficiency. The lowest yield (1993 kg ha-1

)

and lowest water use efficiency was observed for the treatment irrigated as per farmer

practices.

Iqbal M., et al., (1999) tested the effect of controlled deficit irrigation and

season long deficit irrigation on potato yield during the period 1990 – 1995 at Nuclear

Institute for Food and Agriculture, Peshawar, Pakistan. In their study, they applied

seven irrigation treatments. One treatment was given season long deficit irrigation; four

treatments were given stress at particular growth stage each at establishment, flowering,

tuber formation and during ripening, one treatment received optimum watering without

any stress and was control treatment that received water as per farmer‘s schedule. They

observed no yield loss for unstressed treatment, 4% yield loss for treatment that was

irrigated as per traditional practices at 10 to 15 days irrigation interval, 14% loss for

treatment that was kept under stress at flowering stage, 22% loss for treatment kept

26

under stress at tuber formation stage and the highest (40%) yield loss for treatment that

was season long deficit irrigation.

2.1.2 Effect of Deficit Irrigation Practices on Sugar Beet Yield and Water Use

Efficiency

Gharib and EL-Henawy tested the effect of three irrigation regimes at 40, 55

and 70 % depletion of available soil moisture on sugar beet yield and water use

efficiency, at Water Management Research Station at El-Karada, Kafrelshiekh, Egypt,

in 20007/2008 and 2008/2009 seasons. They observed 3.85% increase in root yield,

12.31% increase in sugar yield, 11.90% increase in RWUE and 21.02% increase in

SWUE when the crop was irrigated at 55% depletion in available soil moisture content

in comparison to its irrigation at 40%. On the other hand, root yield was decreased by

28.13%, sugar yield by 21.01%, RWUE by 6.86% and SWUE by 17.05% when crop

was irrigated at 70% depletion at available soil moisture content in comparison to its

irrigation at 40%.

Topak et al., (2010) in their field study in semi-arid regions of Turkey during

2005 and 2006 growing seasons attempted to quantify the effect of seasonal long deficit

irrigation on sugar beet root yield, sugar yield and water use efficiency. They tested the

effect of four level of irrigation designated as full irrigation (FI), 25% deficit irrigation

(DI25), 50% deficit irrigation (DI50) and 75% deficit irrigation (DI75). Irrigations to FI

treatments were applied when about half of the available soil water (50–55%) in the

effective rooting depth was consumed. Irrigations to deficit irrigation treatments were

applied at the rates of 75, 50 and 25 % of FI on the same day by using drip irrigation

system. They observed about 9 to 65 % reduction in root yield when irrigation level

was decreased from no-deficit (FI) to 75% deficit level (DI75). Sugar yield was also

decreased with increase in deficit level (with the exception of DI25 treatment in which

3% increase was observed). The water use efficiency was however increased from 7.46

kg m-3

at full irrigation to 8.32 kg m-3

at DI25, 8.18 kg m-3

at DI50 and 7.50 kg m-3

at DI75,

respectively.

Rinaldi and Vonella (2006) in their field research study at Apulia region in

Southern Italy tested the effect of full irrigation and 40% deficit irrigation on both

spring growing and autumn growing sugar beet crop. They observed that spring

growing sugar beet caused about 22% reduction in root yield and 27% reduction in

sugar yield when 40% deficit irrigation was applied instead of full irrigation. The

27

corresponding reduction for autumn growing sugar beet was about 11% in root yield

and 23% in sugar yield.

Mahmoodi et al., (2008) investigated the effect of irrigation regimes on sugar

beet production. Four levels of irrigation were applied during 2005 cropping season at

Ardabial conditions. The amounts of irrigation tested were: irrigation at 30% of field

capacity, irrigation at 50% of field capacity, irrigation at 70% of field capacity and

irrigation at 90% at field capacity. They noted the highest root yield (78.8 tons ha-1

) for

treatment that was irrigated at 70% of field capacity and the minimum (52.5 tons ha-1

)

at 90% field capacity. Also, the minimum sugar content was observed that was irrigated

at 19.9% of field capacity; however irrigation at 30, 50 and 70% of field capacity had

same effect on sugar content.

Abayomi and Wright, (2002) in their glasshouse research study evaluated the

response of sugar beet yield components to soil moisture deficit imposed at various

growth stages. They found that, although the root yield for unstressed treatment was

higher from both early and late stress treatment, however this difference was non-

significant. On the other hand, significantly highest sugar content (%) and sugar yield

(tons ha-1

) was observed for unstressed treatment. This was followed by early stressed

treatment. Significantly lowest sugar yield was observed for late stressed treatment.

Mehrandish et al., (2012), investigated the fertilizer application effects on sugar

beet qualitative and quantitative characteristics under full and deficit irrigation regimes

at Jovein town, Malek Abad village, Iran. A factorial combination of two irrigation

levels (complete irrigation with irrigation interval of 10 days (region custom) and

deficit irrigation with irrigation interval of 20 days) arranged as a main plots, two levels

of potassium resource and three levels of potassium consumption value as sub-plots

were examined. They reported that root yield was significantly decreased from 59.28

tons ha-1

at full irrigation to 43.89 tons ha-1

at deficit irrigation. Sugar yield was also

significantly decreased from 10.6 tons ha-1

at full irrigation to 7.17 tons ha-1

at deficit

irrigation. However, sugar content (%) was not affected by irrigation quantity.

El-Askari et al., (2003) tested the effect of different irrigation regimes (100, 90,

85, 80 and 75%) of field capacity on sugar beet yield and water use efficiency at

Zankloun research station, water management research institute, (NWRC), Sharkia

Governorate, Egypt, during 1999/2000 winter season. The purpose of their study was to

maximize both the sugar beet production and crop water use efficiency. They observed

highest root yield and water use efficiency for treatment that was irrigated up to 90% of

28

field capacity; however the difference between root yields for all treatments was non-

significant. The sequence of root yield observed by them in their research study was

21.35, 22.23, 18.20, 17.67 and 17.17 (tone/fed.) respectively and the sequence observed

for water use efficiency was 9.15, 10.20, 9.0, 8.93 and 8.82 Kg m-3

, for irrigation

treatments of 100, 90, 85, 80 and 75% of field capacity, respectively. They

recommended the treatment that was irrigated at 90 % of filed capacity for producing

high crop yield and water use efficiency at Eastern Delta region of Egypt.

Kiziloglu et al., (2006) investigated the effect deficit irrigation regimes on sugar

beet yield components and water use efficiency during the 2003 and 2004 growing

seasons under semi-arid cool season climatic conditions at the Ataturk University in

Erzurum, Turkey. The irrigation levels tested were full irrigation (FI), 20% deficit

irrigation (DI20), 40% deficit irrigation (DI40), 60% deficit irrigation (DI60), 80% deficit

irrigation (DI80), and non-irrigation (DI100), respectively. They observed that both root

and sugar yield were linearly decreased from 38.35 and 7.34 tons ha-1

at full irrigation

to 19.96 and 3.84 tons ha-1

at 100% deficit irrigation (non-irrigated treatment). Water

use efficiency was highest for un-irrigated treatment and lowest for 40% deficit

irrigated (DI40) treatment.

Sahin et al., (2014), conducted two years field study at the Agricultural

Research Station of Ataturk University, Erzurum, Turkey, during 2010 and 2011 sugar

beet growing seasons. The purpose was to investigate the effects of two irrigation

techniques, three irrigation regimes and two irrigation intervals, on sugar beet yield

components and irrigation water use efficiency for effective water use. Two irrigation

techniques tested were; full root-zone wetting (FI) and partial root-zone drying (DI).

Two irrigation interval selected were 4 and 8 days. The three different irrigation

regimes applied were 0.70 of pan evaporation (0.70Epan), 0.60 of pan evaporation

(0.60Epan) and 0.50 of pan evaporation (0.50Epan). They observed that irrigation

techniques and irrigation regimes significantly affected sugar beet yield with the

highest root yield (33.80 tons ha-1

) obtained for FI treatment and lowest (26.43 tons ha-

1) for DI treatment. Mean sugar yield was also higher (5 tons ha

-1) for FI treatment

compared to (3.81 tons ha-1

) in DI irrigation treatment. On the other hand, highest

irrigation water use efficiency observed (16.35 kg m-3

) was for DI treatment compared

to (12.12 kgm-3

) in FI irrigation treatment.

Ghamarnia et al., (2012), carried out their research study at the Irrigation and

Water Resources Engineering Research Field Station, Iran, for the purpose to

29

investigate the effect of different irrigation methods and irrigation regimes on sugar

beet yield and water use efficiency in a water limited semi-arid regions. They applied

four levels of irrigation (25% ET, 50% ET, 75% ET and 100% ET,) through drip tape

and conventional furrow irrigation methods during 2006 and 2007 sugar beet growing

seasons. They observed that all the deficit irrigation treatment significantly decreased

both the sugar beet root and sugar yields in both cropping season. From the average of

two years mean data, the decrease observed for each of 25, 50 and 75 % reduction in

irrigation level was 20, 59 and 167 in root yield, and 13, 28 and 66 % in sugar yield,

respectively. On the other hand, 9, 21 and 33 % increase in root irrigation water use

efficiency, and 15, 34 and 59 % increase in sugar water use efficiency was observed for

each of the above three levels of deficit irrigation regimes.

Topak et al., (2016), tested the performance of partial root-zone drip irrigation

for sugar beet production in a semi-arid area at Konya-Çumra, a Central Anatolian

region of Turkey, during 2012 and 2013 cropping seasons and the results for sugar beet

root yield, sugar yield, water use efficiency and fertilizer-nitrogen use efficiency were

compared with those of conventional deficit irrigation and full irrigation. They tested

five irrigation regimes and three nitrogen levels. Irrigation regimes tested were: FI,

CDI50, CDI75, APRD50 and FPRD50. In FI treatment, full irrigation requirements were

applied to both sides of the root system when 35–40% of the available soil water was

depleted in the 0.90-m root zone. CDI50 and CDI75 were conventional deficit irrigation

treatments to which 50 and 75% irrigation water of full irrigation (FI) treatment,

respectively, was applied to both sides of the root system. APRD50 was the alternate

partial root drying treatment to which 50% of the full irrigation treatment was

alternatively applied to both side of the root system by exposing half of the root system

to soil drying and the other half was kept moist. In FPRD50 treatment, 50% of irrigation

requirement was applied throughout the entire season to only one side of the crop root

system. Besides this, they also applied three levels of Nitrogen included N100, N75 and

N50. In N100 treatment, the crop nitrogen requirement was met completely. In N75, 75%

of nitrogen requirement was applied and in N50, only 50% of nitrogen requirement was

full filled. They noted that all the nitrogen levels produced non-significant effects on

both the root and sugar yield. However, irrigation regimes significantly affected root

yield and sugar yield as well as water use efficiency. Compared to the full irrigation

treatment, all the deficit irrigation treatment reduced the sugar beet yield. Reduction

observed was 6.36% for CDI75, 26.97% for CDI50, 19.12% for APRD50 and 23.50% for

30

FPRD50. When comparison was made between the same levels of irrigation, they

observed that APRD50 treatment increased the yield by 10.74% and FPRD50 by 4.75%,

compared to CDI50 treatment. Water use efficiency observed for APRD50 and FPRD50

treatments was also 19.8 and 8.5 % higher compared to CDI50 treatment.

Nourjou, (2008) evaluate the effect of deficit irrigation regimes on sugar beet

yield components, irrigation water use efficiency and crop water use efficiency in

Meandoab Agricultural Research station, Iran, during 1999-2000 cropping season.

They tested the effect of three irrigation regimes and three irrigation intervals.

Irrigation regimes tested were: full irrigation (FI), 75% of the full irrigation (DI25) and

50% of the full irrigation (DI50). Irrigation intervals tested were: 7days, 10 days and 14

days. They reported significantly highest root yield (67.7 tons ha-1

) and sugar yield

(10.2 tons ha-1

) for full irrigation treatment. They noted that 25 and 50% deficit

irrigation treatments reduced the root yield by 13.3 and 50%, respectively, and sugar

yield by 11.1 and 28.9%. Increasing in irrigation interval from 7 to 10 and 14 days

decreased the root yield by 3.5 and 8.6%, respectively. Highest water use efficiency

(WUE) (11.2 kg m-1

) was observed for DI50 treatment. This was followed by DI75 (9.7

kg m-3

). The lowest (8.4 kg m-3

) WUE was observed for full irrigation treatments. They

found linear relationship between root yield and irrigation water used.

Ucan and Gencoglan (2004) tested the effect of six levels of irrigation

application ranging from full irrigation to 65% deficit irrigation on sugar beet yield

components and water use efficiency under semi-arid environment of Iran. Irrigation

water was applied through sprinkler planting pattern. They reported maximum root

yield of 62.350 tons ha-1

, highest sugar yield of 9.40 tons ha-1

, highest water use

efficiency of 4.18 kg m-3

and highest irrigation water use efficiency of 4.68 kg m-3

for

well irrigated-sprinkler irrigation plots. They noted that deficit irrigation regimes

significantly reduced the root and sugar yield as well as irrigation water use efficiency

and crop water use efficiency. By applying 20, 40, 83, 150 and 313 % deficit irrigation,

root yield was reduced by 15, 48, 94, 244 and 457%, sugar yield was decreased by 8,

25, 68, 188 and 360 %, crop water use efficiency was decreased by 8, 27, 38, 94 and

119 %, and irrigation water use efficiency was decreased by 7, 23, 30, 72 and 79 %,

respectively.

Yonts, (2011), investigated the effect of nine irrigation regimes on sugar beet

production by conducting an experiment at the University of Nebraska Panhandle

Research and Extension Center during the 2008 – 2010 cropping seasons. Irrigation

31

regimes applied were 100% of full irrigation, 75% of full irrigation, 50% of full

irrigation, 25% of full irrigation, 0% of full irrigation (no irrigation), 100% of full

irrigation until August 15 then 50% of full irrigation, 75% of full irrigation until August

15 then 25% of full irrigation, 50% of full irrigation until August 15 then 100% of full

irrigation and 25% of full irrigation until August 15 then 75% of full irrigation.

Irrigation to all treatments was applied through sprinkler planting pattern. They found

that sucrose content was varied between as low as 14.9% for un-irrigated treatment to

as high as 16.0% for the 75% irrigation treatment. All irrigation treatment showed

similar sucrose content except the treatments that received no water (0% irrigated) and

the treatment that received 50% of full irrigation until August 15 then received 100% of

full irrigation. Sucrose content for these treatments were statistically less than the other

treatments, but similar to each other. Their results showed that sucrose content was

decreased when the amount of moisture in soil was decreased. They observed the

highest root yield (12.58 tons ha-1

) for the full irrigation treatment and lowest (8.26 tons

ha-1

) for non-irrigated (0% irrigation) treatment. Sugar yield obtained was similar for

full irrigation, 25% deficit irrigation and 50% deficit irrigation treatments. The non

irrigated treatment and 75% deficit irrigation treatment caused 14 and 38 % less sugar

yield respectively, compared to the full irrigation treatment.

2.4 MULCHING EFFECTS

Mulching is a management practice that is used for increasing soil water use

efficiency by conserving moisture. It is a practice that involves the laying/spreading of

organic (crop residues and grasses) or inorganic material (polyethylene sheets etc.) on

the soil surface. The basic purpose is to protect the soil from direct solar radiation,

modify the soil temperature, reduce the rate of evaporation and thus makes available

more soil moisture for plants growth, which ultimately leads toward higher crop yield

and improved water use efficiency. Various kinds of materials such as plastic film,

straw as a mulch, saw dust, sand-gravel, volcanic ash, rubbish of cities and paper

pellets are used in different crops to increase its yield and water use efficiency

2.3.1 Effect of Plastic Film Mulching on Crop Yield and Water Use Efficiency

The potential benefits of film mulches are the earlier and higher overall yields,

reduced evaporation, fewer weed problems, reduced fertilizer leaching, reduced soil

compaction, root pruning eliminated, cleaner product, aids in fumigation and soil

32

solarization, reduced drowning of crops and ability to double/triple crop ( Hochmuth et.

al., 2015; Lament, 1993).

Ashrafuzzaman et al., (2011) evaluated the effect of different types of colored

plastic mulches on growth and yield of chilli during 2005/2006 cropping season. The

mulches tested were the transparent, blue, and black and bare soil. They noted better

crop growth, higher fruit yield and quality, higher soil moisture and higher soil

temperature under mulch conditions compared to bare soil. Within the mulches, Black

Film Mulch produced maximum number of fruits and highest yield. They concluded

that mulching is a valuable tool for increasing chilli production under tropical

conditions, while among the mulches, Black Film Mulch can perform better for

suppressing weeds and increasing fruit yield

Seyfi. and Rashidi, (2007) conducted their field experiment during 2004 and

2005 cropping season for investigating the combine effect of irrigation method and

mulch type on cantaloupe yield and water use efficiency at Garmsar, Iran. Three

irrigation methods, the conventional irrigation, drip irrigation and drip irrigation under

plastic mulch, were tested to cantaloupe between emergence and harvest. They noted

the highest yield and water use efficiency for treatment to which irrigation water was

applied under plastic mulch.

Wu et al., (2016) investigated the effect of film mulching on soil bacterial

diversity, organic matter and rice water use efficiency. They conducted their

experiment on different soils with great environmental variability in Zhejiang Province,

China, under non-flooding condition. The treatments tested were, plastic film mulching

with no flooding, no plastic film mulching and no flooding, and traditional flooding

management. The concluded that film mulching produced the highest positive effects

on the development of total bacterial community compared to the traditional flood

irrigation with out film mulch. Furthermore, they noted that rice water use efficiency

and irrigation water use efficiency for film mulch treatments were 70.2 to 80.4 and

273.7 to 1300 % higher compared to the traditional flood irrigation. Therefore, film

mulching can be effectively utilized as a mean of water saving agriculture in dry areas.

Zegada-Lizarazu and Berliner, (2010), evaluated the effect of inter-row

polyethylene mulch on the water use efficiency and crop productivity of furrow-and

drip-irrigated maize at the Blaustein Institutes for Desert Research, University of the

Negev, Israel. The performance of four planting methods tested were comprising the

furrow irrigation with no-mulch, drip irrigation with no-mulch, furrow irrigation with

33

inter-row polyethylene mulch and drip irrigation with inter-row polyethylene mulch.

Their results indicated that polyethylene mulched treatments produced significantly

highest shoot biomass, and 45 to 64 % higher water use efficiency compared to un-

mulched treatments. The evaporative losses in un-mulched treatments were 37 to 39 %

of the total applied irrigation.

Xu et al., (2015) investigated the effect of plastic mulch on maize yield and

water use efficiency in Northeast China. They conducted their field experiment at six

different sites for six years including dry years as well as rainy years. They observed

higher grain yield and water use efficiency for plastic mulch treatments compared to

the no-mulch. However, increase observed was not uniform for all six years. During

dry years, plastic mulch significantly increased all the biomass, grain yield and water

use efficiency compared to the No Mulch treatment. This was attributed towards

improved top soil temperature and high soil moisture under plastic mulch that caused

rapid plant growth and higher leaf area index during the crop early vegetative stage. As

a result, the plastic mulch improved the dry matter accumulation that ultimately lead

towards significantly higher final biomass, grain yield and water use efficiency. During

the wet years, because of regular precipitation and limited sunshine, the increase in soil

moisture and top soil temperature under plastic mulch was improved only at some

specific crop growth stages and thus was not able to produced higher dry matter

accumulation. This is why the increased observed in maize grain yield and water use

efficiency under plastic film mulch was significantly not higher compared to the no-

mulch treatment. Furthermore, they also found that film mulch triggered the leaf

senescence during the late growth stage irrespective the climatic conditions. They thus

recommended that plastic mulch should be cautiously used taking into account in-

season precipitation.

Dang et al., (2016), conducted two years experimental study at Quzhou

experimental station of China Agricultural University during 2014 and 2015 cropping

seasons for the purpose to evaluate the plastic film-mulched raised beds effects on soil

temperature and crop performance of spring maize in the North China Plain. They

concluded that plastic film mulch treatment significantly improved the soil temperature

in the early crop season. As a result, crop growth was accelerated, evapotranspiration

was reduced, and crop yield and water use efficiency were maximized, in comparison

to no-mulched treatments.

34

Yaghi et al., (2013) studied the influence of two types of plastic film mulch

(transparent and black) with drip irrigation on Cucumber yield and water use efficiency

at Teezen Research Station, Syria, during 2009–2010 growing seasons. Treatments

tested were the drip irrigation and transparent film mulch combination, drip irrigation

and black polyethylene film mulch combination, drip irrigation without mulch and

furrow irrigation without mulch, respectively. They concluded that film mulch and drip

irrigation combination increased the yield by 31 – 44 %, reduced the water

consumption by about 16% and increased the water use efficacy by 56.0 to 71.24%,

respectively, compared to the drip irrigation without mulch. When compared with the

results of furrow irrigation without mulch, the film mulch and drip irrigation

combination produced 53 – 69 % higher yield, 325 to 367 % higher water use

efficiency, and about 64% less water consumption, respectively. The higher yield and

water use efficiency and less water consumption under film mulch was attributed

towards more favorable soil temperature, and reduction in soil evaporation compared to

no-mulch treatments. They concluded that drip irrigation and film mulch combination

was an effective mean for improving WUE and increasing crop yield of cucumber.

Jiang et al., (2016), investigated the effect of plastic film mulching on maize

production in the water scarcity area of Loess Plateau, China, during 2013 cropping

season. They found that film mulching was an effective mean for increasing the

availability of surface water by avoiding the dry soil layer formation during the maize

early growth stage, and ultimately increased the maize water productivity.

Westhuizen, (1980), studied the effects of black polyethylene film mulch on

Chenin blanc Vines production under dry land conditions. He concluded that black

polyethylene film mulch greatly increased the growth of the vines under the water

limited conditions because of moisture conservation, more uniform soil temperature,

less soil compaction and weed control. All these factors improved the root and shoot

growth and improve both survival of the young vines and production.

2.3.2 Effect of Straw Mulch on Crop Yield and Water Use Efficiency

Zhang et al., (2009) investigated the effect of rice straw mulch and gravel mulch

on soil salinity, crop evapotranspiration, crop yield and water use efficiency Swiss

chard in a green house. They noted that rice straw mulch produced 76% and gravel

mulch produced 49% high fresh matter yield compared to no-mulch treatment. They

noted that rice straw mulch produced 76% higher fresh matter yield, 143% higher water

35

use efficiency and 14.6% less cumulative evapotranspiration, where as the gravel

mulch caused 49% higher fresh matter yield and 35.18% less evapotranspiration

compared to the no-mulch treatment. Salinity build up observed was also high for no-

mulch treatment compared to the mulched treatments.

Uwah D. F., and G. A. Iwo, (2011) investigated the effectiveness of organic

mulch on the maize (Zea mays L.) productivity and weed growth at the Teaching and

Research Farm of the Department of Crop Science, University of Calabar during

2007/2008 and 2008/2009 crop growing seasons. They observed that no-mulched

treatment had the lowest soil moisture reserves, highest weed infestation and almost

two times less grain yield compared to the mulched treatment.

Tegen et al., (2016) conducted two years field experiment under playhouse

condition at Bahir Dar, Ethiopia during 2012 and 2013 cropping seasons. The response

of four types of mulches designated as Black Film Mulch (BFM), White plastic mulch

(WPM), Grass mulch (GM) and No Mulch were tested for tomato production. They

found significantly highest marketable yield (60.90 tons ha-1

) for grass straw mulch

treatment. This was followed by Black Film Mulch (52.29 tons ha-1

) and white plastic

mulch (47.36 tons ha-1

) treatments. The un-mulched treatment produced the lowest

(43.76 tons ha-1

) marketable yield. The improvement in tomato marketable yield by the

grass straw mulch application could be attributed to its favorable effect on soil moisture

and soil temperature that subsequently created conducive environment for root growth

and development.

Palada et al., (2000) evaluated the effect of straw mulch and Black Film Mulches on

yield of sweet basil (Ocimum basilicum L.) by conducting a field experiment under

drip planting pattern during 1991-1993 cropping seasons. They concluded that Black

Film Mulch produced significantly highest yield. This was followed by straw mulch.

The un-mulched treatments produced the lowest yield. Furthermore, all the mulch

treatments significantly increased the water use efficiency and lowered the irrigation

water use compared to the no-mulch treatment.

Artyszak et al., (2014) investigated the effect of mustered mulch, straw mulch

and conventional tillage on sugar beet root yield and sugar yield from year 2005-2008

in southern part of Poland. They observed that both mustered mulch and straw mulch

increased the root yield by 9.4 and 11.2 % respectively, compared to the conventional

tillage (no-mulch treatment). Furthermore, increase observed in sugar yield was 8 % for

mustard mulch and 11.30% for straw mulch compared to no-mulch treatment.

36

Quin et al., (2015) reported on a meta-analysis of the mulching effects on maize

and wheat, using hundreds of yield observations from more than 70 studies conducted

in 19 countries. They concluded that the soil mulching significantly increased the yield,

water use efficiency and nitrogen use efficiency of maize and wheat by about 60 and

20 %, respectively in comparison to no-mulching. Thus mulching can significantly

contribute to narrow down the gap between the actual and attainable yields, especially

in water limiting areas.

Iqbal et al., (2003), conducted a pot experiment at the University of Nandipur

for evaluating the effect of irrigation regimes and mulch on forage maize production

and water use efficiency. They noted significant increase both in yield and water use

efficiency for mulched treatments compared to the no-mulch.

Zhao et al., (2014) compared the effects no-mulch, surface straw mulch and

surface straw mulch + buried straw layers on sun flower growth and soil salinity

management. They conducted there experiment from October 2010 to September in the

Hetao Irrigation District, Inner Mongolia, China. The climatic condition of the area was

extreme cold winter and dry summer with annual evaporation was more than 10 times

from the available precipitation. The observed the highest positive effects on plants

growth, soil moisture and salinity management for surface straw mulch and buried

straw layer combination and the lowest for no-mulch treatment.

Shen et al., (2012) studied the straw mulch effects on different types of summer maize

plants yield and water use characteristics at the Experimental Station of the Shandong

Agricultural University in northern China. They collected their experimental data for

different maize verities during 2009 and 2010 cropping seasons. The concluded that

straw mulch could be an effective mean for increasing maize yield and water use

efficiency in dry areas

Zhang et al., (2009) studied the effects of gravel and rice straw mulches on yield,

evapotranspiration and water use efficiency of Swiss chard that was irrigated with

diluted seawater (6.86 dS m-1

) and was grown on Tohaku clay soil. They observed that

cumulative evapotranspiration for no-mulch treatment was 13% higher than rice straw

mulch and 26% higher than gravel mulch. They also noted that, compared to the no-

mulch treatment, rice straw mulch and gravel mulch produced 76 and 49 % higher fresh

matter yield, respectively. Salt accumulation in the top 25 cm soil layer was highest for

no-mulch treatment as compared to the mulched-treatment and the salt concentration

difference was more visible in the top 10 cm surface layer. Water use efficiency

37

observed for rice straw mulch treatment was 143 and 10 % higher compared to no-

mulch and gravel mulch treatments.

Peng et al., (2015) studied the effect of mulch application on soil water storage,

grain yield and water use efficiency of winter wheat at a dry land farming experimental

station, China. They conducted their experiment for three different seasons by applying

six different combinations of straw mulches, two different duration of mulch

application and three different amounts of mulches. They observed no significant

increase in soil water storage, grain yield and water use efficiency for mulched

treatments compared to the no-mulch treatment. However, all the three components

(soil water storage, grain yield and water and water use efficiency) were significantly

improved in normal year.

Toe et al., (2015) investigated the impacts of different combinations of tillage

systems and maize straw patterns on maize yield and water use efficiency during

2012/2013 cropping season in Northern Huang–Huai–Hai Valley, China. Tillage

methods studied were rotary tillage, subsoil tillage. Mulches studied were no-mulch,

100% chopped straw mulch, 100% whole straw (non-chopped) mulch, 50% chopped

straw and 50% whole straw mulches, respectively. They reported that tillage hade

greater impact on maize yield while straw mulching had greater impact on water

consumption and water use efficiency. The highest water consumption and the lowest

water use efficiency were observed for no-mulch treatment. The highest yield and

water use efficiency was noted for 50% chopped straw mulching with subsoil tillage

combination.

2.4 FURROW IRRIGATED RAISED BED PLANTING METHODS

Furrow Irrigated Raised bed planting is a water resources conservation

technology in which field crops are raised on raised bed and irrigation water is applied

through furrow between them (Kamboj et al., 2008). It has been suggested one of the

most effective measures in terms of reduced cultivation cost, improved water use

efficiency and yield optimization (Zhang et al., 2007). It is a precision method and

center piece of technology for in-situ moisture conservation in dry areas and a tool of

effective drainage in wet areas (Khambalkar et al., 2010). During the last few decades,

this technology has been tested for number of field crops that are described as follow:

Khambalkar et al., (2010), compared the effectiveness of sowing the safflower

on furrow irrigated raised bed with tradition method. They noted that the bed planting

38

conserves 9.61% more moisture content, 6.50% higher yield and 38.15% less cost of

operation, compared to the traditional method.

Akbar et al., (2007) evaluated the performance of raised bed for wheat and

maize on farmers field under a research project of Pakistan Agriculture Research

Council (PARC) in collaboration with the Australian Centre for International

Agricultural Research (ACIAR). They reported that bed planting save about 10 to 36 %

irrigation water, produced 6% more wheat yield, 33% more maize yield compared to

the traditional sowing method.

Khan et al., (2015) investigated the effect of different irrigation regimes and

irrigation techniques on maize crop during 2011 cropping season at the experimental

farm of the Institute of Soil and Environmental Sciences, University of Agriculture,

Faisalabad, Pakistan. The irrigation regimes tested were 100, 80 and 60 % field

capacity level and the irrigation techniques tested were the furrow irrigated ridge,

furrow irrigated raised bed, furrow irrigated raised bed with plastic mulch and sprinkler

irrigated flat sowing technique. The reported the highest harvest index and crop yield

for furrow irrigated raised bed that was irrigated at 100% field capacity level. On the

other hand, the conventional ridge-furrow planting with 100% field capacity level

irrigation application resulted higher evapotranspiration, leaf area index and crop cover

but gave relatively low yield and water use efficiency.

Zahoor et al., (2010) carried out their research experiment at Agricultural

Research Farm of NWFP (present KP) Agricultural University, Peshawar, Pakistan for

evaluating the effect of different sowing methods on yield and quality of two sugar beet

verities (KWS 1451 and Kawe Terma). The treatment tested were; Planting sugar beet

on ridges 60 cm apart, Planting sugar beet on ridges 50cm apart, Planting sugar beet on

ridges 40 cm apart, Pair of ridges 50 cm apart and space of 30 cm between ridges, Strip

of three ridges 50 cm apart and space between ridges 35 cm, Pair of rows 30 cm on bed

with bed-to-bed distance of 80 cm, Three-row strip on beds 35 cm apart with bed-to-

bed distance of 120 cm, Pair of rows 50 cm apart on flat and space between the rows 30

cm, Three rows strip 50 cm apart on flat and space between the rows 35 cm. They

observed highest sugar content and sugar yield for two rows bed planting pattern and

recommended this method for the farmers of the area.

Ahmad and Mahmood, (2005) investigated the effect of raised bed sowing on

wheat yield, lodging and water use efficiency. They performed their research on

farmer‘s fields in Punjab, Pakistan, during 2003/2004 cropping season. The results

39

when compared with traditional method of flat sowing indicated that raised-bed sowing

caused about 15% less lodging, 40-50% water saving and 11.2% more grain yield.

Anjum et al., (2014) studied the effect of two planting methods (drip planting

pattern and bed-planting pattern), three irrigation water qualities (good, marginal and

poor) and three irrigation frequencies (2 days, 4 days and 6 days) on corn crop. The

experiment was performed at Agricultural Research Station Faisalabad, Pakistan during

2011/2012 cropping season. They concluded that bed-planting pattern caused greater

plant height, higher dry matter (5.8%) and higher grain yield (21.9%) compared to the

drip-planting pattern.

Ghani et al., (2009) carried out their research study at the Roudasht

experimental station, Isfahan, Iran during 2006/2007 cropping season. The purpose

was to optimize an irrigation (planting) method for obtaining maximum wheat yield

and water productivity. They applied three different quality of water (4, 8 and 12 Ds m-

1) through three different types of raised bed planting methods (furrow irrigated raised

wavy bed, 60cm wide raised bed and 80cm wide raised bed). They concluded that the

60cm wide raised bed was the most efficient planting pattern in terms of obtaining

higher grain yield and water productivity. It was also observed that water productivity

was decreased with increase in salinity level; however, the decrease observed for 60cm

raised bed was lower compared to the other two systems.

Cabangon et al., (2005) studied the effect of irrigation regime and raised bed

system on yield and water productivity during 2002 wet season and 2003 dry season at

the International Rice Research Institute (IRRI) Laguna, Philippines. They compared

the performance of three irrigation planting pattern designated as flat puddle planting,

65cm wide raised bed planting and 130cm wide raised bed planting. The three

irrigation regimes were well-watered, irrigation application when soil water potential

reached at -10 kPa and at -20 kPa, respectively, at 15cm soil depth. They observed the

highest grain yield for flat sowing compared to the raised bed sowing, irrespective of

the bed width. However, bed planting pattern reduced the irrigation water input during

dry season by amount of 200 to 500 mm compared to the flat sowing.

2.5 CROP GROWTH SIMULATION MODELS

The field experimental results are generally site specific that may not be

applicable to other sites with different soil and climatic conditions. Furthermore, field

experiments are expensive, laborious; require large number of field trials and

40

treatments. Also, the obtained results are influenced by the weather condition that

generally varies from year to year that makes it difficult to assess the amount of

irrigation from the field experiments (Iqbal et al., 2014). In solving these problems,

crop growth simulation models can be a helpful tool and can be pre-evaluated through a

well-proven model to refine the field tests and lower their overall costs and risk

uncertainties (Whisler et al., 1986). The models can also be a helpful for water

managers and scientists for defining their research priorities Dourado-Neto et al.,

(1998). Furthermore, they can be used as an important tool to test and develop alternate

management strategies for obtaining maximum yield with minimum possible

application of irrigation water in arid and semi-arid areas (Toumi et al., 2016). They

can also help the researchers to test their experimental results for irrigation planning at

new climatic conditions (Geerts and Raes, 2009) and to use them as a decision support

tools for system management (Steduto et al., 2009). Further more, they can assists in

pre-season and in-season decision making on various management practices such as

irrigation application, fertilizer application, cultivar selection, pesticides application

and other cultural practices. They can also support the policy makers by predicting the

climatic changes, fertilizers, weedicides, pesticides leaching, crop yield forecasting and

soil erosion prediction (Boote et al., 1996).

Depending on there purpose, crop simulation models have been classified into

three broad categories. These are statistical models, scientific models and engineering

models (Dourado-Neto et al., 1998, Steduto et al, 2009). Statistical models state the

relations between the climatic parameters and the crop yield components. These

relations are measured by different statistical techniques such as correlation and

regression etc. Mechanistic models use the fundamental mechanisms of soil and plant

process for simulating specific outcomes and help to improve and understand the

response of crops to climatic changes. Engineering models are based on a mixture of

well-established theory and robust empirical relationships. Their purposes are to

simulate complex processes to make predictions and advice for management decision

making.

From research efforts in crop modeling over the past few decades many

sophisticated scientific types of crop growth models have been developed for different

crops for the purpose to predict crop growth, development and yield in response to

different agro-ecological environment. Some of these models are: CropSyst (Stockle et

al., 2003), EPIC (Williams et al., 1989), the APSIM models (Keating et al., 2003), the

41

DSSAT cropping system model (Jones et al., 2003) etc. However, due to their intricacy,

demand for large number of input parameters and advanced skill requirements for their

calibration and operation made their application difficult for the end users and policy

makers for irrigation planning (Fereres, 2011). For addressing these concerns and

achieving an optimal balance between accuracy, simplicity, and robustness, Food and

Agricultural Organization (FAO) of the United Nations (UN) has developed AquaCrop

model (Steduto et al., 2012).

2.5.1 AquaCrop Model

AquaCrop model has been tested by many researchers for modeling growth of

large number of field crops in various parts of the world under different agro-ecological

conditions. All of them revealed that AquaCrop is a model for scenario analysis that

provides a good balance between robustness and output precision.

Toumi et al., (2016) tested the ability of AquaCrop model for exploring water

saving and improving grain yield of wheat. They simulated the actual evapotranpiratio,

total soil moisture content, canopy cover and grain yield for winter wheat under flood

irrigation in the semi-arid region of Morocco during 2002/2003 and 2003/2004 crop

growing seasons. On the basis of various statistical indicators they reported that

AquaCrop model can be considered as a valuable tool for operational basis irrigation

scheduling planning in the arid and semi-arid regions.

Geerts et al., (2010) on the basis of long series of climate data and frequency

analysis derived optimal irrigation frequencies for quinoa in Bolivia using AquaCrop

model. The purpose was to avoid drought stress and guarantee maximum water use

efficiency. They summarized their results in easy readable charts for policy makers and

extension officers for decision making and farmers for deficit irrigation application in

case of erratic rainfall On the basis of their research results they reported that the

AquaCrop is a user-friendly and robust model that can be prove as an valuable tool for

bridging gap between agricultural modeling experts and farmers requiring sustainable

irrigation guidelines.

Saab et al., (2015) compared the performance of AquaCrop and CropSyst

models in simulating barley growth under different irrigation regimes and nitrogen

levels using three years experimental data collected during 2006 to 2008 cropping

season in Southern Italy. They calibrated both the models for each of three years and

42

validated for another two years. On the basis of model performance parameters, they

reported that AquaCrop performed better than CropSyst model.

Salemi et al., (2011) studied the performance of AquaCrop model for winter

wheat under full and deficit irrigation practices in Gavkhuni river basin, Isfahan

province, Iran. They reported that the AquaCrop performed excellent for simulating

canopy cover, grain yield and water productivity and thus a helpful tool for predicting

wheat yield under water limiting conditions.

Iqbal et al., (2014) tested the AquaCrop ability for simulating wheat production,

actual evapotranspiration and soil water content under different deficit irrigation

regimes at the Luancheng Agro-ecosystem station (North Chain Plain) using the field

experimental data collected 1998–2001. Based on extensive validation and revalidation

results they reported AquaCrop as a valid model that can be used with a reliable degree

of accuracy for optimizing winter wheat grain yield production and water requirement

under water limiting conditions.

Afshar et al., (2014) evaluated the performance of AquaCrop in simulating potato yield

and water use efficiency under different irrigation regimes at VakilAbad Farm of Jiroft

Agro-industrial, Jiroft, Iran. They assessed that AquaCrop model has good ability in

predicting and estimating of evaporation and transpiration of crops (ETc), yield, and

water use efficiency of potato.

Alishiri et al., (2014) evaluated the AquaCrop model for its ability in simulating

sugar beet (Beta vulgaris L.) performance under full and deficit water conditions and

two nitrogen levels in a dry environment in center of Iran. They reported AquaCrop as

a valuable tool for developing on-farm water management strategies for improving

sugar beet yield and water use efficiency under water limited conditions.

Bitri and Grazhdani, (2015) evaluated the performance of AquaCrop model in

simulating sugar-beet production under different irrigation regimes by using

experimental data collected during 2012-2014 cropping seasons from Korça region,

southeastern Albania. The concluded that AquaCrop is a useful tool for the design and

evaluation of deficit irrigation strategies, preventing unnecessary losses from drainage,

soil evaporation and runoff, in addition to enhancing water use efficiency.

Stricevic et al., (2011) tested the AquaCrop performance in simulating maize,

sunflower and sugar beet yield and water use efficiency by using the field data

collected between 2000 and 2007 in Northern Serbia. They reported that AquaCrop can

be used with a high degree of reliability for better planning and management of water

resources for irrigation purposes and estimating crop yield in the climate change

scenarios.

43

CHAPTER III

MATERIALS AND METHODS

3.1 EXPERIMENTAL SITE AND CLIMATIC CONDITIONS

Two years research study was conducted during 2011/2012 and 2012/2013

sugar beet growing seasons at Sugar Crops Research Institute. The institute is located at

the west perimeter of district Mardan in Khyberpakhtun (a part of famous Peshawar

valley, Pakistan) at about 34° north latitude and 72

° east longitude, at an altitude of

305m above mean sea level (Figure 3.1). This region is known for semi-arid sub

tropical continental type of climate with extremely hot summer season and with

frequent dust storms at night during months of May and June. The coldest months are

December and January during which the minimum temperature often falls below

freezing point. June is the hottest month with maximum temperature could go as high

as 45 oC. The average monthly maximum temperature ranged from 17.83 to 41

oC

while the monthly minimum temperature varied from 1.66 to 24.13 oC (Figure 3.2).

Both minimum and maximum temperature in Peshawar valley increased in years 1997

to 2013 compared to early 50 years (1947 – 1996). If the current rise in temperature

continues, it will lead toward occurrence of extreme events more frequently and will

also increase the uncertainty in sustainable crop production in the region. Also it will

increase the crop water requirement due to more evaporation by high temperature.

Long-term mean annual rainfall in the study area is less than 500 mm. The wettest

months are March and August and the driest are October, November and December

(Figure 3.3). Rainfall pattern in the area is quite scanty and uncertain. The trend of

rainfall is toward drier conditions (Figure 3.4). The average rainfall in the valley during

2001 to 2013 was 411.22 mm as compared to 437.13 mm during the last 53 years (1947

– 2000). An increase of about 35% for February and 23% for August was observed

during 2001 – 2013. Little, decrease in the amount of rainfall was observed for during

the winter months (September to January). However, this little decrease is of great

importance because in these months the crop is in early growth stage and need proper

nourishment. Moreover, due to dry conditions, the young seedlings are more liable to

termite attack (It is worth mention that all these climate data information are taken from

the un-published climate report placed at the library of Agriculture Research Institute,

Tarnab, Peshawar). Figure 3.5 presents the mean monthly maximum and minimum air

and soil temperature data collected during the study period 2011/2012 and 2012/2013 at

climatic station of Sugar Crop Research Institute, Mardan. Topography of the study

area is characterized by slightly rolling to almost flat with the land slope ranging from 0

to 4% with an average of about 0.2%, mostly towards the south-east (Gul et. al., 2013).

44

The soil of the study area are exclusively loess and reworked loess (i.e. eroded and re-

deposited by water action) having an isotropic soil structure and genetically

undeveloped (Gul et. al., 2013). Most of the top 1.5 meters soil have medium to

moderately fine texture with 2 to 14% lime content.

Fig. 3.1: Location of the study area.

0

10

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Janu

ary

Febur

ary

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chA

pril

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ust

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r

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C)

Max Temp. ⁰C Min Temp. ⁰C

Fig. 3.2: Mean monthly maximum and minimum temperature for 66 years

in Peshawar valley (1947 - 2013).

45

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Septe

mbe

r

Octob

er

Nov

embe

r

Dec

embe

r

Rain

fall

(m

m)

Fig. 3.3: Mean monthly rainfall for 66 years (1947 - 2013) in Peshawar valley

0

10

20

30

40

50

60

70

80

Janu

ary

Febur

ary

Mar

chA

pril

May

June Ju

ly

Aug

ust

Septe

mbe

r

Octob

er

Nov

embe

r

Dec

embe

r

Rain

fall (

mm

)

Rainfall (2001 - 2013)

rainfall (1947 - 2000)

Fig. 3.4: Comparison made between mean monthly rainfall for the years 1947 -

2000 and 2001 - 2013 in Peshawar valley

46

0

5

10

15

20

25

30

35

November December January February March April May

Tem

peratu

re (

°C)

Max. air T 2011/2012

Min. air T 2011/2012

Max. air T 2012/2013

Min. soil T 2012/2013

0

5

10

15

20

25

30

35

40

November December January February March April May

Tem

pera

ture (

°C)

Max. soil T 2011/2012

Min. soil T 2011/2012

Max. soil T 2012/2013

Min. soil T 2012/2013

Fig. 3.5: Mean monthly maximum and minimum (a) air temperature and (b)

Soil temperature for the study site during 2011/2012 and 2012/2013

cropping seasons

3.2 EXPERIMENTAL TREATMENTS AND DESIGN

Factorial combination of four irrigation levels (main plots), three mulch practices (sub-

plots) and three furrow irrigation systems (sub-sub-plots) were evaluated in randomized

complete block design and replicated three times. The four irrigation regimes tested were full

irrigation (FI), 80% of FI or DI20, 60% of FI or DI40 and 40% of FI or DI60. The mulch

(b)

(a)

47

treatments evaluated were No Mulch (NM), Black Film Mulch (BFM) and Straw Mulch (SM).

