Water-NO3 Mgt Rice

1

BINA/Ag. Engg.Division-8

A Research Report

on

Evaluation of Different Water Management Practices for

Water Savings, Nitrate Leaching and Rice Yield

By

Dr. Md. Asgar Ali Sarkar (Chief Scientific Officer and Head)

Dr. M. H. Ali * (Senior Scientific Officer)

Agricultural Engineering Division

Bangladesh Institute of Nuclear Agriculture BAU Campus, Mymensingh 2202

Bangladesh

*Corresponding Author, Email: [email protected], [email protected]

March 2010

2

Preface

Over the past few decades there has been increased attention to nitrate concentration

in ground water, particularly to leaching associated with agricultural activities. Concerns

grow about subsurface water quality due to advective downward transport of pollutants as

more water moves through the soil profile. Application of excess nutrient fertilizers for crop

production may directly affect subsurface water quality especially for NO3-N, which is highly

mobile.

In Bangladesh, nitrate in groundwater is associated with irrigated rice-based cropping

systems. Rice is generally grown under ponded water. The combination of high N-fertilizer

input culture along with ponded water may lead to increased risk of nitrate leaching.

Considering this point, the reported investigation was carried out. The research results will

help in adopting appropriate water management strategy for water saving, increased rice yield

and specifically for reducing risk of NO3-N leaching responsible for groundwater pollution.

The investigators

3

Summary

Contamination of groundwater with nitrate is attributed to deep percolation of water

containing the chemical. Thus, proper irrigation scheduling can reduce deep percolation and resulting

nitrate loss to a certain extent. Long-term (2000-2005) field and lysimetric study were conducted to

evaluate different water management practices for saving the costly irrigation inputs, maximizing the

rice yield and conversely minimizing the leaching of nitrate-nitrogen (NO3-N) below the root zone.

The study was carried out with recommended N-fertilizer rate for the study area and different

irrigation strategies. The irrigation strategies were: Continuous ponding of 3-5 cm [T1]; continuous

saturation [T2]; alternate flooding (5 cm) and drying to 3, 5 and 7 days after the disappearance of the

ponded water, thereby referred to as T3, T4, and T5, respectively. The water samples were collected

from the outlet pipe provided at the bottom of lysimeter and by ceramic suction cups installed in the

treatment plots in the field, which were then analyzed in the laboratory for NO3-N concentration. The

results showed that the variation in yield among the treatments were small and statistically

insignificant. But irrigation water required in alternate wetting and drying methods (T3 to T5) were 44

to 54 % less than that of continuous ponding and 23 to 36 % less than that of saturation method (T2).

The pattern of NO3-N concentration and the total NO3-N loss varied among treatments both at field

and lysimeter. Nitrate leaching during crop growing period in lysimeter ranged from 1.5 to 3.5 kg/ha.

The cumulative NO3-N concentration data showed that the total NO3-N loss were higher in continuous

ponding and continuous saturation under field condition. Considering the nitrate loss, rice yield and

water saving, the alternate flooding and drying 5 to 7 days after disappearance of ponded water

seemed to be the best strategy for rice cultivation.

4

Table of Contents

Content Page

Title page ....................................... 1

Preface .......................................2

Summary .................................... 3

Table of contents .................................... 4

List of Tables .................................... 5

List of Figures .................................... 5

1 Introduction .................................... 5

2 Material and Methods .................................... 8

2.1 Experimental site, soil and climate ....................................

2.2 Irrigation treatments ....................................

2.3 Experimental plots and culture ....................................

2.3.1 Lysimeter ................................................

2.3.2 Field ................................................

2.3.3 Fertilizer and other cultural practices .........................................

2.4 Drainage collection, water sampling ................................................

2.5 Water balance ................................................

2.6 Water analysis for nitrate .................................................

2.7 Yield data recording .................................................

2.7 Statistical analysis .......................................................

3. Results and Discussion .................................... 12

3.1 Rainfall amount during crop period ....................................

3.2 yield, water use and water productivity ...................................

3.3 NO3 –N leaching ....................................

3.3.1 Drainage water ....................................

3.3.2 NO3 –N concentration in soil profile .............................

3.4 Conclusion .................................

References .............................. 17

5

List of Tables

Table No. Page No.

Table 1. Yield, irrigation requirement and total water use of rice in field under different

treatments .............

Table 2. Average yield and water productivity of rice in field under different treatments

……….

Table 3. Average yield and water productivity of rice in lysimeter under different treatments

……….18

Table 4. Average estimated amount of NO3-N leaching under different treatments in

lysimeter & field ................

List of Figures Fig. No. Page no.

