Verdegaal Brothers Fertilizer

SDI+ Electronics

Improving Pomegranate Fertigation and

Nitrogen Use Efficient with Surface and

Subsurface Drip Irrigation Systems

Contributing Research and Support Staff J.E. Ayars, C.J. Phene, D. Makus, D. Wang, G.S. Banuelos, S. Gao, A. Hendratna, K.R. Day, R. Schoneman, R. Tirado-Corbala, B. Phene, T.M. DeJong, H. Zhang, T. Centofani and UC-KARE Center and USDA-ARS-SJVASC

Supports/Contributors CDFA/Fertilizer Research and Education Program

PARAMOUNT Farming Company LAKOS Separators and Filtration

TORO Irrigation DOROT

SDI+ VERDEGAAL Brothers

Research Objectives

To optimize water-nitrogen interactions to improve Water-use and N-use efficiency of Pomegranate and minimize N leaching losses

a. Determine the effect of three rates of N-fertigation of pomegranate with Drip Irrigation and Subsurface Drip Irrigation on N leaching losses.

b. Determine the seasonal N requirement of DI- and SDI-fertigated pomegranates which improves NUE without yield reduction.

c. Determine if concentrations of macro-, micro-nutrients and healthy bioactive compounds in soil, peel and fruits are influenced by rates of N-fertigation of pomegranate with DI and SDI.

Randomized Complete Block

Design with Subsamples

Surface Drip

Subsurface Drip

50% N

100% N

150% N

Orchard Layout & Design

Five Replications

3.54 acres

16 x 12 ft. spacing

Nitrogen Treatments

Irrigation Treatments

BASIC SDI SYSTEM DESIGN

Installation of Subsurface Drip Irrigation (SDI) line at 20-22 in. depth

N-pHURIC

K2T Phos

Acid AN-20

Sand Media Filter

Lysimeter

Solution

Refill Tank

pH & ECw

meters

N1

SDI DI

N2

SDI DI

N3

SDI DI

Electro-Magnetic Flow Meters

To Lysimeter Refill Tank

Weighing lysimeter (4 x 2 x 2 m) resolution of 0.05 mm of

evapotranspiration

SMP sensor 0.6 m

SMP sensor 0.91 m

SMP sensor 1.22 m

SMP sensor 1.52 m

Water Balance, Evapotranspiration

and Crop Coefficient

Canopy coverage - September 25, 2014

IRRIGATION BY SDI SYSTEMS

0.00

2.50

5.00

7.50

10.00

12.50

15.00

17.50

20.00

22.50

4/30 5/15 5/30 6/14 6/29 7/14 7/29 8/13 8/28 9/12 9/27 10/12

Time, Date

Irr

igati

on

Wate

r, g

al.

/tr

ee

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

Irr

igati

on

Wate

r, m

m

Why is Irrigation Scheduling Important?

Computerized

Control System

Linked

To Real Time

ETc on

Lysimeter

Control System

POMEGRANATE WATER

BALANCE (in.)

Year ETo Precip. Irrig ETc* Drainage

2010 49.73 17.34 1.00 2.10 ???

2011 50.9 10.42 8.49 9.8 0

2012 54.6 8.97 17.7 19.7 0

2013 55 3.21 24.2 26.9 0

2014** 50.6 4.77 28.4 31.1 0

2011 ETc values from 5/1 to 12/8 only.

*Lysimeter ETc adjusted for orchard spacing

**2014 Values are from January 1 to September 21

Crop Evapotranspiration, ETc

Reference Evapotranspiration, ETo Crop Coefficient, kc

ETc = ETo * kc

CIMIS, California Irrigation Management

Information System (www.cimis.water.ca.gov)

The crop coefficient, kc, is

developed to relate ETo to the

crop

Crop Evapotranspiration, ETc

Reference Evapotranspiration, ETo Crop Coefficient, kc

The daily grass reference ET (CIMIS ETo)

and the orchard evapotranspiration (ETc)

measured hourly by the weighing lysimeter

were used to develop irrigation requirement

and crop coefficient for maturing

pomegranate.