In plots with BFM, ridges were formed first and then covered by the black polyethylene film

sheet. Three furrow irrigated raised-bed planting method tested were Conventional Ridge-

Furrow (CRF) planting with one crop row on the furrow ridge, Medium Raised-Bed (MRB)

planting with two rows on 45cm wide bed and Wide Raised-Bed (WRB) planting with three

crop rows on 90cm wide bed (WRB). Detail of the treatments and treatment combinations

of the experimental field are presented in Tables 3.1 to 3.4.

Table 3.1: Main plots: Irrigation treatments.

Treatments Description

FI 100% replenishment of soil water depletion

DI20 20% Deficit Irrigation (i.e. irrigation depth applied was 80% of

FI treatment)


FI treatment)


FI treatment)

Table 3.2: Sub plots: Type of Mulching practices.


NM No Mulch

BFM Black polyethylene film mulch

SM Straw mulch

Table 3.3: Sub-sub plots: Furrow irrigated raised-bed planting methods.


CRF Conventional Ridge-Furrow planting

MRB Medium Raised-Bed planting

WRB Wide Raised-Bed planting

48

Table 3.4: Details of treatments.


FINMCRF Full irrigation, No-Mulch, Conventional Ridge-Furrow Planting

FINMMRB Full irrigation, No-Mulch, Medium Raised-bed planting

FINMWRB Full irrigation, No-Mulch, Wide Raised-Bed planting

FIBFMCRF

Full irrigation, Black Film Mulch, Conventional Ridge-Furrow

planting

FIBFMMRB Full irrigation, Black Film Mulch, Medium Raised-Bed planting

FIBFMWRB Full irrigation, Black Film Mulch, Wide Raised-Bed planting

FISMCRF Full irrigation, Straw Mulch, Conventional Ridge-Furrow planting

FISMMRB Full irrigation Straw Mulch, Medium Raised-Bed planting

FISMWRB Full irrigation Straw Mulch, Wide Raised-Bed planting

DI20NMCRF

20% Deficit Irrigation, No-Mulch, Conventional Ridge-Furrow

Planting

DI20NMMRB 20% Deficit Irrigation, No-Mulch, Medium Raised-Bed planting

DI20NMWRB 20% Deficit Irrigation, No-Mulch, Wide Raised-Bed planting

DI20BFMCRF

20% Deficit Irrigation, Black Film Mulch, Conventional Ridge-

Furrow planting

DI20BFMMRB

20% Deficit Irrigation, Black Film Mulch, Medium Raised-Bed

planting

DI20BFMWRB

20% Deficit Irrigation, Black Film Mulch, Wide Raised-Bed

planting

DI20SMCRF

20% Deficit Irrigation, Straw Mulch, Conventional Ridge-Furrow

planting

DI20SMMRB 20% Deficit Irrigation Straw Mulch, Medium Raised-Bed planting

DI20SMWRB 20% Deficit Irrigation Straw Mulch, Wide Raised-Bed planting

DI40NMCRF


Planting

DI40NMMRB 40% Deficit Irrigation, No-Mulch, Medium Raised-Bed planting

DI40NMWRB

40% Deficit Irrigation, No-Mulch, Wide Raised-Bed planting

49

DI40BFMCRF

40% Deficit Irrigation, Black Film Mulch, Conventional Ridge-

Furrow planting

DI40BFMMRB


planting

DI40BFMWRB


planting

DI40SMCRF

40% Deficit Irrigation, straw mulch, Conventional Ridge-Furrow

planting



DI60NMCRF


Planting

DI60NMMRB 60% Deficit Irrigation, No-Mulch, Medium Raised-bed planting

DI60NMWRB

60% Deficit Irrigation, no-mulch, Wide Raised-Bed planting

DI60BFMCRF 60% Deficit Irrigation, Black Film Mulch, Conventional Ridge-

Furrow planting

DI60BFMMRB


planting

DI60BFMWRB


planting

DI60SMCRF

60% Deficit Irrigation, Straw Mulch, Conventional Ridge-Furrow

planting



Note: Conventional ridge-furrow planting is the planting method practicing by the

farmers in the study area for growing sugar beet, where plantations are carried on

narrow ridges with single crop rows. A Medium Raised-Bed (MRB) planting means

that between each two successive furrows, a raised-bed of about 45.0 cm width was

provided on which two crop rows of sugar beet were raised. A Wide Raised-Bed

(WRB) planting means that between each two successive furrows, a raised-bed of about

90.0 cm width was provided on which three crop rows of sugar beet were raised.

50

3.3 EXPERIMENTAL FIELD PREPARATION

Two years field experiments were carried out at sugar crop research institute,

Mardan for the purpose to evaluate the interaction effects of irrigation regimes,

mulching and furrow irrigated raised-bed planting methods on sugar beet yield

components and water use efficiency. The field size was 7524 m2 (57m * 132m).

Before the commencement of the experiment, the research field was thoroughly

prepared by using different primary and secondary tillage implements. Soil was first

ploughed by chisel plow and then thoroughly inverted by help of disc plow. After that,

rotavator was used for breaking the soil clods, cutting of the remaining residues of

previous crop and pulverizing the soil. The purpose of these practices was to achieve a

desired granular structure for seedbed, minimize resistance to crop root penetration and

to improve soil infiltration and aeration. Field was then properly smoothed and leveled

by planking for facilitating machine sowing operation, uniform distribution of irrigation

water and quick disposal of excess storm water. After completing the field preparation

operations, a complete layout was marked to separate the area for different raised-bed

furrow irrigated planting methods, field water ditches and buffer zones (for preventing

lateral movement of irrigation water from one plot to another). The experimental field

was first divided into twelve main plots; each main plot was then divided into nine sub

plots. Each sub plot was further divided into three sub-sub plots with 58.5 m2 area. This

way the number of smallest experimental units formed were 108 (Fig. 3.6).

3.4 CROP MANAGEMENT PRACTICES

Sugar beet was sown on November 15, 2011 and November 20, 2012, with seed

rate of 4.4 kg ha-1

. Planting was done manually by hand and 3 seeds per hill were

placed at 18cm apart from each other and row to row distance 45cm apart. In plots with

black polyehylene film mulch, ridges and raised-beds were formed first and then

covered by the black polyethylene sheet. Hand seeding of sugar beet seeds was done in

already prepared holes in the black polyethylene sheet at 18 cm spacing. In plots with

Straw Mulch (SM), seeding was done after the ridges and raised-beds were formed.

The straw for mulch purposes (sugar cane trashes) was then manually spread over the

ridges and beds after the seed germination. At 2-4 leaf stage one plant per hill was

maintained. Fertilizers Di-ammonium phosphate (DAP) and Urea were applied at the

rate of 220kg/hectare and 110 kg ha-1

respectively before seeding.

51

Fig. 3.6: Experimental Layout Plan.

While second doze of Urea, at the rate of 110 kg ha-1

, was applied in February. All

other recommended agronomic practices were followed uniformly for all the treatments.

Plant protection measures were adopted to keep the crop free from weeds, insect pests

and diseases. Pre-emergence weedicids Dual Gold (Smetolachlor) at the rate of 2.2 lit

ha-1

was applied for all No-mulch and straw mulch treatments to control the weeds.

However, no chemical weed control measures were applied for black polyehylene film

mulch treatments. Insecticide seven dusts at the rate of 3080 gm ha-1

and Falidal at the

rate of 660 ml ha-1

were sprayed once. In order to control diseases, Dithean M. was

sprayed at the rate of 4.4 kg ha-1

.

52

3.5 SOIL DATA

The data in Table 3.5 present some of the soil general physical and chemical

properties of the experimental site.

Table 3.5: Physical and chemical properties of the experimental site.

S. NO. Parameters Unit Status

1 Textural Class Clay

2 Bulk Density g cm-3

1.24

3 Field Capacity (FC) % 34.26

4 Permanent Welting Point (PWP) % 22.73

5 Total Available Water (AW) Mm m-1

115.26

6 Ph 7.58

9 TDS mg l-1

29.97

10 So42-

meq l-1

17.22

11 CO32-

meq l-1

0.58

12 Saturated hydraulic conductivity Mm day-1

38

14 HCO3- meq l

-1 0.82

15 Ca2+

meq l-1

9.60

16 Mg2+

meq l-1

0.65

17 Cl-1

meq l-1

0.60

3.5.1 Soil Texture

Texture class of soil was found by bouyoucos hydrometer technique using

USDA textural triangle (Gee and Bauder, 1986). A 50 grams soil was taken from field,

air dried for 24 hours and then sieved with a 2 mm sieve. Then 10 ml of 1 normal

sodium hexameta-phosphate was added and the solution was dispersed through

electrical stirrer for 5 minutes. The dispersed suspension was then transferred to one

liter volumetric cylinder and the volume adjusted to one liter by adding the solution.

After mixing the suspension, hydrometer reading was noted for sand after 40 seconds

and for silt after 2 hours. On the basis of hydrometer reading the percent ratio of silt,

sand and clay was determined in the soil and the textural class was assigned by help of

USDA textural triangles.

3.5.2 Soil Bulk Density

In order to determine bulk density, soil samples from 0-30, 30-60 and 60-90 cm

were taken by help of core samplers of known volume. After weighing, all the samples

were placed in an oven at about 105 oC for 24 hour until all the moisture was driven off.

53

The samples were weighed again. Soil bulk density was then determined by using the

following equation as mentioned by Tan (1995).

)(cm soil of volumeTotal

(g) soil driedoven of MassdensityBulk

3 (3.1)

3.5.3 Soil pH and Electrical Conductivity (EC)

Soil pH was measured by help of digital pH meter. For this purpose, soil

samples from 0-30, 30-60 and 60-90 cm depths were taken. The samples were then

thoroughly mixed and saturated soil paste was prepared. pH meter was then

standardized with 4.0 and 9.2 pH buffer solutions (Dellavalle, 1992), and accordingly

pH of the experimental soil was measured. For soil electrical conductivity

determination, an extract was obtained from the saturated soil paste by help of vacuum

pump. Then by help of the digital Jenway electrical conductivity meter, ECe was

measured.

3.5.4 Determination of Soil Moisture Content

Soil moisture content of the experimental plots each before and the irrigation

was determined by thermo-gravimetric method (Michael et al., 1965). For this purpose,

about 100 gram soil samples at three moisture depths (0-30, 30-60 and 60-90 cm) were

taken in moisture boxes and covered them immediately with their lids and transported

them into the soil laboratory of Agricultural Engineering, university of Engineering and

Technology, Peshawar. Soil samples were then placed in oven at 105 oC for about 24

hours and dried. Weight of the dried soil samples was determined. Soil moisture

constant was then determined by following equation:

100WS

WSWSSM

2

21w

(3.2a)

Where;

Pw = Soil moisture content, % by weight

WS1 = Weight of the wet soil sample (g)

WS2 = Weight of the dried soil sample (g)

54

Soil moisture content percent by volume was found as:

densitybulk Soil SMSM wV (3.2b)

Soil moisture levels at field capacity and at permanent wilting point were determined in

the laboratory of Agricultural Engineering Department with the help of pressure plate

apparatus, according to Klute (1986).

3.5.5 Soil Available Water Capacity

The available soil water capacity (the amount of water present in the soil

between field capacity (FC) and permanent wilting point (PWP)) was determined by

following equation.

100

ADPWP)(FCcapacity water soil Available iRZ

(3.3)

Where;

FC = Field capacity (%)

PWP = Permanent wilting point (%)

DRZ = Depth of root zone (mm)

Ai = Soil bulk density (g cm-3

)

3.6 IRRIGATION APPLICATION

Irrigation water was taken by centrifugal pump from a water course near the

experimental site. The depth of irrigation applied was calculated from the pre-irrigation

soil moisture content for each moisture level which was determined by soil sampling at

the depth of 0-30cm, 30-60cm and 60-90cm. The depth of irrigation water provided to

the full irrigation treatment (FI) was determined by equation 3.4 (Michal, 1978). The

amount of irrigation water to DI20, DI40 and DI60 treatments was applied at the rate of

80, 60 and 40 % of FI treatment respectively. All treatments received irrigation at the

same day. Equation 3.5 was used for calculating irrigation time for each plot (Jensen,

1980). Amount of seasonal water used by the crops in each plot was determined by

equation as mentioned by Heerman, (1985).

100

DA)MM(d iibifc (3.4)

55

Where;

D = Amount of water applied during an irrigation, mm

Mfc = Moisture content at field capacity

Mbi = Moisture content in the soil before irrigation

Ai = Soil bulk density (g cm-3

)

Di = Depth of soil layer, mm in the root zone

Q

dAT

(3.5)

Where;

T = Desired irrigation application time (sec).

A = Sub-sub plot area (m2).

D = depth of irrigation applied (mm).

Q = discharge, flow rate through PVC pipe (m3/sec).

WDRISWU (3.6)

Where;

SWU = Seasonal water used (mm)

I = Depth of irrigation applied (mm)

R = Amount of effective rainfall received during growing season (mm)

D = Depth of drainage (mm)

ΔW = Change in soil water storage in the measured 90 cm soil depth.

3.7 EXPERIMENTAL RECORDINGS AND CALCULATIONS

3.7.1 Seed Germination Data

The process of development of a dormant embryo into an active one is called

germination. Germination occurs in sugar beet is epigeal germination in which the

cotyledon is forced above the ground by elongation of the hypocotyls‘. Soon after

sowing, the field was regularly inspected for germination. After the completion of

emergence, the germination data per m-2

in each sub-sub plot was observed by counting

the seedlings number in the middle three crop rows. The per square m (m-2

)

germination was then determined by following formula;

56

length rowdistance row-to-row rows No.of

seedlings germinated of No. Totald

(3.7)

3.7.2 Percent Ground Cover Measurement

The crop canopy cover development from germination to senescence was

assessed by measuring the percentage of ground cover achieved by the plants at an

interval of 15 days relative to full ground cover. This measurement was made for all

plots and for all the three replications. Measurements were made for middle three crop

rows in each plot. The percent canopy cover was determined by help of 100 cm long

and 50 cm wide Perspex sheet. By help of marker, the Perspex sheet was equally sub-

divided into 100 small boxes with each having area of 50 cm2 (10 cm * 5 cm). The

Perspex sheet was held by hand over the plot and the number of ‗full‘ or ‗empty‘ boxes

was counted (Donovan, 2002).

3.7.3 Harvesting

All the 108 experimental plots were manually harvested at maturity in both crop

growing seasons in the last week of May. Prior to harvesting an irrigation was applied

so that to facilitate the eradication of beet roots. The root tops were first separated and

then roots were eradicated. Roots and leaves were separately weighted by balance and

the fresh yields were recorded in terms of kg plot-1

and then converted to tons ha-1

. For

dry weight measurement (the AquaCrop simulate the dry biomass an root yield),

reprehensive samples of beat roots from each sub-sub plots were cut into smaller pieces

to accelerate the drying process because of lager surface area. Both the leaves and

sliced roots were then kept in an oven at 80 °C for 72 hours for dry weight

measurement. Sugar content for each treatment was found in percent using sugar crop

research institute laboratory, Mardan. Sugar yield per hectare was determined using

following formula:

(%)]content sugar *ha [tons yieldRoot )ha (tons yieldSugar 11 (3.8)

3.8 ROOT AND SUGAR IRRIGATION WATER USE EFFICIENCY

Root and sugar water use efficiencies were determined using following

equations:

57

)(m applied water Irrigation

(kg) yieldRoot m kg (RIWUE), Efficiency Water UseIrrigation Root

3

3-

(3.9)

)(m applied water Irrigation

(kg) yieldSugar m kg (SIWUE), Efficiency Water UseIrrigation Sugar

3

3-

(3.10)

3.9 ROOT AND SUGAR IRRIGATION CROP WATER USE EFFICIENCY

)(m used water Seasonal

(kg) yieldRoot m kg (RCWUE), Efficiency Water UseCrop Root

3

3-

(3.11)

)(m used water Seasonal

(kg) yieldSugar m kg (SCWUE), Efficiency Water UseCrop Sugar

3

3-

(3.12)

3.10 CROP YIELD RESPONSE FACTOR (KY)

Crop yield response factor ‗ky‘ was determined from the two years experimental

data of 2011-2012, 2012-2013. In order to determine relative evapotranspiration deficit

(I-Ea/Em) and relative yield decrease (1-Ya/Ym), data regarding to actual

evapotranspiration (Ea), maximum evapotranspiration (Em), actual yield (Ya) and

maximum yield (Ym) were used. The relationship between relative yield decrease (1-

Ya/Ym) and relative evapotranspiration deficit (I-Ea/Em) were plotted. Stewart model

(Stewart et al. 1977) was used for investigating water stress effect on crop yield during

2011/2012 and 2012/2013 sugar beet growing seasons. The Stewart equation is:

)ETET(1

)YY(1K

ma

may

(3.13)

3.11 STATISTICAL ANALYSIS

Relationship between sugar beet root & sugar yields and water used was

assessed using regression analysis. By help of a computer software Statistics 8.1 all the

mentioned data in this study were subjected to an analysis of variance followed by a

pair wise multiple comparison of treatment means by the least significant difference

(LSD) test at 5% probability level.

58

3.12 THE AQUACROP MODEL INPUT DATA

AquaCrop, a crop water productivity model developed by the Land and Water

Division of FAO, simulates yield response to water of herbaceous crops, and is

particularly suited to address conditions where water is a key limiting factor in crop

production (Putu, 2014). For simulation run the model required input data (Figure 3.6)

such as climate data, crop data (planting method, plant density, row spacing, plant

spacing, date of emergence, date of maximum canopy, date of senescence, maturity,

start of yield formation, maximum rooting depth, harvest index etc), irrigation

management data (irrigation method, irrigation events), soil data (soil thickness, field

capacity, permanent wilting point, saturation percentage and saturated hydraulic

conductivity), etc. All these data were collected, recorded and measured in the field.

For calculating daily reference crop evapotranspiration (ET0, mm day-1

), daily

data of maximum and minimum temperatures (Tmax and Tmin, 0C), sun shine hours,

wind velocity (km day-1

), maximum and minimum relative humidity (RHmax and

RHmin, %), precipitation (mm), was obtained from the meteorological station of sugar

crop research institute, Mardan (Figure 3.7). ET0 was then calculated by help of ET0

calculator using the Penman-Monteith approach (Allen et. al., 1998). Penman-Monteith

approach is the most widely used method for calculating daily reference crop

evapotranspiration (ET0) and is also recommended by FAO and is given below:

2

as2n

0u34.01

eeu273T

900GR408.0

ET

(3.14)

Where:

ET0 = Reference crop evapotranspiration (mm/day)

Rn = Net radiation at the crop surface (MJ/m2day)

G = Soil heat flux density (MJ/m2day)

T = Mean daily temperature at 2 m height (°C)

U2 = Wind speed at 2 m height (m/sec)

Es = Saturation vapor pressure (Kpa)

Ea = Actual vapor pressure (Kpa)

es-ea = Saturation vapour pressure deficit (Kpa)

D = Slop vapor pressure curve (Kpa/ °C)

g = Psychrometric constant(Kpa/°C)

59

Fig. 3.7 Diagram of AquaCrop input data (adapted from Raes et al., 2009)

60

Figure 3.8 Daily evolution of climatic parameters during 2011/2012 cropping season: (a)

rain fall and reference evapotranspiration (ETo); (b) sun shine hours, wind

speed, relative maximum and minimum humidity (RHmax, RHmin); (c)

minimum and maximum temperature (Tmax and Tmin).

3.13 MODEL CALIBRATION, VALIDATION AND EVALUATION

Model was calibrated for measured data sets of nine full irrigation treatments in

the experimental season of 2011/2012 and validated for twenty seven deficit irrigation

treatments of the same season. Calibration was done by matching the measured data of

canopy cover, biomass and root yield with the model data. By setting the plant density,

the AquaCrop automatically estimated the initial canopy cover (CCo) and cover per

seedling. The water stress indices, canopy growth coefficient (CGC) and canopy

decline coefficient (CDC) were the key factors affecting the sugar beet canopy cover.

61

The model estimated these parameters when the necessary input data such as seed

germination dates, maximum canopy cover (CCmax), senescence and maturity were

entered. For reproducing the measured CC, the water stress parameters e.g. p (upper), p

(lower) and curve shape factor affecting leaf expansion and early canopy senescence

were changed manually around the default value. For obtaining satisfactory results,

continuous iterations of these parameters were carried out until the best fitting with

observed data was attained. By the same way, the simulated biomass and root yield

were compared with the observed data. The default value of harvest index (HI) was

adjusted to simulate the observed yields in the experimental field. Validation of the

model was done for CC, root yield and biomass by using the independent data set of the

twenty seven deficit irrigation treatments after comparing the field data with the model

data.

3.14 MODEL PERFORMANCE ASSESSMENT

Different statistical parameters such as, Root mean square error (RMSE) (Jacovides

and Kontoyiannis, 1995), Normalized Root Mean Square Error (NRMSE) (Loague and Green,

1991), index of agreement (dindex) (Willmott, 1982), Nash–Sutcliffe Efficiency Factor (EF)

(Nash and Sutcliffe, 1970), and the Mean Bias Error (MBE) (Zacharias et al., 1996) were used

in this research work for examining the AquaCrop model accuracy and applicability under

semi-arid condition of Pakistan. These parameters were determined by the help of following

equations.

2

i

n

1i

i )OS(n

1RMSE

(3.15)

2

i

n

1i

i

obs

)OS(n

1

O

100NRMSE

(3.16)

n

1i

2

ii

2n

1i ii

index

OOOS

)OS(1d (3.17)

n

1i

2ii

n

1i

2

ii

)OO(

)SO(1EF (3.18)

ii OSMBE (3.19)

Where,

Si and Oi represent the simulated and observed values, iO and iS represent the average

observed and simulated values and n is the total number of observations.

62

CHAPTER IV

RESULTS AND DISCUSSIONS

In this chapter results related to the sugar beet root yield, % sugar content, sugar yield,

irrigation water applied, seasonal water used, root irrigation water use efficiency, sugar

irrigation water use efficiency, root crop water use efficiency, sugar crop water use

efficiency, relationship between seasonal evapotranspiration and yield components of

sugar beet and sugar beet yield response factor as affected by irrigation regimes,

mulching and raised-bed planting methods are presented and discussed.

4.1 EFFECT OF IRRIGATION REGIMES ON SUGAR BEET YIELD

COMPONENTS

Statistical analysis of the data revealed that sugar beet root yield (tons ha-1

) was

significantly (at p < 0.05) affected by irrigation regimes (Table 4.1). In both the crop

growing season of 2011/2012 and 2012/2013, highest mean root yield with 68.24 and

66.34 tons ha-1

was observed for full irrigation (FI) treatments. This was followed by

64.16, 61.05 tons ha-1

for 20% deficit irrigation (DI20) and 55.60, 52.01 tons ha-1

for

40% deficit irrigation (DI40) treatments. In both cropping seasons the severe deficit

irrigation treatments (DI60) produced the lowest root yield with 45.80 and 41.69 tons

ha-1

. It is also evident from Table 4.1 that root yield in year 2011/2012 was

comparatively higher than that observed for year 2012/2013. The reason for lower root

yield in 2012/2013 may be attributed towards lower soil and air temperature, and less

solar radiation during the time of sowing and during the initial and crop development

stages in year 2012/2013 (Figure 3.5). The low soil temperature may cause late

germination that subsequently exposed the young seedling to low air temperature.

Furthermore, although the rainfall in the 2011/2012 season was less than the 2012/2013

season, however the favorable inter-season distribution of rainfall may have benefited

the crop. These factors might have affected the crop growth and led towards lower

yield in 2012/2013. Averaging the effect of two years, it was observed that 20% deficit

irrigation (DI20), 40% deficit irrigation (DI40) and 60% deficit irrigation (DI60)

produced 6.98%, 20.06% and 35.02% less root yield respectively, when compared with

Full irrigation (FI) treatment (Figure 4.1a). The low yield obtained with the application

of deficit irrigation regimes could be due to crop water stress as all other management

factors were similar for all treatments. The reduction in root yield with application of

63

deficit irrigation in our study is in accordance with the research conducted in other parts

of the world. Topak et al., (2011), based on there two years experiment, reported 77.3

tons ha-1

yield for full irrigation treatment and the relative reduction was 8.7, 34.9 and

63.6 % for 25, 50 and 75 % deficit irrigation, respectively. Ucan and Gencoglan (2004)

reported maximum yield of 62.350 tons ha-1

yield for well irrigated-sprinkler irrigation

plots. However, by applying 6, 15, 30 and 45 % deficit irrigation, they observed 13, 32,

48, 70 % yield reduction respectively. Tognetti et al. (2003) reported 78.7 tons ha-1

yield for full irrigation treatment and 63.1 tons ha-1

for 50% deficit irrigation using drip

system. Rinaldi and Vonella (2006) reported 53.6 tons ha-1

for full irrigation and 43.9

tons ha-1

for reduced irrigation. Ertas (1984) and Werker and Jaggard (1998) observed

44 and 50 % yield reduction when 34 and 50 % reduction in the evapotranspiration

occurred respectively. Ali et al., (2004) reported 59.58 tons ha-1

yield by applying full

irrigation at Gugranwala, Pakistan. Mahmoodi et. al, 2008 observed that the sugar beet

root yield was decreased from 78.5 tons ha-1

when irrigated up to 70% of field capacity

to 63 tons ha-1

when the irrigation amount full filled only 30% of the field capacity.

According to the two years research studies conducted by Ghamarina et al., (2012),

maximum root yield decreased from 106.20 and 105.4 tons ha-1

under full irrigation

treatment to 40.40 and 38.90 tons ha-1

at 75% deficit irrigation in 2006 and 2007

respectively for drip planting pattern. They also reported 120.73 and 108.90 tons ha-1

yield for full irrigated treatment in planting pattern.

Table 4.1 also presents means of sugar content (%) in relation to different

irrigation regimes. It is evident from the table that, in both years, sugar content was

increased with the increase in irrigation deficit level. Sugar content was the lowest

(14.86, 14.65 %) for full irrigation (FI) treatment and highest (17.29 and 17.03 %) for

60% deficit irrigation (DI60) treatment. A significance level of less than 1% (P<0.01)

was obtained for the effects of different levels of water stresses on sugar content. From

the average of two years experimental data, it was observed that the 20, 40 and 60 %

deficit irrigation application caused 6.25, 13.45 and 17.71 % higher sugar content

respectively when compared with full irrigation treatment (Figure 4.1b).

64

Table 4.1 Effect of irrigation regimes on sugar beet root yield, sugar content and

sugar yield during 2011/2012 and 2012/2013 cropping seasons

Irrigation

regimes

Root yield (Tons ha-1) Sugar content (%) Sugar yield (Tons ha-1)

2011/

2012

2012/

2013

Two

year

average

2011/

2012

2012/

2013

Two

year

average

2011/

2012

2012/

2013

Two

year

average

FI 68.24a1 66.34a 67.29a 14.86d 14.65d 14.76d 10.15a 9.73a 9.94a

DI20 64.16b 61.05b 62.60b 15.74c 15.51c 15.62c 10.11a 9.48a 9.80a

DI40 55.60c 52.01c 53.81c 16.61b 16.39b 16.50b 9.25b 8.542 8.90b

DI60 45.8d 41.69d 43.74d 17.29a 17.03a 17.16a 7.94c 7.12c 7.53c

Note:

1Mean followed by the same letter(s) are statistically non-significant at 1% probability

FI: Full irrigation; DI20: 20% deficit irrigation; DI40: 40% deficit irrigation; DI60: 60%

deficit irrigation

Increases in sugar content with the increase level of deficit irrigation were also reported

by other researchers in other parts of the world. Ucane and Cafer, 2004, reported 5.62,

11.7, 13.22, 16.11 and 17.5 % high sugar content for 6, 15, 30, 45 and 60% deficit

irrigation respectively. Mahmoodi et al., 2008, observed 16.92, 17.45, 17.23 and

15.5 % sugar content by irrigating the field at 30, 50, 70 and 90 % respectively.

Ghamarnia et al., 2006, based on their experiment conducted in 2006 in western Iran

reported 4.45, 17.32 and 37.63 % higher sugar content by applying 25, 50 and 75 %

deficit irrigation. Therefore it is necessary to optimize irrigation application along with

suitable agricultural measure for obtaining high sugar concentration in the sugar beet

production (Ucan and Gencoglan, 2004). Table 4.1 further shows the effect of different

irrigation regimes on sugar yield of sugar beet. In both study years, the highest sugar

yield (10.15, 9.73 tons ha-1

) was observed for full irrigation (FI) treatment. This was

followed by mild deficit irrigation (DI20) treatment with 10.11 and 9.48 tons ha-1

and

severe moderate deficit irrigation (DI40) with 9.25 and 8.54 tons ha-1

, respectively. The

lowest sugar yield was observed for severe deficit irrigation (DI60) with 7.94 and 7.12

tons ha-1

. However sugar yield obtained at mild deficit irrigation (DI20) was not

significantly lower than that produced by full irrigation (FI) treatment. Similar to our

65

studies, Topak et al., (2011) and Ghamarnia et al., (2012) also reported no significant

difference in sugar yield produced by full irrigation and mild deficit irrigation (DI25).

The significant decrease in sugar yield observed in the current study when moderated

and severe water stresses were applied was also in accordance with that observed by

Topak et al., (2011) and Ghamarnia et al., (2012), Baigy et al., (2012). Averaging the

two years sugar yield data, it was observed that DI20, DI40 and DI60 treatments produced

1.46, 10.55 and 24.25 % less sugar yield when compared to FI treatment (Figure 4.1c).

4.2 EFFECT OF MULCHING ON SUGAR BEET YIELD COMPONENTS

Mulching practices comprising of No Mulch, black polyethylene film mulch

and straw mulch all significantly (at p < 0.05) affected yield root yield of sugar beet

(Table 4.2). For the study years 2011/2012 and 2012/2013, significantly highest mean

root yields with 62.78 and 60.55 tons ha-1

were obtained through Black Film Mulch.

This was fallowed by straw mulch with 59.86 and 56.49 tons ha-1

. The no-mulch

treatment gave the lowest root yield with 52.70, 48.77 tons ha-1

(Table 4.2).

-40

-30

-20

-10

0

FI DI20 DI40 DI60

% d

ecrease

in

root

yie

ld

(a)

66

0

5

10

15

20

FI DI20 DI40 DI60

% in

crea

se in

su

gar c

on

ten

t

-30

-20

-10

0

FI DI20 DI40 DI60

% d

ecrease

in

su

gar y

ield

Figure 4.1(a, b, c). Relative increase/decrease in sugar beet (a) root yield (b) sugar

content and (c) sugar yield due to deficit irrigation regimes

Table 4.2. Mulching effect on sugar beet root yield, sugar content and sugar yield

during 2011/2012 and 2012/2013 cropping seasons

Note: 1Mean followed by the same letter(s) are statistically non-significant at 1%

probability.

NM: No Mulch

BFM: Black Film Mulch

SM: Straw mulch

Mulch

Types

Root yield, (Tons ha-1) Sugar content (%) Sugar yield (Tons ha-1)

2011/

2012

2012/

2013 Average

2011/

2012

2012/

2013 Average

2011/

2012

2012/

2013 Average

NM 52.70c1 48.77c 50.74c 15.82c 15.54c 15.54c 8.25c 7.50c 7.88c

BFM 62.78a 60.55a 61.67a 16.35a 16.15a 16.15a 10.21a 9.70a 9.96a

SM 59.86b 56.49b 58.18b 16.20b 16.0b 16.10c 9.63b 8.95b 9.29b

(b)

(c)

67

From the average of two years mean yield data it was observed that both Black Film

Mulch and straw mulch treatments produced 21.54 and 14.66 % higher root yield when

compared with no-mulch treatment (Fig. 4.2(a)). The positive effects of mulches over

No Mulch on sugar beet root yield in this study agreed with Artyszak et al., (2014),

they reported that mulching increased sugar beet root yield by 9.4 and 11.2 %. Shock et

al., (1986) observed about 25 % higher sugar beet root yield for treatment that was

raised under straw mulch in comparison to No Mulch. The increase in crop yield by

mulching was also noted by Tegen et al., (2016) for tomato, Borosic et al., (1998), Klar

& Jadoski (2004) for peppers and Hulsey (2013) for Yellow Zucchini. They reported up

to 70 % increase in yield when the crop was grown under straw or Black Film

Mulchcondition in comparison to No Mulch planting. Jenni et al., (2004) reported 25 %

higher lettuce yield in the polyethylene film-mulched plots compared with un-mulched

plots. Rekowska (1998) reported 16.2 % increased garlic yield when the crop was

grown under Black polyethylene film in comparison to its cultivation without mulch.

Dyduch and Najda (2004) also observed higher yields of celery leaf stalks for the crop

cultivation under polyethylene film mulch in comparison its cultivation under No

Mulch. Mukherjee et al., (2010) reported that tomato yield for mulch treatment was

increased by 23 – 57 % when compared to the No Mulch treatment. The result of

current study however does not agree with that observed by Perez et al (2004) for onion.

They reported 7 – 60 % less yield when sweet onion was grown under straw or Black

Film Mulch compared to that grown under No Mulch. Furthermore, the superiority of

Black Film Mulch over straw mulch and No Mulch in this study supports the

investigation carried out by Chhangani, (2000), Rahman and Khan, (2000) and Vavrina

and Roka, (2000) for onion, Gimenez et al., (2002) for leaf and root vegetable crops

Kumara and Dey, (2011) and Taparasuskiene, and Otilija (2014) for strawberry, Ahmad

et al., (2011) for Chili, Mahajan et al., (2007) for baby corn and Berihun (2011) for

tomato. All of them concluded that Black Film Mulch yielded higher yield than straw

mulch and No Mulch through its effective weed control, soil moisture conservation

increasing soil temperature and micro climate modification. The results of present study

were however in contradictory to the observations carried by Tegen et al., (2016),

Wahome et al. (2001) Siborlabane (2000) for tomato crop which indicated highest

marketable fruits yield for tomato grown with grass mulch treatment followed by plants

grown under Black Film Mulch. The results of our study also disparate with the

investigation of Jamil et al., (2005) for garlic, Adnan et al., (2012) for Freesia, they

68

reported that the highest yield (of the above mentioned crops) was obtained from straw

mulch followed by Black Film Mulch. All mulch treatments also significantly affected

(at p < 0.05) % sugar content of sugar beet with the highest amount of 16.35 and

16.15 % observed in Black Film Mulch treatment. This was followed by straw mulch

with 16.20 and 16.0 %. The No Mulch treatment produced the lowest sugar content

with the amount of 15.82 and 15.54 % for the study years 2011/2012 and 2012/2013,

respectively (Table 4.2). Averaging the effect of two years, it was observed that sugar

beet produced 4.30 % higher sugar content when the crop grown under Black Film

Mulch. The same increase was 3.34 % higher for straw mulch treatment (Fig. 4.2b).

The higher sugar content observed in black polyethylene film mulch treatment in

comparison to No Mulch treatment in the current study coincides with that reported by

Kosterna et al., (2011) for melon. They observed 6.82 – 17.91 % higher sugar content

when melon was raised under Black Film Mulch compared to that without mulch.

Increase observed in sugar content in straw mulch treatment compared to No Mulch

was in agreement with that observed by Shock et al., (1986) who reported 6.21 %

higher sugar content under straw mulch in comparison to No Mulch. The results were

however in contrast with that noted by Artyszak et al., (2014) and Adamavičienė et al.,

(2009). They reported no significant improvement in sugar beet sugar content in straw

mulch treatment in comparison to No Mulch. The effect of different mulching practices

on sugar yield of sugar beet is also presented in Table 4.2. It was observed from the

data that all the mulch treatments significantly affected the sugar yield. In both study

years, the highest sugar yield was observed for treatment under Black Film Mulch

(10.21, 9.70 tons ha-1

). This was followed by treatment under straw mulch (9.63 and

8.95 tons ha-1

). Again the lowest sugar yield was obtained in No Mulch treatment (8.25

and 7.50 tons ha-1

). Averaging the effect of two years, it was observed that sugar yield

of sugar beet was 26 and 18 % higher for Black Film Mulch and straw mulch

respectively, when compared with no-mulch treatment (Fig. 4.2c). The increased in

sugar yield by mulch treatment over No Mulch are in agreement with Artyszak et al.,

(2014) they reported 8.0 – 11.3 % high sugar yield when the sugar beet crop was sown

in mulched condition in comparison to No Mulch.

69

Fig. 4.2 (a, b, c). Relative increase/decrease in sugar beet (a) root yield (b) sugar

content and (c) sugar yield due to deficit mulching practices

0

5

10

15

20

25

30

No mulch Black film mulch Straw mulch

% i

ncr

ease

in s

ugar

yie

ld

0

5

10

15

20

25


% i

ncr

ease

in r

oot

yie

ld

0

1

2

3

4

5


% i

ncr

ease

in s

ug

ar c

onte

nt

(a)

(c)

(b)

70

4.3 EFFECT OF RAISED-BED PLANTING METHODS ON SUGAR BEET

YIELD COMPONENTS

Raised bed planting methods caused significant affect on sugar beet root yield

(Table 4.3). In both study years, the medium raised-bed planting (MRB) that had two

crop rows on the bed produced the highest root yield with 62.70 and 59.37 tons ha-1

.

This was followed by three rows wide-raised bed (WRB) with 57.61 and 54.0 tons ha-1

.

The Conventional Ridge-Furrow (CRF) planting produced the smallest root yield with

55.03 and 52.44 tons ha-1

.

Averaging the effect of two years it was observed that the MRB produced

13.59 % higher root yield, and WRB yielded 3.85 % higher when compared with CRF

(Figure 4.3a). The increased yield in MRB and WRB systems might be attributed

towards the availability of more volume of loose soil, better moisture conservation and

temperature regulation, having stable top and side slopes, in comparison to narrow

ridge in CRF. The results obtained in this study were in accordance to that obtained by

Singh et al., (2009) for Chickpea. The results further revealed that root yield for MRB

was 8 % higher than that of WRB. The low yield under WRB in comparison to MRB

might be due to less lateral seeping of water from the furrow to the center of the bed

and thus unavailability of sufficient water for middle row. On the other hand, the MRB

with two rows on the bed almost has uniform moisture content for both rows. Similar

results were also obtained by Ahmad et al., (2010) for sugar beet, Akbar et al., (2010)

for maize and Ghani et al., (2009) for wheat. These results are however disparate with

that presented by ICARDA, in the second phase of 1st annual progress report,

2010/2011. According to their report the wide raised-bed produced about 14 % more

root yield when compared with medium raised-bed system. In another study, Mahmood

et al., (2013) reported that the two rows and three rows bed planting produced about 11

and 17 % higher wheat yield in comparison to conventional row planting. From their

study it is also clear that three rows bed planting produced 6 % higher grain yield than

that produced by two rows bed planting. However, in their study they kept uniform bed

width (70 cm) for both tow rows planting and three rows planting. In another study,

Sayre and Ramose (1997) compared the effect of 75 cm wide raised-bed having pair of

crop rows with that of 90 cm wide bed having three crop rows for wheat crop and

concluded that 75 cm wide bed produced higher yield (although non significant) from

that produced by 90 cm wide bed. All the three planting methods significantly affected

the sugar content (%) of sugar beet (Table 4.3). In both study years, the highest sugar

71

content (16.72, 16.51 %) was observed for raised bed having three rows on the bed.

This was followed by medium raised- bed (16.19, 15.9 3%) with two rows on the bed.

The conventional ridge-furrow system gave the lowest (15.46, 15.46 %) sugar content.

The higher sugar content in medium raised bed having pair of row is in accordance to

the results obtained by Zahooe et al., (2010). They obtained 16.9 % sugar content for

conventional sowing method and 18.1 % for raised bed sowing with pair of crop rows.

Averaging the effect of two years it was observed that MRB and WRB produced 4.59

and 8.26 % higher sugar content over CRF (Figure. 4.3b). During the study years

2011/2012 and 2012/2013, the highest sugar yield was observed for MRB with 10.08

and 9.38 tons ha-1

. The second highest sugar yield was produced by WRB with 9.55

and 8.82 tons ha-1

. The least was yielded by CRF with 8.46 and 7.96 tons ha-1

(Table

4.3). From the average of two years data, it was observed that both the MRB and WRB

produced 15.62 and 11.88 % higher sugar yield, respectively, when compared with

CRF (Figure 4.3c).

4.4 INTERACTION EFFECT OF IRRIGATION REGIMES AND

MULCHING ON SUGAR BEET YIELD COMPONENTS

Irrigation regimes and mulching combination produced significant (at p < 0.05)

effect on all the sugar beet yield components (Table 4.4). In both study years,

significantly highest root yield was obtained via the interaction effect of full irrigation

and Black Film Mulch(FIBFM), followed by straw mulch and full irrigation

combination (FISM). The lowest root yield was obtained for 60% deficit irrigation

and no-mulch (DI60NM) combination. The highest sugar beet root yield produced in

this study by the interaction effect of full irrigation and mulch is in agreement with the

study carried by Alenazi et al., (2015) for muskmelon and Osama (2015) for Olive.

Taking average of two years mean root yield data, it was observed that, for same level

of irrigation, all mulched treatments produced significantly higher root yield when

compared with un-mulched treatments and all the Black Film Mulchtreatments

produced higher in comparison to straw mulched treatments.

72

Table 4.3. Effect of different planting methods on sugar beet root yield, sugar

content and sugar yield during 2011/2012 and 2012/2013 cropping

seasons

Treatments Root yield, (Tons ha-1) Sugar content (%) Sugar yield (Tons ha-1)

2011/

2012

2012/

2013

Average 2011/

2012

2012/

2013

Average 2011/

2012

2012/

2013

Average

of years

CEF 55.03c 52.44c 53.74c 15.46c 15.25c 15.36c 8.46c 7.96c 8.21c

MRB 62.70a 59.37a 61.04a 16.19b 15.93b 16.06b 10.08a 9.38a 9.73a

WRB 57.61b 54.0b 55.81b 16.72a 16.51a 16.62a 9.55b 8.82b 9.19b

Note:

1Mean followed by the same letter(s) are statistically non-significant at 1% probability.

CER: Conventional ridge-furrow planting with single crop row on its narrow ridge

MRB: Medium raised bed planting with two crop rows on its 45cm wide raised bed

WRB: Wide raised bed planting with three crop rows on its 905cm wide raised bed

0

2

4

6

8

10

12

14

16

Conventional ridge-furrow Medium raised-bed Wide raised-bed

% i

ncr

ease

in r

oot

yie

ld

0

1

2

3

4

5

6

7

8

9


% i

ncr

ease

in s

ugar

conte

nt

(b)

(a)

73

Fig. 4.3 (a, b, c). Relative increase/decrease in sugar beet (a) root yield (b) sugar

content and (c) sugar yield due to different planting methods.

Comparing the interaction results of irrigation regimes and Black Film Mulch

treatments (BFM) to that with interaction of irrigation regimes and No-Mulch, it was

found that the interaction of 20, 40 and 60 % deficit irrigation and Black Film Mulch

(DI20BFM, DI40BFM and DI60BFM) produced significantly higher root yield when

compared with that produced by the interaction of FI, and 20 and 40 % deficit irrigation

with out mulch (FI NM, DI20NM, DI40NM), respectively. Also, root yield resulted

by 20 and 60 % deficit irrigation and straw mulch interaction (DI20SM, DI60SM)

were statistically similar to that produced by NMFI and NMDI40 treatments,

respectively (Table 4.4). From the analysis of average effect of two years mean data, it

was observed that, when the irrigation level was reduced from full irrigation to 20 %

deficit level, root yield was reduced by 4.54 % for BFM, 5.04 % for Straw Mulch (SM)

and 12.0 % for no-mulch (NM) treatment, respectively. Reducing the irrigation level by

40 % caused root yield reduction by about 13.25 % in BFM, 19.70 % in SM and

27.74 % in NM treatments. Further reduction in irrigation application (DI60) caused

about 27.59 % reduction in BFM, 33.24 % in SM and 48.27 % in NM treatments,

respectively (Figure 4.4a).