Fig.1. Rainfall distribution during the crop growing period .................................... 19

Fig. 2(a). NO3-N concentration of drainage water during the crop growing season (Field

and lysimeter) during 2000 .............................................

Fig.2(b). NO3-N concentration of drainage water during the crop growing season (Field

and lysimeter) during 2001 ......................................

Fig.2(c) NO3-N concentration of drainage water during the crop growing season (Field

and lysimeter) during 2002 ......................................

Fig.2(d) NO3-N concentration of drainage water during the crop growing season (Field

and lysimeter) during 2003 .....................................

Fig.2(e) NO3-N concentration of drainage water during the crop growing season (Field

6

and lysimeter) during 2004 .....................................................

Fig.2(f) NO3-N concentration of drainage water during the crop growing season (Field

and lysimeter) during 2005 .............................................

Fig. 3(a). NO3-N concentration of soil sample (Field and lysimeter) during 2000 ..........

Fig.3(b). NO3-N concentration of soil during the crop growing season (Field

and lysimeter) during 2001 ..................................................

Fig.4. Average NO3-N concentration of drainage water collected from the field …..

Fig.5. Average cumulative NO3-N concentration of field and lysimeter soil at harvest ….29

Evaluation of Different Water Management Practices for Water

Savings, Nitrate Leaching and Rice Yield

1 Introduction Modern agriculture is changing its traditional priorities and practices by developing

and adopting new techniques or methods, intending to increase farming production and

maintain soil fertility. The farmers use water to irrigate and chemical fertilizers to increase

soil fertility and production. Under ideal conditions, only the amount of fertilizer that can be

used by the plant would be applied, leaving no residual to move below the root zone.

However, in most cases, not all of the applied nitrogen is assimilated by the plants, allowing

some to move below the root zone. Nitrogen in the soil that is not returned to the atmosphere

in the form of nitrogen gas or ammonia is generally converted to the nitrate form by bacteria.

Nitrate is very mobile, and if there is sufficient water in the soil, it can move readily through

the soil profile.

Addition of water and nitrogenous fertilizer are highly effective means to improve

crop yield. There is a direct relationship between large NO3-N losses, excess N inputs and

inefficient irrigation management (Santos et al., 1997). Extensively and specifically,

intensively cropped areas are sources of ground water contamination. Contamination of

ground water by agricultural chemicals is a major concern throughout the world. Nitrate

contamination is a particular concern for both health and environmental quality. Ground

water is the major source of drinking for both urban and rural people of Bangladesh as well

7

as many parts of the world. Nitrate may cause methemoglobinemia (blue baby syndrom) in

infants (Stone et al., 1997) when it is above the maximum concentration level of 10 mg/l.

Additionally, nitrate interaction with other dietary substances may cause health problems in

human (Maidson and Brunett, 1985).

A large number of research articles found in the literature deals with the problem of

nitrate leaching under different conditions of soils, crops and cultural practices. Most of them

are from studies conducted in crops grown under unsaturated or non-ponded condition

(Moreno et al., 1999; Yets et al., 1992; Ferguson et al., 1991; Casey et al., 2002; Roth and

Fox, 1990). But in irrigated rice cultivation, water is ponded in the field during the whole

growing period. Under such conditions, the leaching of nitrate (amount and patterns) in

agricultural soils can be different from that occurred from dry-land crops. Bawatharnai et al.

(2004) showed that higher rates of irrigation push down the diluted nitrate solution rapidly.

About 50% of the world’s rice area is irrigated by ponding of the field, and produces

75% of the world’s rice production (Tabuchi and Hasegawa, 1995). A high production is

attained by high inputs (water, fertilizer, pesticide, etc.). Among the various factors

contributing to increased rice production, irrigation has the highest effect followed by

fertilizer and variety. Sustainable paddy production depends on the sustainable use of water

resources including the technology that makes minimum use of agricultural chemicals.

In Bangladesh, nitrate in the ground water is a concern in irrigated rice-based

cropping systems. Rice is generally grown under ponded water. The combination of high N-

fertilizer input culture along with ponded water may lead to increase risk of nitrate leaching.

The objective of this study was to minimize nitrate leaching by effective management of

irrigation water in irrigated Boro rice cultivation.

2 Materials and Methods

2.1 Experimental site, soil and climate

The experiments were conducted at the experimental farm of the Bangladesh Institute of

Nuclear Agriculture (BINA), Mymensingh, Bangladesh (Latitude 240 43' N, longitude 900 26'

E, and 7.2 m above mean sea level), during 2000-2005. The local climate is humid and sub-

tropic with summer dominant rainfall. The average annual rainfall at the site (1991-2004) was

about 2260 mm, mostly concentrated over the months of April to September. The texture of

the experimental soil is silty loam.