0.0

00.2

00.4

00.6

00.8

01.0

01.2

01.4

0

0

2

4

6

8

10

12

14

163/1

3/9

3/17

3/25

4/2

4/10

4/18

4/26

5/4

5/12

5/20

5/28

6/5

6/13

6/21

6/29

7/7

7/15

7/23

7/31

8/8

8/16

8/24

9/1

9/9

9/17

Dail

y E

Tc &

ET

o (m

m)

2014 CIMIS ETo, Pomegranate ETc and Kc

CIMIS ETo (mm) ETc Kc (Ly, daily)C

rop

Co

effic

ien

t, Kc

0.0

00.2

00.4

00.6

00.8

01.0

01.2

01.4

02/29

3/8

3/16

3/24

4/1

4/9

4/17

4/25

5/3

5/11

5/19

5/27

6/4

6/12

6/20

6/28

7/6

7/14

7/22

7/30

8/7

8/15

8/23

8/31

9/8

9/16

9/24

10/

210/

10

2014 CIMIS ETo, Pomegranate ETc and Kc

Kc (Ly, daily)C

rop

Co

effic

ien

t, Kc

R² = 0.8292

0.0

00

.50

1.0

01

.50

2/2

9

3/9

3/1

8

3/2

7

4/5

4/1

4

4/2

3

5/2

5/1

1

5/2

0

5/2

9

6/7

6/1

6

6/2

5

7/4

7/1

3

7/2

2

7/3

1

8/9

8/1

8

8/2

7

9/5

9/1

4

9/2

3

10

/2

10

/11

2014 CIMIS ETo, Pomegranate ETc and Kc Kc (Ly, daily) Log. (Kc (Ly, daily))

Cro

p C

oe

fficien

t, Kc

Y = 0.547*ln(x) -2.1059

0.19

[VALUE]

0.40

0.48 0.55

0.61 0.67

0.72 0.76

0.80 0.84

0.88 0.92

0.95

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct

Cro

p C

oef

fici

ent,

Kc

Bi-monthly Pomegranate Kc

Bi-monthly Pomegranate Kc for

2014

1 – 15 Mar 0.19 15 – 30 Mar 0.30

1 – 15 Apr 0.40 16 – 30 Apr 0.48 1 – 15 May 0.55

16 – 30 May 0.61 1 – 15 Jun 0.67

16 – 30 Jun 0.72 1 – 15 Jul 0.76

16 – 30 Jul 0.80 1 – 15 Aug 0.84

16 – 30 Aug 0.88 1 – 15 Sep 0.92

16 – 30 Sep 0.95

Relative Soil Water Content as Affected by Soil Texture

-52.0

-50.0

-48.0

-46.0

-44.0

-42.0

-40.0

-38.0

-36.0

-34.0

-32.0

-30.0

-28.0

-26.0

-24.0

-22.01/0 1/15 1/30 2/14 2/29 3/15 3/30 4/14 4/29 5/14 5/29 6/13 6/28 7/13 7/28 8/12 8/27 9/11 9/2610/11SoilM

atricPoten

al,cb

2014AverageDailySoilMatricPoten al

SMP-24 SMP-36 SMP-48 SMP-60

LysimeterPump&TankfillProblems

3/24Irriga

onStarted

3/10TreeLeafout

4/11FullBloom

SMPControlZone

-1.30

-1.25

-1.20

-1.15

-1.10

-1.05

-1.00

-0.95

-0.90

-0.85

-0.80

-0.75

-0.70

-0.65

-0.60

-0.55

-0.501/0 1/15 1/30 2/14 2/29 3/15 3/30 4/14 4/29 5/14 5/29 6/13 6/28 7/13 7/28 8/12 8/27 9/11 9/2610/11

So

il H

ydra

uli

c G

rad

ien

t, c

b/

cm

2014 Daily Averaged Soil Hydraulic Gradient

HG 36-24 HG 48-36 HG 60-48

HG 48-

36

Zero

Drainage

HG 36-

24

HG 60-48

The Nitrogen Cycle

SOIL N FORMS

N2, NO, N2O, NO3,

NO2 , NH4

INPUTS

Rainfall

Irrigation

Bacterial Nitrification

Organic Matter

Mineralization

OUTPUTS

Denitrification

Leaching

Plant Consumption

Fixation

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60

So

il D

epth

, in

Soil Nitrate, ppm

Soil Nitrate Profile, 12/2013

DI SDI

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Soil

Dep

th,

in

Soil Nitrate, ppm

Soil Nitrate Profile, 12/2013

DI-N1 SDI-N1 DI-N2 SDI-N2 DI-N3 SDI-N3

2013 Yields Marketable Total Irrigation Methods Yield lb/ac Yield, lb/ac

Surface Drip (DI) 29,231a 29,652a

Subsurface Drip (SDI) 30,834a 31,485a

Prob > "F" value NS NS Nitrogen Levels (N)