Mulch and irrigation Interaction also produced significant (at p < 0.05) effect on

sugar content. However on contrary the sugar beet root yield, sugar content was

increased as the irrigation application level was decreased. The highest sugar content

was yielded by DI60BFM interaction. This was followed by DI60SM and DI60NM

treatments. The lowest sugar content was for FINM treatment (Table 4.4). For the

same level of irrigation regime, all the mulch treatments produced significantly higher

0

5

10

15

20


% i

ncr

ease

in s

ugar

yie

ld

(c)

74

sugar content when compared with un-mulched treatments. Among the mulches, no

significant difference in sugar content was found for full irrigation Black Film Mulch

(BFM) and full irrigation Straw Mulch (SM) treatments. However, for the same level of

deficit irrigation, BFM produced significantly higher sugar content (Table 4.4).

Averaging the two years data, an increase in sugar content of amounts 2.52, 4.63 and

4.34 % were observed in each of the NM, BFM and SM treatments, when the irrigation

level was reduced by 20 %. The corresponding increase were 8.40, 9.20 and 9.19 %

respectively, for 40 % deficit irrigation. Decreasing the irrigation level by 60 % caused

12.90, 14.80 and 14.22 % increased in sugar content in each of NM, BFM and SM

treatments, respectively (Figure 4.4b).

Result regarding the interaction effect of deficit irrigation regimes and mulching on

sugar yield of sugar beet are also presented in Table 4.4. It can be seen from the data

that, for No-Mulch conditions, the highest sugar yield was obtained in FINM

treatment. This was followed by DI20NM and DI40NM treatments. The lowest sugar

yield was obtained for DI60NM treatment. However for mulched conditions, the

highest sugar yield was obtained for DI20BFM and DI20SM treatments. This was

followed by FIBFM, FISM and DI40BFM, DI40SM treatments. The lowest sugar

yield was obtained in DI60BFM and DI60SM treatments. The data also revealed that

for the same level of irrigation, BFM treatments produced the highest sugar yield,

followed by straw mulch treatment. The no-mulch treatments gave the lowest sugar

yield. Averaging the effect of two years, it was observed that, both BFM and SM

produced higher sugar yield (although non-significant) at 20% deficit irrigation when

compared with the sugar yield produced by full irrigation. Furthermore it was also

observed from the data that, sugar yield produced by the interaction effect of 40 and

60 % deficit irrigation with Black Film Mulch (DI40BFM, DI60BFM) was

significantly higher when compared with the combine effect of full irrigationNo

Mulch (FI-NM), and 20% deficit irrigationNo Mulch (DI20NM) treatments. Among

the mulches, no significant difference was found between DI40BFM and DI20SM

treatments (Table 4.4). The two years average data further revealed that, in the absence

of any mulch, decreasing the irrigation level by 20, 40 and 60 % caused reduction in

sugar yield by 7.49, 23.41 and 57.60 %, respectively, in comparison to FINM

interaction. However, when the crop was grown under Black Film Mulch, sugar yield

was increased by 10.12, 11.56 and 7.44 %, and decreased by 5.90 % for each of FI,

75

DI20, DI40 and DI60 treatments, respectively, when compared with FINM treatment.

Growing sugar beet under straw mulch caused increase in sugar yield by 7.62 and

8.17 %, and decrease by 3.09 and 18.70 %, for each of FI, DI20, DI40 and DI60 irrigation

levels, respectively, in comparison to FINM treatment (Fig. 4.4c).

Table 4.4 Interaction effect of irrigation regimes and mulching on yield

components of Sugar beet.

FINM: Full irrigation and No Mulch interaction; FIBFM: Full irrigation and Black Film

Mulch interaction; FISM: Full irrigation and Straw mulch interaction; DI20NM: 20% deficit

and No Mulch interaction; DI20BFM: 20% deficit irrigation and Black Film Mulch interaction;

DI20SM: 20% deficit irrigation and Straw mulch interaction; DI40NM: 40% deficit irrigation

and No Mulch interaction; DI40BFM: 40% deficit irrigation and Black Film Mulch; DI40SM:

40% deficit irrigation and Straw mulch interaction; DI60NM: 60% deficit irrigation and No

Mulch interaction; DI60BFM: 60% deficit irrigation and Black Film Mulch interaction;

DI60SM: 60% deficit irrigation and Straw mulch interaction;

Treatments Root yield (tons ha-1) Sugar content (%) Sugar yield (tons ha-1)

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

FINM 66.89c 62.43c 64.26d 14.63j 14.40i 14.52j 9.67d 9.0c 9.33c

FIBFM 69.92a 69.20a 69.56a 15.01i 14.82h 14.91i 10.50b 10.26a 10.38a

FISM 68.71ab 67.37a 68.04b 14.94i 14.74h 14.84i 10.27c 9.93b 10.10b

DI20NM 58.86e 54.74e 56.80f 15.41h 15.14g 15.27h 9.07e 8.29d 8.68e

DI20BFM 67.75b 65.05b 66.40c 16.00f 15.77e 15.89f 10.84a 10.26a 10.55a

DI20SM 65.87c 63.35bc 64.61d 15.81g 15.61f 15.71g 10.43bc 9.90b 10.16b

DI40NM 48.22h 44.65h 46.44i 16.39e 16.11d 16.25e 7.91g 7.21e 7.56g

DI40BFM 61.48d 59.21d 60.35e 16.79c 16.60c 16.69c 10.33bc 9.83b 10.08b

DI40SM 57.10f 52.17f 54.63g 16.65d 16.45c 16.55d 9.51d 8.58d 9.05d

DI60NM 37.64i 33.24i 35.44j 16.84c 16.50c 16.67c 6.35h 5.50f 5.92h

DI60BFM 52g 48.74g 50.37h 17.59a 17.40a 16.50a 9.15e 8.47d 8.81e

DI60SM 47.77h 43.08h 45.42i 17.42b 17.18b 17.30b 8.32f 7.39e 7.86f


76

-50

-40

-30

-20

-10

0

FI DI20 DI40 DI60

% d

ecrease

in

root

yie

ld

NM BFM SM

0

5

10

15

20

FI DI20 DI40 DI60

% in

crease

in

su

gar c

on

ten

t

NM BFM SM

-60

-45

-30

-15

0

15

FI DI20 DI40 DI60

% in

crease

/decrease

in

su

gar y

ield

NM BFM SM

Fig. 4.4 (a, b, c). Relative increase/decrease in (a) root yield (b) sugar content and

(c) sugar yield of sugar beet caused by the interaction effect of

different irrigation regimes and mulching practices.

(a)

(c)

(b)

77

4.5 INTERACTION EFFECT OF IRRIGATION REGIMES AND

PLANTING METHODS ON SUGAR BEET YIELD COMPONENTS

Table 4.5 presents the interaction effects of irrigation regimes and furrow

irrigated raised bed planting methods on sugar beet root yield, sugar content and sugar

yield for 2011/2012 and 2012/2013 cropping season. The data shows that, sugar beet

root yield were significantly (at p < 0.05) affected by the interactive effects of irrigation

regimes and different raised bed planting methods. In both study years, the highest root

yield (72.94, 70.52 tons ha-1

) was obtained when the crop was grown on Medium

Raised-Bed (MRB) with two crop rows and crop received its full irrigation (FI)

requirement. The second and third significantly highest yield was produced by

DI20MRB and FIWRB treatments with 69.17 and 66.59 tons ha-1

and 67.28 and

65.67 tons ha-1

, respectively. The significantly least root yield (43.23, 40.05 tons ha-1

)

was observed for Conventional Ridge Furrow (CRF) system that was given 60 %

deficit irrigation i.e. DI60CRF treatment (Table 4.5). For the same level of irrigation,

all MRB treatments produced significantly higher root yield when compared with CRF

and WRB. Comparing performance of MRB with CRF and WRB under deficit

irrigation, it was observed that root yield produced by MRB at DI20 was significantly

higher than that produced by CRF or WRB at FI. Comparing the performance of CRF

and WRB for the same level of irrigation, it was noted that WRB produced better

results when crop received full irrigation (FI) or kept under mild to moderate deficit

irrigation (DI20 and DI40). However, at 60 % stress level (DI60), root yield under WRB

was not significantly higher than that produced by CRF. Figure 4.5a shows the percent

(%) increase/decrease in root yield caused by different combination of irrigation

regimes and planting methods when compared with the root yield produced by

conventional ridge-furrow planting and full irrigation combination (FICRF). It can be

seen from this Figure that 20, 40 and 60 % deficit irrigation application in CRF system

caused 9.08, 24.11 and 52.91 % root yield reduction compared to that produced by

FICRF. On the other hand, when sugar beet was grown on medium raised bed, the

20 % deficit irrigation produced 6.20 % higher root yield compared to that produced by

CRFFI. For 40 and 60 % deficit irrigation, yield under MRB was only 10 and

35.67 % less than that produced by FICRF. Root yield produced by DI20WRB,

DI40WRB and DI60WRB treatments was 3.41, 21.28 and 49.25 % less, respectively,

compared to FICRF. These results indicated that if farmers of the study area adopt

78

MRB system, they can produce 11.24 % more root yield when optimum irrigation

water is available as generally the situation in the head reaches of the canal and water

courses in Pakistan. The farmers that are getting only 80 % of their allotted quota as

generally the case at middle reaches of the canals, they root yield will be decrease by

about 10 % using the CRF system. However, if they adopt the MRB system, their yield

will still be about 6.20 % high than the farmers of the head reach using CRF system.

Farmers that are suffering from severe water shortage as the case in tail reaches of the

canals in Pakistan due to huge conveyance losses (Ahmad and Ahmad, 1999), they can

loss about 24 to 53 % root yield in CRF system by applying 40 to 60 % deficit

irrigation. However, if they adopt the MRB system, their probable loss will be only

10 % for 40 % deficit irrigation and 35.7 % for 60 % deficit irrigation, respectively

(Figure 4.5a).

Sugar content in sugar beet was also significantly affected by the interaction of

irrigation regimes and raised bed planting methods (Table 4.5). In study years

2011/2012 and 2012/2013, for the same levels of irrigation, sugar content (%) was

highest for all WRB treatments. This was followed by MRB. The CRF treatments

produced the least one. In both years, the highest sugar content with 18.08 and 17.92 %

was observed in DI60WRB treatment. This was followed by MRBDI60 with 17.33

and 17.02 %, and CRFDI60 with 16.45 and 16.13 %, respectively. Averaging the

effect of two years and comparing the % sugar content observed in different treatments

to that with FICRF, it was noted that the sugar contents in DI20CRF, DI40CRF and

DI60CRF 3.92, 7.55 and 11.30 % higher, in FIMRB, DI20MRB, DI40MRB and

DI60MRB were 1.83, 7.61, 13.47 and 15.89 % higher, and in FIWRB, DI20WRB,

DI40WRB and DI60WRB were 4.37, 10.75, 15.79 and 19.72 % higher, respectively

(Figure 4.5b).

Table 4.5 also presents the effect of irrigation regimes and planting methods

interaction on sugar yield of sugar beet for 2011/2012 and 2012/2013 cropping seasons.

Results in this Table show that, in both years, DI20MRB and DI20WRB produced

higher sugar yield (although non-significant) when compared with FIMRB and

FIWRB, respectively. Data also reveled that sugar yield produced by MRB at 40 %

stress level (DI40) was not significantly less than that produced by CRF and WRB

systems at full irrigation application. For the same level of irrigation, sugar yield

79

produced by MRB systems was significantly high in comparison to CRF and WRB

systems.

Table 4.5: Interaction effect of irrigation regimes and planting methods on yield

components of Sugar beet.


FICRF: Full irrigation-Conventional ridge-furrow planting; FIMRB: Full irrigation-Medium

raised bed planting; FIWRB: Full irrigation-Wide raised bed planting; DI20CRF: 20%

deficit-Conventional ridge-furrow planting; DI20MRB: 20% deficit irrigation- Medium raised

bed planting; DI20WRB: 20% deficit irrigation-Wide raised bed planting; DI40CRF: 40%

deficit-Conventional ridge-furrow planting;

DI40MRB: 40% deficit irrigation-Medium raised bed planting; DI40WRB: 40% deficit

irrigation-Wide raised bed planting; DI60CRF: 60% deficit-Conventional ridge-furrow

planting; DI60MRB: 60% deficit irrigation-Medium raised bed planting; DI60WRB: 60%

deficit irrigation-Wide raised bed planting

Treatments Root yield (tons ha-1) Sugar yield (tons ha-1) Sugar content (%)

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

FICRF 64.50d 62.82c 63.67d 9.38d 9.04c 9.21bd 14.53h 14.37h 14.45h

FIMRB 72.94a 70.52a 71.73a 10.84a 10.28a 10.56a 14.85g 14.58g 14.72g

FIWRB 67.28c 65.67b 66.47c 10.22bc 9.87b 10.04b 15.19f 15.02f 15.11f

DI20CRF 59.82e 56.90e 58.37f 9.05e 8.53d 8.79e 15.11f 14.97f 15.04f

DI20MRB 69.17b 66.59b 67.88b 10.92a 10.34a 10.63a 15.77e 15.51e 15.64e

DI20WRB 63.48d 59.65d 61.57e 10.38b 9.58b 9.98b 16.33d 16.04d 16.19d

DI40CRF 52.58g 50.07f 51.30h 8.29g 7.78e 8.04f 15.75e 15.52e 15.63e

DI40MRB 59.73e 55.50e 57.62f 10.05c 9.22c 9.6bc 16.81c 16.60c 16.70c

DI40WRB 54.49f 50.52f 52.50g 9.42d 8.61d 9.02d 17.27b 17.04b 17.16b

DI60CRF 43.23j 40.05h 41.64j 7.12h 6.48g 6.80h 16.45d 16.13d 16.29d

DI60MRB 48.96h 44.89g 46.93i 8.51f 7.66e 8.09f 17.33b 17.02b 17.18b

DI60WRB 45.21i 40.12h 42.66j 8.20g 7.22f 7.71g 18.08a 17.92a 18.00a

80

-55

-45

-35

-25

-15

-5

5

15

CRF MRB WRB

% in

crease

/decrease

in

root

yie

ld

FI DI20DI40 DI60

0

5

10

15

20

25

CRF MRB WRB% i

ncrea

se/d

ecrea

se i

n s

ug

ar c

on

ten

t

FI DI20 DI40 DI60

-40

-30

-20

-10

0

10

20

CRF MRB WRB

% in

crease

/decrease

in

su

gar y

ield

FI DI20DI40 DI60

Fig. 4.5 (a, b, c). Relative increase/decrease in (a) root yield (b) sugar content and

(c) sugar yield of sugar beet caused by the interaction effect of

different irrigation regimes and planting methods.

(b)

(a)

(c)

81

In CRF system, the highest sugar yield in both years was obtained in FICRF treatment.

This was followed by DI20CRF and DI20CRF treatments. The least sugar yield was

produced by DI60CRF treatment. In MRB and WRB systems, highest sugar yield was

produced by DI20MRB and DI20WRB and the least by DI60MRB and DI60WRB

treatments.

Averaging the effect of 2011/2012 and 2012/2013 study years, it was observed

that, in CRF system, when the irrigation application level was reduced by 20, 40 and

60 % to that applied to FI treatment, sugar yield was respectively decreased by about

4.78, 14.55 and 45.44 %, respectively. Sugar yield for FIMRB and FIWRB was

12.78 and 8.27 % higher compared to FICRF. Furthermore, for 20 % deficit irrigation,

sugar yield under MRB and WRB was 13.36 and 7.72 % higher compared to FICRF.

For 40 % deficit irrigation, sugar yield observed in MRB treatment was still 4.06 %

higher than that observed for FICRF. At this 40 % stress level, decreased observed in

WRB was only 2.11 %. When 60% deficit irrigation was applied, the loss in sugar yield

observed was only 13.84 % for MRB and 19.46% for WRB, respectively (Figure 4.5c).

Thus, shifting the conventional ridge furrow-full irrigation planting to medium raised

bed planting would be beneficial practice for all the farmers, mill owners as well as on

environmental point of view.

4.6 INTERACTION EFFECT OF MULCHING AND PLANTING

METHODS ON SUGAR BEET YIELD COMPONENTS

Table 4.6 shows the interaction effect of mulching practices and planting

methods on sugar beet root yield, sugar content and sugar yield for the cropping season

of 2011/2012 and 2012/2013. In both study years, significantly highest root yield with

67.92, 65.56 tons ha-1

was obtained as a result of black film mulch and medium raised

bed interaction (BFMMRB) and significantly lowest with 49.16, 43.70 tons ha-1

for

no-mulch and conventional ridge furrow interaction (NMCRF). For the same type of

mulch, root yield produced by medium raised bed planting (MRB) was significantly

high in comparison to conventional ridge-furrow planting (CRF) and wide raised bed

planting (WRB). Under Black Film Mulch (BFM) and Straw Mulch (SM), root yield

produced by CRF was not significantly different from that produced by WRB.

82

Averaging the effect of two years, it was observed that, CRFBFM and

CRFSM produced 20.86 and 17.27 % high root yield, respectively, when compared

with CRFNM treatment. The corresponding increase was 16.09, 30.43 and 23.95 %

for MRBNM, MRBBFM and MRBSM treatments, and 7.97, 22.10 and 19.06 %,

for WRBNM, WRBBFM and WRBSM treatments (Figure 4.6a).

Table 4.6 also shows the interaction effect of mulches and planting methods on

sugar content of sugar beet for the study years 2011/2012 and 2012/2013. In both study

years, the significantly higher sugar content was observed for WRBBFM and

WRBSM treatments. This was followed by the MRBBFM interaction. The

significantly lowest sugar content was observed for CRFNM treatment. For the same

mulch, wide raised-bed produced the highest sugar content. This was followed by

medium raised-bed. In both years, all the CRF treatments produced the lowest sugar

content. Averaging the effect of two years, an increase in sugar content ranging

between 2.21 and 10.52 % was observed for different planting methods and mulches

combination when compared with CRFNM system (Figure 4.6b).

Table 4.6 further explains the effect of different planting methods and mulches

combination on sugar yield of sugar beet. In both years, significantly highest sugar

yield with 11.09 and 10.53 tons ha-1

were noted for MRBBFM treatment, followed by

BFMWRB combination with 10.32 and 10.57 tons ha-1

. The significantly lowest sugar


were observed for CRFNM treatment. For the same

mulch condition, the highest sugar yield was observed for MRB. This was followed by

WRB. The lowest sugar yield was observed for CRF. Averaging the effect of two years,

NMMRB and NMWRB produced 19.44 and 14.78 % higher sugar yield over CRF-

NM. Under BFM and SM, increase in sugar yield observed over CRFNM was 24.04

and 19.44 % for CRF, 36 and 29.24 % for MRB, and 30.45 and 27.16 % for WRB,

respectively (Figure 4.6c).

83

Table 4.6: Interaction effect of Mulch and planting methods on yield components

of Sugar beet.


NMCRF: No MulchConventional ridge-furrow planting; NMMRB: No MulchMedium

raised bed planting; NMWRB: No MulchWide raised bed planting; BFMCRF: Black Film

MulchConventional ridge-furrow planting; BFMMRB: Black Film MulchMedium raised

bed irrigation planting; BFMWRB: Black Film MulchWide raised bed planting; SMCRF:

Straw mulchConventional ridge-furrow planting; SM-MRB: Straw mulch Medium raised

bed planting; SMWRB: Straw mulchWide raised bed planting

0

5

10

15

20

25

30

35

NM BPFM SM

% i

ncrea

se i

n r

oot

yie

ld CRF MRB WRB

Treatments Root yield (tons ha-1) Sugar content (%) Sugar yield (tons ha-1)

2011-

12

2012-

13

Average

of years

2011-

12

2012-

13

Average

of years

2011-

12

2012-

13

Average

of years

NMCRF 49.16g 43.70e 46.43g 15.2g 14.92f 15.06h 7.40g 6.45g 6.92g

NMMRB 56.77e 53.88c 55.33e 15.85d 15.57d 15.71e 8.89e 8.28e 8.59e

NMWRB 52.18f 48.71d 50.45f 16.40b 16.13bc 16.27c 8.47f 7.76f 8.12f

BFMCRF 58.99d 58.34b 58.67c 15.69e 15.52d 15.60f 9.21d 9.05bd 9.11d

BFMMRB 67.92a 65.56a 66.74a 16.43b 16.18b 16.31c 11.09a 10.53a 10.81a

BFMWRB 61.44c 57.76b 59.60c 16.92a 16.74a 16.83a 10.32b 9.57b 9.95b

SMCRF 56.95e 55.29c 56.12e 15.49f 15.71e 15.40g 8.77e 8.41e 8.59e

SMMRB 63.41b 58.68b 61.05b 16.29c 16.03c 16.16d 10.26b 9.31bc 9.78b

SMWRB 59.22d 55.50c 57.36d 16.84a 16.65a 16.74b 9.87c 9.13cd 9.50c

(a)

84

0

2

4

6

8

10

12

NM BPFM SM

increase

in

% s

ugar c

on

ten

tCRF MRB WRB

0

10

20

30

40

NM BPFM SM

% in

crea

se in

sug

ar y

ield

CRF MRB WRB

Fig. 4.6 (a, b, c). Relative increase in sugar beet (a) root yield (b) sugar content

and (c) sugar yield caused by the interaction effect of different

mulching and raised-bed planting methods.

4.7 INTERACTION EFFECT OF IRRIGATION REGIMES, MULCHING

PRACTICES AND PLANTING PATTERNS ON SUGAR BEET YIELD

COMPONENTS

Table 4.7 shows the interaction effects of irrigation regimes, mulching practices

and planting methods on sugar beet root yield (tons ha-1

), sugar content (%) and sugar

yield (tons ha-1

) for 2011/2012 and 2012/2013 cropping seasons. The data revealed that,

for the same mulching type and planting pattern, the highest root yield was produced by

full irrigation treatments. For the same irrigation regimes and planting pattern, highest

yield was noted for Black Film Mulch. For same irrigation regimes and mulch, the

highest root was observed for medium raised-bed planting pattern. Overall, in both

years, the highest root yield with 75.32 and 73.81 tons ha-1

was produced by

(b)

(c)

85

FIBFMMRB treatment. However, yield produced by DI20BFMMRB (73.98,

70.90 tons ha-1

) was not significantly lower from FIBFMMRB treatment. The lowest


was observed for DI60NMCRF treatment.

Averaging the effect of two years data it was observed that FINMMRB,

FINMWRB, FIBFMMRB, FIBFMWRB, FI-SM-CRF, FI-SM-MRB and FI-

SM-WRB treatments produced 13.81, 6.27, 9.30, 19.87, 12.45, 8.58, 16.19 and 11.43%

higher root yield compared to that produced by the treatment in which plants were

raised on conventional ridge-furrow method without mulch with application of full

irrigation (FINMCRF). For 20, 40 and 60 % deficit irrigation, the conventional

ridge-furrowno-mulch treatments reduced the root yield by about 15.91, 40.89 and

86.60 %, respectively. When the crop was raised on medium raised bed under BFM, the

root yield observed for 20 and 40 % deficit irrigation was 17.52 and 9.36 % higher

compared to FINMCRF. However, when the irrigation application level was further

reduced by 60 %, then 10.59 % reduction in root yield was noted (for this level of

irrigation the NMCRF caused 86.60 % reduction in root yield).

For wide raised bed cropping under BFM, the root yield observed for 20 %

deficit irrigation was 7.21 % higher compared to FINMCRF planting. However, 40

to 60 % deficit irrigation caused root yield reduction by amounts 3.91 to 23.81 %,

respectively. When sugar beet was grown under straw mulch on medium raised bed, the

root yield observed for FI and DI20 was 16.19 and 12.16 % higher than that produced

by FINMCRF. However, 5.47 and 23.91 % reduction in root yield was observed

when the level of irrigation application was further reduced to 40 and 60 %. When crop

was raised on WRB in the presence of straw mulch and the crop received either full

irrigation or 20 % deficit, root yield observed was 11.43 to 7.55 % higher compared to

FINMCRF treatment. However, 40 and 60 % reduction in irrigation level decreased

the root yield by about 11.91 and 35.95 %, respectively (Figure 4.7).

Table 4.7 also revealed all the three combination of irrigation regimes, mulches

and raised bed planting methods significantly affected the sugar content of sugar beet.

In both years, significantly highest sugar content was observed for DI60BFMWRB

and DI60SMWRB treatments and significantly lowest for FINMCRF system. For

the same mulch and planting pattern, the highest sugar content was observed for DI60

treatments and lowest for FI treatments. For the same irrigation regimes and planting

86

pattern, highest sugar content was observed for BFM treatments and lowest for NM

treatments. For the same irrigation regimes and mulch type, highest sugar content was

observed for WRB treatments and lowest for CRF treatments. Averaging the effect of

two years, it was observed that the interaction effect of different irrigation regimes,

mulches and planting methods increased sugar content from 2.02 to 22.82% over

FICRFNM system (Fig. 4.8).

Table 4.7 further revealed that sugar yield of sugar beet was significantly

affected by all the three combinations of irrigation regimes, mulches and planting

methods. In both study years, significantly highest sugar yield was produced by the

interaction effect of DI20BFMMRB with 11.85 and 11.18 tons ha-1

. This was

followed FIBFMMRB with 11.33 and 10.89 tons ha-1

. However, sugar yield

produced by DI20SMMRB and DI20SMWRB were not significantly different from

that produced by FIBFMMRB combination. In both years, lowest sugar yield with

5.60 and 4.66 tons ha-1

was produced by DI60NMCRF treatment. Averaging the

effect of two years, it was observed that FINMMRB and FINMWRB produced

15.67 and 11.43 % more sugar yield when compared with FINMCRF treatment.

When full irrigation was applied in the presence of BFM or straw mulch, an increase in

sugar yield ranging from 11.43 to 23.94 % was observed for different planting methods.

The DI20NMCRF produced 11.18 % less sugar yield over FINMCRF; however all

the remaining DI20 treatments with different combinations of mulching and cropping

patterns increased the sugar yield ranging between 4.30 and 21.40 %. When 40 % water

stress level was applied without mulch and the crop was raised on Conventional Ridge-

Furrow (CRF) system, decrease in sugar yield by an amount of 29.16 % was observed.

However, when sugar beet was raised on medium raised bed (MRB) or wide raised bed

(WRB) and again 40 % stress level was applied without mulch, reduction observed in

sugar yield was only 2.18 and 6.96 %, respectively. Furthermore, when 40 % water

stress level was applied in the presence of Black Film Mulch and straw mulch, sugar

yield was improved with amount ranging from 0.2 to 23.87 % (with the highest for

MRB and lowest for CRF) was observed for all 40 % stressed mulch treatments.

Reduction in sugar yield by an amount of 64.72 % was observed when plant was grown

on CRF without mulch and applied 60 % water stress. However, for the same NM and

DI60 conditions, reduction in sugar yield observed were 31.01 and 36.51 % for MRB

and WRB, respectively. When 60 % deficit irrigation was applied in the presence of

87

Black Film Mulch, only 4.32 % reduction in sugar yield was observed in CRF system.

However the MRB and WRB treatments still showed 10.77 and 4.84 % higher sugar

yield compared to FINMCRF treatment. When 60 % water stress was applied under

straw mulch, reduction observed in sugar yield was 17.69, 1.20, 4.97 %, for each of

CRF, MRB and WRB systems respectively, in comparison to FINMCRF system

(Fig. 4.9).

Table 4.7: Interaction effect of irrigation regimes, mulching and planting methods

on yield components of Sugar beet.

1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

Treatments

Root yield (tons ha-1

) Sugar content (%) Sugar yield (tons ha-1

)

2011- 12

2012- 13

Two year

average

2011- 12

2012-13

Two year

average

2011-12

2012- 13

Two year

average

FINMCRF 62.5jk1

57k 59.75j 14.24u 14.04m 14.14t 8.90mn 8.00klm 8.45m

FINMMRB 70.77c 67.88bcd 69.32c 14.57t 14.32l 14.44s 10.31ef 9.72def 10.02f

FINMWRB 65ghi 62.42ghi 63.75fgh 15.08pqr 14.85ij 14.97nop 9.8hi 9.27fghi 9.54hi

FIBFMCRF 65.62fgh 66.13def 65.88de 14.69st 14.56kl 14.62r 9.64hi 9.63efg 9.63gh

FIBFMMRB 75.32a 73.81a 74.57a 15.05qr 14.75jk 14.9opq 11.33bc 10.89ab 11.11b

FIBFMWRB 68.83cd 67.66bcde 68.25c 15.29nop 15.15h 15.2lm 10.52e 10.08cde 10.39de

FISMCRF 65.39gh 65.33defg 65.36ef 14.67st 14.51kl 14.59rs 9.59hij 9.48fg 9.54hi

FISMMRB 72.73b 69.86bc 71.29b 14.95r 14.65jk 14.8pq 10.87d 10.23cd 10.55cde

FISMWRB 68de 66.92cde 67.46cd 15.21opq 15.06hi 15.13mn 10.34ef 10.08cde 10.21ef

DI20NMCRF 54.42q 48.67o 51.55no 14.87rs 14.61jk 14.74qr 8.09q 7.11no 7.6p

DI20NMMRB 64.41hij 61.95hi 63.18gh 15.35mno 15.1hi 15.22lm 9.89gh 9.35fgh 9.62gh

DI20NMWRB 57.74no 53.61lm 55.68kl 16jkl 15.69g 15.85ijk 9.24klm 8.41jk 8.83l

DI20BFMCRF 63.36ijk 61.37hi 62.37hi 15.43mn 15.25h 15.34l 9.78hi 9.36fg 9.57h

DI20BFMMRB 73.98ab 70.90ab 72.44b 16.02jk 15.77g 15.90ij 11.85a 11.18a 11.52a

DI20BFMWRB 65.90fgh 62.88fghi 64.39efg 16.54hi 16.29ef 16.41h 10.90d 10.24cd 10.57cd

DI20SMCRF 61.69kl 60.67ij 61.18ij 15.03qr 15.04hi 15.04no 9.28jkl 9.12ghi 9.20ijk

DI20SMMRB 69.12cd 66.92cde 68.02c 15.94kl 15.65g 15.79jk 11.02cd 10.47bc 10.75c

DI20SMWRB 66.80efg 62.45ghi 64.63efg 16.45i 16.15f 16.30h 10.99cd 10.09cde 10.54cde

DI40-NM-CRF 45.14u 39.68rs 42.41s 15.51m 15.21h 15.36l 7.00s 6.04p 6.52r DI40-NM-MRB 51.41r 49.15no 50.28op 16.57hi 16.33ef 16.45gh 8.52op 8.02klm 8.27mn DI40-NM-WRB 48.11st 45.11pq 46.62r 17.1de 16.79c 16.95d 8.23pq 7.57mn 7.9op DI40-BFM-CRF 57.37op 57.90jk 57.62k 15.94kl 15.75g 15.85ijk 9.14klm 9.12ghi 9.13jkl DI40-BFM-MRB 67.42def 64.41efgh 65.92de 17.06ef 16.83c 16.92de 11.47b 10.84ab 11.16b DI40 -BFM-WRB 59.67mn 55.33kl 57.50k 17.41c 17.21b 17.31c 10.39ef 9.52fg 9.96fg DI40-SM-CRF 55.25q 52.45lmn 53.85lm 15.79l 15.6g 15.70k 8.73no 8.18kl 8.46m DI40-SM-MRB 60.36lm 52.95lm 56.65k 16.85fg 16.63cd 16.74ef 10.17fg 8.80hij 9.49hi DI40-SM-WRB 55.68pq 51.11mno 53.39mn 17.3cd 17.13b 17.21c 9.63hi 8.75ij 9.19ijk DI60-NM-CRF 34.58x 29.46u 32.02v 16.18j 15.8g 15.99i 5.60u 4.66q 5.13s DI60-NM-MRB 40.49v 36.56st 38.53t 16.92ef 16.52de 16.72f 6.85st 6.04p 6.45r DI60-NM-WRB 37.85w 33.70t 35.78u 17.43c 17.17b 17.30c 6.60t 5.79p 6.19r

88

-90

-70

-50

-30

-10

10

FI N

M C

RF

FI N

M M

RB

FI N

M W

RB

FI B

FM C

RF

FI B

FM M

RB

FI B

FM W

RB

FI SM

CRF

FI SM

MRB

FI SM

WRB

DI20 NM

CRF

DI20 NM

MRB

DI20 NM

WRB

DI20 BFM

CRF

DI20 BFM

MRB

DI20 BFM

WRB

DI20 SM

CRF

DI20 SM

MRB

DI20 SM

WRB

DI40 NM

CRF

DI40 NM

MRB

DI40 NM

WRB

DI40 BFM

CRF

DI40 BFM

MRB

DI40 BFM

WRB

DI40 SM

CRF

DI40 SM

MRB

DI40 SM

WRB

DI60 NM

CRF

DI60 NM

MRB

DI60 NM

WRB

DI60 BFM

CRF

DI60 BFM

MRB

DI60 BFM

WRB

DI60 SM

CRF

DI60 SM

MRB

DI60 SM

WRB

% in

crease/d

ecrease in

root

yie

ld

Fig. 4.7. % increase/decrease in root yield of sugar beet caused by interaction effect of different irrigation

regimes, mulching practices and planting methods relative to FI-NM-CRF treatment

89

0

5

10

15

20

25

FI NM

CRF

FI NM

MRB

FI NM

WRB

FI BFM

CRF

FI BFM

MRB

FI BFM

WRB

FI SM

CRF

FI SM

MRB

FI SM

WRB

DI2

0 NM

CRF

DI2

0 NM

MRB

DI2

0 NM

WRB

DI2

0 BFM

CRF

DI2

0 BFM

MRB

DI2

0 BFM

WRB

DI2

0 SM

CRF

DI2

0 SM

MRB

DI2

0 SM

WRB

DI4

0 NM

CRF

DI4

0 NM

MRB

DI4

0 NM

WRB

DI4

0 BFM

CRF

DI4

0 BFM

MRB

DI4

0 BFM

WRB

DI4

0 SM

CRF

DI4

0 SM

MRB

DI4

0 SM

WRB

DI6

0 NM

CRF

DI6

0 NM

MRB

DI6

0 NM

WRB

DI6

0 BFM

CRF

DI6

0 BFM

MRB

DI6

0 BFM

WRB

DI6

0 SM

CRF

DI6

0 SM

MRB

DI6

0 SM

WRB

% in

crea

se in

su

ga

r co

nte

nt

Fig 4.8. % increase in sugar contents of sugar beet caused by interaction effect of different irrigation regimes, mulching

practices and planting methods relative to FI-NM-CRF treatment

90

-80

-60

-40

-20

0

20

40

FI NM

CRF

FI NM

MRB

FI NM

WRB

FI BFM

CRF

FI BFM

MRB

FI BFM

WRB

FI SM

CRF

FI SM

MRB

FI SM

WRB

DI2

0 NM

CRF

DI2

0 NM

MRB

DI2

0 NM

WRB

DI2

0 BFM

CRF

DI2

0 BFM

MRB

DI2

0 BFM

WRB

DI2

0 SM

CRF

DI2

0 SM

MRB

DI2

0 SM

WRB

DI4

0 NM

CRF

DI4

0 NM

MRB

DI4

0 NM

WRB

DI4

0 BFM

CRF

DI4

0 BFM

MRB

DI4

0 BFM

WRB

DI4

0 SM

CRF

DI4

0 SM

MRB

DI4

0 SM

WRB

DI6

0 NM

CRF

DI6

0 NM

MRB

DI6

0 NM

WRB

DI6

0 BFM

CRF

DI6

0 BFM

MRB

DI6

0 BFM

WRB

DI6

0 SM

CRF

DI6

0 SM

MRB

DI6

0 SM

WRB

%in

crea

se/d

ecre

ase

in

su

ga

r y

ield

Fig. 4.9. % increase/decrease in sugar yield of sugar beet caused by interaction effect of different irrigation regimes, mulching

practices and planting methods relative to FINMCRF treatment

91


RAISED-BED PLANTING METHODS ON THE AMOUNT OF

APPLIED IRRIGATION

4.8.1 Main Effects

The amount of irrigation water applied to sugar beet crop during the 2011/2012

and 2012/2013 cropping season is presented in Table 4.8 and depicted in Fig. 4.10.

Comparing the results of main treatments, it was noted that in both study years, among

the irrigation regimes, the highest (676.26, 631.57 mm) mean irrigation water was

applied in full irrigation treatments (FI) and the lowest (270.71, 252.53mm) in 60 %

deficit irrigation treatment (DI60).

Among the mulch treatments, the No Mulch (NM) treatments received the

highest mean irrigation with 575.74 and 472.73 mm. This was followed by Straw

Mulch (SM) with 471.84 and 459 mm. The lowest water was applied in Black Film

Mulch treatments with 432.59 and 394.57 mm.

Among the furrow irrigated raised bed planting methods, the highest amount of

irrigation water was applied to conventional ridge-furrow planting pattern (CRF) with

488.91 and 456.17 mm. This was followed by wide raised-bed 473.0 and 488.02 mm.

The medium raised bed (MRB) planting methods received the lowest amount of water

with 458.28, 422.10 mm. In previous studies, UCAN and Cafer (2004) reported 1232

and 1331 mm water in full irrigation treatment and 298 and 449 mm in deficit irrigation.

Weeden (2000) reported that, in areas like USA, Egypt and Pakistan, about 500 to 1000

mm irrigation water was applied for sugar beet. Topak et al., (2011) in their research

study conducted during 2005-06 seasons in middle Anatolian, Turkey, applied 244.2

mm in 75 % deficit irrigation treatment and 977 mm in full irrigation. The depth of

irrigation water applied in full irrigation treatment in our study is different than

reported in the literature cited. This difference may be due to the variation in climatic

conditions and mode of irrigation application.

92

Table 4.8. Mean depths of irrigation water applied (mm) to different treatments

Treatments Irrigation water applied (mm)

2011/2012 2012/2013

Irrigation

regimes

FI 676.26a1

631.57a

DI20 541.02b 505.25b

DI40 405.77c 378.94c

DI60 270.71d 252.53d

Mulch types

NM 515.74a 472.73a

BFM 432.59c 394.57c

SM 431.84b 459.00b

Planting

methods

CRF 488.91a 456.17a

MRB 458.28c 422.10c

WRB 473.00b 448.02b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

100

200

300

400

500

600

700

800

FI DI20 DI40 DI60 NM BFM SM CRF MRB WRB

Irri

gati

on w

ater

app

lied

(m

m) 2011/2012 2012/2013

Irrigation Regimes Mulch Types Furrow Irrigatin Systems

Fig. 4.10. Effect of irrigation regimes, Mulch type and planting method on amount of

irrigation water applied (mm) to sugar beet crop during 2011/2012 and

2012/2013 cropping

4.8.2 INTERACTION EFFECT OF IRRIGATION REGIMES AND

MULCHING ON IRRIGATION APPLICATION DEPTH

The interaction effect of irrigation regimes and mulching practices on the

amount of irrigation water applied is shown in Table 4.9 and depicted in Figure 4.11.

Results revealed that different combinations of mulching and irrigation regimes

produced significant effect on the amount of irrigation water applied (Table 4.9). In

both years, the highest mean depth with 736.77 and 675.33 mm was applied to FINM

93

treatment and the lowest with 269.63 and 262.28 mm received by DI60BFM.

Averaging the effect of two years, the amount of irrigation water saved by the

interaction effect of irrigation regimes and straw mulch was ranged between 5.83 and

62.33 %, and that saved by the interaction effect of irrigation regimes and Black Film

Mulch was ranged between 16.32 and 66.53 %, when compared with full irrigationNo

Mulch treatment (Figure 4.12). The interaction effect of irrigation regimes and

mulching on the amount of irrigation water saving observed in the current study was in

accordance to that reported in other parts of the world for different crops. Hess (1997)

reported that sugar beet grown under organic mulch at Wattisham, Mepal and

Rosewarne areas, saved about 58, 45 and 36 mm water when compared to the no-mulch

treatment. Chaudhry et al., (2004) concluded from their investigation that growing

Eucalyptus under polyethylene sheet and straw mulch can save 45 and 30 % irrigation

water respectively. Similar results were also reported by Ramalan and Nwokeocha,

(2000) and Shrivastava et al., (1994), for tomato.

Table 4.9. Interaction effects of irrigation regimes and mulch types on amount of

irrigation water applied


Irrigation regimes

Mulching

Irrigation water applied (mm)

2011-12 2012-13

FI NM 736.77a1

675.33a

FI BFM 617.95c 563.675c

FI SM 674.06b 655.70b

DI20 NM 589.41d 540.27d

DI20 BFM 494.41f 450.93f

DI20 SM 539.25e 524.56e

DI40 NM 442.06g 405.20g

DI40 BFM 370.81i 338.20i

DI40 SM 404.44h 393.42h

DI60 NM 294.71j 270.13j

DI60 BFM 247.20l 225.47l

DI60 SM 269.63k 262.28k

94

4.8.3 Interaction Effect of Irrigation Regimes and Planting Methods on

Irrigation Application Depth

Table 4.10 shows that the interaction of different irrigation regimes and raised

bed furrow irrigated planting methods significantly (at p < 0.05) affected the amount of

irrigation water applied. In both study years, the highest irrigation amounts (698.44,

651.67 mm) were applied to FICRF treatment and the lowest (261.87, 241.20 mm) to

DI20MRB. For the same irrigation level, the CRF treatments got the highest amount of

water. This was followed by WRB treatments. The MRB treatment received the least

amount of irrigation water (Figure 4.13). Averaging the effect of two years data, it was

observed that the irrigation water saved by the combine effect of irrigation regimes and

planting pattern in comparison to FICRF system was ranged between 6.85 and

62.74% (Figure 4.14).

Table 4.10 Interaction effects of irrigation regimes and planting methods on amount

of irrigation water applied


probability.

Irrigation regimes

Planting methods


2011/2012 2011/2012 Average of years

FI CRF 698.44a1

651.67a 675.06a

FI MRB 654.68c 603.00c 628.84c

FI WRB 675.65b 640.03b 657.84b

DI20 CRF 558.75d 521.33d 540.04d

DI20 MRB 523.75f 482.40f 503.07f

DI20 WRB 540.57e 512.03e 526.30e

DI40 CRF 419.07g 391.00g 405.03g

DI40 MRB 392.81i 361.80i 377.31i

DI40 WRB 405.43h 384.02h 394.73h

DI60 CRF 279.38j 267.67j 270.02j

DI60 MRB 261.87l 241.20l 251.54l

DI60 WRB 270.29k 256.01k 263.15k

95

0

100

200

300

400

500

600

700

800

FI

NM

FI

BPFM

FI

SM

DI20

NM

DI20

BPFM

DI20

SM

DI40

NM

DI40

BPFM

DI40

SM

DI60

NM

DI60

BPFM

DI60

SM

Irrig

ati

on

wa

ter a

pp

lied

(m

m)

2011/2012

2012/2013

Fig. 4.11. Interaction effect of Irrigation regimes and mulching on the amount of


cropping season.

0

10

20

30

40

50

60

70

FI

NM

FI

BPFM

FI

SM

DI20

NM

DI20

BPFM

DI20

SM

DI40

NM

DI40

BPFM

DI40

SM

DI60

NM

DI60

BPFM

DI60

SM

Irrig

ati

on

wa

ter s

av

ed

(%

)

Fig. 4.12. Relative irrigation water saving by the interaction effects of irrigation

regimes and mulching practices

96

0

100

200

300

400

500

600

700

800

FI C

RF

FI MRB

FI WRB

DI2

0 CRF

DI2

0 M

RB

DI2

0 W

RB

DI4

0 CRF

DI4

0 M

RB

DI4

0 W

RB

DI6

0CRF

DI6

0 M

RB

DI6

0 W

RB

Irrig

ati

on

wate

r u

sed

(m

m)

2011/2012

2012/2013

Fig. 4.13. Interaction effect of Irrigation regimes and planting methods on the

amount of irrigation water applied to sugar beet during 2011/2012 and

2012/2013 cropping season

0

10

20

30

40

50

60

70

FI CRF

FI MRB

FI WRB

DI2

0 CRF

DI2

0 M

RB

DI2

0 W

RB

DI4

0CRF

DI4

0MRB

DI4

0WRB

DI6

0CRF

DI6

0MRB

DI6

0WRB

Irrig

ati

on

wa

ter s

av

ed

(%

)

Fig. 4.14. Relative irrigation water saving by the interaction effects of irrigation

regimes and planting methods

97

Table 4.11. Interaction effects of mulching and planting methods on amount of

irrigation water applied to sugar beet crop in year 2011/2012

and 2012/2013.


probability.