8

2.2 Water management strategies / Irrigation treatments

Water management practices followed were:

T1 = Continuous ponding (3-5 cm)

T2 = Continuous saturation

T3 = Alternate flooding (5 cm) and drying for 3-days after disappearance of the ponded

water

T4 = Alternate flooding (5 cm) and drying for 5-days after disappearance of the ponded

water and

T5 = Alternate flooding (5 cm) and drying for 7 days after disappearance of the ponded

water

2.3 Experimental setup and cultural practices

The experiment was set up in field and lysimeter simultaneously. In both cases the

treatments and cultural practices were same but different only in crop environment. In field,

the crop was grown under normal and natural condition having no three-dimensional barrier

of water and solute flow. In contrast, crops grown in control condition in lysimeter having

barrier of the lysimeter walls for horizontal movement of water and solute. Moreover, in

micro-level experimental environment, the crops have climatic and nutrient receiving

competition, and error factor for heat reflection due to lysimeter’s visible surface walls

compared to the field condition. Some features of both experimental conditions are described

below.

2.3.1 Lysimeter

Each lysimeter tank (drainage type) has a surface area of 2m2 (2m x 1m) with soil

depth of 1.5m. The investigation was carried out in 5 tanks, one for each treatment. Each tank

has separate arrangements for irrigation, drainage and soil water measurements. Hassan et al.

(1995) provided a detailed description of the construction of the lysimeter.

2.3.2 Field

In the field, the experimental design was RCBD with four replications. The unit plot

size was 5m x 4m. Line to line and plant to plant distances within the line were maintained

as 20cm and 15cm, respectively.

9

2.3.3 Fertilizer and other cultural practices

The experiment was fertilized with the recommended doses of urea @ 215 kg/ha, TSP

@ 180 kg/ha and MP @ 100 kg/ha. Seedling of 35~40 days old was transplanted on mid

January every year and the crop was harvested on third week of May. All but urea fertilizer

were applied at transplanting time. The urea was applied as top dressing in three equal splits

at 7, 39 and 64 days after transplantation. Weeding was done as per need. Insecticide was

sprayed at the pre-flowering and the grain formation stages. Soil samples from each treatment

plot for both the field and lysimeter were also collected up to 90 cm depth at land preparation

and at harvest to determine the NO3-N content in profile.

2.4 Drainage water collection and water sampling

Vacuum gauge water samplers (85 cm deep) were installed in all the treatment plots in

one replication. Moreover, 38cm depth water samplers were installed in T1, T2, T3 and T5

treatment plots and 120cm water samplers were installed in only T1, T4 and T5 treatment plots

in one replication. Water samples were collected after the normal accumulation of water into

the sampler through the ceramic cup. Whenever normal accumulation was insufficient, each

sampler was sucked for 20-30 minutes by a hand suction pump (having vacuum gauge) and

then the accumulated water was collected. The water samples were then analyzed into the

laboratory for NO3-N concentration. From the lysimeter plots, drainage water was collected

by opening the bottom drainage outlet pipe situated at 120cm below the soil surface.

In case of lysimeter, the NO3-N leached below the root zone (at 1.2m depth) for each

sampling was calculated using the following formula:

LN = V x Cd ..........................................(1)

Where,

LN = amount of NO3-N (mg) leached below the root zone

V = volume of water leached below the root zone (Litre)

Cd = concentration of NO3-N (mg/L) of the drainage water collected below the root

zone.

Total NO3-N leached during the growing season was calculated by summing up LN for each

sampling and expressed as amount per unit area (Kg/ha).

10

2.5 Water balance

The general water balance equation at plot level in paddy field can be written as:

P + I = ET + R + D .............................................. (2)

where, P is precipitation (cm), I is irrigation water (cm), ET is evapo-transpiration (cm), R is

surface runoff (cm) and D is deep percolation. The sum of the terms in the left hand and right

hand side of the equation are water gain and water loss, respectively. Simplifying the

equation for ET becomes:

ET = I + (P – R) – D

or ,

ET = I + Peffective – D ................................(3)

where, Peffective is effective rainfall which was calculated following the method outlined by

Dastane (1974). Any amount above 75 mm/day and rainfall in excess of 125 mm in 10 days

was treated as non-effective. In case of deep percolation, it was taken as 2 mm/day (equal to

saturated hydraulic conductivity) for the whole growing period for ponding and saturated

treatments, and one-third of the growing days with the same rate for the other treatments. For

lysimeter, excess water was collected from the drainage outlet pipe provided at the bottom of

each tank and the cumulative amount was considered as the total deep percolation for each

treatments.

2.6 Water analysis for NO3-N

The collected samples were analyzed in laboratory for NO3-N concentration following

the method of Rand et al. (1976).