(N-1) 62 lb N/ac 28,930a 29,511a

(N-2) 149 lb N/ac 30,353a 30,861a

(N-3) 249 lb N/ac 30,934a 31,455a

Prob > "F" value NS NS

Effects of irrigation and nitrogen treatments on

WUE and NUE of pomegranate in 2013.

IRRIGATION WUE- WUE NUE-N1 NUE-N2 NUE-N3

TREATMENTS PRIME JUICE

lb/ac-in lb fruit/lb N/ac

DI 383a 165a 118a 67a 39a

SDI 456b 184a 132a 53b 41a

% SDI > DI 19.10% 11.50% 11.90% -20.90% 5.10%

Weed Biomass Study

Z LSMEAN separation at the probability shown.

Weed IR surface Seed bank

Effects: biomass temperature seeds g/m

2 (d.w. basis) (º C) (per 450 cc soil)

Irrigation method: (I)

Surface drip 569 aZ

49.9 b 15.3 a

Sub-surface drip 81 b 57.0 a 1.0 b Prob. > ‘F’ value: <0.0001 < 0.0001 <0.0001

Nitrogen rate: (N)

46 lbs/ac 250 b 53.7 ab 8.3 a

148 lbs/ac 416 a 55.2 a 9.7 a 249 lbs/ac 310 ab 51.6 b 6.5 a Prob. > ‘F’ value: 0.07 0.12 NS

I X N interaction: NS NS NS

Effects of Irrigation and Fertigation

Treatments on Residual Weed Biomass

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

3.2

4/11 5/11 6/10 7/10 8/9 9/8

%

2012

N1 N2 N3

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

3.2

4/11 5/11 6/10 7/10 8/9 9/8

%

2013

N1 N2 N3

TOTAL NITROGEN IN LEAF TISSUE (%)

N app

N app

42

44

46

48

50

52

54

56

58

60

62

64

4/11 5/11 6/10 7/10 8/9 9/8

%

2012

N1 N2 N3

N app

42

44

46

48

50

52

54

56

58

60

62

64

4/11 5/11 6/10 7/10 8/9 9/8

%

2013

N1 N2 N3

N app

TOTAL CARBON IN LEAF TISSUE (%)

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

3.2

4/11 5/11 6/10 7/10 8/9 9/8

%

2014

TOTAL NITROGEN IN LEAF TISSUE (%)

N1 N2 N3

N app

42

44

46

48

50

52

54

56

58

60

62

64

4/11 5/11 6/10 7/10 8/9 9/8

%

2014

TOTAL CARBON IN LEAF TISSUE (%)

N1 N2 N3

N app

Analysis of Neutraceutical

Compounds in Pomegranates

1. No significant differences in pH and Soluble solids were measured between treatments.

2. Mineral Elements:

--In N1-SDI concentrations of Cu, Fe and Na > all other treatments.

--Concentration of Ni in N1-DI > all other treatments.

--B and Ca concentrations in juice of N1-DI and N1-SDI > N3-DI and N3-SDI.

--Mn concentration in N3-SDI > all other treatments.

--No significant differences were observed for all other elements..

3. No significant differences in total phenolics between treatments were observed.

4. No significant differences between treatments for all anthocyanins and non-anthocyanins

compounds were observed.

5. No significant difference in vitamin C was observed between treatments.

Conclusions

Following four and half years of intensive pomegranate irrigation and

fertigation research with high frequency surface drip irrigation (DI) and

subsurface drip irrigation (SDI), preliminary results have demonstrated

that the high frequency SDI system has the potential to provide:

1. More efficient water use efficiency (WUE) than DI,

2. Larger tree than DI,

3. Lower weed population and mass than DI,

4. Lower potential for nitrate-nitrogen (N) leaching than DI,

5. Improved orchard cultural practices, development and production

6. No significant differences in pomegranate fruit and juice quality.