4.8.4 Interaction Effect of Mulching and Planting Methods on Irrigation

Application Depth

The mean interaction effects of different types of mulches and furrow irrigated

raised bed planting patterns‘ on applied irrigation water are presented in table 4.11 and

depicted in Figure 4.15. The data shows that, the highest (539, 490 mm) mean irrigation

water in both study years was applied to NMCRF treatment. This was followed by

(512, 479 mm) SMCRF. The least (424, 381 mm) mean irrigation water was received

by BFMMRB treatment. Averaging the effect of two years and comparing the results

with NMCRF treatment, the water saved by different irrigation treatments was ranged

between 3.58 and 21.72%. The highest amount was saved by BFMMRB treatment

and the lowest by NMWRB (Figure 4.16).

Mulching

Planting methods


2011/2012 2011/2012

NM CRF 539.00a1

490.00a

NM MRB 495.53c 448.70e

NM WRB 512.68b 479.50b

BFM CRF 441.23g 404.60g

BFM MRB 424.03i 381.50i

BFM WRB 432.52h 397.60h

SM CRF 486.50d 473.90c

SM MRB 455.27f 436.10f

SM WRB 473.76e 466.97d

98

0

100

200

300

400

500

600

NM CRF NM MRB NMWRB BFMCRF BFMMRB BFMWRB SMCRF SMMRB SWRB

Irrig

ati

on

wa

ter a

pp

lied

(m

m)

2011/2012

2012/2013

Fig. 4.15. Interaction effect of mulch types and planting methods on the amount of


cropping season

0

5

10

15

20

25

NM CRF NM MRB NMWRB BFMCRF BFMMRB BFMWRB SMCRF SMMRB SWRB

Irrig

ati

on

wa

ter s

av

ed

(%

)

Fig. 4.16. Relative irrigation water saving by the interaction effects of different

mulching and planting methods

99


PLANTING METHODS ON THE AMOUNT OF SEASONAL WATER

USED

4.9.1 Main Effects

The amount of irrigation water used by the sugar beet crop during the

2011/2012 and 2012/2013 cropping season for each individual treatment was computed

by using precipitation, amount of irrigation applied and soil water content. Comparing

the results of main effects (Table 4.12), it was noted that the amount of seasonal water

used was increased with the increasing rate of irrigation application. In both study years,

the lowest (442, 470 mm) seasonal water used values were obtained for 60 % deficit

irrigation treatment (DI60) and highest (930, 897 mm) for full irrigation (FI) treatment

(Figure. 4.17). Averaging the two years data the decrease observed in seasonal water

used was ranged between 15 and 45 % for deficit irrigation treatments in comparison to

FI treatment (Fig. 4.18). The decreased observed in seasonal water used with

decreasing rate of irrigation application for sugar beet crop in the current study was also

supported by El-Askari et al., (2003) Rinaldi and Vonella, (2004), Topak et al., (2011)

for sugar beet, and Khan et al., (2015) for wheat.

Table 4.12 also shows that the mulching treatments significantly affected the

amount of seasonal water used. The highest amount of seasonal water used was

observed for NM treatment. This was followed by SM treatment. The lowest seasonal

water used was noted for BFM treatment (Fig. 4.17). Averaging the effect of two years,

it was observed that the seasonal water used by treatments under BFM was 13 % less

and that used by treatment under SM was 5 % less, when compared with NM treatment

(Fig 4.18). Decrease in water used due to mulch was also reported by Masanta and

Mallik (2009), and Barros and Hanks (1993) for wheat, and Zhang et al., (2009) for

Swiss chard, Obalum et al., (2011) for soybean. The data of Table 4.12 further shows

that all three furrow irrigated raised bed planting methods significantly affected the

amount of seasonal water used. The highest amount was noted for conventional ridge

furrow system (CRF). This was followed by wide raised bed (WRB) system. The

lowest seasonal water used was noted for medium raised bed (MRB) system (Fig. 4.17).

Averaging the effect of two years, the amount of seasonal water used was 6.00 and

2.00 % less for MRB and WRB respectively, in comparison to CRF system (Figure

4.18). These results were in accordance to that reported by Akbar et al., (2010).

100

Table 4.12. Mean amount of seasonal water used (mm) by main treatments

Treatments Seasonal water used (mm)

2011/2012 2012/2013

Irrigation

regimes

FI 829.69a1

824.56a

DI20 699.03b 704.98b

DI40 572.88c 588.36c

DI60 442.02d 470.90d

Mulch types

NM 682.89a 681.91a

BFM 589.73c 597.01c

SM 635.10b 662.69b

Planting

methods

CRF 652.98a 663.71a

MRB 618.16c 625.30b

WRB 636.58b 652.60a


probability.

0

100

200

300

400

500

600

700

800

900

FI DI20 DI40 DI60 NM BFM SM CRF MRB WRB

Sea

son

al

wate

r u

sed

(m

m)

2011/2012

2012/2013

Irrigation regimes Mulch types Furrow irrigation systems

Fig. 4.17. Effect of irrigation regimes, Mulch type and planting method on amount

of irrigation water used (mm) by sugar beet crop during 2011/2012 and

2012/2013 cropping

101

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

FI DI20 DI40 DI60 NM BFM SM CRF MRB WRB%

decrea

se in

sea

son

al w

ate

r u

se

Irrigation regimes Mulch types Planting patterens

Fig. 4.18. % decrease in seasonal water used of sugar beet under different

irrigation regimes, mulch types and planting methods for 2011/2012 and

2012/2013 cropping year

4.9.2 Interaction Effect of Irrigation Regimes and Mulching on Sugar Beet

Seasonal Water Used

The data on seasonal water used (SWU) of sugar beet as influenced by

irrigation regimes and mulches combination for 20112/2012 and 2012/2013 cropping

season are presented in Table 4.13. The data show that the amount of SWU was ranged

from 412 to 896 mm in 2011/2012 season, and 441 – 871 mm in 2012/2013. In both

seasons, the lowest value in the range was obtained in the DI60 treatments with BFM,

while the highest value in the range was recorded in the FI treatment with NM. No

significant difference between the means of SWU of the two seasons was indicated by

the analysis of variance test. However, a significant difference (p < 0.05) in the means

of SWU was found between the interaction of irrigation regimes and mulch types.

These results imply that seasonal water use (SWU) was largely influenced by both the

amount of irrigation applied (irrigation regimes) and mulching. This is may be because

of the fact that SWU was largely dependent on irrigation application depth that affects

the water supply and availability within the root zone, and presence or absence of

mulching that effects the amount of evaporation that takes place from the soil surface

and tops of the soil. The high amount of seasonal water used by FI-NM treatments in

102

the current study may be due to the high water supply and its availability within the

root zone, and also because of high evaporation that may have taken place from the

bare surface and top most part of the soil especially during the crop initial stages which

was probably not compensated for an increase in transpiration following better

vegetative growth under mulch at a later stage, hence the difference in the total water

use. Similar results were obtained by Ramalan and Nwokeocha, (2000), Obalum et al.,

(2011) for soybean. The results however in contradiction to that observed by Igbadun et

al., (2012), for onion. Averaging the effect of two years seasonal water used data and

comparing the results with FI-NM treatment it was observed that seasonal water used

was decreased from 2 to 47 % by different combinations of irrigation regimes and type

of mulch (Figure. 4.19).

-60

-50

-40

-30

-20

-10

0

FI NM

FI B

PM

FI SM

DI20- N

M

DI20 BPM

DI20 SM

DI40 NM

DI40 BPM

DI40 SM

DI60 NM

DI60 BPM

DI60S

M

% d

ecrea

se i

n s

ea

so

na

l w

ater u

sed

Fig. 4.19. Relative decrease in seasonal water used of sugar beet under different

combination of irrigation regimes and mulch types

103

Table 4.13. Interaction effects of irrigation regimes and mulch types on amount of

sugar beet seasonal water used during 2011/2012 and 2012/2013

cropping seasons.


FI-NM: Full irrigation No Mulch; FI BFM: Full irrigation Black Film Mulch; FI SM: Full

irrigation Straw mulch; DI20 NM: 20% deficit No Mulch; DI20 BFM: 20% deficit irrigation

Black Film Mulch; DI20 SM: 20% deficit irrigation Straw mulch; DI40 NM: 40% deficit No

Mulch; DI40 BFM: 40% deficit irrigation Black Film Mulch; DI40 SM: 40% deficit irrigation

Straw mulch; DI60 NM: 60% deficit No Mulch; DI60 BFM: 60% deficit irrigation Black Film

Mulch; DI60 SM: 60% deficit irrigation Straw mulch

4.9.3 Interaction Effect of Irrigation Regimes and Planting Methods on Sugar

Beet Seasonal Water Used

The combine effects of irrigation regimes and planting methods on sugar beet

seasonal water used for 2011/2012 and 2012/2013 cropping seasons are presented in

Table 4.14. The data show that seasonal water used was significantly affected (at p <

0.05) by all combinations of irrigation regimes and planting methods. In both season,

the highest (852.55, 845.8 mm) amount of water was used by FICRF treatment and

the lowest (430.82, 457 mm) by DI60-MRB treatments. For the same irrigation regimes,

the highest amount of irrigation water was used by conventional ridge furrow system.

This was followed by wide raised bed system. This may be due to the highest amount

of irrigation water applied to these treatments. Averaging the effect of two years and

comparing the results with FICRF systems, the decreased observed in the seasonal

water used was ranged from 2 to 48 % (Figure. 4.20). For the same irrigation level,

percent decreased was highest for MRB systems and the lowest for CRF.

Irrigation regimes

Mulching

Seasonal water used (mm)

2011/2012 2012/2013 Average of years

FI NM 895.82a1

870.66a 849.18a

FI BFM 764.69c 753.79c 800.40c

FI SM 828.56b 849.24b 831.81b

DI20 NM 751.20d 742.59d 721.36d

DI20 BFM 648.65f 649.17f 679.32f

DI20 SM 697.25e 723.20e 705.36e

DI40 NM 613.51g 621.39g 595.40g

DI40 BFM 533.43i 544.42i 563.31i

DI40 SM 571.71h 599.26h 583.16h

DI60 NM 471.04j 492.99j 467.44j

DI60 BFM 412.15l 440.66l 433.91k

DI60 SM 442.87k 479.07k 451.90k

104

Table 4.14 Interaction effects of irrigation regimes and planting methods on amount

of sugar beet seasonal water used in year 2011/2012 and 2012/2013


probability.

-60

-50

-40

-30

-20

-10

0

FI-

CRF

FI-

MRB

FI-

WRB

DI20-

CRF

DI20-

MRB

DI20-

WRB

DI40-

CRF

DI40-

MRB

DI40-

WRB

DI60-

CRF

DI60-

MRB

DI60-

WRB

% d

ecrease

in

irrig

ati

on

wate

r u

se

Fig. 4.20. Relative decrease in seasonal water used of sugar beet under different

combination of irrigation regimes and planting methods

Irrigation regimes

Planting methods


2011/2012 2012/2013

FI CRF 852.55a1

845.80a

FI MRB 805.81c 794.98c

FI WRB 830.70b 832.90b

DI20 CRF 718.94d 723.78d

DI20 MRB 678.74f 679.89f

DI20 WRB 699.42e 711.29e

DI40 CRF 587.80g 602.99g

DI40 MRB 557.25i 569.36i

DI40 WRB 573.60h 592.72h

DI60 CRF 452.62j 482.25j

DI60 MRB 430.82l 456.99l

DI60 WRB 442.61k 473.47k

105

4.9.4 Interaction Effect of Mulching and Planting Methods on Sugar Beet

Seasonal Water Used

The interaction effect of three types of mulches (NM, BFM and SM) and three

planting methods (CRF, MRB and WRB) on the amount of seasonal water used by

sugar beet during the 2011/2012 and 2012/2013 cropping seasons are presented in

Table 4.15 and depicted in Fig. 4.21. In both season highest (708, 701 mm) seasonal

water was observed for NMCRF treatment and the lowest (579, 582 mm) for

BFMMRB combination. For the same mulch conditions, the highest seasonal water

was used by CRF treatments. By averaging the two years data it was observed that

seasonal water used by different combination of mulch and planting methods was 3 to

18 % less when compared with NMCRF system (Fig. 4.22). The maximum amount of

water used by CRF systems in comparison to MRB and WRB systems may be due to

the fact that the number of irrigation furrows in per hectare area was 46 to 61 % more

when compared with MRB and WRB systems. This high amount of furrow may caused

increase in the amount of direct evaporation from the sides and beds of furrows and

thus led towards high water used. Furthermore, the medium and wide beds may have

the ability to conserve moisture more efficiently in comparison to narrow ridge.

Table 4.15 Interaction effects of Mulching and planting methods on amount of

sugar beet seasonal water used in year 2011/2012 and 2012/2013


probability.

Mulching

Cropping patterns


2011/2012 2011/2012

NMCRF 707.68a1

700.97a

NMMRB 660.99c 656.15e

NMWRB 680.01b 688.60b

BFMCRF 600.89g 610.08g

BFMMRB 579.08i 582.01i

BFMWRB 589.21h 598.94h

SMCRF 650.37d 680.07c

SMMRB 614.40f 637.75f

SMWRB 640.52e 670.26d

106

500

550

600

650

700

750

NM-

CRF

NM-

MRB

NM-

WRB

BFM-

CRF

BFM-

MRB

BFM-

WRB

SM-CRF SM-

MRB

SM-

WRB

Sea

son

al ir

rig

ati

on

wa

ter u

sed

(m

m)

2011/2012

2012/2013

Fig. 4.21. Interaction effects of mulching and planting methods on amount of

seasonal water used (mm) by sugar beet crop during 2011/2012 and

2012/2013 cropping seasons.

-20

-16

-12

-8

-4

0

NM-

CRF

NM-

MRB

NM-

WRB

BFM-

CRF

BFM-

MRB

BFM-

WRB

SM-

CRF

SM-

MRB

SM-

WRB

% d

ecrease in

season

al w

ate

r u

ses

Fig. 4.22. % decrease in seasonal water used of sugar beet under different

combination of mulching and planting methods for 2011/2012 and

2012/2013 cropping year

107


PLANTING METHODS ON IRRIGATION WATER USE EFFICIENCY

The sole and interaction effects of irrigation regimes, mulching practices and

raised-bed planting methods on Root Irrigation Water Use Efficiency (RIWUE) and

Sugar Irrigation Water Use Efficiency (SIWUE) for 2011/2012 and 2012/2013

cropping seasons are illustrated in tables 4.16 to 4.22.

4.10.1 Main Effects

4.10.1.1 Effect of irrigation regimes on sugar beet root and sugar irrigation

water use efficiency

From the analysis of data it was observed that irrigation regimes significantly

affected (p < 0.05) both the Root Irrigation Water Use Efficiency (RIWUE) and Sugar

Irrigation Water Use Efficiency (SIWUE) (Table 4.16). In both cropping seasons, the

highest RIWUE with 17.26, 16.85 kg m-3

and highest SIWUE with 3 and 2.88 kg m-3

were observed for 60 % deficit irrigation (DI60) treatment. While the lowest RIWUE

with 10.19 and 10.63 kg m-3

and lowest SIWUE with 1.52, 1.56 kg m-3

were observed

for full irrigation (FI) treatment (Figure 4.23).

Comparing the average results of two years mean data, a relative increase of

about 16.52, 34.01 and 63.88 % in RIWUE and 23.38, 50 and 90.91 % in SIWUE were

observed for each of DI20, DI40 and DI60 treatments over FI (Figure 4.24). Earlier,

Topak et al., (2011) observed 0 to 50 % increase in RIWUE and 0 to 141 % increase in

SIWUE when the irrigation level was decreased from 100 to 25 % in drip planting

pattern. Sahin et al., (2014) reported 0 to 6.5 % increase in IWUE when the irrigation

level was decreased from 0 to 6 %.

Averaging the two years data, the sequence for RIWUE obtained was 17.06 kg

m-3

> 13.95 kg m-3

> 12.13 kg m-3

> 10.14 kg m-3

and that observed for SIWUE was

2.94 kg m-3

> 2.31 kg m-3

> 1.90 kg m-3

> 1.54 kg m-3

for irrigation regimes with DI60,

DI40, DI20 and FI, respectively. The increased sequence of root irrigation water use

efficiencies with increased levels of irrigation deficit obtained in this study was in

contrast to that observed by Ucan K. and C. Gencoglan, (2004). They reported a

decrease in RIWUE with increase in irrigation deficit with a sequence of 46.80 kg ha-1

mm-1

> 43.80 kg ha-1

mm-1

> 38.00 kg ha-1

mm-1

> 36.10 kg ha-1

mm-1

> 27.20 kg ha-1

mm-1

> 26.10 kg ha-1

mm-1

when the irrigation levels were applied in the sequence of

FI (full irrigation), DI15 (15% deficit irrigation), DI25 (25% deficit irrigation), DI40

108

(40% deficit irrigation), DI25 (50% deficit irrigation) and DI65 (65% deficit irrigation),

respectively. The results however, in agreement with that obtained by Topak et al.,

(2011). They observed increased in RIWUE in the sequence of 11.50 kg m-3

> 10.30 kg

m-3

> 9.64 kg m-3

> 7.91 kg m-3

for irrigation regimes with DI75 (75% deficit irrigation),

DI50 (50% deficit irrigation), DI25 (25% deficit irrigation) and FI (full irrigation),

respectively.

4.10.1.2. Effect of mulching on sugar bee root and sugar irrigation water use

efficiency

The effect of mulches on both root and sugar irrigation water use efficiency

(RIWUE, SIWUE) were significant (at p < 0.05) (Table 4.10). Comparing mean data of

all mulch treatments it is evident that the highest root irrigation water use efficiency

values observed were for Black Film Mulch (15.71 and 16.50 kg m-3

), followed by

Straw (13.61 and 13.05 kg m-3

) and No Mulch (10.71 and 10.73 kg m

-3). Sugar

irrigation water use efficiencies values observed for Black Film Mulch were 2.61 and

2.70 kg m-3

for the years 2011/2012 and 2012/2013 respectively, followed by 2.23 and

2.11 kg m-3

for straw mulch. Where, the non-mulched plots had the lowest SIWUE of

1.71 and 1.68 kg m-3

(Fig. 4.25). Overall combined effect of two years of mulching

showed that both the Black Film Mulch and Straw Mulch treatments respectively have

50.28 & 24.35 % higher root irrigation water use efficiencies and 56.80 & 28.40%

higher sugar irrigation water use efficiencies as compared with the no-mulch treatment

(Fig. 4.26). The positive effects of mulching on water use efficiency are also supported

by Iqbal et al., (2003), for forage maize, Shulan et al., (2014), for maize crop, Hussain

A., (2015) for common beans and Alenazi et al., (2015) for muskmelon.

4.10.1.3. Effect of planting methods on sugar bee root and sugar irrigation water

use efficiency

All the three planting methods significantly (at p < 0.5) affected the root and

sugar irrigation water use efficiency (Table 4.11). From the comparison of mean data,

the highest root water use efficiency (RIWUE) with 14.17 and 15.05 kg m-3

and highest

Sugar Irrigation Water Use Efficiency (SIWUE) with 2.42 and 2.43 kg m-3

, were

observed for Medium Raised-Bed (MRB) planting. This was followed by Wide Raised-

Bed (WRB) planting with 13.12 and 12.84 kg m-3

RIWUE, and 2.23 and 2.15 kg m-3

109

SIWUE. Both the lowest RIWUE with 12.18 and 12.38 kg m-3

and lowest SIWUE with

1.91 and 1.91 kg m-3

were observed for Conventional Ridge-Furrow (CRF) planting.

Comparing the average results of two years data, an increase of 21.25 and

5.70 % in RIWUE, and 26.70 and 14.66 % in SIWUE were observed for medium and

wide raised bed planting in comparison to conventional ridge-furrow system (Fig. 4.26).

The higher IWUE observed in the current study for raised bed system in comparison to

ridge-furrow system was in alignment with that reported by Khan et al., (2015) for

maize. The results further revealed that RIWUE was decreased by about 13 % and

SIWUE by about 10 % when the size of raised bed was increased from 45 to 90 cm.

The main cause of the low IWUE observed in the current study for WRB in comparison

to MRB may be because of poor crop growth in the middle row in WRB system. These

results are in contradiction with that reported by ICARDA, 2011, according to which

wide raised bed caused higher root and sugar irrigation water use efficiency in

comparison to narrow raised-bed. The difference may be because of difference in

number of crop rows and variation in soil and climatic conditions. According to the

ICARDA report, RIWUE was increased by 45 % and SIWUE was increased by 50 %

when the width of raised-bed was increased from 65 to 130 cm. However, Yan and

Gong, 2001, found no significant difference in the WUE for corn crop when the width

of raised-bed was increased from 60 to 120 cm, and Ghane et al., (2009) observed 18%

higher IWUE for wheat crop that was raised on 60 cm wide bed in comparison to 80

cm bed.

Table 4.16. Effect of irrigation regimes on root and sugar irrigation water use

efficiencies


probability.

Irrigation

regimes

RIWUE (kg m-3) SIWUE (kg m-3)

2011/2012 2012/2013 Average

of years 2011/2012 2012/2013

Average

of years

FI 10.19d1 10.63d 10.41d 1.52d 1.56d 1.54d

DI20 12.00c 12.26c 12.13c 1.90c 1.91c 1.90c

DI40 13.92b 13.97b 13.94b 2.32b 2.30b 2.31b

DI60 17.26a 16.85a 17.06a 3.00a 2.88a 2.94a

110

Table 4.17. Effect of different types of mulching on root and sugar irrigation water use

efficiencies

Mulching RIWUE (kg m

-3)

SIWUE (kg m

-3)

2011/2012 2012/2013

Average

of years 2011/2012 2012/2013

Average

of years

NM 10.71c1 10.73c 10.72c 1.71c 1.68c 1.69c

BFM 15.71a 16.50a 16.11a 2.61a 2.70a 2.65a

SM 13.61b 13.05b 13.33b 2.23b 2.11b 2.17b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

Table 4.18 Effect of different planting methods on root and sugar irrigation water

use efficiencies

Furrow

Irrigation

systems

RIWUE (kg m-3

)

SIWUE (kg m-3

)

2011/201

2

2012/201

3

Averag

e

of

years

2011/201

2

2012/201

3

Averag

e of

years

CRF 12.18c1 12.38c 12.28c 1.91c 1.91c 1.91c

MRB 14.73a 15.05a 14.89a 2.42a 2.43a 2.42a

WRB 13.12b 12.84b 12.98b 2.23b 2.15b 2.19b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

3

6

9

12

15

18

FI DI20 DI40 DI60 FI DI20 DI40 DI60

Ro

ot

an

d s

ug

ar

irri

ga

tio

n w

ate

r

use

eff

icie

ncy

(k

g m

-3)

RIWUE SIWUE

Fig. 4.23. Effect of irrigation regimes on root and sugar irrigation water use

efficiency of sugar beet for 2011/2012 and 2012/2013 cropping seasons

2011/2012

2012/2013

111

0

10

20

30

40

50

60

70

80

90

100

FI DI20 DI40 DI60

% i

ncrea

se i

n r

oo

t a

nd

su

ga

r i

rrig

ati

on

wa

ter u

se e

ffic

ien

cy

(k

g m

-3)

RIWUE SIWUE

Fig 4.24. % increase in average root and sugar irrigation water use efficiency by

deficit irrigation treatments in comparison to full irrigation.

0

2

4

6

8

10

12

14

16

18

NM BPFM SM NM BPFM SM

Ro

ot

an

d s

ug

ar i

rrig

ati

on

wa

ter

use e

ffic

ien

cy

(k

g m

-3)

RIWUE SIWUE

Fig 4.25. Mulching effect on root and sugar irrigation water use efficiency of

sugar beet for 2011/2012 and 2012/2013 cropping seasons.

2011/2012 2012/2013

112

0

10

20

30

40

50

60

NM BPFM SM

% i

ncrea

se i

n r

oo

t a

nd

su

ga

r i

rrig

ati

on

wa

ter u

se e

ffic

ien

cy

RIWUE SIWUE

Fig. 4.26. % increase in average root and sugar irrigation water use efficiency by

Black Film Mulchand straw mulch treatments in comparison to no-

mulch treatment

0

2

4

6

8

10

12

14

16

CRF MRB WRB CRF MRB WRB

Ro

ot

an

d s

ug

ar i

rrig

ati

on

wa

ter

use

eff

icie

ncy

(k

g h

a m

-3)

RIWUE SIWUE

Figure 4.27. Effect of furrow irrigated raised bed planting methods on root and sugar

irrigation water use efficiency of sugar beet for 2011/2012 and

2012/2013 cropping seasons

2011/2012 2012/2013

113

0

5

10

15

20

25

30

CRF MRB WRB

% i

ncrea

se i

n r

oo

t a

nd

irrig

ati

on

wa

ter u

e e

ffic

ien

y

RIWUE SIWUE

Figure 4.28. % increase in average root and sugar irrigation water use efficiency by

medium and wide raised bed furrow irrigated planting in comparison to

conventional ridge-furrow planting

4.10.2 Interaction Effects

Means of root and sugar irrigation water use efficiency (RIWUE, SIWUE) as

influenced by the first and the second order interactions are presented in Table 4.19,

4.20, 4.21 and 4.22.

4.10.2.1. Interaction effect of irrigation regimes and mulching on sugar beet root

and sugar irrigation water use efficiency

Table 4.19 shows the interaction effect of four irrigation regimes and three

mulch types on sugar beet Root Irrigation Water Use Efficiency (RIWUE) and Sugar

Irrigation Water Use Efficiency (SIWUE) for 2011/2012 and 2012/2013 cropping

seasons. The analysis of the data revealed that irrigation regimes and mulches

interaction had significant effect (p < 0.05) on root and sugar water use efficiency in

both study years. Both the root and sugar irrigation water use efficiencies were

increased as the application of irrigation level decreased from FI under the mulching

order of No Mulch, Straw Mulch and Black Film Mulch to DI60 under the mulching

order of No Mulch, straw and plastic mulch. However, in both years, both the root and

sugar irrigation water use efficiencies was decreasing within the same level of irrigation

application under the mulching order of Black Film, Straw and No Mulch respectively.

For both cropping seasons, the highest mean root irrigation water use efficiency (21.13

114

kg m-3

, 21.68 kg m-3

) and highest mean sugar irrigation water use efficiency (3.72 kg

m-3

, 3.76 kg m-3

) were recorded from treatment that received 60 % deficit irrigation

(DI60) under Black Film Mulch. The second highest mean root irrigation water use

efficiency (17.82 kg m-3

, 16.49 kg m-3

) and mean sugar irrigation water use efficiency

(3.10 kg m-3

, 2.82 kg m-3

) was recorded from treatment DI60 under straw mulch. The

lowest mean root irrigation water use efficiency (9.00 kg m-3

, 9.28 kg m-3) and lowest

mean sugar water use efficiency (1.32 kg m-3

, 1.34 kg m-3

) were noted for treatment

that received full irrigation (FI) under No Mulch. Averaging the two years data, no

significant difference was found between treatments FISM and DI20NM, treatments

FIBFM and DI20SM, treatments DI20BFM and DI40SM, and treatments DI40BFM

and DI60SM of root irrigation water use efficiency and FISM and DI40NM, FISM

and DI20NM, and DI20BFM and DI40 SM of sugar irrigation water use efficiency (p

< 0.05) (Table 4.19).

Figure 4.29 shows the percent increase (average of two years) in root and sugar

irrigation water use efficiency observed for interaction effect of different irrigation

regimes and mulches over FI NM treatment. It can be seen from this Figure that the

interaction effect of DI60 BFM, DI60 SM and DI60 NM caused 134, 88 and 38 %

higher Root Irrigation Water Use Efficiency (RIWUE) and 181, 123 and 59 % higher

Sugar Irrigation Water Use Efficiency (SIWUE), respectively in comparison to FI

NM treatment. While the interaction effect of DI40 BFM, DI40 SM and DI40 NM

yielded 87, 50 and 20 % higher RIWUE and 114, 71 and 35 % higher SIWUE, the

interaction of DI20 BFM, DI20 SM and DI20 NM caused 54, 33 and 11 % higher

RIWUE and 68, 44 and 16 % higher SIWUE, and the interaction of FI BFM and FI

SM caused 29 and 12 % higher RIWUE and 32 and 16 % higher SIWUE, respectively,

when compared with FI NM treatment. The current study results indicated that,

increasing in the irrigation water application level in the order of Black Film Mulch,

Straw Mulch and No Mulch respectively, caused a corresponding decrease in mean

RIWUE and SIWUE. Similar results were also reported by Hussain, A., (2015) for

common bean in central Rift Valley of Ethiopia, Alenazi et al., (2015) for muskmelon.

Results of current study in terms of increase IWUE with decrease in irrigation level

under black film and straw mulches was also supported by Igbadun et al., (2012) for

onion in Samaru, Nigeria.

115

Table 4.19. Interaction effect of irrigation regimes and mulching on root and sugar

irrigation water use efficiencies

Irrigation

regimes

mulching

RIWUE (kg m-3

) SIWUE (kg m-3

)

2011/201

2

2012/201

3

Average

of years

2011/201

2

2012/201

3

Averag

e of

years

FI NM 9.00i1

9.28i 9.14h 1.32j 1.34h 1.33i

FI BFM 11.34g 12.30f 11.82e 1.70h 1.82ef 1.76g

FI SM 10.22h 10.30h 10.26g 1.53i 1.52g 1.52h

DI20 NM 10.03h 10.19h 10.11g 1.55i 1.55g 1.54h

DI20 BFM 13.74d 14.46d 14.10c 2.20e 2.28c 2.24d

DI20 SM 12.25f 12.12f 12.19e 1.94f 1.89e 1.91f

DI40 NM 10.95g 11.07g 11.01f 1.80g 1.79f 1.79g

DI40 BFM 16.64c 17.55b 17.09b 2.80c 2.91b 2.85c

DI40 SM 14.17d 13.30e 13.73c 2.36d 2.19c 2.27d

DI60 NM 12.85e 12.37f 12.61d 2.17e 2.05d 2.11e

DI60 BFM 21.13a 21.68a 21.41a 3.72a 3.76a 3.74a

DI60 SM 17.82b 16.49c 17.16b 3.10b 2.83b 2.97b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

40

80

120

160

200

FI N

M

FI BPFM

FI S

M

DI2

0 N

M

DI2

0 B

PFM

DI2

0 S

M

DI4

0 N

M

DI4

0 B

PFM

DI4

0 S

M

DI6

0 N

M

DI6

0 B

PFM

DI6

0 S

M% i

ncrea

se i

n r

oo

t a

nd

su

ga

r i

rrig

ati

on

wa

ter u

se e

ffic

ien

cy

RIWUE SIWUE

Figure 4.29. Relative increase in root and sugar irrigation water use efficiencies

caused by interaction effect of irrigation regimes and mulching practices

116

4.10.2.1 Interaction Effect of Irrigation Regimes and Planting Methods on

Sugar Beet Root and Sugar Irrigation Water Use Efficiency

The interaction effects of four irrigation regimes and three raised bed planting

methods (i.e. Conventional Ridge-Furrow (CRF) planting, Medium Raised-Bed (MRB)

planting, and Wide Raised-Bed (WRB) planting) on root and irrigation water use

efficiencies for 2011/2012 and 2012/2013 cropping seasons are presented in Table.

4.20. From the analysis of data, it was found that both the root irrigation water use

efficiency and sugar irrigation water use efficiency were significantly effected (p <

0.05) by irrigation regimes and planting methods interaction. Both of them were

increased as the application of irrigation level was decreased from full irrigation (FI) to

60% deficit irrigation (DI60) under the planting pattern order of CRF, WRB and MRB.

For the same level of irrigation, the highest root and sugar irrigation water use

efficiencies were observed for MRB system. This was followed by WRB and CRF. For

both cropping seasons, the highest mean root irrigation water use efficiency with 18.98

and 18.92 kg m-3

, and highest mean sugar irrigation water use efficiency with 3.30 and

3.23 kg m-3

were recorded from treatment that received 60 % deficit irrigation (DI60)

and crop was grown on furrow irrigated medium raised-bed with two crop rows on each

side of the bed DI60MRB. The second highest mean root irrigation water use

efficiency with 17 and 15.91 kg m-3

and mean sugar irrigation water use efficiency with

3.09 and 2.87 kg m-3

were observed from DI60WRB treatment The lowest mean

RIWUE with 9.32 and 9.75 kg m

-3, and lowest mean SIWUE with 1.36 and 1.40 kg m

-3

were recorded for DI60CRF. Averaging the two years data, no significant difference in

RIWUE was found between treatments FI MRB and DI20 WRB, treatments

DI20MRB and DI40WRB, treatments DI40MRB and DI60CRF. Similarly, the

treatments FIMRB and DI20CRF, DI40MRB and DI60CRF had the statistically

same values of SIWUE (at p < 0.05) (Table 4.20).


irrigation water use efficiencies observed for interaction effect of different irrigation

regimes and planting methods over FICRF treatment. It can be seen from this Figure

that the interaction effect of DI60MRB, DI60WRB and DI60CRF caused 98.85,

72.72 and 65.37 % higher RIWUE and 136.96, 115.94 and 86.23 % higher SIWUE,

respectively in comparison to FI CRF treatment. Furthermore, the interaction effect

of DI40 MRB, DI40 WRB and DI40 CRF caused 62.43, 41.345 and 35.26 % higher

117

RIWUE and 87.68, 68.12 and 46.38 % higher SIWUE, the interaction of DI20 MRB,

DI20WRB and DI20CRF caused 43.02, 24.03 and 14.90 % higher RIWUE and 54.35,

39.13 and 19.57 % higher SIWUE, and the interaction of FIMRB and FIWRB

caused 20.67 and 6.93 higher RIWUE and 22.46 and 11.59 % higher SIWUE,

respectively, when compared with FICRF treatment. The current study results

indicated that, increase in irrigation water application level in the order of medium

raised-bed, wide raised-bed and conventional ridge furrow planting methods

respectively resulted a corresponding decrease in mean root and sugar irrigation water

use efficiency values. The lowest IWUE observed in the current study for sugar beet in

FICRF treatment was also supported by Khan et al., (2015) for maize crop.

Table 4.20. Interaction effects of irrigation regimes and planting methods on root

and sugar irrigation water use efficiencies

Irrigation

regimes

Planting

methods

RIWUE (kg m-3

) SIWUE (kg m-3

)

2011/201

2

2012/201

3

Averag

e

of

years

2011/201

2

2012/201

3

Averag

e of

years

FI CRF 9.32i1

9.75h 9.53i 1.36i 1.40j 1.38j

FI MRB 11.21g 11.78e 11.50f 1.67g 1.72h 1.69h

FI WRB 10.03h 10.35g 10.19h 1.53h 1.56i 1.54i

DI20 CRF 10.84g 11.06f 10.95g 1.64g 1.66h 1.65h

DI20 MRB 13.32d 13.94c 13.63d 2.10e 2.17e 2.13e

DI20 WRB 11.85f 11.77e 11.82f 1.94f 1.89h 1.92g

DI40 CRF 12.75e 13.03d 12.89e 2.01f 2.03f 2.02f

DI40 MRB 15.40c 15.57b 15.48c 2.59c 2.59c 2.59c

DI40 WRB 13.61d 13.33d 13.47d 2.35d 2.27d 2.32d

DI60 CRF 15.81c 15.71b 15.76c 2.61c 2.55c 2.57c

DI60 MRB 18.98a 18.92a 18.95a 3.30a 3.23a 3.27a

DI60 WRB 17.00b 15.91b 16.46b 3.09b 2.87b 2.98b


probability.

118

0

20

40

60

80

100

120

140

FI

CRF

FI

MRB

FI

WRB

DI20

CEF

DI20

MRB

DI20

WRB

DI40

CRF

DI40

MRB

DI40

WRB

DI60

CRF

DI60

MRB

DI60

WRB

% i

ncrea

se i

n r

oo

t a

nd

su

ga

r i

rrig

ato

n

wa

ter u

se e

ffic

ien

cy

RIWUE SIWUE

Figure 4.30. % increase in average root and sugar water use efficiency by interaction

effect of different irrigation regimes and planting methods over FI CRF

treatment

4.10.2.3. Interaction effects of mulching and cropping patterns on sugar beet root

irrigation water use efficiency and sugar irrigation water use efficiency

The interaction effect of mulching and cropping patterns investigated

significantly (at p < 0.05) affected the root and sugar irrigation water use efficiencies

(RIWUE & SIWUE) of sugar beet in 2011/2012 and 2012/2013 cropping seasons

(Table 4.21). For the same type of mulch the highest RIWUE and highest SIWUE were

observed for MRB planting. This was followed by WRB. Averaging the effect of two

years and comparing the results of different treatments, the highest mean RIWUE with

17.88 kg m-3

and highest mean SIWUE with 2.95 kg m-3

were observed for MRBBFM

treatment. This was followed by WRBBFM with mean RIWUE of 15.42 kg m-3

and

mean SIWUE of 2.95 kg m-3

. The CRFNM treatment showed the lowest RIWUE

with 9.35 kg m-3

and lowest SIWUE with 1.42 kg m-3

, respectively. Figure 4.31 shows

the percent increase of RIWUE and SIWUE of different mulching and planting

methods interactions over NMCRF treatment. It is evident from this Figure that

NMMRB and NMWRB have 30.48 and 13.37 % higher RIWUE, and 35.92 and

22.54 % higher SIWUE when compared with NMCRF treatment. The highest percent

increase over NMCRF treatment was observed for black film treatments with

119

BFMMRB, BFMWRB and BFMCRF have 91.23, 64.92 and 60.64 % higher

RIWUE, and 107.75, 85.21 and 66.20 % higher SIWUE over NMCRF treatment. The

second highest average percent increase in root and sugar irrigation water use

efficiency was noted for straw mulch treatments with SMMRB, SMWRB and

SMCRF having values of 56.15, 38.18, 33.4 8% higher RIWUE and 67.61, 54.23 and

36.62 % higher SIWUE, respectively. The higher irrigation water use efficiency in the

current study, resulted by the interaction effect of furrow irrigated raised-bed planting

and straw mulch compared to that resulted by conventional ridge furrow and straw

mulch interaction, was much higher than that reported by Kahlon and Khera, (2015) for

potato. The difference might be due to the difference in soil and climatic conditions and

plant characteristics.

Table 4.21. Interaction effect of mulching and planting methods on root and sugar

irrigation water use efficiencies

Mulching

Planting

methods

RIWUE (kg m-3

)

SIWUE (kg m-3

)

2011/201

2

2012/201

3

Averag

e

of years

2011/201

2

2012/201

3

Average

of years

NM CRF 9.5i1 9.20f 9.35h 1.45g 1.38h 1.42g

NM MRB 11.96g 12.44d 12.20f 1.91e 1.95f 1.93e

NM WRB 10.67h 10.54e 10.60g 1.76f 1.71g 1.74f

BFM CRF 14.49d 15.55b 15.02c 2.30d 2.44c 2.36c

BFM MRB 17.27a 18.48a 17.88a 2.88a 3.03a 2.95a

BFM WRB 15.37b 15.46b 15.42b 2.64b 2.62b 2.63b

SM CRF 12.55f 12.40d 12.48f 1.96e 1.91f 1.94e

SM MRB 14.96c 14.24c 14.60d 2.46c 2.30d 2.38c

SM WRB 13.33e 12.52d 12.92e 2.27d 2.11e 2.19d


probability.

120

0

20

40

60

80

100

120

NM

CRF

NM

MRB

NM

WRB

BPFM

CRF

BPFM

MRB

BPFM

WRB

SM

CRF

SM

MRB

SM

WRB

% in

crea

se in

ro

ot

an

d s

ug

ar

wa

ter u

se e

ffic

ien

cy

RIWUE SIWUE

Fig. 4.31. Relative increase in root and sugar irrigation water use efficiencies by

interaction effect of different mulching and cropping patterns

4.10.2.4. Interaction effects of irrigation regimes, mulching and planting

methods on sugar beet root and sugar irrigation water use

efficiencies

The interaction effects of four levels of irrigation i.e. full irrigation (FI), 20%

deficit irrigation (DI20), 40% deficit irrigation (DI40), 60% deficit irrigation (DI60), three

types of mulching i.e. No-Mulch (NM), Black Film Mulch (BFM) and Straw Mulch

(SM), and three planting methods i.e. Conventional Ridge Furrow planting (CRF),

Medium Raised-Bed (MRB) planting and Wide Raised-Bed (WRB) planting for

2011/2012 and 2012/2013 cropping seasons is presented in Table 4.22. From the

analysis of data it was observed that both the Root Irrigation Water Use Efficiency

(RIWUE) and Sugar Irrigation Water Use Efficiency (SIWUE) were significantly

affected by irrigation regimes, mulching and planting methods interaction. In both

years, for the same mulching condition and planting pattern, both the Root Irrigation

Water Use Efficiency (RIWUE) and Sugar Irrigation Water Use Efficiency (SIWUE)

were increased as the application of irrigation level was decreased from FI to DI60. Also,

for the same level of irrigation and planting pattern, RIWUE and SIWUE were

increased under the mulching order of BFM, SM and NM. Furthermore for the same

level of irrigation and mulching, RIWUE and SIWUE were increased under the

planting methods order of MRB, WRB and CRF. For both cropping seasons, the

significantly highest mean RIWUE (22.75, 24.39 kg m-3

) and highest mean SIWUE

121

(4.02, 4.23 kg m-3

) were recorded from DI60BFM MRB treatment The second and

third highest SIWUE with 3.85 and 3.64 kg m-3

in year 2011/2012, and with 3.30 and

3.43 kg m-3

in 2012/2013 were recorded for DI60BFMWRB and DI60BFMCRF

interactions, respectively. However, the RIWUE for these two treatments were not

significantly (at p < 0.05) different from each other (Table 4.22). The significantly

lowest mean RIWUE (8.12, 8.15 kg m-3

) and significantly (P< 0.05) lowest mean

SIWUE (1.16, 1.14 kg m-3

) were recorded for treatment that received full irrigation (FI)

under No-Mulch and crop was grown in form of CRF i.e. for FINMCRF interaction.

Averaging the two years data, no significant difference was found among treatments

FINMMRB, FIBFMCRF, DI40NMWRB and DI60NMCRF, among

FINMMRB, FISMWRB and DI20NMWRB, among FINMWRB,

FISMCRF and DI40NMCRF, among FINMMRB and DI20NMCRF, among

FINMCRF and DI20NMCRF, between DI60BFMCRF and DI60BFMWRB,

between DI40BFMMRB and DI60SMMRB, among DI20BFMMRB,

DI40BFMCRF, DI40BFMWRB, DI60SMCRF and DI60SMWRB, among

FIBFMMRB, FIBFMMRB, DI20BFMCRF, DI20BFMWRB, DI20SMMRB,

DI40SMCRF and DI40SMWRB, among FIBFMMRB, DI20BFMCRF,

DI40SMCRF and DI40SMWRB, among FIBFMMRB, DI20BFMCRF,

DI40NMMRB, DI40SMCRF and DI60NMWRB, among DI20SMWRB,

DI40NMMRB and DI60NMWRB, among FIBFMWRB, DI20NMMRB and

DI20SMWRB, among FIBFMWRB, FISMMRB, DI20NMMRB and

DI20SMCRF, among FIBFMCRF, FIBFMWRB, FISMMRB,

DI20SMCRF, DI40NMWRB and DI60NMCRF at (p < 0.05) (Table 4.22).

Figure 4.32 shows the percent increase in the two years average mean RIWUE

and SIWUE for different irrigation regimes mulching planting methods interactions

relative to FINMCRF treatment. The highest increase in RIWUE with189.91% and

SIWUE with 258.70% was observed for DI60BFMMRB treatment. This was

followed by DI60BFMWRB with 150.55 % higher RIWUE and 225.65 higher

SIWUE. The third maximum increase in RIWUE with 149.32 and in SIWUE with

192.61% was observed in DI60BFMCRF treatment, respectively.