2.7 Yield data recording

Agronomic data and yield parameters were recorded in time. The yield of the whole

unit plot was collected and then converted to Kg/ha.

2.8 Statistical analysis

The yield data was analyzed following analysis of variance technique using MSTATC

statistical package. The means were separated using ‘Least Significant Difference’ test at 5

% significance level.

11

3 Results and Discussion

3.1 Rainfall amount during the crop period

The amount and distribution of rainfall during the rice growing period (transplanting to

harvest) are showed graphically in Fig. 1. The amount of rainfall up to 90 days from

transplanting (starting of grain formation) in all the years are low, thus, there were no

problem to maintain the scheduled irrigation treatments.

3.2 Yield, water use and water productivity

Field

Yield and components of water use of rice under different irrigation management

practices are presented in Table 1. The irrigation treatments showed insignificant difference

in yield. Pattern of yield variation among the treatments varied among years. The average

yield, ET, water productivity (WP) and irrigation water productivity (IWP) are summarized

in Table 2. On an average, the treatment T2 produced the highest yield followed by T5

(Table 1). But the variations in yield among the treatments are small.

The alternate drying and re-watering ( in treatments T3 and T5) may have contributed

to physio-biochemical changes and adjustment, which made the plants less sensitive to water

stress, thus less adverse impact on yield. The results are comparable with the recent findings

(Liang et al. 2002 ). Liang et al. (2002) demonstrated that alternate drying and re-watering

had a significant compensatory effect that could reduce transpiration. Turner (1986) reported

that plants can adapt to slowly developing water deficit so that the water potential at which

physiological activity is affected is changed. It was also reported that osmotic adjustment

allows for the maintenance of photosynthesis and growth by stomatal adjustment and

photosynthetic adjustment (Turner, 2004).

Another aspect is that monocarpic plants such as wheat and rice need the initiation of

whole plant senescence so that stored carbohydrates in stems and leaf sheaths can be

remobilized and transferred to their grains. Delayed whole plant senescence lead to poorly

filled grains and unused carbohydrate in straws (Zhang and Yang, 2004). Slow grain filling

may often be associated with delayed whole plant senescence. Zhang and Yang (2004)

showed that the early senescence induced by water deficit does not necessarily reduce grain

yield even when plants are grown under normal nitrogen (N) condition. The gain from

accelerated grain-filling rate and improved translocation outweighed the possible loss of

12

photosynthesis as a result of shortened grain filling period when subjected to water stress

during grain filling.

On an average, the treatment T1 consumed highest amount of irrigation water (128

cm) followed by T2 (89 cm), but the yield difference is only 0.28 t/ha. The treatment T3 saved

20 cm of irrigation water compared to T2 accompanied by a yield reduction of 0.31 t/ha.

Similarly, the treatment T5 saved 32 cm water with a yield reduction of only 0.25 t/ha.

As the yield difference is small, water productivity and productivity of irrigation

water are of reversed trend of water use, i.e. the highest with the lowest irrigation water (T5)

and the lowest with the highest irrigation water (T1).

Lysimeter

The average yield, water use and water productivity for the lysimeter grown rice are

presented in Table 3. It is observed that yield in lysimeter is higher than that of the field. This

may be due to less competition of micro-climatic in the lysimeter crops, specially the

sunlight. Alike field, here also, yield varied among treatments by narrow range. Here, the

treatment T4 produced the highest yield. The irrigation water consumed followed the similar

trend as that of the field.

3.3 NO3-N leaching

3.3.1 Drainage water

The concentration of NO3-N in the drainage water under different treatments are

shown in Fig. 2(a) to Fig. 2(f). The fertilizer N were applied at 7, 39 and 64 days after

transplanting (DAT). Leaching of NO3-N in general increased not immediately after the

application of fertilizer, but lagging few days (Fig. 2(a)). The pattern of NO3-N concentration

and thus the NO3-N loss varied among treatments, and also among field and lysimeter.

During the crop period in 2000, the NO3-N concentration in the field at later stage (75 DAT)

were higher in T3, and T4. The cumulative NO3-N concentration data (Fig. 2(b)) to Fig. 2(e))

showed that in most cases the total NO3-N loss were higher in T1 and T2 under field condition

and in T4 and T5 under lysimeter. The higher value under stressed condition in lysimeter may

be due to the higher inflow rate of water through the passage in between lysimeter wall and

13

soil. The total amount of NO3-N loss under lysimetric condition varied between 1.09 to 2.0

kg/ha (Table 4), having an average of 1.55 kg/ha.