122

Table 4.22. Interaction effects of irrigations regimes, mulching and planting

methods on root and sugar irrigation water use efficiencies

Irrigation regimes

mulching

planting methods

RIWUE (kg m-3) SIWUE (kg m-3)

2011/

2012

2012/

2013

Average of

years

2011/

2012

2012/

2013

Average

of

years

FI NM CRF 8.12u1 8.15t 8.13r 1.16w 1.14w 1.15w

FI NM MRB 10.00rs 10.59opq 10.30mn 1.46uvw 1.52stu 1.48tu

FI NM WRB 8.88t 9.11rst 9.00pq 1.34w 1.35uv 1.35v

FI BFM CRF 10.42qr 11.44lmno 10.93lm 1.53tu 1.67pqrs 1.59st

FI BFM MRB 12.45mn 13.55ghi 12.99fgh 1.87nop 2.00klm 1.93no

FI BFM WRB 10.05rs 11.91klmn 11.54jkl 1.71qrs 1.80nopq 1.75pqr

FI SM CRF 9.42st 9.65wrs 9.53op 1.38vw 1.40tuv 1.39uv

FI SM MRB 11.19p 11.21mno 11.20kl 1.67rst 1.64qrs 1.66rs

FI SM WRB 10.05rs 10.03pqr 10.04no 1.53tu 1.51stu 1.52t

DI20 NM CRF 8.84tu 8.69st 8.77qr 1.32w 1.27vw 1.69v

DI20 NM MRB 11.38op 12.09klm 11.73jk 1.74pqr 1.82nop 1.78pq

DI20 NM WRB 9.86rs 9.78qr 9.82no 1.58stu 1.54rst 1.56st

DI20 BFM CRF 12.58lmn 13.28ghij 12.93fgh 1.94mno 2.03jkl 1.98mn

DI20 BFM MRB 15.28h 16.28ef 15.78d 2.45h 2.57h 2.50fgh

DI20 BFM WRB 13.35jk 13.84gh 13.59f 2.21jk 2.25hi 2.23j

DI20 SM CRF 11.10pq 11.20mno 11.16kl 1.67rst 1.69opqr 1.68qrs

DI20 SM MRB 13.29jkl 13.44ghi 13.37f 2.12jkl 2.10ijk 2.11kl

DI20 SM WRB 12.35mn 11.70lmn 12.03ij 2.03lm 1.89lmn 1.96mno

DI40 NM CRF 9.78rs 9.45rs 9.59op 1.52uv 1.43tuv 1.48tu

DI40 NM MRB 12.12no 12.79 12.45hi 2.01lmn 2.09ijk 2.04lmn

DI40 NM WRB 10.96pq 10.97nop 10.97lm 1.87nop 1.84mno 1.86op

DI40 BFM CRF 15.19h 16.70e 15.95d 2.42h 2.63fg 2.52fg

DI40 BFM MRB 18.59d 19.71c 19.15c 3.16de 3.13c 3.23c

DI40 BFM WRB 16.12f 16.24ef 16.18d 2.81f 2.79ef 2.80e

DI40 SM CRF 13.27jkl 12.93hijk 13.10fgh 2.10kl 2.02kl 2.06lm

DI40 SM MRB 15.50gh 14.20g 14.84e 2.61g 2.36h 2.48gh

DI40 SM WRB 13.73ij 12.77ijk 13.25fg 2.38hi 2.19ij 2.28ij

DI60 NM CRF 11.26p 10.52opq 10.89lm 1.82opq 1.66pqrs 1.75pqr

DI60 NM MRB 14.33i 14.29g 14.31e 2.42h 2.36h 2.39hi

DI60 NM WRB 12.95klm 12.30jkl 12.63ghi 2.26ij 2.11ijk 2.19jk

DI60 BFM CRF 19.76c 20.79b 20.27b 3.30d 3.43c 3.35c

DI60 BFM MRB 22.75a 24.39a 23.57a 4.02a 4.23a 4.12a

DI60 BFM WRB 20.87b 19.87bc 20.37b 3.85b 3.64b 3.75b

DI60 SM CRF 16.42f 15.82ef 16.12d 2.70fg 2.55g 2.62f

DI60 SM MRB 19.85c 18.10d 19.98c 3.46c 3.11d 3.28c

DI60 SM WRB 17.19e 15.56f 16.37d 3.16e 2.84e 3.00d


probability.

123

0

50

100

150

200

250

FI N

M C

RF

FI N

M M

RB

FI N

M W

RB

FI B

PFM

CRF

FI B

PFM

MRB

FI B

PFM

WRB

FI S

M C

RF

FI S

M M

RB

FI S

M W

RB

DI2

0 NM

CRF

DI2

0 NM

MRB

DI2

0 NM

WRB

DI2

0 BPF

M C

RF

DI2

0 BPF

M M

RB

DI2

0 BPF

M W

RB

DI2

0 SM

CRF

DI2

0 SM

MRB

DI2

0 SM

WRB

DI4

0 NM

CRF

DI4

0 NM

MRB

DI4

0 NM

WRB

DI4

0 BPF

M C

RF

DI4

0 BPF

M M

RB

DI4

0 BPF

M W

RB

DI4

0 SM

CRF

DI4

0 SM

MRB

DI4

0 SM

WRB

DI6

0 NM

CRF

DI6

0 NM

MRB

DI6

0 NM

WRB

DI6

0 BPF

M C

RF

DI6

0 BPF

M M

RB

DI6

0 BPF

M W

RB

DI6

0 SM

CRF

DI6

0 SM

MRB

DI6

0 SM

WRB

% i

ncrea

se i

n r

oo

t a

nd

irrig

ati

on

wa

ter u

se e

ffic

ien

cy

RIWU SIWUE

Fig. 4.32. Relative increase in average root and sugar irrigation water use efficiency by interaction effect of different irrigation

regimes, mulching and furrow irrigated raised bed planting methods

124


PLANTING METHODS ON CROP WATER USE EFFICIENCY

Effect of irrigation regimes, mulching and planting methods, and their

interactions on Root Crop Water Use Efficiency (RCWUE) and Sugar Crop Water Use

Efficiency (RCWUE) for 2011/2012 and 2012/2013 cropping seasons are illustrated in

tables 4.23 to 4.29 and in Figures 4.33 to 4.39

4.11.1 Main Effects

4.11.1.1. Effect of irrigation regimes on sugar bee root and sugar crop water use

efficiency

RCWUE of sugar beet was significantly (at p<0.05) affected by irrigation regimes

(Table 4.23). However, in year 2012/2013, no significant difference in RCWUE was

found between 40 and 60 % irrigation deficit level. The possible reason may be due to

the zero rainfall during the crop initial stage (in January) that may affected the crop

growth, and ultimately its yield in the treatment that were kept under moderate to

severe stress condition. Also, artificial irrigation was not possible during this period due

to routine canal closure in Pakistan during January and February. For the study years of

2011/2012 and 2012/2013, the RCWUE (10.49, 8.95 kg m-3

) and highest SCWUE (1.82

and 1.53 kg m-3

) were observed for 60 % deficit irrigation (DI60) treatment and the

lowest RCWUE (8.29, 8.11 kg m-3

) and lowest SCWUE (1.23, 1.19 kg m-3

) was

observed for full irrigation (FI) treatment. Averaging the two years data, the sequence

for RCWUE was 9.72 kg m-3

> 9.38 kg m-3

> 9.00 kg m-3

> 8.20 kg m-3

for irrigation

regimes of DI60, DI40,DI20 and FI, respectively. The sequence for average SIWUE was

1.67 kg m-3

> 1.55 kg m-3

> 1.41 kg m-3

> 1.21 kg m-3

for different irrigation regimes

DI60, DI40, DI20 and FI, respectively (Table 4.23). The increased sequence of root

irrigation water use efficiencies with increased levels of irrigation deficit obtained in

this study was in accordance to the study made by Topak et al., (2011) and M.

A.Esmaeili (2011). However, these results are not in agreement with that reported by

Ucan K. and C. Gencoglan, (2004).

From the two years average data, an increase of 9.76, 14.39 and 18.54 % of

RCWUE and 16.53, 28.10 and 38.02 % SCWUE was observed for each of DI20, DI40

and DI60 treatments, respectively over FI treatment (Fig. 4.33). The % increase in

RCWUE reported in current study was close to that reported by Topak et al., (2011).

Their observed increase in root crop water use efficiency was 11.4% for 25% deficit

125

irrigation, 9.5 % for 50 % deficit irrigation and 3.2 % for 75 % deficit irrigation,

respectively, compared to full irrigation. In another study, Gharib and El-Henawy,

(2011) reported that RCWUE was increased by 21.02 and 17.05 % when the irrigation

was applied at 55 and 70 % soil moisture depletion levels in comparison to irrigation

application at 40 % moisture depletion. The results of our study however in disparate

with that reported by Ucan and Gencoglan, (2004). They observed that root crop water

use efficiency was decreased in order of 6.80, 9.07, 30.23 and 47.85 % for decrease in

irrigation level in order of 15% (DI15), 25% (DI25), 40% (DI40) and 60% (DI60),

respectively.

Table 4.23 Effect of irrigation regimes on root and sugar crop water use efficiencies

Irrigation

regimes

RCWUE (kg m-3

)

SCWUE (kg m-3

)

2011/201

2

2012/201

3

Averag

e

of

years

2011/201

2

2012/201

3

Averag

e of

years

FI 8.29d1 8.11c 8.20d 1.23d 1.19d 1.21d

DI20 9.26c 8.74b 9.00c 1.46c 1.36c 1.41c

DI40 9.82b 8.94a 9.38b 1.63b 1.47b 1.55b

DI60 10.49a 8.95a 9.72a 1.82a 1.53a 1.67a 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

5

10

15

20

25

30

35

40

FI DI20 DI40 DI60

% I

ncrea

se i

n r

oo

t a

nd

su

ga

r c

ro

p

wa

ter u

se e

ffic

ien

cy

RCWUE SCWUE

Figure 4.33. Relative increase in root and sugar crop water use efficiency by

irrigation regimes

126

4.11.1.2. Effect of mulching on sugar bee root and sugar crop water use efficiency

All the three types of mulches significantly (at p < 0.05) affected both the

root and sugar crop water use efficiency (Table 4.24). Comparing mean data of all

mulch treatments, the highest Root Crop Water Use Efficiency (RCWUE) for both

2011/2012 and 2012/2013 cropping seasons were observed for Black Film Mulch with

10.96 and 10.30 kg m-3

. This was followed by straw mulch treatment with 9.66 and

8.61 kg m-3

. The No Mulch treatment exhibited the lowest values with 7.79 and 7.14 kg

m-3

, respectively. Sugar crop water use efficiencies (SCWUE) values were also highest

for Black Film Mulch in both seasons with 1.80 and 1.67 kg m-3

, followed by 1.57 and

1.38 kg m-3

for straw mulch. The non-mulched treatment had the lowest SCWUE with

values of 1.24 and 1.11 kg m-3

(Table 4.24). Overall combined effect of two years data

for mulching revealed that both the black polyethylene and straw mulch treatments

respectively had 39.14 & 19.50 % higher root crop water use efficiencies and 48.72 &

25.64 % higher sugar crop water use efficiencies as compared with the no-mulch

treatment (Figure. 4.34). The results of current study in terms of increased sugar beet

crop water use efficiency by mulching was in agreement with that reported by Ma,

(1999) and Xie et al., (2005) for wheat crop. The low water use efficiency observed for

un-mulched plots might be due to the uninterrupted supply of solar radiation that

reached the earth surface and thus increased the amount of non-beneficial evaporation

and ultimately led towards lower water use efficiency as observed by Mukherjee et al.,

(2010). On the other hand mulch acted as barrier in between soil surface (evaporating

site) and microclimate that caused reduction in vapor pressure gradient in between them.

This reduced not only the moisture loss from soil surface through evaporation but also

reduced the upward movement of soil water from the lower to upward soil layer (Sarkar

et al., 2007). The comparatively less increased in yield under straw mulch might be due

to the growth of weeds that forced the crop to compete for moisture and nutrient uptake.

This brought moderate improvement in root and sugar crop water use efficiencies

amounting 19.50 and 25.64 %, respectively over NM condition. The highest values of

RCWUE (39.14 %) and SCWUE (48.42 %) over No Mulch were observed for Black

Film Mulch (BFM). The highest water use efficiency under Black Film Mulch may be

because of zero weeds growth and notable reduction in evaporation that helped in

maintaining higher moisture content in the crop root zone. In addition, BFM helps in

creating favorable environment around the root zone by accelerating its thermal status,

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T3X-512KGJY-1&_user=3415236&_coverDate=12%2F01%2F2010&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1756364947&_rerunOrigin=google&_acct=C000060485&_version=1&_urlVersion=0&_userid=3415236&md5=93d2e6cbe1f49439802296fb8abd1e3b&searchtype=a#bib0125


127

reducing diurnal variation during winter season, steady movement of soil moisture and

ultimately greater root penetration in the soil (Sarkar and Singh, 2007).

Table 4.24. Effect of different types of mulching on root and sugar crop water use

efficiencies

Mulching RCWUE (kg m

-3)

SCWUE (kg m

-3)

2011/2012 2012/2013

Average

of years 2011/2012 2012/2013

Average

of years

NM 7.79c1 7.14c 7.64c 1.24c 1.11c 1.17c

BFM 10.96a 10.30a 10.63a 1.80a 1.67a 1.74a

SM 9.66b 8.61b 9.13b 1.57b 1.38b 1.47b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

10

20

30

40

50

60

NM BPFM SM

% in

crea

se in

ro

ot

an

d s

ug

ar c

ro

p

wa

ter u

se e

ffic

ien

cy

RCWUE

SCWUE

Fig. 4.34. Relative increase in root and sugar water use efficiency caused by black

film and straw mulches treatments

4.11.1.3. Effect of planting methods on sugar beet root and sugar crop water use

efficiency

All the three furrow irrigated raised bed planting methods significantly (at p <

0.05) affected both the Root Crop Water Use Efficiency (RCWUE) and Sugar Crop

Water Use Efficiency (SCWUE) (Table 4.25). From comparison of two years mean

data, the highest RCWUE with 10.42 and 9.63 kg m-3

and highest SCWUE with 1.70

and 1.54 kg m-3

were observed for Medium Raised-Bed (MRB) planting. This was

followed by Wide Raised-Bed (WRB) with 9.31 and 8.38 kg m-3

RCWUE, and 1.39


128

and 1.47 kg m-3

SCWUE, respectively. Both the lowest root irrigation water use

efficiency RCWUE with 8.69 and 8.05 kg m-3

and lowest SCWUE with 1.35 and 1.23

kg m-3

were observed for Conventional Ridge-Furrow (CRF) planting. From the

analysis of two years average data, an increase of 19.71 and 5.62 % for RCWUE and

25.58 and 13.95 % SIWUE were observed for medium and wide raised bed planting

methods, respectively, when compared with conventional ridge-furrow planting (Figure

4.35). The results of current study are in agreement with that reported by Khan et al.,

(2015), for maize crop. Better performance of medium and wide raised bed planting

methods over conventional ridge-furrow system could be due to the fact that the bed

size is comparatively less erected (and thus more stable) and bigger in size than ridges

which can hold more moisture contents for longer time and ultimately higher root and

sugar yields accompanied by saving of irrigation water (Ahmad et al., 2010). As a

result, higher root and sugar crop water use efficiencies were obtained. It was further

observed from the data that the root crop water use efficiencies in MRB was almost

four times higher and sugar crop water use efficiency was almost two times higher in

comparison to WRB system. The relative low WUE in WRB may be attributed towards

the wider beds that made it difficult for the middle crop row to get optimum amount of

irrigation water and thus caused less yield and ultimately low root and sugar crop water

use efficiency (Ghani et al., 2009). Akbar et al., (2010) also reported that wider beds

experienced difficulty with lateral water movement from the furrows and thus caused

lower water use efficiency in comparison to medium raised-bed planting pattern.

However, according to the report published by ICARDA (2011), the root and sugar

crop water use efficiency in wider bed (130 cm width) was more than medium width

(65 cm width). However the numbers of crop rows were not mentioned in this report

for either type of raised bed. In another study on cotton crop, Kahlown et al., (2003)

reported that although the 60c and 90 cm wide raised-bed furrow irrigation method

gave higher CWUE in comparison to the conventional farmers use practices, however,

they found no significant difference between the performance of 60 and 90 cm wide

raised-beds.

129

Table 4.25 Effect of different planting methods on root and sugar crop water use

efficiencies

Planting

methods

RCWUE (kg m-3

)

SCWUE (kg m-3

)

2011/201

2

2012/201

3

Averag

e

of

years

2011/201

2

2012/201

3

Averag

e of

years

CRF 8.69c1 8.05c 8.37c 1.35c 1.23c 1.29c

MRB 10.42a 9.63a 10.02a 1.70a 1.54a 1.62a

WRB 9.31b 8.38b 8.84b 1.57b 1.39b 1.47b 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

5

10

15

20

25

30

CRF MRB WRB

% i

ncrea

se i

n r

oo

t a

nd

su

ga

r c

ro

p

wa

ter u

se e

ffic

ien

cy

RCWUE

SCWUE

Figure 4.35. Relative increase in root and sugar water use efficiency caused by

medium and wide raised bed planting methods.

4.11.2. Interaction Effects

Means of root and sugar crop water use efficiency (RCWUE, SCWUE) as

influenced by the first and the second order interactions are presented in Table 4.26,

4.27, 4.28 and 4.29 and Figure 4.36, 4.37, 4.38 and 4.39.

4.11.2.1. Interaction effect of irrigation regimes and mulching on sugar beet root

and sugar crop water use efficiency

From the analysis of results, it was found that the interactions of different

levels of irrigation i.e. full irrigation (FI), 20% deficit irrigation (DI20), 40% deficit

irrigation (DI40) and 60% deficit irrigation (DI60), with black film and straw mulches

130

significantly affected (at p < 0.05) the RCWUE and SCWUE in both the cropping

seasons of 2011/2012 and 2012/2013 (Table 4.26). In both study years, in the presence

of Black Film Mulch, both the root and sugar irrigation water use efficiencies were

significantly increased as the application of irrigation level was decreased from FI to

DI60. The increase in crop water use efficiency with decreasing level of irrigation

application under film mulch in the current study was in agreement with that reported

by Xai et al., (2005) for wheat and Mukherjee et al., (2010) for tomato. Under the straw

mulch situation, RCWUE in 2011/2012 and SCWUE in both study years were

significantly increased by the decreasing level of irrigation application. However, in

2012/2013, RCWUE resulted by DI20, DI40 and DI60 were non-significantly different

from each other. Under no-mulch situation and with increasing level of irrigation

deficit, in year 2011/2012, increased observed was non-significant for RCWUE and

significant for SCWUE. In year 2012/2013, RCWUE was non-significantly increased

by DI20, non-significantly decreased by DI40 and significantly decreased by DI60

treatments, respectively. The low CWUE for NM treatments in comparison to BFM or

SM treatments in the current study was also supported by Hussain, (2015) for common

been, Osama and El-Gammal, (2015) and Zhou et al., (2011) for wheat crop.

Furthermore, both the root and sugar irrigation water use efficiencies were decreased

within the same level of irrigation application under the mulching order of black film,

straw and No Mulch respectively. The decrease in sugar beet CWUE for the same level

of irrigation application under the mulching order of black film, straw and No Mulch

was also supported by Mastana and Malik, (2009), for wheat crop in West Bengal. In

both study years, maximum mean root crop water use efficiency (12.64, 11.07 kg m-3)

and maximum mean sugar crop water use efficiency (2.23, 1.92 kg m-3

) were recorded

from treatments that received 60 % deficit irrigation (DI60) under Black Film Mulch.

The second maximum mean root crop water use efficiency (10.82, 9.06 kg m-3) and

mean sugar crop water use efficiency (1.89, 1.55 kg m-3

) were recorded from treatment

DI60 under straw mulch. For both cropping seasons, the minimum mean root irrigation

water use efficiency (7.40, 7.19 kg m-3

) and minimum mean sugar water use efficiency

(1.08 kg m-3

, 1.04 kg m-3

) were recorded for treatment that received full irrigation (FI)

under No Mulch (Table 4.26). From the analysis of two years average data, no

significant difference at (p < 0.05) was found between treatments FI NM and DI60

NM, FI BFM and DI20 SM, FI BFM and DI40 SM, DI20 NM and DI40 NM,

131

and DI40 NM and DI60 NM for root crop water use efficiency, and among FI SM,

DI40 NM and DI60 NM, between FI SM and DI20 NM .for sugar crop water use

efficiency, respectively.

Figure 4.36 shows the relative percent increase (average of two years) in

RCWUE and SCWUE observed for different irrigation regimes and mulching

interaction. It can be seen from this Figure that the interaction effect of DI60 BFM,

DI60 SM and DI60 NM caused 62.47, 35.75 and 1.2 3% higher RIWUE and 95.28,

61.32 and 16.04 % higher SIWUE, respectively in comparison to FI NM treatment.

While the interaction effect of DI40 BFM, DI40 SM and DI40 NM yielded 53.84,

28.36 and 3.29 % higher RIWUE and 77.36, 46.23 and 16.04 % higher SIWUE, the

interaction of DI20 BFM, DI20 SM and DI20 NM caused 40.41, 25.07 and 4.52 %

higher RIWUE and 53.77, 34.91 and 10.38 % higher SIWUE, and the interaction of FI

BFM and FI SM caused 25.75 and 11.37 higher RIWUE and 29.25 % and 14.15 %

higher SIWUE, respectively, when compared with FI NM treatment.

Table 4.26 Interaction effect of irrigation regimes and mulching on root and sugar crop

water use efficiencies

Irrigation regimes

mulching

RCWUE (kg m-3

) SCWUE (kg m-3

)

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

FI NM 7.40j1

7.19f 7.30j 1.08i 1.04g 1.06j

FI BFM 9.16g 9.19c 9.18ef 1.37f 1.36e 1.37g

FI SM 8.31h 7.94e 8.13g 1.24h 1.17f 1.21hi

DI20 NM 7.86i 7.40f 7.63h 1.21h 1.12f 1.17i

DI20 BFM 10.64d 10.04b 10.25c 1.68d 1.59c 1.63d

DI20 SM 9.47f 8.78d 9.13f 1.50e 1.37e 1.43f

DI40 NM 7.88i 7.20f 7.54hi 1.29g 1.16f 1.23h

DI40 BFM 11.56b 10.89a 11.23b 1.94b 1.81b 1.88b

DI40 SM 10.01e 8.72d 9.37e 1.67d 1.43d 1.55e

DI60 NM 8.02i 6.76g 7.39ij 1.35f 1.12f 1.23h

DI60 BFM 12.64a 11.07a 11.86a 2.23a 1.92a 2.07a

DI60 SM 10.82c 9.06cd 9.91d 1.89c 1.55c 1.71c 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

132

0

10

20

30

40

50

60

70

80

90

100

FI N

M

FI BPFM

FI SM

DI2

0 N

M

DI2

0 B

PFM

DI2

0 S

M

DI4

0 N

M

DI4

0 B

PFM

DI4

0 S

M

DI6

0 N

M

DI6

0 B

PFM

DI6

0 S

M

% i

ncrea

se i

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nd

su

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p

wa

ter u

se e

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ien

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RCWUE SCWUE


interaction effect of different irrigation regimes and mulches practices

4.11.2.2. Interaction effects of irrigation regimes and planting methods on

sugar beet root and sugar crop water use efficiency

Data regarding Root Crop Water Use Efficiency (RCWUE) and Sugar Crop

Water Use Efficiency (SCWUE) as influenced by the interaction of different irrigation

regimes i.e. full irrigation (FI), 20% deficit irrigation (DI20), 40% deficit irrigation

(DI40), 60% deficit irrigation (DI60), and planting methods i.e. conventional ridge-

furrow planting (CRF), medium raised-bed planting (MRB) and wide raised-bed

planting (WRB) are presented in Table 4.27. It is evident from the results that, in year

2011/2012, significantly (p < 0.05) highest mean Root Crop Water Use Efficiency

(RCWUE) with 11.47 kg m-3

was observed for MRB DI60 treatment. This was

followed by DI40 MRB with 10.82 kg m-3

.

In year 2012/2013, highest mean RCWUE with 9.85 kg m-3

was observed for

DI20 MRB treatment. However, this was not significantly higher from that observed

for DI40 MRB with 9.84 kg m-3

and DI60 MRB with 9.81 kg m-3

, respectively. In

both years, the highest mean SIWUE with 1.99 and 1.69 kg m-3

were observed for DI60

MRB treatment. The lowest RCWUE with 7.62 and 7.49 kg m-3

and lowest SCWUE

with 1.11 and 1.08kg m

-3 for FI CRF treatment. The results further revealed that, both

mean RCWUE and mean SCWUE were increased as the irrigation level was decreased

from full irrigation (FI) to 60% deficit irrigation (DI60) under the planting methods

133

order of CRF < WRB < MRB. However, in year 2012/2013, small incremental

decrease in RCWUE was observed when the irrigation application level was decreased

from 20 % up to 60 % in medium raised-be system and from 40 % to 60 % in WRB

system. The increase in crop water use efficiency with decrease in irrigation application

level for raised-bed observed in the current study for sugar beet was in agreement with

that reported by Shah, (2013), for maize and wheat crops. Analyzing the average effect

of two years mean data, the increased observed in RIWUE was in sequence of 10.69 kg

m-3

> 10.33 kg m-3

> 10.06 kg m-3

> 9.43 kg m-3

> 9.09 kg m-3

> 9.04 kg m-3

> 9.01

kg m-3

> 8.79 kg m-3

> 8.72 kg m-3

> 8.16 kg m-3

> 8.04 kg m-3

> 7.55 kg m-3

for

irrigation regimes and planting methods interactions sequence of DI60 MRB > DI40

MRB > DI20 MRB > DI60 WRB > DI40 WRB > DI60 CRF > FI MRB > DI20

WRB > DI40 CRF > DI20 CRF > FI WRB > FI CRF, respectively. The increased

observed in SIWUE was in sequence of 1.84 kg m-3

> 1.73 kg m-3

> 1.70 kg m-3

>

1.58 kg m-3

> 1.56 kg m-3

> 1.47 kg m-3

> 1.43 kg m-3

> 1.37 kg m-3

> 1.33 kg m-3

>

1.23 kg m-3

> 1.21 kg m-3

> 1.09 kg m-3

for irrigation regimes and planting methods

interactions sequence of DI60 MRB > DI40 MRB > DI60 WRB > DI20 MRB >

DI40 WRB > DI60 CRF > DI20 WRB > DI40 CRF > FI MRB > DI20 CRF > FI

WRB and FI CRF, respectively.


irrigation water use efficiency observed for interaction effect of different irrigation

regimes and planting methods over FI CRF treatment. The increase observed in

RCWUE was ranged between 19.36 and 41.59 % for MRB, between 6.49 and 24.49 %

for WRB and between 8.08 and 19.74 % for CRF, while the percent increase in

SCWUE observed was ranged between 22.02 and 68.81 % for MRB, between 11.01

and 55.96 % for WRB and between 12.84 and 34.86 % for CRF, for different amounts

of irrigation application, respectively. These results showed that the medium raised-bed

furrow irrigating planting pattern was the most efficient one, followed by the wide

raised-bed system. While the conventional ridge furrow system was the least efficient

system.

134

Table 4.27 Interaction effects of irrigation regimes and planting methods on root

and sugar crop water use efficiencies


probability.

0

10

20

30

40

50

60

70

80

FI C

RF

FI M

RB

FI W

RB

DI2

0 CEF

DI2

0 M

RB

DI2

0 W

RB

DI4

0 CRF

DI4

0 M

RB

DI4

0 W

RB

DI6

0CRF

DI6

0 M

RB

DI6

0 W

RB

% i

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p w

ate

r

use e

ffic

ien

cy

RCWUE SCWUE


interaction effect of irrigation regimes and planting methods

Irrigation regimes

Planting methods

RCWUE (kg m-3

) SCWUE (kg m-3

)

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

FI CRF 7.62g1

7.49e 7.55i 1.11j 1.08h 1.09h

FI MRB 9.10e 8.91b 9.01ef 1.35h 1.30f 1.33f

FI WRB 8.15f 7.93d 8.04h 1.24i 1.19g 1.21g

DI20 CRF 8.39f 7.93d 8.16h 1.27i 1.19g 1.23g

DI20 MRB 10.26c 9.85a 10.06c 1.62df 1.53c 1.58c

DI20 WRB 9.14e 8.44c 8.79fg 1.50f 1.36e 1.43e

DI40 CRF 9.05e 8.39c 8.72g 1.43g 1.31ef 1.37f

DI40 MRB 10.82b 9.84a 10.33b 1.82c 1.64b 1.73b

DI40 WRB 9.58d 8.59bc 9.09e 1.66d 1.47d 1.56c

DI60 CRF 9.68d 8.40c 9.04e 1.60e 1.36e 1.47d

DI60 MRB 11.47a 9.81a 10.69a 1.99a 1.69a 1.84a

DI60 WRB 10.33c 8.54c 9.43d 1.88b 1.54c 1.70b

135

4.11.2.3. Interaction effects of mulching practices and planting methods on

sugar beet root and sugar crop water use efficiencies

The interaction of mulching planting methods significantly (at p < 0.05)

affected both the Root Crop Water Use Efficiency (RCWUE) and sugar crop water use

efficiencies (SCWUE) (Table 4.28). In both study years highest RCWUE with 12.03

and 11.44 kg m-3

and highest SCWUE with 1.99 kg and 1.86 kg m-3

were obtained

when the crop was raised on medium raised-bed under Black Film Mulch (BFM

MRB). Also, for same type of mulch, the highest RCWUE in both seasons was

observed for MRB. This was followed by WRB. In both years, the least RCWUE and

SCWUE were observed for CRF. For the same type of planting methods, highest root

and sugar crop water use efficiency was noted for MRB, followed by WRB. Both

RCWUE and SCWUE were lowest for CRFNM treatment. From the analysis of two

years average data, no significant difference was observed between the treatments NM

MRB and SM CRF, BFM CRF and SM MRB for RCWUE and between

treatments NM MRB and SM CRF for SCWUE. The values of percent increase in

RCWUE by the different mulching and planting methods interaction over NM CRF

treatment was in order of 78.15 > 55.24 > 50.53>50.52>34.75 > 30.50 > 27.62 > 12.29

for M FIS sequence of BFM MRB > BFM WRB > BFM CRF > SM MRB >

SM WRB > SM CRF > NM MRB > NM WRB. The increase observed for

SCWUE was in order of 93.94 > 74.75 > 62.63 > 56.57 > 50.51 > 34.34 > 33.33 >

21.21 for mulching and planting methods interaction sequence of BFM MRB > BFM

WRB > SM MRB > BFM CRF > SM WRB > SM CRF > NM MRB > NM

WRB, respectively (Fig. 4.38).

The % increase (30.50%) in crop water use efficiency (CWUE) for sugar beet

observed in this study in SM CRF treatment over NM CRF was in agreement with

that reported by Ramalan and Nwokeocha, (2000), for tomato and Hussain, (2015), for

common beans. They reported that SM CRF interaction increased the crop water use

efficiency (CWUE) of tomato crop by about 41 % and for common bean crop by about

20 to 50, when compared with the value obtained in NM CRF interaction. Similarly,

CRF and film mulch interaction increased the common beans CWUE by about 60 to

80 % in comparison to NM CRF interaction. In another study, Zhou et al., (2011)

reported about 6 % increase in wheat crop WUE for SM CRF interaction in

136

comparison to NM CRF treatment. Xen et al., (2016) reported 17.83 and 0.63 %

increase in corn CWUE for plastic mulch CRF and SM CRF interactions in

comparison to NM CRF. While the increase reported for plastic mulch CRF

interaction over SM CRF interaction was about 17.08 %.

Table 4.28. Interaction effect of mulching and planting methods on root and sugar

crop water use efficiencies

Mulching

Planting methods

RCWUE (kg m-3

) SCWUE (kg m-3

)

2011/

2012

2012/

2013

Average

of years

2011/

2012

2012/

2013

Average

of years

NM CRF 6.98h1

6.20f 6.59g 1.06g 0.92g 0.99h

NM MRB 8.64f 8.17d 8.41e 1.37e 1.27e 1.32f

NM WRB 7.74g 7.05e 7.40f 1.27f 1.14f 1.20g

BFM CRF 10.11c 9.72b 9.92c 1.60d 1.15c 1.55d

BFM MRB 12.03a 11.44a 11.74a 1.99a 1.86a 1.92a

BFM WRB 10.72b 9.74b 10.23b 1.82b 1.64b 1.73b

SM CRF 8.96e 8.23d 8.60e 1.39e 1.26e 1.33f

SM MRB 10.57b 9.28c 9.92c 1.73c 1.48c 1.61c

SM WRB 9.44d 8.33d 8.88d 1.60d 1.39d 1.49e 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

0

10

20

30

40

50

60

70

80

90

100

NM

CRF

NM

MRB

NM

WRB

BFM

CRF

BFM

MRB

BFM

WRB

SM CRF SM

MRB

SM

WRB

% I

ncrea

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nd

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r

cro

p w

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r u

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cy

RCWUE SCWUE


interaction effect of mulching practices and planting methods

137

4.11.2.4. Interaction effects of irrigation regimes, mulching practices and planting

methods on sugar beet root and sugar crop water use efficiencies

The results regarding the interaction effect of irrigation regimes, mulching

practices and planting methods on Root Crop Water Use Efficiency (RCWUE) and

Sugar Crop Water Use Efficiency (SCWUE) are presented in Table 4.29.

Interaction effects of irrigation regime, No Mulch and Conventional Ridge-Furrow

planting (FI, DI20, DI40, and DI60) NM CRF

From the analysis of data for 2011/2012 and 2012/2013 cropping seasons, the

difference observed in mean RCWUE and mean SCWUE was non significant (at p <

0.05) among all four treatments (FI NM CRF, DI20 NM CRF, DI40 NM

CRF and DI60 NM CRF). In year 2011/2012, RCWUE was increased from 6.73 kg

m-3

at FI to 6.99 kg m-3

, 7.11 kg m-3

and 7.11 kg m-3

at DI20, DI40, DI60, respectively

and SCWUE was increased from 0.96 kg m-3


, 1.10 kg m-3

and 1.15

kg m-3

at DI20, DI40, DI60, respectively. In year 2012/2013, the values of RCWUE was

slightly increased from at 6.35 kg m-3


at DI20 and then decreased to

6.23 kg m-3

and 5.83 kg m-3

at DI40 and DI60, respectively and the values of SCWUE

were negligibly increased from 0.89 kg m-3


and 0.95 kg m-3

at DI20

and DI40, and then decreased to 0.89 at DI60, respectively (Table 4.29).

Interaction effects of irrigation regime, Black Film Mulch and Conventional Ridge-

Furrow planting (FI, DI20, DI40, and DI60) BFM CRF

From the analysis of data regarding the interaction effect of BFM and CRF for different

levels of irrigation regimes, a significant (at p < 0.05) increase in mean RCWUE and

mean SCWUE was noted when the level of irrigation application was decreased from

FI to DI60. Significantly highest RCWUE and SCWUE were obtained for DI60,

followed by DI40 and DI20 treatments. The significantly lowest values were observed

for FI BFM CRF treatment. The sequence of RCWUE obtained in both years was

8.43 kg m-3

and 8.62 kg m-3

< 9.57 kg m-3

and 9.24 kg m-3

< 10.60 kg m-3

and 10.40 kg

m-3

< 10.82 kg m-3

and 10.62 kg m-3

for irrigation application levels of FI, DI20, DI40,

and DI60, respectively. The sequence obtained for SCWUE was in order of 1.24 kg m-3

and 1.26 kg m-3

< 1.48 kg m

-3, and 1.41 kg m

-3 < 1.69 kg m

-3and 1.64 kg m

-3 < 1.98 kg

138

m-3

and 1.75 kg m-3

for irrigation application order of FI, DI20, DI40, and DI60,

respectively (Table 4.29).

Interaction effects of irrigation regime, Straw Mulch and Conventional Ridge-

Furrow planting (FI, DI20, DI40, and DI60) SM CRF

From the analysis of interaction results of irrigation regimes (FI, DI20, DI40, and DI60)

straw mulch conventional ridge furrow planting, it was noted that the values of

RCWUE and SCWUE in year 2011/2012 were significantly (at p < 0.05) increased

when the irrigation application level was decreased from FI to DI60. The sequence

obtained for RCWUE was in order of 7.72 kg m-3

< 8.63 kg m

-3, and 9.44 kg m

-3 <

10.08 kg m-3

and for SCWUE was in order of 1.13 kg m-3

< 1.30 kg m

-3, and 1.49 kg m

-

3 < 1.66 kg m

-3, for irrigation application order of FI < DI20 < DI40 < DI60, respectively.

Increase in root and sugar crop water use efficiency with decreasing level of applied

irrigation was also observed in year 2012/2013 data, however, the values of RCWUE

for deficit levels of DI20, DI40, and DI60 and values of SCWUE for deficit levels of DI20

and DI40 were not significantly (at p < 0.05) different from each other.

The results for CRF system under different irrigation levels and mulching

system reveal that, in the absent of any kind of mulch, decrease in irrigation level have

no significant influence on sugar beet root and sugar crop water use efficiency.

However, if one uses mulching (especially BFM), a visible improvement in both root

and sugar water use efficiency can be achieved (Table 4.29)

Interaction effects of irrigation regime, No Mulch and Medium Raised-Bed Planting

(FI, DI20, DI40, and DI60) NM MRB

Analyzing the interaction results of irrigation regimes (FI, DI20, DI40, and DI60) No

Mulch medium raised-bed planting, it was noted that the value of RCWUE in year

2011/2012 was significantly (at p < 0.05) increased from 8.17 kg m-3

at full irrigation

(FI) to 8.87 kg m-3

at 20% deficit irrigation (DI20). However, RCWUE values (8.65 kg

m-3

, 8.81 kg m-3

) at 40% and 60% deficit irrigation levels (DI40, DI60) were not

significantly different from that obtained at DI20. Decrease in irrigation level also

caused significant increase in SCWUE from 1.19 kg m-3


at DI20.

When irrigation level was further decreased from DI20 to DI40, further increase in

SCWUE was observed (1.43 kg m-3

), however this was not significantly (at p < 0.05)

different from that obtained at DI20. When 60% deficit irrigation (DI60) was applied,

139

SCWUE value was enhanced to 1.50 kg m-3

, which was significantly higher than that

obtained at DI20 and DI40. In 2012/2013, when amount of irrigation level was reduced

from full irrigation (FI) to DI20, the value of RCWUE was non-significantly (at p <

0.05) increased from 8.15 kg m-3

to 8.68 kg m-3

. Further reduction in irrigation level

caused corresponding decrease in RCWUE to the value of 8.18 kg m-3

at DI40 and 7.68

kg m-3

at DI60. The value obtained at DI40 was significantly (at p < 0.05) not different

from that observed at FI and at DI20. Similarly, the value of SCWUE at FI (1.16 kg m-3

)

was significantly lower than that obtained at DI20 (1.31 kg m-3

), DI40 (1.34 kg m-3

), and

DI60 (1.27 kg m-3

); however, no significant difference was found among the values of

DI20, DI40, and DI60 (Table 4.29).

Interaction effects of irrigation regime, Black Film Mulch and Medium Raised-Bed

Planting (FI, DI20, DI40, and DI60) BFM MRB

From the analysis of interaction results of irrigation regimes (FI, DI20, DI40, and

DI60)BFMMRB, it was observed that in both study years both the values of RCWUE

and SCWUE for all the four levels of applied irrigation were significantly (at p < 0.05)

different from each other. The significantly highest RCWUE with 13.58 and 12.35 kg

m-3

was obtained for DI60BFMMRB treatment. This was followed by

DI40BFMMRB with 12.88 and 12.15 kg m-3

and DI20BFMMRB with 11.63 and

11.24 kg m-3

, respectively. The least values with 10.04 and 10.02 kg m-3

in both years

were observed for FIBFMMRB treatment. Similar sequence was also observed for

SCWUE with highest values (2.40 kg m-3

, 2.15 kg m-3

) were noted for

DI60BFMMRB treatment, followed by DI40BFMMRB with 2.19 and 2.04 kg m-3

and DI20BFMMRB with 1.86 and 1.78 kg m-3

, respectively. In both years, the least

SCWUE with 1.51 and 1.48 kg m-3

was observed for FIBFMMRB combination

(Table 4.29).

Interaction effects of irrigation regime, Straw Mulch and Medium Raised-Bed

Planting (FI, DI20, DI40, and DI60) SM MRB

From the analysis of results for irrigation regimes (FI, DI20, DI40, and DI60) straw

mulch medium raised-bed planting pattern, it was observed that in year 2011/2012,

both the values of RCWUE and SCWUE for all the four levels of applied irrigation

were significantly (at p < 0.05) different from each other. The significantly highest

RCWUE with 11.96 kg m-3

and highest SCWUE with 2.09 kg m-3

were obtained for

140

DI60SMMRB treatment. This was followed by DI40 SM MRB with 10.94 and

1.84 kg m-3

and DI20 SM MRB with 10.27 and 1.64 kg m-3

, respectively. The least

values with 9.09 and 1.36 kg m-3

were observed for FI SM MRB. The increasing

trend in both RCWUE and SCWUE with decreasing level of irrigation was also

observed for 2012/2013 data with significantly (at p < 0.05) highest (9.69, 1.67 kg m-3

)

and lowest (8.57 1.26 kg m-3

) values were obtained for DI60 SM MRB and FI

SM MRB treatments, respectively. However, no significant (at p < 0.05) difference

was observed between the values of treatments DI20 SM MRB (9.64, 1.51 kg m

-3)

and DI40 SM MRB (9.19, 1.53 kg m-3

), respectively (Table 4.29).

Interaction effects of irrigation regime, No Mulch and Wide Raised-Bed Planting (FI,

DI20, DI40, and DI60) NM WRB

From the analysis of data for data for irrigation regimes NM WRB, the sequence

for RIWUE obtained was 8.06 kg m-3

> 7.89 kg m-3

> 7.72 kg m-3

> 7.29 kg m-3

for

year 2011/2012, and 6.78 kg m-3

> 7.20 kg m-3

> 7.15 kg m-3

> 7.08 kg m-3

for year

2012/2013, for irrigation application levels of DI60, DI40, DI20 and FI, respectively.

Results for year 2011/2012 show that RCWUE was increased when the level of

irrigation application was decreased, however, the values for all the three deficit

irrigation levels were significantly (at p < 0.05) not different from each other. In year

2012/2013, the highest RCWUE was observed for DI20NMWRB treatment; however,

values of all the four treatment were statistically same at p < 0.05. The sequence

obtained for SCWUE was 1.41 kg m-3

> 1.35 kg m-3

> 1.24 kg m-3

> 1.10 kg m-3

for

year 2011/2012, and 1.16 kg m-3

< 1.21 kg m-3

> 1.12 kg m-3

> 1.05 kg m-3

for year

2012/2013, for irrigation application levels of DI60, DI40, DI20 and FI, respectively. The

data for 2011/2012 show that SCWUE was increased when the irrigation level was

decreased, however, again like the NM CRF interaction; the values for all three

deficit irrigation regimes (DI20, DI40 and DI60) were not significantly different from

each other at p < 0.05. For 2012/2013, value of SCWUE was increased when the

irrigation level was decreased from FI to DI20, however further reduction in irrigation

level decreased the SCWUE from 1.24 kg m-3

at DI20 to 1.21 kg m-3

at DI40 and 1.16 kg

m-3

at DI60. It can be concluded from these results that, if sugar beet crop has to be

raised on any type of planting pattern without the application of any kind of mulch,

then the best irrigation deficit regimes for obtaining significantly higher root and sugar

water use efficiency in water limiting area is DI20 (Table 4.29).

141

Interaction effects of irrigation regime, Black Film Mulch and Wide Raised-Bed

Planting (FI, DI20, DI40, and DI60) BFM WRB

From the analysis of data for Interaction effects of irrigation regimes (FI, DI20, DI40,

and DI60)BFMWRB, it was observed that all the values of RCWUE and all the

values of SCWUE in study year 2011/2012 were significantly (at p < 0.05) different

among each other for all the four levels of applied irrigation. The significantly highest

RCWUE (12.50 kg m-3

) and highest SCWUE (2.30 kg m-3

) were obtained for

DI60BFMWRB interaction. These were followed by 11.20 and 1.95 kg m-3

for

DI40BFMWRB, and 10.19 and 1.69 kg m-3

for DI20BFMWRB interactions. The

least values with 9.02 and 1.38 kg m-3

were noted for FIBFMWRB treatment. In

year 2012/2013, RCWUE observed for FIBFMWRB (8.39 kg m-3

) was significantly

(at p < 0.05) lower than that observed for DI20BFMWRB (9.65 kg m-3

),

DI40BFMWRB (10.13 kg m-3

) and DI60BFMWRB (10.25 kg m-3

), respectively.

However, no significant difference was found between the treatments

DI20BFMWRB and DI40BFMWRB, and between DI40BFMWRB and

DI60BFMWRB. On the other hand, all four means of SCWUE in year 2012/2013

were significantly different (at p < 0.05) from each other with the highest value was

noted for DI60BFMWRB (1.88 kg m-3

), followed by DI40BFMWRB with 1.74 kg

m-3

and DI20BFMWRB with 1.57 kg m-3

. The least SCWUE with 1.35 kg m-3

was

observed for FIBFMWRB interaction (Table 4.29).

Interaction effects of irrigation regime, Straw Mulch and Wide Raised-Bed Planting

(FI, DI20, DI40, and DI60) SM WRB

From analysis of the interaction effects of irrigation regimes (FI, DI20, DI40, and DI60)

SM WRB for 2011/2012 and 2012/2013 cropping seasons, it was noted that means of

both RCWUE and SCWUE in both study years were increased when the level of

irrigation application was decreased. In year 2011/2012, the significantly lowest mean

RCWUE value with 8.14 kg m-3

was observed for FIBFMWRB treatment and

significantly highest with 10.43 kg m-3

for DI60 BFM WRB. No significant

difference (at p < 0.05) was found between the mean values of DI20BFMWRB (9.51

kg m-3

) and DI40BFMWRB (9.67 kg m-3

). However, both of them were significantly

higher than the treatment FIBFMWRB and significantly lower than

DI60BFMWRB. In year 2012/2013, treatment FIBFMWRB yielded significant

lowest RCWUE with 7.78 kg m-3

, however no significant difference was found among

142

DI20BFMWRB (8.53 kg m-3

), DI40BFMWRB (8.43 kg m-3

) and DI60BFMWRB

(8.59 kg m-3

). Furthermore, in year 2011/2012, all the four values of SCWUE were

significantly different from each other with 1.92 kg m-3

the highest observed for

DI60BFMWRB, followed by DI20BFMWRB and DI40BFMWRB with 1.67 and

1.56 kg m-3

, respectively. The lowest SCWUE with 1.24 kg m-3

was observed for

FIBFMWRB. In year 2012/2013, just like RCWUE results, significantly highest

(1.57 kg m-3

) and significantly lowest (1.17 kg m-3

) SCWUE values were obtained for

DI60BFMWRB and FIBFMWRB, treatments, respectively, however, no

significant difference (at p < 0.05) was found between the values of treatments

DI20BFMWRB with 1.38 kg m-3

and DI40BFMWRB with 1.44 kg m-3

,

respectively (Table 4.29).

From the average of two years mean RCWUE and SCWUE data, the percent

increase observed for different interactive treatments over FI NM CRF, is

presented in Figure 4.39. Results revealed that, for the same level of irrigation and

mulch, the highest RCWUE and SCWUE were obtained for medium raised-bed

planting pattern. This was followed by wide raised-bed system. The conventional ridge-

furrow system showed the lowest increase. For the same irrigation level and planting

pattern, highest percent increase was observed for black film mulch treatments,

followed by straw mulch. The lowest increase was observed for No-mulch treatments.

For conventional ridge-furrow no-mulch planting, highest percent increase (2.14 % in

RCWUE and 5.38 % in SCWUE) were observed when 20 % (DI20) irrigation was

applied. For medium raised-bed no-mulch planting, also highest increase (34.25 % in

RCWUE and 48.39 % in SCWUE) were observed for (DI20). For wide raised-bed no-

mulch planting, highest increase (15.29 % for RCWUE and 37.63 % for SCWUE) were

observed when 40 % irrigation was applied. Under mulch conditions, the highest %

increase was observed when 60 % deficit irrigation was applied. Overall, DI60 BFM

showed the maximum increase in both RCWUE and SCWUE with 98.17 %, 144.09 %

for MRB, followed by 74.01 %, 123.66 % for WRB and 71.87 %, 100.00 % for CRF,

respectively. The next highest increase in RCWUE and SCWUE was observed for

DI60SM with 65.60 % and 101.08 % for MRB, 45.26 % and 87.10 % for WRB and

43.88 % and 64.52 % for CRF, respectively (Fig. 4.39).

143

Table 4.29 Interaction effects of irrigations, mulching and planting methods on root

and sugar crop water use efficiencies

Irrigation regimes

mulching Planting

methods

RCWUE (kg m-3) SCWUE (kg m-3)

2011/

2012

2012/

2013 Average of years

2011/

2012

2012/

2013

Average

of years

FI NM CRF 6.73t1 6.35rs 6.54p 0.96u 0.89t 0.93w

FI NM MRB 8.17op 8.15lm 8.16kl 1.19qr 1.16pqr 1.18rs

FI NM WRB 7.29rs 7.08pq 7.19o 1.10st 1.05s 1.08tu

FI BFM CRF 8.43no 8.62ijkl 8.53ijk 1.24pq 1.26mnop 1.25pqr

FI BFM MRB 10.04gh 10.02def 10.03e 1.51ij 1.48ghi 1.49hij

FI BFM WRB 9.02klm 8.93hij 8.98h 1.38mn 1.35jklm 1.36mn

FI SM CRF 7.72qr 7.48nop 7.60mn 1.13rs 1.08rs 1.11st

FI SM MRB 9.09jkl 8.57jkl 8.83hi 1.36mno 1.26mnop 1.31nop

FI SM WRB 8.14opq 7.78mn 7.96lm 1.24pq 1.17opqr 1.20qr

DI20 NM CRF 6.99st 6.37rs 6.68p 1.04t 0.93t 0.98vw

DI20 NM MRB 8.87lm 8.68hijkl 8.78hij 1.36mno 1.31lmn 1.34mno

DI20 NM WRB 7.72qr 7.15opq 7.43no 1.24pq 1.12qrs 1.18r

DI20 BFM CRF 9.57i 9.24gh 9.40fg 1.48jkl 1.41ijk 1.44jkl

DI20 BFM MRB 11.63c 11.24b 11.43c 1.86f 1.78d 1.82c

DI20 BFM WRB 10.19fg 9.65fg 9.92e 1.68g 1.57fg 1.63ef

DI20 SM CRF 8.63mn 8.17klm 8.40jk 1.30op 1.23nop 1.26pq

DI20 SM MRB 10.27fg 9.64fg 9.95e 1.64gh 1.51ghi 1.57fg

DI20 SM WRB 9.51ij 8.53jkl 9.02gh 1.56hi 1.38jkl 1.47ijk

DI40 NM CRF 7.11st 6.23rs 6.67p 1.10st 0.95t 1.03uv

DI40 NM MRB 8.65mn 8.18klm 8.42jk 1.43klm 1.34klm 1.38lm

DI40 NM WRB 7.89pq 7.20nopq 7.54no 1.35no 1.21opq 1.28op

DI40 BFM CRF 10.60ef 10.40cd 10.50d 1.69g 1.64f 1.66e

DI40 BFM MRB 12.88b 12.15a 12.51b 2.19c 2.04b 2.12b

DI40 BFM WRB 11.20d 10.13cdef 10.67d 1.95e 1.74de 1.84c

DI40 SM CRF 9.44ijk 8.54jkl 8.99h 1.49ijk 1.33klm 1.41klm

DI40 SM MRB 10.94de 9.19ghi 10.06e 1.84f 1.53gh 1.68de

DI40 SM WRB 9.67hi 8.43jkl 9.05gh 1.67g 1.44hij 1.55gh

DI60 NM CRF 7.11st 5.83s 6.47p 1.15rs 0.92t 1.03uv

DI60 NM MRB 8.88lm 7.68mno 8.28kl 1.50ijk 1.27mno 1.38lm

DI60 NM WRB 8.06opq 6.78qr 7.42no 1.41lmn 1.16pqr 1.28op

DI60 BFM CRF 11.85c 10.62c 11.24c 1.98e 1.75de 1.86c

DI60 BFM MRB 13.58a 12.35a 12.96a 2.40a 2.15a 2.27a

DI60 BFM WRB 12.50b 10.25cde 11.38c 2.30b 1.88c 2.08b

DI60 SM CRF 10.08gh 8.74hijk 9.41fg 1.66g 1.41ijk 1.53ghi

DI60 SM MRB 11.96c 9.69efg 10.83d 2.09d 1.67ef 1.87c

DI60 SM WRB 10.43fg 8.59jkl 9.50f 1.92ef 1.57fg 1.74d 1Mean followed by the same letter(s) are statistically non-significant at 5%

probability.

144

-10

10

30

50

70

90

110

130

150

F NM

CRF

FI NM

MRB

FI NM

WRB

FI BFM

CRF

FI BFM

MRB

FI BFM

WRB

FI SM

CRF

FI SM

MRB

FI SM

WRB

DI2

0 NM

CRF

DI2

0 NM

MRB

DI2

0 NM

WRB

DI2

0 BFM

CRF

DI2

0 BFM

MRB

DI2

0 BFM

WRB

DI2

0 S

M C

RF

DI2

SM

MRB

DI2

0 SM

WRB

DI4

0 NM

CRF

DI4

0 NM

MRB

DI4

0 NM

WRB

DI4

0 BFM

CRF

DI4

0 BFM

MRB

DI4

0 BFM

WRB

DI4

0 SM

CRF

DI4

0 SM

MRB

DI4

0 SM

WRB

DI6

0 NM

CRF

DI6

0 NM

MRB

DI6

0 NM

WRB

DI6

0 BFM

CRF

DI6

0 BFM

MRB

DI6

0 BFM

WRB

DI6

0 SM

CRF

DI6

0 SM

MRB

DI6

0 SM

WRB

% i

ncr

ease

in

root

an

d s

ugar

wate

r u

se e

ffic

ien

cy

RIWUE SIWUE

Fig. 4.39. Relative increase in root and sugar crop water use efficiency by interaction effect of different irrigation regimes,

mulching practices and furrow irrigated raised bed planting methods

145

4.12 RELATIONSHIP BETWEEN SEASONAL EVAPOTRANSPIRATION

AND YIELD COMPONENTS OF SUGAR BEET

In the semi-arid areas of Pakistan, the relationships between sugar beet root

yield and seasonal evapotranspiration (ET) was best described by quadratic function (y

= -8E-0.5x2

+ 0.1505x - 2.8888, Figure 4.40) obtained by regression analysis after

pooling all the data sets for Black Film Mulch and straw mulch treatments and that

were applied under different planting methods (CRF, MRB and WRB). This, implying

that root yield plateau at some evapotranspiration level and decreases with additional

water supply. The polynomial relation between seasonal water used and crop yield

under mulch condition is in accordance with the finding of Wang and Shangguan,

(2015), for wheat crop and Abdrabbo et al., (2009) for cucumber crop. The results

however, disparate with that concluded by Barros and Hanks, 1993, for been crop.

They reported a linear relationship between dry matter yield and ET. Looking at other

results of this study, in No Mulch plots (under different planting methods) a linear

correlation (y = 0.0675x + 4.6626, Figure. 4.41) was found between the root yield and

seasonal ET. Similar findings were reported by Suheri et al., (2007), Ucan and Cafer,

(2004) and Kiziloglu et al., (2006) for sugar beet. This trend might be due to more

evaporation from No Mulch plots as compared to mulch plots that caused a decrease in

soil moisture in crop root zone and thus makes available less water for transpiration.

Figure 4.42 and Figure 4.43 show relationship between sugar yield and

evapotranspiration (ET) for sugar beet crop under different management practices.

Relationship obtained was curvilinear both for mulched and un-mulched conditions and

were described by quadratic function y = -2E - 05x2 + 0.0235x + 1.2946 and y = -1E -

05x2 + 0.0259x -3.3209, respectively.

146

y = -8E-05x2 + 0.1505x - 2.8888

R2 = 0.496

20

30

40

50

60

70

80

200 400 600 800 1000

ET (mm)

Root

yie

ld (

kg h

a-1)

Figure. 4.40 Relationship between sugar beet root yield and evapotranspiration (ET)

under straw and Black Film Mulch situation in Semi-arid area of

Pakistan

y = 0.0675x + 4.6626

R2 = 0.7576

20

30

40

50

60

70

80

300 500 700 900 1100

ET (mm)

Root

yie

ld (

tons

ha-1

)

Figure. 4.41 Relationship between sugar beet root yield and evapotranspiration (ET)

under no-mulch situation in Semi-arid area of Pakistan

147

y = -2E-05x2 + 0.0235x + 1.2946

R2 = 0.2918

5

6

7

8

9

10

11

12

13

300 400 500 600 700 800 900 1000

ET (mm)

Su

gar

yie

ld (

ton

s h

a-1)

Figure. 4.42 Relationship between sugar beet sugar yield and evapotranspiration (ET)

for under straw and Black Film Mulchunder straw and Black Film

Mulchsituation in Semi-arid area of Pakistan

y = -1E-05x2 + 0.0259x - 3.3209

R2 = 0.6082

2

3

4

5

6

7

8

9

10

11

300 400 500 600 700 800 900 1000

ET (mm)

Su

gar

yie

ld (

ton

s h

a-1)

Figure. 4.43. Relationship between sugar beet sugar yield and evapotranspiration (ET)

for no-mulch situation in Semi-arid area of Pakistan

148

4.13 SUGAR BEET YIELD RESPONSE FACTOR (Ky)

Table 4.30 shows the two years average values of sugar beet root (ky)root yield

response factor obtained for different levels of season long deficit irrigation regimes

that were applied under different mulching and raised bed furrow irrigation/planting

methods. The highest ky value (1.02) was obtained when severe deficit irrigation (DI60)

was applied under no-mulch (NM) in conventional ridge-furrow planting pattern (CRF)

and the lowest (0.20) observed when mild deficit irrigation (DI20) was applied under

black polyethylene film mulch (BFM) in medium raised bed planting (MRB). Results

of this study indicated that Ky value was increased when the seasonal water used was

decreased, irrespective of the mulching conditions and water application system. For

DI20 treatments, ky was ranged between 0.20 and 0.89, for DI40 between 0.43 and 0.96,

and for DI60 between 0.66 and 1.02. For the same mulching condition, the highest Ky

value was observed for CRF system, followed by WRB. The lowest was observed for

MRB system. The increase in ky value with decrease level of seasonal water used in the

current study was in accordance to that reported by Igbadun et al., (2012). By

comparing the results between different mulching systems, the highest range of Ky

(0.58 to 1.02) was observed for No Mulch application, followed by straw mulch (0.88

to 0.77). The lowest (0.20 to 0.67) was for black polyethylene film mulch. When the

results of different irrigation/planting pattern were compared, the highest ky was

observed for CRF system that was ranged between 0.38 and 1.02. This was followed by

WRB with ky ranged between 0.28 and 0.97. The lowest range was for MRB with ky

values varied between 0.20 and 0.99.

Table 4.30 also shows sugar yield response (ky)sugar to different combinations of

deficit irrigation regimes, mulching patterns and raised bed planting methods. (Ky)sugar

was ranged between 0.44 and 0.85 for raising the crop on three different types of raised

bed planting pattern with out the application of any types of mulch with the highest

value was observed for DI60-CRF and the lowest for DI20-MRB treatment. When sugar

beet was raised under black polyethylene film mulch, the (ky) range was reduced to

0.00 (for DI20-MRB treatment) to 0.55 (for DI60-MRB). Under straw mulch, ky values

obtained were ranged between 0.00 (for FI-MRB treatment) and 0.76 (for DI60-CRF).

These results show that mild deficit irrigation (DI20) has no negative effect on sugar

yield and thus can be used for planning the irrigation scheduling for sugar beet in the

semi-arid areas of Pakistan for achieving higher water use efficiency.

149

Figures, 4.44, 4.45 and 4.46 show the graphical representation of the seasonal

root and sugar yield response factors (Ky)root and (Ky)sugar values for nine different

combinations of mulching and planting methods. The seasonal (Ky)root values obtained

were 0.99, 0.93 and 0.93 for NM-CRF, NM-MRB and NM-WRB combinations, 0.53,

0.53, and 0.61 for BFM-CRF, BFM-MRB and BFM-WRB combinations and 0.65, 0.68

and 0.71 for SM-CRF, SM-MRB and SM-WRB combinations, respectively. The values

of (ky)root (0.93 and 0.99) obtained in the current study when sugar beet was raised on

CRF system without the application of any kind of mulch were closed to that that

reported by Topak et al., (2011) (0.97 and 0.89), Doorenboss and Kassam, (1979) (1.0),

Utset el al., (2007) (1.0), Shrestha et al., (2010) (1.01). However, for mulched

conditions, (ky)root values of this study were much lower from that obtained by

Doorenboss and Kassam, (1979). The lower ky values under mulch situation suggests

that mulching helped to cushion the impact of the deficit irrigation on yield.

The seasonal (Ky)sugar values obtained were 0.69, 0.81 and 0.81 for NM-CRF,

NM-MRB and NM-WRB combinations, 0.29, 0.31, and 0.50 for BFM-CRF, BFM-

MRB and BFM-WRB combinations and 0.47, 0.43 and 0.45 for SM-CRF, SM-MRB

and SM-WRB combinations, respectively.

Table 4.30. Effect of deficit irrigation regimes (applied under different planting

pattern and mulching conditions) on sugar beet yield response factor (ky)

Treatment Class Yield Response

Factor (Ky)

Irrigation/Planting pattern Mulching

Type

Irrigation Regime (Ky)root (Ky)sugar

CRF NM DI20 0.89 0.73

CRF NM DI40 0.96 0.79

CRF NM DI60 1.02 0.85

MRB NM DI20 0.58 0.44

MRB NM DI40 0.93 0.63

MRB NM DI60 0.99 0.80

WRB NM DI20 0.82 0.58

150

WRB NM DI40 0.89 0.64

WRB NM DI60 0.97 0.80

CRF BFM DI20 0.38 0.21

CRF BFM DI40 0.43 0.47

CRF BFM DI60 0.60 0.64

MRB BFM DI20 0.20 0.00

MRB BFM DI40 0.40 0.27

MRB BFM DI60 0.63 0.65

WRB BFM DI20 0.39 0.14

WRB BFM DI40 0.55 0.37

WRB BFM DI60 0.67 0.55

CRF SM DI20 0.42 0.55

CRF SM DI40 0.58 0.64

CRF SM DI60 0.72 0.76

MRB SM DI20 0.30 0.00

MRB SM DI40 0.69 0.56

MRB SM DI60 0.73 0.69

WRB SM DI20 0.28 0.01

WRB SM DI40 0.69 0.62

WRB SM DI60 0.77 0.68

151

For NM-CRFroot ky = 0.99, R2 = 0.98

For NM-MRBroot ky = 0.93, R2 = 0.95

For NM-WRBroot ky = 0.93, R2 = 0.97

For NM-CRFsugar ky = 0.81, R2 = 0.96

For NM-MRBsugar ky = 0.69, R2 = 0.89

For NM-WRBsugar ky = 0.69, R2 = 0.93

0

0.1

0.2

0.3

0.4

0.5

00.10.20.30.40.5

1 - (Eta / ETm)

1 -

(Y

a / Y

m)

NM-CRF(root) NM-MRB(root)

NM-WRB(root) NM-CRF(sugar)

NM-MRB(sugar) NM-WRB(sugar)

Linear (NM-CRF(root)) Linear (NM-MRB(root))

Linear (NM-WRB(root)) Linear (NM-CRF(sugar))

Linear (NM-MRB(sugar)) Linear (NM-WRB(sugar))

Fig. 4.44 Sugar beet yield response factor for different furrow irrigation/planting

systems with out application of any kinds of mulches

152

For BFM-MRBsugar ky = 0.31, R2 = 0.80

For BFM-CRFsugar ky = 0.29, R2 = 0.67

For BFM-WRBsugar ky = 0.50, R2 = 0.94

For BFM-WRBroot ky = 0.61, R2 = 0.88

For BFM-MRBroot ky = 0.53, R2 = 0.86

For BFM-CRFroot ky = 0.53, R2 = 0.91

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

00.10.20.30.40.5

1 - (ETa / ETm)

1 -

(Y

a /

Ym

)

BFM-CRF(root) BFM-MRB(root)BFM-WRB(root) BFM-CRF(sugar)BFM-MRB(sugar) BFFM-WRB(sugar)Linear (BFM-CRF(sugar)) Linear (BFM-MRB(sugar))Linear (BFFM-WRB(sugar)) Linear (BFM-WRB(root))Linear (BFM-MRB(root)) Linear (BFM-CRF(root))


systems with application of black polyehylene film mulch (BFM)

153

For SM-CRFroot ky = 0.65, R2 = 0.93

For SM-MRBroot ky = 0.68, R2 = 0.89

For SM-WRBroot ky = 0.71, R2 = 0.89

For SM-CRFsugar ky = 0.47, R2 = 0.86

For SM-MRBsugar ky = 0.43, R2 = 0.75

For SM-WRBsugar ky = 0.45, R2 = 0.77

0

0.1

0.2

0.3

0.4

00.10.20.30.40.5

1 - (ETa / ETm)

1 -

(Y

a /

Ym

)

SM-CRF(root) SM-MRB(root)SM-WRB(root) SM-CRF(sugar)SM-MRB(sugar) SM-WRB(sugar)

Linear (SM-CRF(root)) Linear (SM-MRB(root))Linear (SM-WRB(root)) Linear (SM-CRF(sugar))Linear (SM-MRB(sugar)) Linear (SM-WRB(sugar))


systems with application of Straw Mulch (SM)

154

CHAPTER V

AQUACROP MODEL CALIBRATION, VALIDATION AND EVALUATION

5.1 MODEL PARAMETERS

For canopy cover, in addition to the CCo, CDC, and CGC, the values of crop

growing days (calendar year) in each crop development stages i.e. germination,

maximum canopy, senescence and maturity were adjusted using the observed data

obtained over each full irrigation field during the 2011/2012 cropping season (Figure

5.1). Although these parameters were almost identical to each other for the same

mulching conditions irrespective of planting pattern, however, significant differences

were observed among different mulching fields. The quickest emergence, maximum

canopy, senescence and maturity were observed for BFM fields and the slowest for SM

fields (Table 5.1). This may be due to the difference in soil temperature observed under

different mulching conditions.

0

50

100

150

200

250

emergence max. CC senescence maturity

Day

s af

ter

sow

ing

CRF-NM CRF-BFM CRF-SM MRB-NM MRB-BFM MRB-SM WRB-NM WRB-BFM WRB-SM

Figure 5.1. Days after sowing of four phonological stages obtained from the calibration fields

during 2011/2012 cropping season.

Note: CRF: Conventional Ridge-Furrow irrigation system; MRB: Medium Raised-Bed

irrigation system; WRB: Wide Raised-Bed irrigation system; NM: No Mulch; BFM:

Black Film Mulch; SM: Straw Mulch

The comparatively higher temperature under BFM conditions, especially during the

crop initial stages may be the cause of quick germination that led towards quick

maximum canopy and quick maturity. This is why that about 10 to 15 days higher crop

period was observed for NM or SM in comparison to BFM. The water stress

155

parameters e.g. pexp (upper), pexp (lower), curve shape factor, psen (upper) and psto

(upper) affecting leaf expansion and early canopy senescence have been also adjusted

and presented in Table 5.1. The values obtained are slightly different than the other

studies testing the AquaCrop for sugar beet (Reza et al. 2014). The difference in the

water stress parameters may be due to variation in environmental variables, soil texture,

and method of irrigation application.

Table 5.1. Main parameters in the AquaCrop model calibrated for Sugar beet.

Parameters Conventional Ridge-

Furrow

irrigation system

Medium Raised-Bed

irrigation system

Wide Raised-Bed

irrigation system

NM-

FI

BFM-

FI

SM-

FI

NM-

FI

BFM-

FI

SM-

FI

NM-

FI

BFM-

FI

SM-

FI Plant density per m2 at 90%

emergence

10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00

Time to emergence, days 15.00 7.00 21.00 15.00 7.00 18.00 12.00 7.00 22.00

Time from sowing to

maximum canopy, days

126.00 110.00 135.00 126.00 110.00 135.00 127.00 110.00 138.00

Number of days from

sowing to maturity

190.00 180.00 195.00 190.00 180.00 195.00 190.00 180.00 198.00

Maximum effective rooting

depth, m

1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Canopy decline coefficient

(CDC), %/day

9.70 6.40 11.60 9.60 11.60 5.80 8.00 7.40 4.70

Canopy growth coefficient

(CGC), %/day

8.50 9.10 8.20 8.50 9.10 8.00 8.20 9.40 8.10

Time to senescence, days 165.00 165.00 180.00 165.00 165.00 180.00 165.00 160.00 185.00

Maximum canopy cover

(CCx), %

95.00 91.00 95.00 96.00 95.00 95.00 95.00 95.00 95.00

Canopy expansion stress

coefficient pexp(upper)

0.15 0.20 0.20 0.20 0.20 0.20 0.20 0.10 0.10

Canopy expansion stress

coefficient pexp(lower)

0.45 0.55 0.55 0.55 0.55 0.55 0.55 0.45 0.45

Canopy expansion shape

factor

3.20 0.50 0.50 2.00 0.50 2.00 0.50 0.50 0.50

Stomata conductance

threshold psto(upper)

0.55 0.55 0.55 0.55 0.55 0.65 0.55 0.45 0.55

Stomata stress coefficient

curve shape

2.80 2.80 2.80 2.80 2.80 2.80 2.80 2.80 2.50

Senescence stress

coefficient psen(upper)

0.45 0.45 0.55 0.55 0.55 0.55 0.55 0.45 0.55

Senescence stress

coefficient curve shape

1.20 3.00 3.00 2.00 3.00 2.00 3.00 3.00 2.70

Water productivity

(normalized), g m-2

17.00 17.00 18.00 17.80 17.60 18.60 18.00 16.70 18.00

Reference harvest index, % 68.00 69.00 68.00 71.00 73.00 69.00 69.00 69.00 68.00

Note: FI: Full Irrigation, NM: No-Mulch, BFM: Black Film mulch and SM: Straw mulch

156

5.2 CALIBRATION RESULTS FOR CANOPY COVER (CC)

AquaCrop model was used to predict the sugar beet CC under different in-field

water management strategies. The calibrated values of CC under three mulching

conditions and three furrow irrigated raised bed planting methods for full irrigation are

shown in Figure 5.2 (a, b and c).It was observed that the results of all the nine

calibrated fields for CC were better and closer to observed data. However, a slight

mismatch between the simulated and observed CC was noted in BFM and SM

treatments during the crop initial and final growth stages. This may be due to a

relatively faster growth during the initial crop stage and faster decline during the final

stage of the measured CC in BFM treatment. On the other hand, slow growth during

initial stage and slow decline during final crop stage of measured CC was observed in

SM treatment. Table 5.2 depicts quantitative performance based on different statistical

indicators. For calibrated CC of full irrigation treatments under different management

practices. Consequently, the Root Mean Square Error (RMSE) was found in acceptable

range i.e. between 3 and 11.35 %. The Normalized Root Mean Square Error (NRMSE)

ranged between 5.69 and 22.42 % and is considered good for the AquaCrop simulation.

The Index of agreement (dindex) ranged from 0.93 to 0.97, Nash–Sutcliffe Efficiency

factor (EF) ranged between 0.92 and 0.99, and MBE ranged from -3 to 2.23 %,

respectively. These results show that the AquaCrop model was in an excellent

agreement between the observed and simulated values of CC for all the calibrated fields

irrespective of the mulching condition and planting pattern.

Table 5.2 Statistical values based on the simulated and measured canopy cover for

the calibration fields (FI) during the 2011/2012 cropping season.

Planting

methods

Mulch

Type RMSE NRMSE dindex EF MBE

CRF

NM 5.17 10.04 0.96 0.98 -0.15

BFM 7.97 13.43 0.93 0.96 -3

SM 5.35 10.73 0.97 0.98 -0.31

MRB

NM 11.35 22.42 0.91 0.92 0.31

BFM 5.89 9.9 0.94 0.98 -2.17

SM 5.23 10.58 0.96 0.99 2.23

WRB

NM 3 5.69 0.97 0.99 0.38

BFM 8.56 14.98 0.91 0.95 0.54

SM 4.48 8.95 0.97 0.99 2.23

157

0

30

60

90

30 60 90 120 150 180

Days after planting

Can

op

y c

ov

er (

%)

(a)

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

op

y c

ov

er (

%)

(b)

0

20

40

60

80

100

30 60 90 120 150 180Days after planting

Can

op

y c

ov

er (

%)

Simlated CC-NMObserved CC-NM Simlated CC-BFM

Observed CC-BFM Simlated CC-SMObserved CC-SM

(c)

Figure 5.2. Observed versus simulated canopy cover of sugar beet for calibration fields:

(a) Conventional ridge-furrow irrigation system (b) Medium raised bed irrigation

system (c) Wide raised bed irrigation system.

5.3 VALIDATED RESULTS FOR CANOPY COVER (CC)

AquaCrop model was validated for the CC by using the data of three deficit

irrigation regimes i.e. (DI20, DI40 and DI60), that were applied under three different

158

mulching practices and three planting methods in 2011/2012 cropping season. Like the

calibration results, under and over prediction of the CC were noted in the validation

(Figure 5.3). This over and under estimation might be attributed toward differences in

different phonological stages observed for different mulch conditions. Table 5.3

presents the AquaCrop model performance values for validated CC. The RMSE,

NRMSE, dindex, EF, and MBE values between the simulated and observed data under

DI20 were not significantly different than the calibration results.

Table 5.3 Statistical values based on the simulated and the measured canopy cover

for validated fields (DI) during the 2011/2012 cropping season

Furrow

Planting methods

Irrigation

Regimes

Mulch

Types RMSE NRMSE dindex EF MBE

Conventional

Ridge-Furrow

planting

DI20

NM 3.63 7.42 0.97 0.99 1.31

BFM 7.62 13.94 0.91 0.96 0.92

SM 6.45 13.62 0.94 0.97 2.31

DI40

NM 4.70 10.16 0.95 0.99 3.54

BFM 10.26 19.99 0.89 0.91 2.67

SM 6.95 15.96 0.93 0.97 4.62

DI60

NM 6.22 18.50 0.93 0.97 -1.00

BFM 10.33 20.82 0.89 0.90 -1.17

SM 13.86 34.05 0.90 0.85 -0.62

Medium

Raised-Bed planting

DI20

NM 8.00 16.87 0.92 0.96 3.46

BFM 6.37 10.78 0.93 0.97 -1.75

SM 6.21 12.69 0.96 0.98 2.38

DI40

NM 8.87 19.67 0.90 0.94 5.85

BFM 10.47 19.00 0.90 0.92 2.25

SM 7.46 16.44 0.93 0.97 5.38

DI60

NM 9.08 20.66 0.90 0.94 6.38

BFM 16.89 34.53 0.84 0.76 6.75

SM 8.87 20.26 0.92 0.95 3.38

Wide

Raised-bed planting

DI20

NM 4.06 8.05 0.95 0.99 2.77

BFM 8.93 15.71 0.90 0.94 -0.23

SM 5.36 10.97 0.95 0.98 3.46

DI40

NM 8.05 17.50 0.91 0.95 6.45

BFM 11.66 23.03 0.86 0.87 6.00

SM 6.74 14.33 0.94 0.97 4.92

DI60

NM 11.18 26.34 0.87 0.89 8.62

BFM 11.55 24.18 0.87 0.87 7.00

SM 4.41 9.90 0.95 0.99 0.38

However, a significant difference was observed with the increased stress levels (DI40

and DI60), especially in un-mulched fields. In conventional ridge-furrow planting, the

minimum value of NRMSE (7.42%) was observed for DI20-NM field and the highest

159

(34.05%) for DI60-SM field. In medium raised-bed planting, the minimum value of

NRMSE (10.78%) was observed for DI20-BFM field and the highest (34.53%) for DI60-

NM field. In wide raised-bed planting pattern, both the minimum (8.05%) and

maximum (26.34%) values of RMSE were obtained for No-mulch fields‘ under DI20

and DI60 stress levels, respectively. The values of dindex and EF ranged from 0.89−0.97

to 0.85−0.99 for conventional ridge planting pattern, from 0.84 to 0.96 and 0.76 to 0.98

for medium raised-bed planting pattern and from 0.86 to 0.95 and in the range

0.87−0.99 for wide raised-bed planting pattern, respectively. The MBE was ranged

between -1.75 and 8.62. In general, the results obtained in simulating CC using

AquaCrop model are good and are in concurrence with other studies for other crops,

such as wheat, canola, capsicum (Salemi et al. 2011; Zeleke et al. 2011; Salunkhe et al.

2015; Toumi et al. 2016).

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

(%

)

(a)

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

(%

)

(b)

160

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

CC

(%

)

Simlated-NM

Observed-NM Simlated-BFM

Observed-BFM Simlated-SM

Observed-SM

(c)

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

op

y c

ov

er (

%)

(d)

0

20

40

60

80

100


Can

op

y c

ov

er (

%)

(e)

161

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

(%

)

Simlated-NMObserved-NM

Simlated-BFMObserved-BFM

Simlated-SMObserved-SM

(f)

0

20

40

60

80

100


Can

op

y c

ov

er (

%)

(g)

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

(%

)

(h)

162

0

20

40

60

80

100

30 60 90 120 150 180

Days after planting

Can

opy c

over

(%

)

Simlated CC-NM

Observed CC-NM Simlated CC-BFM

Observed CC-BFM Simlated CC-SM

Observed CC-SM

(i)

Figure 5.3. Observed versus simulated canopy cover of sugar beet for validated fields: (a)

Conventional ridge furrow irrigation system-DI20; (b) medium raised bed

irrigation system- DI20; (c) wide raised bed irrigation system-DI20; (d)

Conventional ridge furrow irrigation system-DI40; (e) medium raised-bed

irrigation system-DI40; (f) wide raised-bed irrigation system-DI40; (g)

Conventional ridge-furrow irrigation system-DI60; (h) medium raised-bed

irrigation system-DI60; (i) wide raised-bed irrigation system-DI60

5.4 CALIBRATED RESULTS FOR SUGAR BEET BIOMASS AND ROOT

YIELD

Comparison between the simulated and observed biomass and root yield of

sugar beet and percentage deviations of the simulated values from the observed are

shown in Table 5.4. It can be seen that the model accurately simulated both the biomass

and root yield for all the calibrated fields. The deviations of the simulated values from

observed in these fields were ranged between −0.38 and 1.09% for biomass and from -

0.36 to -1.26% for root yield. A better agreement between the observed and simulated

values of biomass and root yield for all the calibration fields were found with R2

between 0.93 and 0.99 (biomass) and 0.79 to 0.99 (root yield) (Table 5.5). Similarly,

the RMSE values for biomass was in the range 0.13-0.22 tons ha-1

, NRMSE ranged

0.61−1.13%, dindex between 0.58 and 0.77, EF from 0.51 to 0.81, and MBE between

0.08 and 0.21, respectively. For root yield, RMSE ranged from 0.047 to 1.17 tons ha-1

,

NRMSE between 0.44 and 1.44, dindex from 0.48 and 0.84, EF between 0.47 and 0.84,

and MBE between −0.01 and 0.72, respectively. The low values of RMSE and NRMSE,

and higher values of dindex and EF show that the measured and simulated values were

statistically in good agreement for calibrated data set (Table 5.5).

163

Table 5.4. Observed and simulated results of calibrated biomass and root yield of

sugar beet during 2011/2012 cropping season

Planting

methods

Mulch

Type

Biomass (Tons ha-1) Root yield (Tons ha-1)

Observed Simulated Deviation

(%) Observed Simulated

Deviation

(%)

CRF

NM 18.22 18.15 -0.38 12.41 12.33 -0.64

BFM 19.73 19.61 -0.61 13.54 13.46 -0.59

SM 19.69 19.57 -0.61 13.54 13.37 -1.26

MRB

NM 19.27 19.48 1.09 13.27 13.17 -0.73

BFM 21.13 21 -0.6 15.01 14.94 -0.49

SM 20.05 20.18 0.67 13.97 13.89 -0.58

WRB

NM 19.07 19.19 0.63 13.09 13.02 -0.53

BFM 19.89 19.97 0.4 13.78 13.73 -0.36

SM 19.69 19.83 0.71 13.33 13.32 -0.08

Table 5.5 Statistical results between the simulated and observed biomass and root

yield for the calibration fields during the 2011/12 irrigation season

Planting

pattern

Mulch

Type

Biomass (Tons ha-1) Root Yield (Tons ha-1)

R2

RMSE

(Tons

ha-1)

NRMSE (%)

dinde

x EF

MBE

(Tons

ha-1)

R2

RMSE

(Tons

ha-1)

NRMS

E (%)

dind

ex EF

MBE

(Tons

ha-1)

CRF

NM 0.99 0.17 0.94 0.58 0.64 -0.06 0.98 0.18 1.44 0.48 0.47 -0.08

BFM 0.93 0.14 0.71 0.67 0.54 -0.13 0.99 0.08 0.63 0.66 0.58 -0.08

SM 0.93 0.15 0.78 0.76 0.72 -0.12 0.99 1.17 1.22 0.64 0.51 -0.16

MRB

NM 0.99 0.22 1.13 0.76 0.81 0.21 0.97 0.11 0.84 0.84 0.86 -0.09

BFM 0.99 0.13 0.61 0.61 0.53 -0.13 0.9 0.07 0.44 0.72 0.67 0.72

SM 0.97 0.16 0.78 0.77 0.64 0.13 0.99 0.11 0.78 0.63 0.56 -0.08

WRB

NM 0.99 0.13 0.67 0.6 0.52 0.12 0.98 0.07 0.56 0.66 0.59 -0.07

BFM 0.96 0.15 0.73 0.67 0.75 0.08 0.96 0.14 1.05 0.72 0.69 -0.05

SM 0.99 0.14 0.72 0.63 0.51 0.14 0.79 0.08 0.58 0.74 0.77 -0.01

164

5.5 SUGAR BEET BIOMASS AND ROOT YIELD VALIDATION

5.5.1 Validation Results for Conventional Ridge-Furrow (CRF) Planting

Validation for CRF planting is shown in Table 5.6 which indicated good agreement

between the simulated biomass and root yield with their observed values. Based on

percent deviation, the simulated biomass varied from 12.15 to 17.98 tons ha-1

for NM,

16.94 to 19.39 for BFM and from 15.42 to 19.4 tons ha-1

for SM for different deficit

irrigation levels that were applied under CRF planting pattern. It was evident that

except the BFM-DI60 treatment, no significant deviation was observed between

simulated and measured values. However, for BFM-DI60 treatment, the simulated

biomass was significantly deviated (-10.04 %) from the observed values. A significant

deviation (13.14 %) of the simulated root yield from the measured values was found

when the crop was kept under moderate stress (DI40) without use of any mulch (NM).

For all of the remaining treatments, the deviation was insignificant and was from 7.81

to -0.51 % (Table 5.6).

In order to statistically analyze the AquaCrop model, performance for CRF

planting under different deficit irrigation regimes and mulching is shown in Table 5.7.

It is evident from this Table that the model provided efficient results in predicting both

the biomass and root yield when the crop was kept under DI20, irrespective of the

mulching conditions. This could be realized from low RMSE values ranged between

0.10 and 0.16 tons ha-1

, NRMSE between 0.54 and 0.85 %, dindex between 0.59 and

0.67, EF between 0.42 and 0.57, and MBE between 0.09 and 0.15 tons ha-1

, for biomass

and root yield, respectively. The correlation between simulated and observed values

was also good with R2 in the range e 0.90 to 0.99. Under DI40, the model overestimated

both the yield and biomass which is evident from the low dindex (0.09−0.29) and EF (-

3.30 to 79.48), for both biomass and root yield, respectively. The overestimation

observed was highest for NM followed by SM. Minimum overestimation was observed

for (BFM as shown in Table 5.7. Under 60% stress level (DI60), the model exhibited

highest overestimation in case of BFM (dindex: 0.10−0.11; EF: -50.92 to -70.55) both for

biomass and root yield. However the results were good at this stress level (DI60) under

NM and SM (R2: 0.91−0.99; dindex: 0.32−0.77; and MBE: -0.05 to -0.21 tons ha

-1 for

biomass and root yield respectively) (Table 7).

165

Table 5.6. Observed and simulated results of validated biomass (tons ha-1

) of sugar

beet under conventional Ridge-Furrow planting.

Mulch

Type

Irrigation

Regime



(%)

Observed

Simulated

Deviation

(%)

NM

DI20 17.89 17.98 0.50 12.11 12.19 0.66

DI40 16.05 17.41 8.47 10.35 11.71 13.14

DI60 12.24 12.15 -0.74 7.93 7.72 -2.65

BFM

DI20 19.39 19.54 0.77 13.34 13.43 0.67

DI40 18.16 18.59 2.37 12.32 12.59 2.19

DI60 16.94 15.24 -10.04 10.84 9.91 -8.58

SM

DI20 19.40 19.53 0.67 13.22 13.34 0.91

DI40 17.85 19.15 7.28 12.03 12.97 7.81

DI60 15.42 15.39 -0.19 9.77 9.72 -0.51

Table 5.7 Statistical results of the validated fields under conventional ridge-furrow

planting for different irrigation regimes and mulching types.

Irrigation

Regime

Mulch

Type


R2 RMSE

Tons ha-1

NRMSE

(%)

dindex EF MBE

Tons

ha-1

R2 RMSE

Tons

ha-1

NRMSE

(%)

dindex EF MBE

Tons

ha-1

DI20 NM 0.94 0.1 0.54 0.67 0.57 0.09 0.98 0.1 0.85 0.67 0.53 0.08

BFM 0.9 0.16 0.85 0.59 0.42 0.15 0.94 0.1 0.79 0.62 0.52 0.09

SM 0.99 0.14 0.71 0.62 0.52 0.13 0.94 0.13 1.02 0.69 0.5 0.12

DI40 NM 0.86 1.36 8.48 0.09 -

79.5

1.36 0.55 1.37 13.23 0.11 -

52.6

1.36

BFM 0.93 0.44 2.43 0.29 -3.3 0.44 0.98 0.27 2.17 0.26 -

4.93

0.27

SM 0.75 1.31 7.32 0.11 -

39.4

1.3 0.74 0.95 7.87 0.1 -

58.6

0.94

DI60 NM 0.99 0.09 0.7 0.67 0.63 -0.08 0.92 0.32 4.04 0.32 -

1.44

-0.21

BFM 0.99 1.73 10.23 0.11 -

50.9

-1.7 0.91 0.93 8.57 0.1 -

70.6

-0.93

SM 0.96 0.09 0.56 0.77 0.68 -0.07 0.96 0.08 0.86 0.54 0.55 -0.05

166

5.5.2 Validation Results for Medium Raised-Bed (MRB) Planting

Table 5.8 shows the comparison of the measured and simulated biomass and

root yield and their percentage deviations from the observed values for MRB planting

pattern under three deficit irrigation levels and mulching practices. For NM treatments

under DI20 condition, no significant deviations (2.13% and 1.46%) of the simulated

biomass and root yield from the measured values were found. However, the deviation

observed was significant for increased stress level. For DI40, the deviation was found

11.47% for biomass and 19.67% for root yield. The deviation further increased up to

14.11% for biomass and 26.87% for root yield for DI60 conditions. For BFM and SM

treatments, the deviation of the predicted biomass and root yield from the measured

were non-significant for all stress levels. The percent deviation observed for biomass

was ranged between −0.43 and 5.56 while it was between -0.68 and 7.68 for root yield

under BFM. Similarly under SM treatment, the percent deviation ranged between -3.73

and 0.86 for biomass and from -7.85 to 0.70 for root yield (Table 5.8). It is evident that

for both BFM and SM, the deviation observed was highest under for DI60.