From the field data, it was observed that there was a reduction in nitrate leaching

under the irrigation strategy in which irrigation water was applied at 3 to 7 days after

disappearance of ponded water (treatment T3 to T5), without insignificant reduction in rice

yield. Other studies (Skopp et al., 1990; Doran, 1980) have demonstrated that the increased

soil-water increased mineralization rates, exposing more nitrate to leaching. Lower

mineralization in lysimeter may occur due to a decrease in organic matter (Casey et al.,

2002). Unfortunately, a record of soil organic-matter content at various stages of the study

was not kept to verify whether mineralization rates were increasing or decreasing.

3.3.2 NO3-N concentration in soil profile

The NO3-N concentration at various depths at sowing and harvest under different

treatments are shown in Fig. 3(a) and Fig. 3(b). The NO3-N concentration showed fluctuating

pattern at different depths and also varied among treatments. During the year 2000 (Fig.

3(a)), the NO3-N concentration in field soil at harvest was higher than the sowing time and

showed gradually higher trend in the more irrigated plots than the water stressed plots.

Moreover, it was found that the maximum NO3-N concentration was at 90 - 120 cm soil

depth in T1. On the other hand, in lysimeter, the highest NO3-N was found at 0 - 30 cm depths

in T1.

The cumulative NO3-N concentration increased gradually in lysimeter in the deeper

soil profiles (Fig. 3(b)). Moreover, higher concentration trend was also observed in the water

stressed plots (T3, T4). This may be attributed by the interspaces in between soil and lysimeter

wall. But in the field, NO3-N showed a gradually higher downward trend in deeper soil layers

in the more irrigated plots than the water stressed plots. It indicated that the irrigated plots

with ponded water allowed the free downward movement of NO3-N causing its higher

leaching rate. The average (over years) cumulative NO3-N of water and soil are presented in

Fig.4 and Fig.5, respectively.

From the field data, it revealed that there was a reduction in nitrate leaching under the

irrigation strategy in which irrigation water was applied at 3 to 7 days after disappearance of

ponded water (treatment T3 to T7), without insignificant reduction in rice yield.

14

3.4 Conclusion

Considering the nitrate loss, rice yield and water saving, the alternate flooding and drying for

5 to 7 days after disappearance of ponded water seemed to be the best strategy for rice

cultivation.

References

Casey, F.X.M., N. Derby, R.E. Knighton, D.D. Steele, and E.C. Stegman (2002). Initiation

of irrigation effects on temporal nitrate leahing. Vadose Zone J. 1, 300-309.

Dastane, N.G. (1974). Effective rainfall in irrigation agriculture. FAO Irrigation and Drainage

Paper 25, FAO, Rome, p. 61

Doran, J.W. (1980). Soil microbial and biochemical changes associated with reduced tillage.

Soil Sci. Soc. Am. J. 44, 765-771.

Ferguson, R. B., C. A. Shapiro, G. W. Hergert, W. L. Kranz, N. L. Klocke and D. H. Krull

(1991). Nitrogen and irrigation management practices to minimize nitrate leaching

from irrigated corn. J. Prod. Agric. 4: 186-192.

Hassan, A. A., A. A. Sarkar and A. H. Sarder (1995). Design and construction of non-

weighing gravity type lysimeter for agro-hydrological studies. Lysimeter report-

BINA / Ag. Engg/4, 1995.

Liang, Z.S., F.S. Zhangand J.H. Zhang (2002). The relations of stomatal conductance, water

consumption, growth rate to leaf water potential during soil drying and rewatering

cycle of wheat. Botanical Bulletin of Academia Sinica, 43: 187 – 192

Maidson, R.J. and J.O. Brunett (1985). Overview of the occurrence of nitrate in groundwater

of the United States. U.S. Geol. Surv. Water Supply Pap. 2275.

Moreno, F., J. A. Cayuela, J. E. Fernandez, E. Fernandezboy, J. M. Murillo and F. Cabrera

(1999). Water balance and nitrate leaching in on irrigated maize crop in SW spain.

In: Kirda, et al. (edit.) Crop Response to Deficit Irrigation.

15

Rand, M. C., A. E. Greenberg, and M. J. Taras (1976). Standard Methods for the

examination of Water and Wastewater. Published by American Public Health

Association. pp. 189-205

Rashid, M.A., A.F.M. Saleh, and L.R. Khan (2005). Water savings and economics of

alternate wetting and drying irrigation for rice. Bangladesh J. Water Resour. Res.

20: 81-93.

Ritter, W. F. (1989). Nitrate leaching under irrigation in the united states – a review. J. Env.

Sci. and Health. Part-A: Env. Sci. and Engg., A24: 4, 349-378

Roth, L. V. and R. H. Fox (1990). Soil nitrate accumulations following nitrogen-fertilized

corn in Pennsylvania, J. Environ. Qual., 19: 243-248.