Table 5.9 depicts the AquaCrop model performance for MRB planting under three

deficit irrigation levels and three mulching conditions. It can be seen from this Table

that, for DI20, irrespective of the mulching conditions, the agreement between the

measured and simulated values was statistically significant (R2: 0.96−0.99; RMSE:

0.09−0.41 tons ha-1

; NRMSE: 0.46−2.61%; dindex: 0.60−0.72; EF: 0.46−0.56%; MBE:

−0.09 to −2.31 tons ha-1

) for biomass and root yield respectively. For DI40 under NM,

the model exhibited close results with those obtained for CRF system for the same

conditions with R2 (0.83-0.86), RMSE (1.98−2.10), NRMSE (11.50−19.75), dindex

(0.11−0.15), EF (−20.0 to −51.09) and MBE (1.97−2.10) for biomass and root yield

respectively. However, for BFM and SM, the results under MRB system were

significantly higher than those obtained under CRF planting pattern. This is because of

the lower RMSE, NRMSE and MBE, and higher R2, dindex and EF for MRB compared

to CRF planting pattern. For DI60, underestimation was observed for NM and BFM

treatments and over estimation for SM treatment.

167

Table 5.8. Observed and simulated results of validated biomass and root yield of

sugar beet under Medium Raised-Bed planting.

Mulch

Types

Irrigation

Regime




Deviation

(%)

NM

DI20 18.90 19.30 2.13 12.73 13.04 2.46

DI40 17.23 19.21 11.47 10.64 12.73 19.67

DI60 15.55 17.74 14.11 8.67 11.00 26.87

BFM

DI20 20.84 20.75 -0.43 14.81 14.71 -0.68

DI40 20.07 20.33 1.30 13.56 14.29 5.38

DI60 17.51 18.48 5.56 11.72 12.62 7.68

SM

DI20 19.87 20.04 0.86 13.68 13.76 0.58

DI40 18.34 18.38 0.20 12.07 12.15 0.70

DI60 16.42 15.81 -3.73 10.29 9.48 -7.85

Table 5.9. Statistical results of the validated fields under Medium Raised-Bed

(MRB) planting for different irrigation regimes and mulching.

Irrigation

Regimes

Mulch

Type


R2

RMSE

Tons

ha-1

NRMSE

(%) dindex EF

MBE

Tons

ha-1

R2

RMSE

Tons

ha-1

NRMSE

(%) dindex EF

MBE

Tons

ha-1

DI20

NM 0.99 0.41 2.17 0.62 0.49 0.40 0.99 0.33 2.61 0.60 0.46 2.31

BFM 0.97 0.10 0.46 0.69 0.56 -0.09 0.99 0.10 0.68 0.61 0.52 -0.10

SM 0.96 0.19 0.93 0.72 0.56 0.17 0.99 0.09 0.63 0.64 0.50 0.08

DI40

NM 0.86 1.98 11.5 0.15 -

20.3 1.97 0.83 2.10 19.75 0.11

-

51.09 2.10

BFM 0.95 0.27 1.33 0.35 -

1.96 0.26 0.91 0.76 5.61 0.26 5.25 0.73

SM 0.92 0.10 0.80 0.66 0.52 0.08 0.88 0.13 0.70 0.81 0.73 0.04

DI60

NM 0.85 2.23 14.34 0.22 -

9.10 2.20 0.84 2.36 27.21 0.17

-

17.64 2.33

BFM 0.87 0.99 5.68 0.22 -

9.30 0.98 0.88 0.93 7.92 0.23 -9.33 0.90

SM 0.77 0.81 4.88 0.09 -84 -0.78 0.95 0.93 9.05 0.15 -33 -0.81

168

5.5.3 Validation Results for Wide Raised-Bed (WRB) Planting

Table 5.10 shows the comparison of the measured and simulated biomass and

root yield and their percentage deviations from the observed values for WRB planting

under different deficit irrigation levels and mulching practices. Good agreement

between simulated and measured biomass and root yield was found for all stress levels

applied under SM treatments. The percent deviation observed was ranged between -

0.46 and 2.86 for biomass and between -1.25 and 7.25 for root yield. Under BFM

treatment, the model performed very well for DI20 and DI40 treatments with percent

deviation ranged between -0.44 and 5.38 for biomass, and between 0.73 and 9.56 for

root yield. However deviation was significant (10.87−14.73) for DI60. For NM

treatments, the model performance was good only under DI20 with 4.90 % deviation for

biomass and 5.46 % for root yield. In addition, both for DI40 and DI60 water stresses the

percent deviation of the simulated values from measured were significant (13 to

16.33 %) for biomass and (14.91 to 24.05%) for root yield. Based on RMSE, NRMSE,

dindex, EF and MBE for validated biomass and root yield for WRB planting pattern

under different mulches and irrigation regimes are shown Table 5.11. Consequently, for

DI20 the model simulated both the biomass and root yield with a high degree of

reliability under BFM and SM. The outcome could be analyzed from RMSE (0.09−0.14

tons ha-1

), NRMSE (0.47 to 1.04 %), dindex (0.62−0.76), EF (0.52−0.77), and MBE (-

0.09 to 0.13 tons ha-1

), respectively. However, the simulation values were poor when

DI20 was applied with NM treatment where the statistical values found were: RMSE

(0.72−0.92 tons ha-1

), NRMSE (4.94−5.71 %), dindex (0.10−0.13), NSE (-69.32 to -

30.63), and MBE (0.70−0.93 tons ha-1

), respectively. For DI40, the model overestimated

both the biomass and root yield irrespective of the mulching conditions. However, the

overestimation was high in NM treatment compared to BFM and SM treatments.

Consequently, different statistical values found were: RMSE (0.52−2.25 tons ha-1

),

NRMSE (2.94−14.97 %), dindex (0.11−0.16), EF (-59.49 to -22.22), and MBE

(0.51−2.21 tons ha-1

) for both biomass and root yield, respectively (Table 5.11). For

DI60, the model highly overestimated both the biomass and root yield for NM and BFM

treatments, with RMSE ranged between 0.54 and 2.10 tons ha-1

, NRMSE from 10.91 to

24.10 %, dindex between 0.04 and 0.08, EF from -135.60 and 6.93, MBE between 1.51

and 2.38 tons ha-1

, respectively. In contrary, the model estimation was in good

agreement under SM with RMSE in the range of 0.10−0.30 tons ha-1

, NRMSE between

169

1.35% and 0.66%, dindex from 0.67 to 0.77, EF between 0.53 and 0.78, and MBE

between -0.12 and -0.06 tons ha-1

, respectively (Table 5.11).

Table 5.10. Observed and simulated results of validated biomass (tons ha-1

) and root

yield (tons ha-1

) of sugar beet under Wide Raised-Bed planting

Mulch Type

Irrigation

Regime




Deviation

(%)

No Mulch

DI20 18.77 19.69 4.90 12.64 13.33 5.46

DI40 16.92 19.12 13.00 11.07 12.72 14.91

DI60 14.57 16.95 16.33 8.69 10.78 24.05

Black

polyehylene

film mulch

DI20 19.58 19.49 -0.44 13.22 13.32 0.73

DI40 18.22 19.20 5.38 11.93 13.07 9.56

DI60 15.98 17.72 10.87 10.25 11.76 14.73

Straw Mulch

DI20 19.62 19.75 0.66 13.14 13.26 0.91

DI40 17.84 18.35 2.86 11.19 12.00 7.24

DI60 15.30 15.23 -0.46 9.59 9.47 -1.25

Table 5.11. Statistical results of the validated fields under Wide Raised-bed planting

for different irrigation regimes and mulching types.

Irrigation

Regimes

Mulch

Type


R2

RMSE

(Tons

ha-1)

NRMSE

(%) dindex EF

MBE

(Tons

ha-1)

R2

RMSE

(Tons

ha-1)

NRMSE

(%) dindex EF

MBE

(Tons

ha-1)

DI20

NM 0.92 0.93 4.94 0.13 -30.63 0.93 0.97 0.72 5.71 0.10 -69.32 0.70

BFM 0.99 0.09 0.47 0.76 0.77 -0.09 0.93 0.12 0.93 0.62 0.56 0.10

SM 0.99 0.13 0.67 0.64 0.52 0.13 0.94 0.14 1.04 0.69 0.57 0.12

DI40

NM 0.63 2.25 13.31 0.11 -51.11 2.21 0.51 1.66 14.97 0.11 -59.49 1.65

BFM 0.87 0.99 5.41 0.13 -34.70 0.98 0.74 1.14 9.54 0.11 -48.16 1.14

SM 0.96 0.52 2.94 0.16 -22.22 0.51 0.74 0.81 7.26 0.15 -23.71 0.81

DI60

NM 0.54 2.40 16.49 0.07 -

135.60 2.38 0.50 2.10 24.10 0.08

-

113.20 2.09

BFM 0.79 1.74 10.91 0.08 -

105.77 1.74 0.62 1.51 14.71 0.04 6.93 1.51

SM 0.95 0.13 1.35 0.67 0.53 -0.12 0.87 0.10 0.66 0.77 0.78 -0.06

170

CHAPTER VI

SUMMARY, CONCLUSION AND RECOMMENDATIONS

6.2 SUMMARY

Management of available water resources in arid and semi-arid regions of the

world under increasing levels of water stress is a major challenge to water managers.

Very limited fresh water will be available for agricultural use in the near future, mainly

due to the rising living standard and ballooning population coupled with increased

competition from industrial and domestic sectors. Adequate and sustainable agricultural

water management in these areas is crucial at all levels. Managing water resources at

macro-level is relatively expensive and time taking, even though it is unavoidable.

Conversely, the field level water management is relatively of low cost, more practicable

and easily workable that can be managed in short period. In Pakistan, sugar beet is an

important sugar crop after sugar cane and is sown in October to November and is

harvested in late May. The North-West part of the country offer one of the best lands

for sugar beet in the whole sub-continent. Sugar beet is an important source of raw

material to sugar mills during the period when sugar cane is not available and the mills

generally run under utilization. Furthermore, it is also used as a vegetable ad its pulps

animal fodder in the area. However, in comparison to other sugar beet producing

countries, its yield is very low in Pakistan. One of the main causes of low yield is its

competition for limited available irrigation water irrigation water in the country with

other crops of the area. Thus, it will be very difficult to utilize the full irrigation

potential for sugar beet for obtaining maximum yield in irrigated agriculture of Pakistan.

Due to this, efforts are made to explore the effect of inputs for increasing yield rather

than increasing acreage and thus play a crucial role for efficient management and

effective utilization of the available fresh water resources in water scarce areas.

In this context, two years experimental study was conducted at the Sugar Crop

Research Institute, Mardan, Pakistan, during 2011/2012 and 2012/2013 cropping

seasons. The influence of four irrigation regimes, three mulching practices and three

furrows irrigated raised bed planting methods on sugar beet yield components and

water use efficiency was evaluated at sugar crop research institute, Mardan, Pakistan,

during 2011/2012 and 2012/2013 cropping seasons. Irrigation regimes tested were; Full

irrigation (FI) i.e. no-deficit, 20 % deficit irrigation (DI20), 40 % deficit irrigation (DI40)

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and 60 % deficit irrigation (DI60). The mulch treatments evaluated were no-mulch

(NM), black polyethylene film mulch (BFM) and Straw Mulch (SM). The planting

methods tested were Conventional Ridge-Furrow (CRF) planting with one crop row on

the ridge, Medium Raised-Bed (MRB) planting with two crop rows on the raised bed

and Wide Raised-Bed (WRB) planting with three crop rows on the raised bed.Sugar

beet Varity Kaweterma was sown on November 15, 2011 and November 20, 2012. In

plots with black polyethylene film mulch, ridges and raised-bed were formed first and

then covered by the black polyethylene sheet. Hand seeding of sugar beet seeds was

done in already prepared holes in the black polyethylene sheet at 18 cm spacing. In

plots with Straw Mulch (SM), seeding was done after the ridges and raised-beds were

formed. The straw for mulch purposes (sugar cane trashes) was then manually spread

over the ridges and beds after the seed germination. All recommended agronomic

practices were applied throughout the cropping season. All the necessary soil physical

and chemical properties and crop data were determined accordingly in the field and in

the laboratory. Amount of seasonal water used by the crops in each plot was

determined by Heerman model. Relationship between sugar beet root & sugar yields

and water used was assessed using regression analysis. By help of a computer software

Statistics 8.1 all the mentioned data in this study were subjected to an analysis of

variance followed by a pair wise multiple comparison of treatment means by the least

significant difference (LSD) test at 5% probability level. For simulating the AquaCrop

model, the required input data was collected, recorded and measured in the field.

Model was calibrated for measured data sets of nine full irrigation treatments in the

experimental season of 2011/2012 and validated for twenty seven deficit irrigation

treatments of the same season. Different statistical parameters such as, Root mean

square error (RMSE), normalized root mean square error (NRMSE), index of

agreement (dindex), Nash–Sutcliffe Efficiency factor (EF) and the mean bias error

(MBE) were used to assess the AquaCrop model accuracy and applicability under semi-

arid condition of Pakistan. Different irrigation regimes, mulching systems and raised

bed furrow irrigated planting parterres had a considerable effect on sugar beet yield

components and water use efficiency.

172

Sole effects of irrigation

Comparison of mean data in irrigation management for the study years

2011/2012 and 2012/2013 showed that, the highest root and sugar yield were obtained

in full irrigation treatment (FI) and the lowest in the treatment that was given 60%

deficit irrigation (DI60). However, sugar content was increased with the increase level

of irrigation deficit with the lowest value in FI treatment and the highest in DI60

treatment. Averaging the effect of two years, it was observed that 20, 40 and 60 %

deficit irrigation (DI20, DI40 and DI60) produced 6.98, 20.06 and 35.02 % less root yield

and 1.48, 10.55 and 24.30 % less sugar yield and 6%, 13 and 17 % higher sugar content,

respectively, when compared with Full irrigation (FI) treatment. All the irrigation water

applied (IWA), seasonal water used (SWU), Root Irrigation Water Use Efficiency

(RIWUE), Sugar Irrigation Water Use Efficiency (SIWUE), Root Crop Water Use

Efficiency (RCWUE) and Sugar Crop Water Use Efficiency (SCWUE), were highest

for FI treatment and lowest for DI60.

Sole effects of mulching

Mulching practices comprising of No Mulch, black polyethylene film and straw

mulch significantly affected all of the yield components, water used and water use

efficiency. The highest root yield, sugar yield, sugar content, irrigation water use

efficiency and crop water use efficiency, and the lowest irrigation water applied and

seasonal water used, were observed in black polyethylene film mulch treatment,

followed by straw mulch, and least for no-mulch treatment. Averaging the effect of

two years it was observed that both black polyethylene film mulch and straw mulch

treatments produced 21.54 and 14.66 % higher root yield, 26 and 18 % higher sugar

yield, and 4.30 and 3.34 % higher sugar content, 50.28 and 24.35 % higher RIWUE,

56.80 and 28.40 % higher SIWUE, 39.14 and 19.50 % higher RCWUE, 48.72 and

25.64 % higher SCWUE, respectively, when compared with No-Mulch treatment

Sole effect of planting methods

In both years, the Medium Raised-Bed (MRB) having two crop rows on the 45

cm bed gave the highest root yield, sugar yield, RIWUE, SIWUE, RCWUE and

SCWUE. This was followed by wide-raised bed (WRB) with three crop rows on the 90

cm bed. All these values observed were lowest for conventional ridge-furrow planting

(CRF) with single crop row on the ridge. However, the highest sugar content was

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observed for WRB. This was followed by MRB and CRF, respectively. Irrigation water

applied and seasonal water used were the highest for CRF treatment, followed by WRB

and MRB planting methods. Averaging the effect of two years it was observed that,

both MRB and WRB planting methods produced 13.59 and 3.85 % higher root yield,

15.62 and 10.61 % higher sugar yield, 4.59 and 8.26 % higher sugar content, 21.25 and

5.70 % higher RIWUE, 26.70 and 14.66 % higher SIWUE, 19.71 and 5.62 % higher

RCWUE, and 25.58 and 13.95 % higher SCWUE, respectively, compared to

conventional-ridge planting pattern

Interaction Effect of Irrigation Regimes and Mulches

Mulch and irrigation combination produced significant (at p < 0.05) effect on all

the sugar beet yield components, irrigation water applied (IWA), seasonal water used

(SWU), RIWUE, SIWUE, RCWUE and SCWUE. The highest root yields were

obtained via the interaction effect of full irrigation and black polyethylene film mulch

(FIBFM), followed by straw mulch and full irrigation combination (FISM), and the

lowest for 60 % deficit irrigation and No-Mulch (DI60NM) combination. Root yield

observed for BFMDI20, BFMDI40 and BFMDI60 treatments were significantly

higher when compared with NMFI & SMDI20, NMDI20 & SMDI40, and NMDI40

& SMDI60, respectively. Sugar content (%) was highest for black polyethylene film

mulch (DI60BFM) treatment. This was followed by DI60SM and DI60NM treatments.

20 % deficit irrigation application in the presence of black film (DI20BFM) produced

the highest sugar yield than all other treatments. This was followed by DI20SM. Also,

sugar yield produced by DI40BFM and DI60BFM interactions were significantly

higher when compared with FINM and DI20NM treatments, respectively. The two

years average data also revealed that, in the absence of any mulch, decreasing the

irrigation level by 20, 40 and 60 % caused reduction in sugar yield by 7.49, 23.41 and

57.60 %, respectively, in comparison to FINM treatment. However, when the crop

was grown under black polyethylene film mulch, sugar yield was increased by 10.12,

11.56 and 7.44 %, and decreased by 5.90 % for each of FI, DI20, DI40 and DI60

treatments, respectively, when compared with FINM treatment. Growing sugar beet

under straw mulch caused increase in sugar yield by 7.62% and 8.17 %, and decrease

by 3.09 and 18.70 %, for each of FI, DI20, DI40 and DI60 irrigation levels, respectively,

in comparison to FINM treatment. The highest mean depth applied to FINM

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treatment and the lowest received by DI60BFM. The amount of irrigation water saved

by the interaction effect of irrigation regimes and straw mulch was ranged between 5.83

and 62.33 %, and that saved by the interaction effect of irrigation regimes and black

polyethylene film mulch was ranged between 16.32 and 66.53 %, when compared with

full irrigation-No Mulch treatment. A significant difference (p < 0.05) in the means of

SWU was found between the interaction of irrigation regimes and mulch types. These

results imply that seasonal water use (SWU) was largely influenced by both the amount

of irrigation applied (irrigation regimes) and mulching. Averaging the effect of two

years seasonal water used data and comparing the results with FINM treatment it was

observed that seasonal water used was decreased from 2 to 47 % by different

combinations of irrigation regimes and type of mulch. The highest mean RIWUE,

SIWUE, RCWUE and SCWUE were recorded from DI60 BFM. This was followed by

DI60 SM. The lowest observed was for FINM treatment.

Interaction Effect of Irrigation Regimes and Furrow Irrigated raised bed planting

methods on Sugar Beet Yield Components and Water Use Efficiency

In both study years, the highest root yield was obtained when the crop was

grown on Medium Raised-Bed (MRB) with two crop rows and crop received its full

irrigation (FI) requirement. The second highest yield was obtained when crop was

grown on medium raised bed (MRB) and received 20 % deficit irrigation (DI20). The

least root yield was observed for conventional ridge furrow system (CRF) that was

given 60 % deficit irrigation (DI60). For the same level of irrigation, all the MRB

treatments produced significantly higher root yield when compared CRF and WRB

systems. Comparing performance of MRB with CRF and WRB systems, it was

observed that root yield produced by MRB at DI20 was significantly higher than that

produced by CRF or WRB at FI. Comparing the performance of CRF and WRB

systems for the same level of irrigation, it was noted that WRB system produced better

results when crop received full irrigation (FI) or kept under mild to moderate deficit

irrigation (DI20 and DI40). However, at 60 % stress level (DI60), root yield under WRB

system was not significantly higher than the yield produced by CRF system. Results

further reveals that all the planting methods and irrigation regimes interaction

significantly (at p< 0.05) affected sugar yield. In both years, DI20MRB and

DI20WRB produced higher sugar yield (although non-significant) when compared

175

with FIMRB and FIWRB, respectively. Data also revealed that sugar yield produced

by MRB at 40 % stress level (DI40) was not significantly less than that produced by

CRF and WRB systems at full irrigation application. For the same level of irrigation,

sugar yield produced by MRB systems was significantly higher in comparison to CRF

and WRB systems. In CRF system, the highest sugar yield in both years was obtained

in FICRF treatment. This was followed by DI20CRF and DI20CRF treatments. The

least sugar yield was produced by DI60CRF interaction.

Interaction effect of Mulch and planting methods on yield and water use efficiency

In both study years, significantly highest root and sugar yields were obtained as

a result of black polyethylene film mulch and medium raised bed interaction

(BFMMRB) and significantly lowest for no-mulch and conventional ridge furrow

interaction (NMCRF). For the same mulch, root and sugar yield produced by MRB

system was significantly higher in comparison to CRF and WRB systems. Under black

polyethylene film mulch and straw mulch, root yield produced by CRF system was not

significantly different from that produced by WRB system. It was also observed that,

CRFBFM and CRFSM produced 20.86 and 17.27 % high root yield, respectively,

when compared with CRFNM treatment. The corresponding increase in the root yield

was 16.09, 30.43 and 23.95 % for MRBNM, MRBBFM and MRBSM treatments,

and 7.97, 22.10 and 19.06 %, for WRBNM, WRBBFM and WRBSM treatments,

when compared with CRFNM treatment, respectively. The interaction effect of

mulching and planting methods investigated significantly (<0.05) affected the root and

sugar water use efficiency (RWUE & SWUE) of sugar beet. For the same type of

mulch the highest RWUE & SWUE in both seasons‘ were observed for MRB system

having two plant rows on the bed. This was followed by WRB with three plant rows on

the bed. Averaging the effect of two years and comparing the results of different

treatments, the highest mean RWUE and highest SWUE was observed for MRBBFM

treatment. This was followed by WRBBFM.

Interaction effect of Irrigation Regimes, Mulching and furrow irrigated raised bed

planting methods on Sugar beet yield components and water use efficiency

Results regarding the combine effect of irrigation regimes, mulching and planting

methods on sugar beet root yield, sugar content (%) and sugar yield for 2011/2012 and

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2012/2013 cropping seasons revealed that, in both years, the highest root yield (75.32,

73.81 tons ha-1

) was observed for FIBFMMRB treatments. However, yield produced

by DI20BFMMRB was not significantly lower from that of FIBFMMRB

interaction. The lowest yield was observed for DI60NMCRF treatment. Results also

revealed that, in both years, significantly highest sugar content was observed for

DI60BFMWRB and DI60SMWRB treatments and significantly lowest for

FINMCRF system. Data of the current study further revealed that sugar yield was

significantly affected by all the three combinations of irrigation regimes, mulching and

planting methods. In both study years, significantly highest sugar yield was produced

by the interaction effect of DI20BFMMRB. This was followed by FIBFMMRB

combination. However, sugar yield produced by DI20SMMRB and DI20SMWRB

were not significantly low from FIBFMMRB combination.

Interaction effect of irrigation regimes, mulching and planting methods on root

and sugar irrigation water use efficiency (RIWUE and SIWUE)

Both the root and sugar irrigation water use efficiency was significantly affected by

irrigation regimes, mulching and planting methods interaction. In both years, for the

same mulching condition and planting methods, both the root water use efficiency

(RIWUE) and sugar water use efficiency (SIWUE) were increased as the application of

irrigation level was decreased from FI to DI60. Also, for the same level of irrigation and

planting pattern, RIWUE and SIWUE were increased under the mulching order of

BFM, SM and NM. Furthermore for the same level of irrigation and mulching, RIWUE

and SIWUE were increased under the planting methods order of MRB, WRB and CRF.

The highest average increase over FI NM CRF treatment was observed for DI60

BFM MRB interaction with 189.91 % higher RIWUE and 258.70 % higher SIWUE.

The second highest increase was observed for DI60 BFM WRB with 150.55 %

higher RIWUE and 225.65 % higher IWUE, and the third for DI60 BFM CRF

treatment with 149.32 % higher RIWUE and 192.61 % higher SIWUE, respectively.

For the same level of irrigation and mulching condition the highest root and irrigation

water use efficiency were recorded for MRB. This was fallowed by WRB. The CRF

caused the lowest increase. For the same level of irrigation and planting pattern, the

highest increase was observed fir BFM treatments. This was followed by SM. The No

Mulch treatments caused the lowest increase.

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Interaction effect of irrigation regimes, mulching and planting methods on root

and sugar crop water use efficiency (RCWUE and SCWUE)

Results for conventional ridge furrow systems

By analyzing the interaction effects of irrigation regimes (FI, DI20, DI40, and DI60)

No Mulch (NM) Conventional Ridge-Furrow system (CRF), the difference observed

in mean RCWUE and mean SCWUE was non significant (at p < 0.05) among all four

treatments (FI NM CRF, DI20 NM CRF, DI40 NM CRF and DI60 NM

CRF). The results for CRF system under different irrigation levels and mulching

system reveal that, in the absent of any kind of mulch, decrease in irrigation level have

no significant influence on sugar beet root and sugar crop water use efficiency.

Results for medium raised bed (MRB) plantin

Analyzing the interaction results of irrigation regimes (FI, DI20, DI40, and DI60)

No Mulch Medium Raised-Bed planting for year 2011/2012, significant difference

in RCWUE was found between FI and 20 % deficit irrigation (DI20). However,

RCWUE at DI20 was not significantly different than that obtained at DI40 and DI60.

From the analysis of the interaction results of irrigation regimes (FI, DI20, DI40, and

DI60) black polyethylene film mulch and medium raised-bed planting pattern, it

was observed that in both study years both the values of RCWUE and SCWUE for all

the four levels of applied irrigation were significantly (at p < 0.05) different from each

other. Almost similar trend was also observed for straw mulch treatment.

Results for wide raised bed (WRB) irrigation/planting pattern

Analyzing the results for NM WRB system, it was observed that both the RCWUE

and SCWUE were increased when the level of irrigation application decreased,

however, the values for all the three deficit irrigation levels were significantly not

different from each other. Analyzing the interaction effects of irrigation regimes (FI,

DI20, DI40, and DI60) black polyethylene film mulch wide raised-bed planting, it

was observed that all the values of RCWUE and all the values of SCWUE in study year

2011/2012 were significantly (at p < 0.05) different among each other for all the four

levels of applied irrigation. Analyzing the interaction effects of irrigation regimes (FI,

DI20, DI40, and DI60) straw mulch wide raised-bed planting pattern for 2011/2012

and 2012/2013 cropping seasons, it was noted that means of both RCWUE and

178

SCWUE in both study years were increased when the level of irrigation application was

decreased.

AquaCrop model Calibration and validation

AquaCrop model was used to predict the sugar beet CC under different in-field water

management strategies. It was observed that the results of all the nine calibrated fields

for CC were better and closer to observed data. On the basis of different statistical

indicators results, it was observed that the AquaCrop model was in an excellent

agreement between the observed and simulated values of CC for all the calibrated fields

irrespective of the mulching condition and planting pattern. AquaCrop model was

validated for the CC by using the data of three deficit irrigation regimes i.e. (DI20, DI40

and DI60, that were applied under three different mulches and three planting methods in

2011/2012 cropping season. The RMSE, NRMSE, dindex, EF, and MBE values between

the simulated and observed data under DI20 were not significantly different than the

calibration results. However, a significant difference was observed with the increased

stress levels (DI40 and DI60), especially in un-mulched fields.

Results revealed that the model accurately simulated both the biomass and root

yield for all the calibrated fields. The low values of RMSE and NRMSE, and higher

values of dindex and EF show that the measured and simulated values were statistically

in good agreement for calibrated data set. Validation results for conventional ridge

furrow planting (CRF) indicated good agreement between the simulated biomass and

root yield with their observed values. It was evident that except the CRFBFMDI60

treatment, no significant deviation was observed between simulated and measured

values. In medium raised bed planting, no significant deviations of the simulated

biomass and root yield from the measured values were found for MRBNMDI20.

However, the deviation observed was significant for increased stress level. For BFM

and SM treatments, the deviation of the predicted biomass and root yield from the

measured were non-significant for all stress levels. In wide raised bed planting, good

agreement between simulated and measured biomass and root yield was found for all

stress levels applied under SM treatments. Under BFM treatment, the model performed

very well for DI20 and DI40 treatments. For NM treatments, the model performance was

good only under DI20. For DI60, the model highly overestimated both the biomass and

root yield for NM and BFM treatment.

179

Relationship between seasonal evapotranspiration and yield components of sugar

beet

For mulching condition, the relationships between sugar beet root yield and

seasonal evapotranspiration (ET) was best described by quadratic function and for un-

mulched condition, a linear correlation was found between the root yield and seasonal

ET. This trend might be due to more evaporation from No-Mulch plots as compared to

mulch plots that caused a decrease in soil moisture in crop root zone and thus makes

available less water for transpiration. The relationship between sugar yield and

evapotranspiration (ET) obtained was curvilinear both for mulched and un-mulched

conditions and were described by quadratic function.

Crop Yield response Factor (ky)

The highest ky value (1.02) was obtained when severe deficit irrigation (DI60) was

applied under no-mulch (NM) in conventional ridge-furrow planting pattern (CRF) and

the lowest (0.20) observed when mild deficit irrigation (DI20) was applied under black

polyethylene film mulch (BFM) in medium raised bed planting pattern (MRB). Results

of this study indicated that Ky value was increased when the seasonal water used was

decreased, irrespective of the mulching conditions and water application system. The

seasonal (Ky)root values obtained were 0.99, 0.93 and 0.93 for NM-CRF, NM-MRB and

NM-WRB combinations, 0.53, 0.53, and 0.61 for BFM-CRF, BFM-MRB and BFM-

WRB combinations and 0.65, 0.68 and 0.71 for SM-CRF, SM-MRB and SM-WRB

combinations, respectively. The seasonal (Ky)sugar values obtained were 0.69, 0.81 and

0.81 for NM-CRF, NM-MRB and NM-WRB combinations, 0.29, 0.31, and 0.50 for

BFM-CRF, BFM-MRB and BFM-WRB combinations and 0.47, 0.43 and 0.45 for SM-

CRF, SM-MRB and SM-WRB combinations, respectively.

6.2. CONCLUSIONS

Base on the two years field data, the sugar beet yields and water use efficiency

were significantly affected by different irrigation application levels, mulching and

furrow irrigated raised bed planting methods. In contrast to full irrigation, deficit

irrigation regimes of 20, 40 and 60 % (DI20, DI40 and DI60) significantly reduced the

root yields that amounts 6.97, 20.03 and 35 % respectively. Sugar yield was also

negatively affected by the application of deficit irrigation. However, sugar yield

recorded at mild stress (DI20) was not significantly affected as compared to full

180

irrigation (FI) application. Data further revealed that both the Root Irrigation Water Use

Efficiency (RIWUE) and Sugar Irrigation Water Use Efficiency (SIWUE) were

increased with the decrease in irrigation application levels. The highest mean RIWUE

and SIWUE of 17.85 and 3.00 kg m-3

were obtained for DI60 and the lowest of 10.19

and 1.52 kg m-3

for FI treatment. Root Crop Water Use Efficiency (RCWUE) and

Sugar Crop Water Use Efficiency (SCWUE) were also the lowest (8.49 and 1.19 kg m-

3) for FI and the highest (10.49 and 1.82 kg m

-3) for DI60.

Different mulch treatments significant affected sugar beet yield and its

components and the highest mean root yield (61.67 tons ha-1

) and the highest mean

sugar yield (9.96 tons ha-1

) were produced when sugar beets were planted on raised bed

under Black Film Mulch (BFM), followed by Straw Mulch (SM) with 58.18 tons ha-1

root yield and 9.29 tons ha-1

sugar yield. As compared to the No-Mulch treatment, the

BFM produced 21.64, 3.54 and 26.54 % higher root yield, sugar content and sugar

yield, respectively. BFM treated plots resulted the highest RIWUE of 16.11 kg m-3

and

the highest SIWUE of 2.65 kg m-3

, followed by SM of 13.33 kg m-3

RIWUE and 2.17

kg m-3

SIWUE, respectively. The CRWUE and SCWUE were also the highest for BFM

as compared to SM and NM plots.

Comparing planting methods, significantly higher root yield of 61.04 tons ha-1

was produced by MRB. The highest sugar yield of 9.73 tons ha-1

, RIWUE (14.89 kg m-

3), RCWUE (2.42 kg m

-3), SIWUE (10.02 kg m

-3) and SCWUE (1.62 kg m

-3) were also

recorded in MRB planting. Comparing MRB with CRF, MRB planting method

produced higher root yield (13.59%), sugar yield (15.62%), RCWUE (19.71%),

SCWUE (25.58%), RIWUE (21.25%) and SCWUE (26.70%) accordingly.

The interaction among irrigation regimes and mulching significantly affected all

the yield and water use efficiency components. Significantly higher mean root yield of

69.56 tons ha-1

was recorded for FIBFM treatment. The 20 % deficit irrigation (DI20)

with BFM application produced the highest sugar yield of 10.55 tons ha-1

which was

13.08 % higher than FINM treatment. Both RIWUE and SIWUE increased with

increase in deficit irrigation levels from DI20 to DI60 with all mulch treatments (NM,

SM and BFM). For same level of deficit irrigation in combination with NM, SM and

BFM, the RIWUE and SIWUE were highest for BFM. Similar trend was also observed

for RCWUE and SCWUE. From the two years average data, the highest RIWUE (21.41

kg m-3

), SIWUE (3.74 kg m-3

), RCWUE (11.86 kg m-3

) and SCWUE (2.07 kg m

-3)

181

were noted for DI60BFM treatment, respectively. These values were 134, 181, 62.47

and 95.28 % higher, respectively, compared to that resulted by for FINM treatment.

Results further revealed that all the yield and water use efficiency components

were significantly affected by the interactive effects of irrigation regimes and different

planting methods. From the average of two years data, it was found that the FIMRB

planting produced the highest mean root yield (71.73 tons ha-1

) among all irrigation

regimes and planting methods combinations. However, highest sugar yield (10.63 tons

ha-1

) was obtained under DI20MRB treatment. When DI20MRB results were

compared with FICRF treatment, it was found that the previous produced 6.60 and

15.42 % higher root and sugar yield, respectively. Similarly, the RIWUE, SIWUE,

RCWUE and SCWUE obtained for DI20MRB were 43.02, 54.35, 35.89 and 44.95 %

higher, respectively, as compared with FICRF

The interactions of irrigation regimes, mulching and planting methods

significantly affected sugar beet yield and water use efficiency components. The

interaction of FIBFMMRB produced significantly higher root yield (74.57 tons ha-1

)

among all the interactions. However, significantly higher sugar yield was obtained from

DI20BFMMRB. Even DI40BFMMRB produced the same sugar yield as that was

obtained from FIBFMMRB.

Comparing the results of DI40BFMMRB with conventional practices

(FINMCRF), it was observed that the root yield, sugar yield, RIWUE, SIWUE,

RCWUE and SCWUE obtained from the former were 10.32, 32.07, 135.55, 180.87,

91.28 and 127.96 % higher from the later.

Results also revealed that, in the presence of mulches, the relationships between

sugar beet root yield and seasonal evapotranspiration (ET) was best described by

quadratic function. However, for un-mulched conditions, a linear correlation was found

between the root yield and seasonal ET. The relationship between sugar yield and

evapotranspiration (ET) obtained was curvilinear both for mulched and un-mulched

conditions and were better described by quadratic function. The yield response factors

(Ky)root obtained were 0.99, 0.93 and 0.93 for NM-CRF, NM-MRB and NM-WRB

combinations, 0.53, 0.53, and 0.61 for BFM-CRF, BFM-MRB and BFM-WRB

combinations and 0.65, 0.68 and 0.71 for SM-CRF, SM-MRB and SM-WRB

combinations, respectively. The yield response factors (Ky)sugar obtained were 0.69,

182

0.81 and 0.81 for NM-CRF, NM-MRB and NM-WRB combinations, 0.29, 0.31, and

0.50 for BFM-CRF, BFM-MRB and BFM-WRB combinations and 0.47, 0.43 and 0.45

for SM-CRF, SM-MRB and SM-WRB combinations

AquaCrop model reasonably predicted canopy cover (CC), root yield and

biomass under full irrigation, planting methods and mulching. Validation results for

conventional ridge furrow planting (CRF) indicated good agreement between the

simulated biomass and root yield with their observed values. In medium raised bed

planting, no significant deviations of the simulated biomass and root yield from the

measured values were found for MRBNMDI20. However, the deviation observed in

biomass and root was significant for increased levels of deficit irrigation. In wide raised

bed planting, good agreement between simulated and measured biomass and root yield

was found for all deficit irrigation levels applied under SM treatments. Under BFM

treatment, the model performed very well for DI20 and DI40 treatments. For NM

treatments, the model performance was good only under DI20. For DI60, the model

highly overestimated both the biomass and root yield for NM and BFM treatment.

6.3 RECOMMENDATIONS

For obtaining higher sugar yield and better water use efficiency, it is strongly

recommended that the sugar beet growers should raised their crop on medium raised-

bed covered with black film mulch and should apply 20 % deficit irrigation instead of

full irrigation. This practice, beside the reducing the cost of production of both the

farmers and the mill owners, will also helpful in mitigating the water logging and soil

salinity which are some of the main hurdles in promoting agriculture activities in most

of canal irrigated areas of Pakistan. Furthermore, it will also be a valuable strategy in

reducing the fertilizers and other chemical leaching to the ground water and thus will

minimize the risk of ground water pollution, which is also one of the key environmental

issues in the country like Pakistan. In the tube-will irrigated area, it will not only be

helpful to minimize the risk of groundwater mining and thus avoiding environmental

catastrophic, but will also reduce the power consumption. Also, the saved water can be

used for bringing new areas under irrigation.

If farmers of the study area adopt on medium raised-bed planting system, they

can produce 11.24 % more root yield when optimum irrigation water is available as

generally the situation in the head reaches of the canal and water courses in Pakistan.

183

The farmers that are getting up to 80 % of their allotted quota as generally the case at

middle reaches of the canals, they root yield will be decrease by about 10 % using the

conventional ridge-furrow planting. However, by adopting the medium raised-bed

system, their yield will still be about 6.20 % higher than the farmers of the head reach

using conventional ridge-furrow planting system. Farmers that are suffering from

severe water shortage as the case in tail reaches of the canals in Pakistan due to huge

conveyance losses (Ahmad and Ahmad, 1999), they can loss about 24 to 53 % root

yield in conventional ridge-furrow planting system by applying 40 to 60 % deficit

irrigation. However, if they adopt the medium raised-bed system, their probable loss

will be only 10 % for 40 % deficit irrigation and 35.7 % for 60 % deficit irrigation,

respectively

The yield response factor value (ky) updated in this study (from that of original

data that was published by Doorenbos and Kassam (1979) by using different

management practices, should be used in any soil water balance model. For developing

irrigation strategies and determine suitable areas for sugar beet production in semi-arid

areas, such models with the incorporated Ky values can then be used as a decision

support system.

In current study the effect of irrigation regimes, mulching practices and raised-

bed irrigation systems on the improvement of socio-economic status of the farming

communities have not been addressed. Follow-up studies with respect to this aspect are

recommended.

Studies dealing with the effect of various agronomic practices on Sugar beet

yield components and water use efficiency such as sowing date, row spacing and

fertilizer application along with the quality of irrigation water have not yet been

considered. Such studies may result in a further improvement of the yield of sugar beet

in semi-arid environment of Pakistan.

In this study, AquaCrop model was calibrated and validated for sugar beet

Variety Kaveterma under different irrigation and land management practices for the

semi-arid climatic conditions of Pakistan. The parameterized variables should be

further tested under different irrigation methods, sugar beet verities, soil texture and

agro climate conditions coupled with economic and environmental analysis for support of

appropriate decisions. The model should also be tested for different planting dates for

optimization of sugar beet yield and water use efficiency under semi-arid environment.

184

REFRENCES

Adamavičienė A., K. Romaneckas, E. Šarauskis and V. Pilipavičius, (2009).

Nonchemical weed control in sugar beet crop under an intensive and conservation soil

tillage pattern: II. Crop productivity. Agronomy Research 7(Special issue I), 143–148.

Akbar G., G. Hamilton, Z. Hussain, M. Yasin, (2007). Problems and potentials of

permanent raised bed cropping systems in Pakistan. Pakistan Journal of Water

Resources, 11(1):11-21.

Abayomi Y. A., and D. Wright, (2002). Sugar beet leaf growth and yield response to

soil water deficit. African CROP SCIENCE YOURNAL. 10 (1): 51 – 66.

Adnan Y., Z. Muhammad, B. Mukhtar, R. Atif, T. Usman, A. Muhammad, N.

Muhammad, and A. Muhammad, (2012). Effect of different types of mulching on

growth and flowering of Freesia alba CV. Aurora. Pak. J. Agri. Sci., Vol. 49(4), 429-

433.

Afshar A., G. R., Afsharmanesh, M. Adeli, and A. Malekian, (2014). Assessment of

AquaCrop Model in the Simulation of Potato Yield and Water Use Efficiency under

Different Water Regimes. J. BIOL. ENVIRON. SCI., 2014, 8(23): 79-86.

Ahmad I., H. Zahoor, R. Shuaib, N. M. Noor. and A. N., Summar, (2011). Response of

vegetative and reproductive components of Chili to inorganic and organic mulches. Pak.

J. Agri. Sci., Vol. 48(1), 19-24.

Ahmad M., and S. Ahmad, (1999). Water management in arid zones of Pakistan: issues

and options.

Ahmad R. N. N. and Mahmood, (2005). Impact of raised bed technology on water

productivity and lodging of wheat. Pakistan Journal of Water Resources. 9(2).

Ahmad Z., P. Shah, Kakar K. M., H. El-Sharkawi., P/ B. S., Gama, E. A., Khan, T.

Honna, and S. Yamamoto, (2010). Sugar beet (Beta vulgaris L.) response to different

planting methods and row geometries II: Effect on plant growth and quality. Journal of

Food, Agriculture & Environment Vol.8 (2): 7 8 5 - 7 9 1.

Akbar G., G. Hamilton and S. Raine, (2010). Permanent raised bed configurations and

renovation methods affect crop performance. 19th World Congress of soil science, soil

solutions for a changing world 1 – 6 August 2010, Brisbane, Australia. pp: 171-174.

Al Jbawi, E.M. and H. I. Al Zubi, 2016. Effect of Sowing Dates and Length of Storage on

Storability in Sugar Beets (Beta vulgaris L.) Piles. Scholarly J. Agric. Sci. 6(1), pp. 25-31.

Alenazi M., H. Abdel-Razzak, A. Ibrahim, M. Wahb-Allah and A. Alsadon, (2015).

Response of muskmelon cultivars to plastic mulch and irrigation regimes under

greenhouse conditions. J. Anim. Plant Sci. 25(5): 1398-1410.

185

Ali M. A., M. A. Shah and A. C. Shaukat, (2004). Sowing date and plant spacing effect

on agro-qualitative traits of sugar beet (Beta Vilgaris) in different ecological zones of

Punjab. J. Agric. Res., 42(1).

Alishiri R., F. Paknejad and F. Aghayari, (2014). Simulation of sugarbeet growth under

different water regimes and nitrogen levels by aqua croP. Int. J. Biosci. 4 (4): 1-9.

Alizai M. Y. (1975). The Pattern of Sugar beet Concentration in Peshawar Valley.

Allen R. G, L. S. Pereira, D. Raes, M. Smith, (1998) Crop evapotranspiration-

guidelines for computing crop water requirements. Irrig Drain Paper No. 56. FAO,

Rome, Italy, pp. 300.

Anjum L., N. Ahmad, M. Arshad and R. Ahmad, (2014). Effect of Different Irrigation

and Management Practices on Corn Growth Parameters. Pak. j. life soc. Sci., 12(2):

106‐113.

AquaCrop, CropSyst and WOFOST models in the simulation of sunflower growth

under different water regimes. Am Soc Agron 101(3): 509–521.