Santos, D.V., P.L. Sousa, and R.E. Smith (1997). Model simulation of water and nitrate

movement in a level-basin under fertigation treatments. Agric. Water Manage., 32:

293-306

Sarkar, A. A., A. A. Hassan, M. H. Ali and N. N. Karim (2002). Supplemental irrigation for

Binashail rice cultivation at two agro-ecological zones of Bangladesh. Bangladesh J.

of Agril. Sci., 29(1): 95-100

Skoop, J., M.D. Jawson, and J.W. Doran, (1990). Steady-state microbial activity as a function

of soil water content. Soil Sci. Soc. Am. J. 54, 1619-1625

Stone, K.C., P.G. Hunt, M.H. Johnson, and T.A. Matheny (1997). Groundwater nitrate-N

concentrations on an eastern coastal plans watershed. Paper presented in an ASAE

meeting on Aug.10-14, 19997, Paper No. 97-2152, 560 Niles Road, St. Joseph, MI

49085-9659, USA.

Tabuchi, T. and S. Hasegawa (edit.)(1995). Paddy field in the world. Japanese Society of

Irrigation, Drainage and Reclamation Engineering, Tokyo, 353p.

Turner, N. C. (1986). Adaptation to water deficits: a changing perspective. Aust. J. Plant

Physiol., 13: 175-190

Turner, N.C. (2004). Sustainable production of crops and pastures under drought in a

Mediterranean environment. Annals of Applied Biology, 144: 139-147

Yates, M. V., D. E. Stottlemyer, and J. L. Meyer 1992. Irrigation and fertilizer management

to minimize nitrate leaching in Avocado production. Proc. of Second World

Avocado Congress, pp. 331-335.

Zhang, J. and J. Yang (2004). Improving harvest index is an effective way to increase crop

water use efficiency. In: Proc., 4th Int. Crop Sci. Congress, held at Brisbane, Sept.

2004, on the theme “Crop Science for Diversified Planet”.

16

Moreno, F., J. A. Cayuela, J. E. Fernandez, E. Fernandezboy, J. M. Murillo and F. Cabrera

(1999). Water balance and nitrate leaching in on irrigated maize crop in SW spain.

In: Kirda, et al. (edit.) Crop Response to Deficit Irrigation.

Yates, M. V., D. E. Stottlemyer, and J. L. Meyer (1992). Irrigation and fertilizer management

to minimize nitrate leaching in Avocado production. Proc. of Second World

Avocado Congress, pp. 331-335.

Ferguson, R. B., C. A. Shapiro, G. W. Hergert, W. L. Kranz, N. L. Klocke and D. H. Krull

(1991). Nitrogen and irrigation management practices to minimize nitrate leaching

from irrigated corn. J. Prod. Agric. 4: 186-192.

Casey, F. X. M., N. Derby, R. E. Knighton, D. D. Steele and E. C. Stegman (2002). Initiation

of irrigation effects on temporal nitrite leaching. Vadose Zone Journal, 1: 300-309.

Roth, L. V. and R. H. Fox (1990). Soil nitrate accumulations following nitrogen-fertilized

corn in Pennsylvania, J. Environ. Qual., 19: 243-248.

17

Table 1. Yield, irrigation requirement and water productivity under different treatments

Year

Treat- ment

Yield t/ha

Irrigationcm

Rainfallcm

Runoff cm

Deep percol.

Water use, cm

2000

T1 5.57 76.62 80.00 24.00 39.78 92.84 T2 5.39 61.12 80.00 24.00 35.13 81.99 T3 5.98 55.75 80.00 24.00 33.52 78.23 T4 6.14 55.00 80.00 24.00 33.3 77.7 T5 5.84 46.50 80.00 24.00 30.75 71.75

2001

T1 3.94 125.7 36.97 18.49 43.27 100.91 T2 4.47 100.00 36.97 18.49 35.55 82.93 T3 3.31 78.00 36.97 18.49 28.94 67.54 T4 3.49 78.00 36.97 18.49 28.94 67.54 T5 4.03 68.00 36.97 18.49 25.94 60.54

2002

T1 4.73 148.52 66.07 33.03 54.46 127.1 T2 4.7 84.87 66.07 33.03 35.37 82.54 T3 4.28 72.67 66.07 33.03 31.71 74.00 T4 3.95 54.91 66.07 33.03 26.38 61.57 T5 3.93 49.67 66.07 33.03 24.81 57.90

2003

T1 5.31 169.00 44.13 22.06 5.32 185.75 T2 5.58 128.00 44.13 22.06 45.02 105.05 T3 5.27 90.00 44.13 22.06 33.62 78.45 T4 5.46 85.00 44.13 22.06 32.12 74.95 T5 4.97 80.00 44.13 22.06 30.62 71.45

2004

T1 4.63 120.09 26.90 0 0 146.99 T2 5.27 79.24 26.90 0 0 106.14 T3 5.01 58.83 26.90 0 0 85.73 T4 4.39 46.87 26.90 0 0 73.77 T5 5.51 42.5 26.90 0 0 69.40

2005

T1 3.1 129.00 61.62 30.81 47.94 111.87 T2 3.56 82.00 61.62 30.81 33.84 78.97 T3 3.31 59.00 61.62 30.81 26.94 62.87 T4 3.15 54.00 61.62 30.81 25.44 59.37 T5 3.17 54.00 61.62 30.81 25.44 59.37

18

Table 2. Average yield, irrigation water applied, total water use (ET), water productivity

(WP) and irrigation water productivity (IWP) under different water management practices under field condition.

Treat-ments

Yield (t/ha)

Irrigation (cm)

Effective Rainfall

(cm)

Deep percolation

(cm)

ET (cm)

WP

(kg/ha-mm)

IWP

(kg/ha-mm)

T1 4.55 128 39 24 143 3.18 3.55

T2 4.83 89 39 24 104 4.64 5.43

T3 4.52 69 39 8 100 4.52 6.55

T4 4.43 62 39 8 93 4.76 7.15

T5 4.58 57 39 8 88 5.20 8.04

Table 3. Average yield, water use (ET), water productivity (WP) and water productivity

(IWP) under lysimeter. Treat-ments

Yield (t/ha)

Irrigation (cm)

Rainfall (cm)

Runoff (cm)

Deep percolation,

(cm)

Water use

(cm)

WP

(kg/ha- mm

IWP

(kg/ha- mm)

T1 7.54 77.0 56.8 21.0 14.8 101.7 7.4 9.8

T2 7.79 68.2 56.8 21.0 13.0 77.1 10.1 11.4

T3 7.91 48.5 56.8 21.0 9.2 75.0 10.5 16.3

T4 7.98 42.6 56.8 21.0 13.7 68.1 11.7 18.7

T5 7.22 41.8 56.8 21.0 11.9 68.6 10.5 17.3

Table 4. Average estimated amount of NO3-N leaching under lysimeter and field condition

Treatment

NO3-N leaching (kg/ha)

Lysimeter FieldT1 1.59 52.3

T2 1.56 48.3

T3 1.53 23.5

T4 2.00 17.6

T5 1.09 16.9

19

Fig.1. Rainfall amount during crop growing period

2000

0

15

30

45

60

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121

Days from transplanting

Rai

nfal

l (m

m)

2001

0

15

30

45

601 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121


Rai

nfal

l (m

m)

2002

0

20

40

60

80

100

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121


Rai

nfal

l (m

m)

2003

0

20

40

60

80

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121


Rai

nfal

l (m

m)

2004

0

20

40

60

80

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103

109

115

121


Rai

nfal

l (m

m)

2005

0

20

40

60

80

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101

106


Rai

nfal

l (m

m)

20

Fig.2(a). NO3-N concentration of drainage water during the crop growing season (Field and

lysimeter) during 2000

Lysimeter I1

0

2

4

6

8

10

0 25 50 75 100 125 150Days after transplanting

NO

3-N

Con

c.,m

g/L

I2

02468

10

0 25 50 75 100 125 150

I3

0

2

4

6

8

10

0 25 50 75 100 125 150

I4

0

2

4

6

8

10

0 25 50 75 100 125 150

I5

0

2

4

6

8

0 25 50 75 100 125 150

Field I1

0

2

4

6

8

10

0 25 50 75 100 125 150Days after transplanting

NO

3 C

onc.

, mg/

L

I2

0

2

4

6

8

10

0 25 50 75 100 125 150

I3

0

2

4

6

8

10

0 25 50 75 100 125 150

I4

0

2

4

6

8

10

0 25 50 75 100 125 150

I5

0

2

4

6

8

10

0 25 50 75 100 125 150

21

Fig.2(b). Cumulative NO3-N concentration of drainage water in field during 2001

Sampling at 38 cm depth-50

-40

-30

-20

-10

018 38 39 55 77 81 105 123

DATN

O3-

N (m

g/)l

T1T2T3T4

DAT

-50

-40

-30

-20

-10

09 19 35 51 67 88 111 123

Sampling at 85 cm depth

NO

3-N

(mg/

l)

T1T2T3T4T5

DAT

-50

-40

-30

-20

-10

09 19 35 51 67 88 111 123


NO

3 (m

g./l)