Arash K., (2013) The evaluation of water use efficiency in common bean (Phaseolus

vulgaris L.) in irrigation condition and mulch. Sci Agric 2(3): 60−64.

Arshad A. M, W. Ibrahim, (2014) Effect of regulated deficit irrigation on

photosynthesis, photosynthetic active radiation on yield of sorghum cultivar. J Biol

Agric Healthcare 4(2): 107−116.

Artyszak A., D. Gozdowski and K. Kucińska, (2014), The yield and technological

quality of sugar beet roots cultivated in mulches. Plant Soil Enviro. 60 (10): 464–469.

Ashrafuzzaman M., M. A. Halim, M. R. Ismail, S.M. Shahidullah and M. A. Hossain,

(2011). Effect of plastic mulch on growth and yield of chilli (Capsicum annuum L.).

Braz. arch. biol. technol. 54 (2) 321-330.

Asian Development Outlook (2013) Asia's Energy Challenge. Asian Development

Bank. http://www.adb.org/publications/asian-development-outlook-2013-asias-energy-

challenge.

Awan U. K, U. W. Liaqat, M. Choi, A. Ismaeel, (2016) A SWAT modeling approach to

assess the impact of climate change on consumptive water use in Lower Chenab Canal

area of Indus basin. Hydrol Res doi: 10.2166/nh.2016.102.

Baigy M. J., F. G. Sahebi, I Pourkhiz, A. Asgari and F. Ejlali, (2012). Effect of deficit-

irrigation management on components and yield of sugar beet. International journal of

Agronomy and Plant Production. 3 (S), 781-787.

Berihun B., 2011. Effect of mulching and amount of water on the yield of tomato under

drip irrigation. Journal of Horticulture and Forestry Vol. 3(7), pp. 200-206.

http://www.adb.org/publications/asian-development-outlook-2013-asias-energy-challenge

http://www.adb.org/publications/asian-development-outlook-2013-asias-energy-challenge

186

Birstow K. L., (1998). The role of mulch and its architecture in modifying soil

temperature. Australian Journal of Soil Research, 26 (2). http://www.researchgate.

net/publication.

Bitri B., and S. Grazhdani, (2015). Validation of Aqua Crop model in the simulation of

sugar beet production under different water regimes in southeastern Albania. IJESIT. 4

(6): 171 – 181,4 (6).

Boote, K.J., J. W. Jones and N. B. Pickering, (1996). Potential uses and limitations of

crop models. Agron J 88:704-716.

Bozkurt S., B Ödemiş and C Durgaç, (2015). Effects of deficit irrigation treatments on

yield and plant growth of young apricot trees. New Zealand Journal of Crop and

Horticultural Science. 43 (2).

Budagovsky, A.I. The evaporation of soil moisture / A.I. Budagovsky // "The science".

–M. 1964. – 244.

Burt C. M., A.J. Strelkoff, K. H. Solomon, R. D. Bilesner, L. A. Hardy, T. A. Howell

and D. E. Eisenhauer, (1997). Irrigation performance measues: efficiency and

uniformity. J. Irrig. Drain. Engg, 123: 423-44.

Chai Q., Y. Gan, C. Zhao, H-Lian Xu, R. M. Waskom, Y. Niu and K. H. M. Siddique,

(2016). Regulated deficit irrigation for crop production under drought stress. A review.

Agron. Sustain. Dev. 36:3.

Chartzoulakis K and M. Bertaki, (2015). The Effects of Irrigation and Drainage on

Rural and Urban Landscapes, Patras, Greece. Sustainable water management in

agriculture under climate change. Agriculture and Agricultural Science Procedia 4: 88 –

98.

Chaudhry M. R., A. A. Malik and M. Sidhu, (2004). Mulching Impact on Moisture

Conservation ─ Soil Properties and Plant Growth. Pakistan Journal of Water Resources,

8(2).

Cabangon R. J., G. Lu and T. P. Tuong, (2002). Modelling irrigated cropping systems,

with special attention to rice-wheat sequences and raised bed planting Proceedings of a

workshop at CSIRO Land and Water, Griffith 25-28 February 2002. Bed experiments

at IRRI and China: A Report.

Cabangon R. J., T.P. Tuong and J.D. Janiya, (2005). Rice grown on raised beds: effect

of water regime and bed confi guration on rice yield, water input and water productivity

Chhangani S., 2000. Effect of mulches (synthetic and non-synthetic) on water

conservation and bulb yield of irrigated onion (Allium cepa L.) cultivated in semi-arid

zone of Borno State, Nigeria. J. of Ecophysiology. 3: 5-9

Chukalla AD, Krol MS, Hoekstra AY (2015) Green and blue water footprint reduction

in irrigated agriculture: effect of irrigation techniques, irrigation strategies and

mulching. Hydrol Earth Syst Sci 19(12): 4877−4891.

http://www.researchgate/

187

Cumbus I. P., and P.H. Nye, (1985). Root zone temperature effects on growth and

phosphate absorption in Rape Brassica napus cv. Emerald, J. Exp. Bot. 36, pp. 219–227.

Dang J., W. Liang, G. Wang, P. Shi, D. Wu, (2016). A preliminary study of the effects

of plastic film-mulched raised beds on soil temperature and crop performance of early-

sown short-season spring maize (Zea mays L.) in the North China Plain. The Crop

Journal.

Dellavalle, N.B. (ed.). 1992. Determination of soil-paste pH and conductivity of

saturation extract.

Diaz-Perez J. C., W. M. Randli, G. Boyhan, R. W. Walcott, G. D. Gidding, D. Bertrand,

Sanders H. F. and R. D. Gitaitis, (2004). Effects of mulch and irrigation system on

sweet onion: I. Bolting, plant growth and bulb yield and quality. J. AMER. SOC.

HORT. SCI. 129(2): 218-224.

Donovan T. M. O, (2002). The Effects of Seed Treatment, Sowing date, Cultivar and

Harvest date on the Yield and Quality of Sugar Beet. M. Sc Thesis. Department of Crop

Science, Horticulture and Forestry, University College Dublin, Belfield, Dublin 4.

Dourado-Neto D., D. A. Teruel, K. Reichardt, D.R. Nielsen, J. A. Frizzone and O.O.S.

Bacchi, (1998). Principles of crop modeling and simulation: I. uses of mathematical

models in agricultural science. Sci. agric., Piracicaba, 55: 46-50.

Dyduch J., A. Najda, (2004). The effect of soil mulching on yielding two cultivars of

celery (Apium graveolens L. var. Dulce Mill./Pers.). Fol. Univ. Agric. Stetin. Agricult.

239(95): 75-80.

Edyta K., A. Zaniewicz-Bajkowska, R. Rosa, J. Franczuk, I. Borysiak-Marciniak and K.

Chromińska, (2010). Effect of black synthetic mulches on the fruit quality and selected

components of nutritive value of melon. Acta Sci. Pol., Hortorum Cultus 9(3): 27-36.

El-Askari, K., M. Melaha, A. Swelam, and A.A. Gharieb. 2003. Effect of different

irrigation water amounts on sugar beet yield and water use efficiency in Eastern Delta.

Paper nr 136. 9th

ICID International Drainage Workshop, Utrecht, the Netherlands. 10-

13 September. International Commission on Irrigation and Drainage (ICID), New Delhi,

India.

Elizabeth Rehm and Farzana Noshab. Asian Development Bank. Asian Development

Outlook 2013. Asia‘s Energy Challenge.

English, M. & S. N. Raja, (1996). Perspectives on deficit irrigation. Agricultural Water

Management 32: 1-14.

Ertas M. R., (1984) Konya ovasi kos¸ullarinda sulama suyu miktarinda yapilan

kisintinins¸eker pancari verimine etkileri (in Turkish with English absract). Konya

188

Bo¨lge Topraksu Aras¸tirma Enstitu¨su¨ Mu¨du¨rlu¨g˘u¨, genel yayin No. 100, Konya, s

34.

Esmaeili M. A., (2011) Evaluation of the effects of water stress and different levels of

nitrogen on sugar beet (Beta Vulgaris). International Journal of Biology 3 (2).

Food and Agricultural Organization of the United Nations (FAO), (2007). Coping with

water scarcity. Challenge of twenty first century. World Water Day, 22 March, 2007.

Farahani HJ, Gabriella I, Theib YO (2009) Parameterization and evaluation of the

AquaCrop model for full and deficit irrigated cotton. Agron J 101: 469–476

Food and Agricultural Organization of the United Nations (FAO) (2017). Pakistan at a Glance.

Gebretsadik T. W., (2016). Rapid population growth and Environmental degradation in

Ethiopia: Challenges and Concerns. J. Ecol. Nat. Environ. 2 (4): 28-24.

Geerts S., D. Raes, M. Garcia, (2010). Using AquaCrop to derive deficit irrigation

schedules. Agric. Water Manag., 98: 213–216.

Geerts, S., and D. Raes. 2009. Deficit irrigation as an on-farm strategy to maximize

crop water productivity in dry areas. Agric. Water Manage. 96:1275–1284.

Geometries II: Effect on plant growth and quality. Journal of Food, Agriculture &

Environment 8 (2): 785 – 791.

Ghamarina H., A. Issa, S. Saloome, N. Samera and K. Erfan, (2012). Evaluation and

comparison of drip and conventional irrigation methods on sugar beets in a semi arid

region. Case study. J. irrig. Drain Eng. 138 (1): 90-97.

Ghane E, M. Feizi, B. Mostafazadeh-Fard and E. Landi, (2009). Water Productivity of

Winter Wheat in Different Irrigation/Planting Methods using Saline Irrigation Water.

Int. J. Agric. Biol. 11 (2): 131:137.

Gharib H. S., and A.S. EL-Henawy, (2011). Response of sugar beet (Beta Vulgaris, L)

to irrigation regime, nitrogen rate and micronutrients application.

Gimenez C, Otto RF, Castilla N (2002). Productivity of leaf and root vegetable crops

under direct cover. Scientia Hort. 94: 1-11. .Pandey AK, Prakash V, Gupta HS (2002).

Government of Pakistan (GOP). 2014-2015. Pakistan Economic Survey. Economic Affairs

Division, Pakistan.

Gulshan M., Rakesh S., Ashwani K. and Singh K. G., (2007). Effect of plastic mulch

on economizing irrigation water and weed control in baby corn sown by different

methods. African Journal of Agricultural Research Vol. 2 (1), pp. 019-026.

Heris A. M, Nazemi AH, Sadraddini AA (2014) Effects of deficit irrigation on the yield,

yield components, water and irrigation water use efficiency of spring canola. Iran J

Biodivers Environ Sci 5(2): 44−53.

189

Hess T. M., (1997). Irrigation water requirements (Version 2.01) {IWR}. Cranfield

University, Silsoe, UK. (Taken from Water saving potential in agriculture: Findings

from the existing studies and application to case studies. Final Report. European

Commission DG ENV 12 January 2012). http://digitalcommons.unl.edu/animalscinbcr/312.

Hulsey J. H., (2013). Effects of different mulching methods on organic yellow zucchini.

The Undergraduate Thesis to the CALS Honors Program and the Title of Summa Cum

Laude production. Agricultural Operations Management Undergraduate University

of Florida Graduating in Fall of 2013.

Husen A., (2015). Comparison of drip and furrow irrigation methods under deficit

irrigation and mulching on growth, yield and water productivity of common beans

(Phaseolus Vulgaris) in central rift vally of Ethiopia. M.Sc. Thesis submitted to the

school of natural resource and environmental engineering, school of graduate studies,

Haramaya University, Haramaya.

Hussain Z., M. A. Khan and M. Irfan, (2010). Water energy and economic analysis of

wheat production under raised bed and conventional irrigation systems: A case study

from a semi-arid area of Pakistan. international journal of agriculture & biology.

ICARDA, (2011). Community-Based Optimization of the Management of Scarce

Water Resources in Agriculture in West Asia and North Africa Water benchmarks

Phase-II. Annual reports and work plans.

Iftikhar A. Zahoor H., Shuaib R. Noor N. M. and Summar A. N., (2011). Response of

vegetative and reproductive components of Chili to inorganic and organic mulches. Pak.

J. Agri. Sci., Vol. 48(1), 19-24.

Igbadun H. E., A.A. Ramalan and E. Oiganji, (2012). Effects of regulated deficit

irrigation and mulch on yield, water use and crop water productivity of onion in

Samaru, Nigeria. Agric. Water Manage. 109, 162–169.

Iqbal M. A, Y. Shen, R. Stricevic, H. Pei, H. Sun and E. Amiri, (2014). Evaluation of

the FAO AquaCrop model for winter wheat on the North China Plain under deficit

irrigation from field experiment to regional yield simulation. Agric. Water Manage, 135

(31): 61–72.

Iqbal M. A. and A, M. Saleem, (2015). Sugar Beet Potential to Beat Sugarcane as a

Sugar Crop in Pakistan. American-Eurasian J. Agric. & Environ. Sci., 15 (1): 36-44.

Iqbal, M. M., M. Shah, S. Mohammad, W. & Nawaz, H. 1999. Field response of potato

subjected to water stress at different growth stages. In: Kirda C, P. Moutonnet, C. Hera,

D.R Nielsen, eds. Crop yield response to deficit irrigation. p. 213-223. Dordrecht, The

Netherlands, Kluwer Academic Publishers.

Jacovides, C.P. and Kontoyiannis H. 1995. Statistical procedures for the evaluation of

evapotranspiration computing models. Agric. Water Manage. 27:365-371.

Jalota, S. K., 1993. Evaporation through soil mulch in relation to mulch characteristics

and evaporability. Aus. J. Soil Res. 31: 131-136.

190

Jenni S., D. Brault, K. A. Stewart, (2004). Degradable mulch as an alternative for weed

control in lettuce produced on organic soils. Acta Hort. 638: 111-118.

Jensen ME (1980) Design and operation of farm irrigation system. Am Soc Agric Eng,

Michigan, USA.

Jiang R., X. Li, M. Zhou, H. J. Li, Y. Zhao, J. Yi, L. L. Cui, M. Li, J. G. Zhang and D.

Qu, (2016). Plastic film mulching on soil water and maize (Zea mays L.) yield in a

ridge cultivation system on Loess Plateau of China. SOIL SCIENCE AND PLANT

NUTRITION. 62 (1): 1–12.

Jones, J.W., G. Hoogenboom, C. H. Porter, K. J. Boote, W. D Batchelor, L. A. Hunt, P.

W. Wilkens, U. Singh, A. J. Gijsman, J. T. Ritchie, (2003). The DSSAT cropping

system model. Eur. J. Agron. 18:235– 65.

Kabir M. A., M. A. Rahim and D. A. N. Majumder, (2016). Productivity of garlic under

different tillage methods and mulches in organic condition. Bangladesh J. Agril. Res.

41(1): 53-66.

Kahlown A. K., M. Ashraf and M. Yasin, (2003). Water management for efficient

management of irrigation water and optimum crop production. Research report.

Pakistan Council of Research in Water Resources. P O BOX 1849, Islamabad.

Kamboj B. R., R.K. Malik, Rajbir Garg, Ashok Yadav, Sher Singh, N. K. Goyal, O. P.

Lathwal, Yash Pal Malik and O. P. Mehla, (2008). Bed Planting – A Novel Technique

to Encourage Multiple Land Use. Technical Bulletin (29). Directorate of Extension

Education, CCS Haryana Agricultural University, Hisar, India. pp. 24.

Karamer E., 2016. U.S Sugar Beet Price Analysis.

Keating, B.A., Carberry, P.S. Hammer, G.L. Probert, M.E. Robertson, M.J. Holzworth,

D. Huth, N.I. Hargreaves, J.N.G., Meinke, H. Hochman, Z., McLean, G., Verburg, K.,

Snow, V., Dimes, J.P., Silburn, M., Wang, E., Brown, S., Bristow, K.L., Asseng, S.,

Chapman, S., McCown, R.L., Freebairn, D.M., Smith, C.J., 2003. An overview of

APSIM; a model designed for farming.

Khambalkar V. P., S. M. Nage, C. M. Rathod, A. V. Gajakos, Shilpa Dahatonde,

(2010). Mechanical sowing of safflower on broad bed furrow. AJAE 1(5):184-187.

Khamraev Sh.R. and Yu.G. Bezborodov, (2016). Rsults of research on the reduction of

physical evaporation of moisture from the cotton fields. UDС 633.511:631.67.

http://oaji.net/articles/2016/245-1467360334.pdf.

Khan A. G, A.Hassan, M. Iqbal and Ehsan Ullah, (2015). Assessing the performance of

different irrigation techniques to enhance the water use efficiency and yield of maize

under deficit water supply. Soil Environ. 34(2): 166-179.

Khoso, S., F.H. Wagan, A.H. Tunio and A.A. Ansari. 2015). An overview on emerging water

scarcity in Pakistan, its causes, impacts and remedial measures. 1:35-44

191

Kiziloglu F.M., Sahin U., Angin I., and Anapali O., 2006. The effect of deficit

irrigation on water-yield relationship of sugar beet (Beta vulgaris L.) under cool

season and semi-arid climatic conditions. International Sugar Journal 108:90-94.

Klute, A., 1986. Methods of Soil Analysis, Part 1 (Physical and Mineralogical

Methods), Agronomy 9 (second ed.), Amer. Soc. Agron., Chapter 36, 901-926.

Kosterna E., A. Zaniewicz-Bajkowska, J. Franczuk, R.t Rosa,K. Chromińska, I.

Borysiak-Marciniak and M. Panasz, (2011). Effect of synthetic mulches on melon

(Cucumis melo L.) yielding. Folia Hort. 23/2 (2011): 151-156.

Kumar S., and Dey P., (2011). Effect of different mulches and irrigation methods on

root growth, nutrient uptake, water use efficiency and yield of strawberry. Scientia

Horticulturae 127, (3) 318-324.

Kyle W., Freeman, K. Girma, D. B. Arnall, B. Tuba, S. L. Holtz, K. D. Lawles, O.

Walsh, B. Chung, K. D. Sayre, A. R. Klatt and W. R. Raun (2003-2005). Bed and flat

planted winter wheat as influenced by row configuration.

Lacombe G., P. and A. Nicol, (2016). Climate Change Science, Knowledge and

Impacts on Water Resources in South Asia: A Review. Produced for Regional

Conference on Risks and Solutions: Adaptation Frameworks for Water Resources

Planning, Development and Management in South Asia. Lament W. J, (1993). Plastic

Mulches for the Production of Vegetable Crops. HortTechnology . 3 (1): 35-39.

Liu EK, He WQ, Yan CR (2014) White revolution to white pollution- agricultural

plastic film mulch in China. Environt Res Lett 9: (091001).

Loague, K. and R.E. Green. 1991. Statistical and graphical methods for evaluating solute

transport models: Overview and application. Journal of Contaminant Hydrology. 7:51-73.

Iqbal M., A.-ul-Hassan and A. Hussain, (2003).. Effect of mulch, irrigation and soil

type on biomass and water use efficiency of forage maize Pak. J. Agri. Sci.,Vol. 40 : 3-

4, 2003.

Jamil M., M. Munir, M. Qasim, J. Baloch and K. Rehman. Effect of Different Types of

Mulches and Their Duration on the Growth and Yield of Garlic (Allium Sativum L.).

Int. Jour. of Agric. & Bio. 1560–8530/2005/07–4–588–591.

Ma, Z.-M., 1999. The yield effects and its influencing mechanism for bunch planting

wheat covered with plastic film under limited irrigation. Agric. Res. Arid Areas 17, 67–

71 (in Chinese, with English abstract).

Mahagan G., Rakesh S., Ashwani K. and Singh K. G., (2007). Effect of plastic mulch

on economizing irrigation water and weed control in baby corn sown by different

methods. African Journal of Agricultural Research Vol. 2 (1), pp. 019-026.

Mahmood A., A. Wahla, R. Mahmood

and L. Ali, (2013). Influence of flat and bed

sowing methods on growth and yield parameters of wheat in rice-wheat cropping

system. Mycopath (2013) 11(1): 33-37

192

Mahmoodi R., H. Maralian and Aghabarati, (2008). Effects of limited irrigation on root

yield and quality of sugar beet (Beta Vulgaris L.). African Journal of Biotechnology

7(24). pp. 4475-4478.

Masanta S. and S. Mallik, (2009). Effect of mulch and irrigation on yield and water use

efficiency of wheat under Patloi Nala micro-watershed in Purulia district of West

Bengal. Journal of Crop and Weed, 5(2): 22-24.

Masri M. I., B.S.B.Ramadan, A.M.A. El-Shafai and M.S. El-Kady. Effect of water

stress and fertilization on yield and quality of sugar beet under drip and sprinkler

irrigation systems in sandy soil. International Journal of Agriculture Sciences. 5

(3): 414-425.

Matković A., D. Božić, V. Filipović, D. Radanović, S. Vrbničanin and T. Marković,

(2015). Mulching as a physical weed control method applicable in medicinal plants

cultivations.

Mehmood M., T. Rasool, M. Iqbal and M. Iqbal, 2015. Journal of Environmental

and Agricultural Sciences 3 (2015): 35-41.

Mehrandish M., M. J. Moeini and M. Armin, (2012). Sugar beet (Beta vulgaris L.)

response to potassium application under full and deficit irrigation. Euro. J. Exp. Bio.,

2012, 2 (6):2113-2119.

Mekonnen M. M. And A. Y. Hoekstra, (2016). Four billion people facing severe water

scarcity. Sci. Adv. 2 : e1500323.

Mellouli H. J., B. van Wesemael, J. Poesen and R. Hartmann, (2000). Evaporation

losses from bare soils as influenced by cultivation techniques in semi-arid regions.

Agric Water Manage. 42: 3555-369.

Michael, A. M., 1978. Irrigation theory and practice. Vikas publishing house pvt ltd.

Milovanović, (2016). Sugar beet molasses: properties and applications in osmotic dehydration

of fruits and vegetables. Food and Feed Research . 43 (2), 135-144.

Mukherjee A., M. Kundua and S. Sarkara, (2010). Role of irrigation and mulch on yield,

evapotranspiration rate and water use pattern of tomato (Lycopersicon esculentum L.).

Agric. Water Manage. 98 (1): 182-189.

Mulubrehan K. and T.G. Gebretsadikan, (2016). Yield and water use efficiency of

furrow irrigated potato under regulated deficit irrigation, Atsibi-Wemberta, North

Ethiopia. 170: 133-139Munir Ahmad and Dr. Shahid Ahmad. Pub. No.WRRI (99):9.

Nagaz K., Masmoudi M. M., and Mechila N. B., (2012). Yield response of drip-

irrigated onion under full and deficit irrigation with saline water in arid regions of

Tunisia. ISRN Agronomy. Volume (2012).

Naheed, G. and G. Rasul. 2010. Projections of crop water requirement in Pakistan under global

warming. Pakistan Journal of Meteorology. 13:45-51.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T3X-512KGJY-1&_user=3415236&_coverDate=12%2F01%2F2010&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1756364947&_rerunOrigin=google&_acct=C000060485&_version=1&_urlVersion=0&_userid=3415236&md5=93d2e6cbe1f49439802296fb8abd1e3b&searchtype=a#implicit0

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T3X-512KGJY-1&_user=3415236&_coverDate=12%2F01%2F2010&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_searchStrId=1756364947&_rerunOrigin=google&_acct=C000060485&_version=1&_urlVersion=0&_userid=3415236&md5=93d2e6cbe1f49439802296fb8abd1e3b&searchtype=a#implicit0

http://www.sciencedirect.com/science/journal/03783774

193

Naresh R. K., B. Singh, S. P. Singh, P. K. Singh, A. Kumar and A. Kumar, (2012).

Furrow irrigated raised bed (FIRB) planting technique for diversification of rice-wheat

system for western IGP region. Int. J. LifeSc. Bt & Pharm. Res. 1 (3).

Nash, J.E. and J.V. Sutcliffe. 1970. River flow forecasting through conceptual models. Part I: a

discussion of principles. J. Hydrol. 10:282-290.

Nawaz A, R. Lal, R. K. Shrestha and M. Farooq, (2016). Mulching affects soil

properties and greenhouse gas emissions under long-term no-till and plough-till

systems in alfisol of central ohio. Land Degrad. Develop.

Noorjo, A., and M. Baghaekia, (2004). ―Study on the irrigation scheduling effects in

different growth stages on quantity and quality of sugar beet in Khoy region, Iran.‖

Sugarbeet J., 20(1), 27–38 (in Persian).

Nourjou, A. 2008. The effects of water deficit on yield and yield components of sugar

beet and water productivity. Iranian Journal of Irrigation and Drainage 2:31-42.

Obalum S. E., C. A. Igwe1, M. E. Obi1 and T. Wakatsuki, (2011). Water use and grain

yield response of rainfed soybean to tillage-mulch practices in southeastern Nigeria. Sci.

Agric. 68 (5): pp. 554-561

OECD, 2008. Enviromental outlook to 2030.

Olego M. A., F. Visconti, M. J. Quiroga, J. M. De Paz and E. Garzón-Jimeno, 2016. Assessing

the effects of soil liming with dolomitic limestone and sugar foam on soil acidity, leaf nutrient

contents, grape yield and must quality in a Mediterranean vineyard. Spanish Journal of

Agricultural Research 14 (2), e1102.

Osama, H. M. El-Gammal, (2015). Effect of Sustained Deficit Irrigation and Rice

Straw Mulching on Yield and Fruit Quality of Manzanillo Olive Trees. Journal of

Agriculture and Veterinary Science. 8 (9): 32-42

Ozberk I., Y. Coskun, A. Ilkhan, M. Koten, B. Karli and J. Ryan, (2009). Comparison

of Bed Planting-furrow Irrigation with Conventional Planting-flood Irrigation in Durum

Wheat (T. durum Desf) in Southeastern Turkey. Pakistan Journal of Biological

Sciences 12 (10): 772-778

Palada M. C., S. M. A. Crossmen, J. A. Kowalski and C. D. Collingwood. Evaluation

of rganic and Synthetic Mulches for Basil Production under Drip Irrigation. Journal of

Herbs, Spices & Medicinal Plants. 6 (4)

Park J., I. J. Rush, B. Weichenthal, and T. Milton, 2001. The Effect of Feeding Pressed

Sugar Beet Pulp in Beef Cattle Feedlot Finishing Diets. Nebraska Beef Cattle Reports. Paper

312.

Peng Z., W. Ting, W. Haixia, W. Min, M. Zxingping, M. Siwei, Z. Rui, J. Zhikuan and

H. Qingfang, (2015). Effects of straw mulch on soil water and winter wheat production

in dry land farming. Scientific report No. 5, Article No. 10725.

Putu, S., (2014). Introduction to aquacrop-tutorial.

194

Qadir M., E. Quillérou, V. Nangia, G. Murtaza, M. Singh, R.J. Thomas, P. Drechsel,

(2014). Economics of salt-induced land degradation and restoration. Natural Resources

Forum 38 (2014) 282–295

Qin W., C. Hu and O. Oenema, (2015). Soil mulching significantly enhances yields and

water and nitrogen use efficiencies of maize and wheat: a meta-analysis. Scientific

Reports | 5:16210 | DOI: 10.1038/srep16210. www.nature.com/scientificreports/

Rahman A., M. A. Rahman, N. C. D. Barma and T. P. Tiwari, (2016). Triple Cereal

System With Fertilizer And Planting Management For Improving Productivity In

Coastal Saline Soils Of Bangladesh. Bangladesh J. Agril. Res. 41(1): 1-15.

Rahman MS, Khan, MAH (2001). Mulching – induced alteration of microclimatic

parameters on the morpho-physiological attributes in onion (Allium cepa L.). Plant

Prod. Sci, Bangladesh 4: 241-248.

Ramalan A. A., and C. U. Nwokeocha, (2000). Effects of furro irrigation methods,

mulching and soil water suction on the growth, yield and water use efficiency of tomato

in the Nigerian Savanna. Agric. Water Manage. 45, 317–330.

Rekowska E., (1998). The effect of different methods of soil mulching on the quantity

and quality of the yield of garlic. Rocz. AR w Poznaniu CCCIV, Ogrodnictwo 27: 251-

256.

Ren X., P. Zhang, X. Chen, J. Guo and Z. Jia,(2016). Effect of Different Mulches under

Rainfall Concentration System on Corn Production in the Semi-arid Areas of the Loess

Plateau. Sci Rep. 6: 19019.

Reza A, Paknejad F, Aghayari F (2014) Simulation of sugarbeet growth under different

water regimes and nitrogen levels by AquaCrop. Intl J Biosci 4(4): 1−9.

Rezaverdinejad V, Afshin K, Ali S (2014) Evaluation and comparison of AquaCrop

and FAO models for yield prediction of winter wheat under environmental stresses. J

Bio Environ Sci 4(6): 438–449.

Rinaldi M, Vonella AV 2006. The response of autumn and spring sown sugar beet

(Beta vulgaris L.) to irrigation in Southern Italy: water and radiation use efficiency.

Field Crop Res 95:103–114.

Rinaldi M. and A. V. Vonella, (2004). Water use efficiency in sugar beet, subjected to

different sowing times and irrigation regimes in a Mediterranean environment. "New

directions for a diverse planet". Proceedings of the 4th International Crop Science

Congress. Brisbane, Australia, 26 September - 1 October 2004.

Rothaar W, Kamal S, Haq SH (1965) Sugar beet seed production in the northern

regions of West Pakistan. Tech Bull No. 7, Dept Agric Govt West Pak.

Rozman, Č., Kljajić, M., & Pažek, K. (2015). Sugar beet production: A system dynamics model

and economic analysis. Organizacija, 48(3), 145-154.

195

Sahin U., Ors S.., Kiziloglu FM., and Kuslu YK., 2014. Evaluation of water use and

yield responses of drip-irrigated sugar beet with different irrigation techniques. Chilean

J. Agric. Res. 74 (3): 302-310.

Salemi H., M. A M. Soom, T. S. Lee, S. F. Mousavi, A. Ganji and M. K. Yusoff,

(2011). Application of AquaCrop model in deficit irrigation management of Winter

wheat in arid region. African Journal of Agricultural Research. 610: 2204–2215.

Salunkhe R, Kale MU, Wadatkar SB Rao KVR (2015) Validation of crop model for

drip irrigated Capsicum under polyethylene mulch. Intl J Trop Agric 33(2): 359−364

Šarić L. C., B. V. Filipčev, O. D. Šimurina, D. V. Plavšić, B. M. Šarić, J. M. Lazarević and I.

Lj. Sarkar S., and S.R. Singh, (2007). Interactive effect of tillage depth and mulch on

soil temperature, productivity and water use pattern of rainfed barley (Hordium vulgare,

L.), Soil Tillage Res. 92: pp. 79–86.

Sarkar S., M. Pramanik and S.B. Goswami, (2007). Soil temperature, water use and

yield of yellow sarson (Brassica napus, var glauca) in relation to tillage intensity and

mulch management under rainfed lowland eco system in eastern India. Soil Tillage Res.

93: 94–101.

Sayre K. D. and O. H. M. Ramose, (1997). Application of raised-bed planting system to

wheat. WPSR No. 31.

Senthilkumar S., T. Suganya, K. Deepa, J. Muralidharan and K. Sasikala, 2016.

Supplementation of molasses in livestock feed. International Journal of Science, Environment.

5(3): 1243-1250.

Seyfi K. and M. Rashidi, (2007). Effect of Drip Irrigation and Plastic Mulch on Crop

Yield and Yield Components of Cantaloupe. Int. J. Agri. Biol., 9 (2): 247-249.

Shah S. S. H., (2013). Effect of sowing methods, mulching materials and irrigation on

water use efficiency and soil characteristics for sustainable crop production. Ph.D

desertion, Institute of Soil & Environmental Sciences, University of Agriculture,

Faisalabad (Pakistan).

Shen J. Y., D.D. Zhao, H.F. Han, X.B. Zhou and Q.Q. Li, (2012). Effects of straw

mulching on water consumption characteristics and yield of different types of summer

maize plants. PLANT SOIL ENVIRON. 58 (4): 161–166.

Shock C. C., E. Charles, Stanger, and H. Futter, (1986). Malheur Experiment Station,

Ontario, Oregon, 1986. Observations on the effect of straw mulch on sugar beet stress

and productivity. Malheur Experiment Station, Ontario, Oregon.

Shrivastava P. K., M. M. Parikh,N. G., Sawami and S. Raman, (1994). Effect of drip

irrigation and mulching on tomato yield. Agric. Water Manage. 25: 179-184.

Siborlabane (2000). Effect of mulching material to produce better yield and quality of

fresh market tomato. Hortic. Sci. 38(4):142-149.

196

Singh A, Sankar S, Sanchita M (2013) Modelling irrigated wheat production using the

FAO AquaCrop model in West Bengal, India, for sustainable agriculture. Irrig Drain

62: 50–56.

Singh P., P. Pathak, S. P. Wani and K. L. Sahrawat, (2009). Integrated watershed

management for increasing productivity and water-use efficiency in semi-arid

tropical India. Journal of Crop Improvement, 23:4, 402-429.

Siyal A. A., A.S. Mashorib, K.L. Bristowc and M.Th. van Genuchten, (2016). Alternate

furrow irrigation can radically improve water productivity of okra. Agric. Water

Manage. 173: 55–60.

Sounda G, A. Mandal, G. Moinuddin and S. K. Mondal, (2006). Effect of irrigation and

mulch on yield, consumptive use of water and water use efficiency of summer

groundnut. Journal of crop and weed 2(1): 29-32.

Steduto P, Hsiao TC, Fereres E, Raes D (2012) Crop yield response to water, FAO Irrig

Drain Paper No. 66: 124-131.

Steduto, P., Hsiao, T.C., Raes, D., Fereres, E., 2009. AquaCrop—the FAO Crop Model

to Simulate Yield Response to Water: I. Concepts and Underlying Principles. Agron. J.

101:426–437.

Stewart, J.I., R. M. Hagan, W. O. Pruitt, R. E. Danielson, W. T. Franklin, R. J. Hanks, J.

P. Riley, E. B. Jackson, (1977). Optimizing crop production through control of water

and salinity levels. Utah: Utah Water Res. Lab. PWRG 151-1. 191p.

Stikić R., Z. Jovanović and L. Prokić, (2014). Mitigation of plant drought stress in a

changing climate. 38 (1): Botanica SERBICA 35-42.

Stockle, C.O., Donatelli, M., Nelson, R., (2003). CropSyst, a cropping systems

simulation model. Eur. J. Agron. 18 (3–4), 289–307. Second special issue ―Proceedings

of the 2nd International Symposium on Modelling Cropping Systems, Florence, Italy‖.

Stricevic R., M. Cosic, N. Djurovic, B. Pejic and L. Maksimovic, (2011). Assessment

of the FAO AquaCrop model in the simulation of rainfed and supplementally irrigated

maize, sugar beet and sunflower. Agric.. Water Manage. 98 (10): 1615 – 1621.

Tagar A, Chandio FA, Mari IA, Wagan B (2012) Comparative study of drip and furrow

irrigation methods at farmer‘s field in Umarkot. Intl J Bio Biomol

Agril Food Biotech Eng 6(9): 788−792.

Taleghani, D.,J. Gohari, J., Tohidloo, Gh. & a. Roohi, (1998). Final report of studying

water and N use efficiency in optimum and stress condition in each sugar beet

cultivation arrangement. Sugar Beet Researches Institute.

Tan, K.H. 1995. Soil sampling preparation and analysis, Marcel Dicker, Inc. New

York, USA.

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Hagan%22%20author_fname%3A%22R.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Pruitt%22%20author_fname%3A%22W.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Danielson%22%20author_fname%3A%22R.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Franklin%22%20author_fname%3A%22W.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Hanks%22%20author_fname%3A%22R.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Riley%22%20author_fname%3A%22J.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Riley%22%20author_fname%3A%22J.%22&start=0&context=656526

http://digitalcommons.usu.edu/do/search/?q=author_lname%3A%22Jackson%22%20author_fname%3A%22E.%22&start=0&context=656526

197

Tao Z., C. Li, J. Li, Z. Ding, J. Xu, X. Sun, P. Zhou and M. Zhao, (2015) . Tillage and

straw mulching impacts on grain yield and water use efficiency of spring maize in

Northern Huang–Huai–Hai Valley. The crop journal. 3:445-450.

Taparasuskiene L. and Otilija M., (2014). Effect of mulch on soil moisture depletion

and strawberry yield in sub-humid area. Pol. J. Environ. Stud. Vol. 23, No. 2: 475-482.

Tariq, J.A. and K. Usman. 2009. Regulated deficit irrigation scheduling of maize crop.

2009. Sarhad J. Agric. 25(3): 441-450.

Tavakoli A, Mehran RM, Alieza RS (2015) Evaluation of the AquaCrop model for

barley production under deficit irrigation and rainfed condition in Iran. Agric Water

Manage 161: 136–146.

Tegen H., Y. Dessalegn and W. Mohammed, (2016). Influence of mulching and

varieties on growth and yield of tomato under polyhouse. J. Hortic. For. 8 (1): 1-11.

Tiercelin, J.R., Vidal, A., 2006. Traite´ıd‘Irrigation, 2nd Ed. Paris, France.

Tognetti R, M. Palladino, A. Minnocci, S. Defline, A. Alvino, (2003). The response of

sugar beet to drip and low-pressure sprinkler irrigation in Souther Italy. Agric. Water

Manage. 60:135–155.

Topak A, S. Sinan, and A. Bilal, (2011). Effect of different drip irrigation regimes on

sugar beet (Beta vulgaris L.) yield, quality and water use efficiency in Middle

Anatolian, Turkey.

Topak, R. B. Acar, Uyanoz, R., and E. Ceyhan, (2016). Performance of partial root-

zone drip irrigation for sugar beet production in a semi-arid area. Agric. Water Manage.

176: 180-190.

Toumi JS, Er-Raki, Ezzahar J, Khabba S, Jarlan L, Chehbouni A (2016) Performance

assessment of AquaCrop model for estimating evapotranspiration, soil water content

and grain yield of winter wheat in Tensift Al Haouz (Morocco): Application to

irrigation management. Agric Water Manage 163: 219–235.

Ucan K. and C. Gencoglan, (2004). The effect of water deficit on yield and yield

components of sugar beet. Turk J Agric. 28:163-172.

UNESCO-WWAP, 2012. Managing Water under Uncertainty and Risk. WWDR4.

Usman, M. 2016. Contribution of Agriculture Sector in the GDP Growth Rate of Pakistan. J.

Glob. Econ. 44:1-3

USSL (1954) Diagnosis and improvement of saline and alkali soils. USDA, Handbook,

60, p. 147.

Uwah D. F., and G. A. Iwo, (2011). Effectiveness of organic mulch on the productivity

of maize (Zea Mays L.) and weed growth. J. Anim. Plant Sci. 21(3): 525-530.

http://www.sciencedirect.com/science/article/pii/S2214514115000860









http://ascelibrary.org/author/Acar%2C+Bilal

198

Vavrina CS, Roka FM (2000). Comparison of plastic mulch and bareground production

and economics for short-day onion in a semitropical environment. Horticultural.

Technol. 10: 326-330.

Wahome P. K., D. N. Mbewe, J. I. Rugambisa and V. D. Shongwe, (2001). Effects of

Mulching and Different Irrigation Regimes on Growth, Yield and Quality of Tomato

(Lycopersicon esculentum Mill.‗Rodade‘). Faculty of Agriculture, Luyengo Campus,

University of Swaziland.

Wang CR, Tian XH, Li XH (2004) Effects of plastic sheet-mulching on ridge for water-

harvesting cultivation on WUE and yield of winter wheat. Sci Agric Sinica 37(2):

208−214.

Water Benchmarks of CWANA, (2011). Community-Based Optimization of the

Management of Scarce Water Resources in Agriculture in West Asia and North Africa

Water benchmarks Phase-II Annual reports and work plans.

Weeden B. W. R, (2000). Potential of sugar beet on the Atherton Tableland. 00/167,

Project No. DAQ 211A, Barton. 2-14.

Werker A. R. and K. W. Jaggard, (1998). Dependence of sugar beet yield on light

interception and evapotranspiration. Agric For Meteorol 89:229–240.

Westhuizen J. H. Van Der, (1980). The effect of Black Plastic Mulch on Growth,

Production and Root Development of Chenin blanc Vines under dryland conditions S.

Afr. J. Enol. Vitic. 1 (1).

Whisler FD, Acock B, Baker RE, Fye HF, Hodges JR, Lambert HE, Lemmon JM, Mc

Kinion, Reddy VR (1986) Crop simulation models in agronomic systems.

Williams, J.R., C. A. Jones, and P. T. Dyke, (1989). EPIC—Erosion/productivity

impact calculator. 1. The EPIC model. USDA-ARS, Temple, TX.

Willmott, C.J. 1982. Some comments on the evaluation of model performance. Bulletin of

American Meteorological Society. 63:1309-1313.

World Wide Fund for Nature (WWF) Report. 2012. Development of Integrated River Basin

Management (IRBM) for Indus Basin – Challenges and Opportunities.

Wu, M.Y., R. C. Hao and L. H. Wu, (2016) Effects of Continuous Plastic Film

Mulching on Soil Bacterial Diversity, Organic Matter and Rice Water Use

Efficiency. Journal of Geoscience and Environment Protection, 4, 1-6.

Xie Z., Y. Wang and F. Li, (2005). Effect of plastic mulching on soil water use and

spring wheat yield in arid region of northwest China. Agric. Water Manage. 75 (71–83).

Xu J, C. Li, H. Liu, P. Zhou, Z. Tao and P. Wang, (2015). The Effects of Plastic Film

Mulching on Maize Growth and Water Use in Dry and Rainy Years in Northeast China.

PLoS ONE 10(5): e0125781. doi:10.1371/journal.pone.0125781.

199

Yaghi T., A. Arslan and F. Noum, (2013). Cucumber (Cucumis sativus, L.) water use

efficiency (WUE) under plastic mulch and drip irrigation. Agric. Water Manage.

128:149– 157.

\Yonts, C.D. 2011. Development of season long deficit irrigation strategies for

sugarbeet. International Sugar Journal 113:728-731.

Yu W., Yi-C. Yang, A. Savitsky, D. Alford, C. Brown, J. Wescoat, D. Debowicz, and S.

Robinson, (2013). Direc tions In D e velopment Countries and Regions.The Indus

Basin of Pakistan The Impacts of Climate Risks on Water and Agriculture.

Zacharias, S., C.D. Heatwole and C.W. Coakley. 1996. Robust quantitative techniques for

validating pesticide transport models. Trans. ASAE. 39:47-54.

Zahoor A., P. Shah, K. M. Kakar, H. El-Sharkawi, and P. B. S. Gama, E. A. Khan, T.

Honna and S. Yamamoto, (2010). Sugar beet (Beta vulgaris L.) response to different

planting methods and row geometries II: Effect on plant growth and quality. Journal of

Food, Agriculture & Environment, 8 (2):785-791.

Zegada-Lizarazu W. and P. R. Berliner, (2010). Inter-row Mulch Increase the Water

Use Efficiency of Furrow-Irrigated Maize in an Arid Environment. J. Agronomy &

Crop Science. 197: 237–248.

Zeleke KT, Luckett D, Cowley R (2011) Calibration and testing of the FAO AquaCrop

model for Canola. Agron J 103(6): 1610–1618 .

Zhang J., J. Sun, A. Duan, J. Wang, X. Shen and X. Liu, (2007). Effects of different

planting patterns on water use and yield performance of winter wheat in the Huang-

Huai-Hai plain of China. Agric. Water Manage. 92: 41-47.

Zhang Q. T., O. A. B. Ahmed, M. Inoue, M. C. Saxena, K. Inosako and K. Kondo,

(2009). Effects of mulching on evapotranspiration, yield and water use efficiency of

Swiss chard (Beta vulgaris L. var. flavescens) irrigated with diluted seawater. JFAE. 7

(3 &v4): 650-654.

Zhao Y., H. Pang, J. Wang, L. Huo,Y. Li, (2014). Effects of straw mulch and buried

straw on soil moisture and salinity in relation to sun flower growth and yield. Field

Crops Research 161: 16–25.

Zhou J. -b., C.- y. Wang, H. Zhang, F. Dong, X.- f. Zheng, W. Gale and S. –x. Li,

(2011). Effect of water saving management practices and nitrogen fertilizer rate on crop

yield and water use efficiency in a winter wheat–summer maize cropping system.

Field Crops Research 122: 157–163.

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