T1T4T5

DAT

-60

-50

-40

-30

-20

-10

09 19 35 51 67 88 111 123

Lysimeter

NO

3-N

(mg/

l)

T1T2T3T4T5

22

Fig. 2(c). Cumulative NO3-N concentration of drainage water in field during 2002


-300

-250

-200

-150

-100

-50

08 29 33 43 58 65 87 117 132

DATN

O3-

N (m

g/)l

T1T2T3T5

DAT

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

8 29 33 43 58 65 87 117


NO

3-N

(mg/

l)

T1T2T3T4T5

DAT

-300

-250

-200

-150

-100

-50

08 29 33 43 58 65 87 117 132


NO

3 (m

g./l)

T1

T4

DAT

-140

-120

-100

-80

-60

-40

-20

08 29 33 43 58 65 87 117

Sampling from lysimeter

NO

3-N

(mg/

l)

T1T2T3T4T5

23

Fig.2(d). Cumulative NO3-N concentration of drainage water in field and lysimeter 2003


-60

-50

-40

-30

-20

-10

08 29 33 43 58 65 87 117

132

DAT

NO 3

-N C

onc.

, mg/

l

T1

T2

T3


-100

-80

-60

-40

-20

08 29 33 43 58 65 87 117 132

DAT

T1

T2

T4

T5


-70

-60

-50

-40

-30

-20

-10

08 29 33 43 58 65 87 117 132

DAT

T1

T4

Sampling from lysimeter-70

-60

-50

-40

-30

-20

-10

08 29 33 43 58 65 87 117 132

T1

I2

T3

T4

T5

24

Fig. 2(e). Cumulative NO3-N concentration of drainage water in field during 2004


-100

-80

-60

-40

-20

09 19 35 51 67 88 111

DATN

O3-

N (m

g/)l

T1T2T3

DAT

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

09 19 35 51 67 88 111


NO

3-N

(mg/

l)

T1T2T3

DAT

-60

-50

-40

-30

-20

-10

09 19 35 51 67 88 111


NO

3 (m

g./l)

T1T4

25

Fig. 2(f). Cumulative NO3-N leaching rate in rice experiment at BINA field during 2005

DAT

-45

-40

-35

-30

-25

-20

-15

-10

-5

01 2 3 4 5 6 7


NO 3

-N (

mg.

/l)

T1T2T5

DAT

-45

-40

-35

-30

-25

-20

-15

-10

-5

00 8 24 39 67 93

Sampling at 85 depth

NO 3

-N (m

g./l)

T1T2T3T4T5

DAT

-35

-30

-25

-20

-15

-10

-5

00 8 24 39 67 93


NO

3-N

(mg.

/l)

T1T4

26

Fig.3(a). NO3-N concentration in soil profile at sowing time and at harvest during 2000

Field

0

1

2

3

4

5

6

0-30 30-60 60-90 90-120Soil depth, cm

NO

3 -N

con

c., m

g/l

MeanofsowingtimeI1

I2

I3

Lysimeter

0

2

4

6

8

10

0-30 30-60 60-90 90-120Soil depth, cm

NO

3 -N

con

c., m

g/l

Mean ofSowingtime I1

I2

I3

I4

27

Fig.3(b). Cumulative NO3-N concentration of soil sample during 2001

Lysimeter

-20

-15

-10

-5

0

0-30 30-60 60-90 90-120Days after transplanting (DAT)

NO

3-N

(mg/

)l

T1T2T3T4

DAT

-20

-15

-10

-5

00-30 30-60 60-90 90-120

Field

NO

3-N

(mg/

l)

T1T2T3T4T5

28

Fig.4. Average NO3-N concentration of drainage water collected from the field

38 cm depth

0

20

40

60

80

9 20 40 65 87 120DAS

NO

3 co

nc. ,

mg/

l

I1I2I3I4I5

85 cm depth

0

20

40

60

80

100

9 20 40 65 87 120DAS

NO

3 co

nc. ,

mg/

l

I1I2I3I4I5

120 cm depth

0

20

40

60

9 20 40 65 87 120DAS

NO

3 co

nc. ,

mg/

l I1I2I5

29

Fig. 5. Average cumulative NO3-N concentration of field and lysimeter soil at harvest

Lysimeter soil

0

6

12

18

0-30 30-60 60-90 90-120Soil depth (cm)

NO

3-N

con

cent

ratio

n (p

pm)

I1I2I3I4I5

Field soil

0

6

12

18

0-30 30-60 60-90 90-120

Soil depth (cm)

NO

3-N

con

cent

ratio

n (p

pm)

I1I2I3I4I5

Water-NO3 Mgt Rice

Documents

Transcript of Water-NO3 Mgt Rice