Water Requirement of Water Requirement of Irrigated GarlicIrrigated Garlic

James E. AyarsJames E. AyarsUSDA-ARS WMRUSDA-ARS WMR

OutlineOutline

IntroductionIntroduction Project OverviewProject Overview ResultsResults ConclusionsConclusions

ConclusionsConclusions

Water requirement for garlic 425 mm (16-Water requirement for garlic 425 mm (16-17 inches)17 inches)

No difference in yield between 100 and No difference in yield between 100 and 125% Et125% Etc c

Significant difference below 100% EtcSignificant difference below 100% Etc Peak KPeak Kcc – 1.3 – 1.3

IntroductionIntroduction

Shift in cropping patterns on west side of the Shift in cropping patterns on west side of the San Joaquin ValleySan Joaquin Valley Reduction in water supplyReduction in water supply Loss of drainage water disposal capacityLoss of drainage water disposal capacity

Short season low water requirement cropsShort season low water requirement crops LettuceLettuce PeppersPeppers GarlicGarlic

No water requirement data for vegetable crop No water requirement data for vegetable crop grown in this areagrown in this area

Materials and MethodsMaterials and Methods

Replicated trial - split plot with 4 repsReplicated trial - split plot with 4 reps 3 irrigation systems3 irrigation systems

Flood/dripFlood/drip Surface drip (SD)Surface drip (SD) Subsurface drip – buried 20 cm (SSD) (8 inches)Subsurface drip – buried 20 cm (SSD) (8 inches)

4 irrigation levels4 irrigation levels 50, 75, 100, 125% of ETc50, 75, 100, 125% of ETc

Planted October 10, 2005 and Harvest July 12-Planted October 10, 2005 and Harvest July 12-18, 200618, 2006

Sprinkled for germinationSprinkled for germination

BB BB L3 L4 L2 L1

M1

L1 L4 L3 L2

M2

L4 L3 L1 L2

M3

Replication I

L1 L2 L3 L4

M2

L1 L4 L2 L3

M1

L3 L1 L4 L2

M3

Replication II

L4 L2 L3 L1

M3

L3 L2 L1 L4

M2

L2 L4 L3 L1

M1

Replication III

L1 L2 L4 L3

M3

L2 L1 L3 L4

M1

L2 L1 L3 L4

M2

Replication IV

Fig. 1. Vegetable crop field layout at the University of California West Side Research and Education Center located near Five Points, CA. Split plot design with three irrigation methods (M1, M2, M3) as main plots and four irrigation levels (L1, L2, L3, L4) as subplots, in four replications. Each subplot is 270 feet long and consists of four 40-inch wide beds. Irrigation levels are based on a percentage of the crop lysimeter evapotranspiration (ET lys). M1 = furrow, M2 = surface drip, and M3 = subsurface drip; L1 = 50% ETlys, L2 = 75% ETlys, L3 = 100% ETlys, and L4 = 125% ETlys. B = border rows.

North

M and M Cont’dM and M Cont’d

Soil – Panoche silt clay loamSoil – Panoche silt clay loam Weighing lysimeter used to measure Etc Weighing lysimeter used to measure Etc Irrigation Management Irrigation Management

Accumulate 1 mm ETc to irrigate Lysimeter and SSDAccumulate 1 mm ETc to irrigate Lysimeter and SSD Accumulate 2 mm ETc to irrigate drip field (SD)Accumulate 2 mm ETc to irrigate drip field (SD) Flood/drip irrigated weekly equal to accumulated EtcFlood/drip irrigated weekly equal to accumulated Etc

ETc accumulation modified by irrigation treatmentETc accumulation modified by irrigation treatment CIMIS weather station used for reference ET CIMIS weather station used for reference ET Weighing grass lysimeter also used for reference ETWeighing grass lysimeter also used for reference ET Canopy cover measured with IR cameraCanopy cover measured with IR camera

CIMIS StationCIMIS Station

Grass Lysimeter

Photographing Canopy Photographing Canopy SizeSize

ResultsResults

25 50 75 100 125 150

Irrigation Treatments

0

100

200

300

400

500

600

App

lied

Wat

er (m

m)

Flood/dripSurface DripSubsurface Drip

4/13/06 4/23/06 5/3/06 5/13/06 5/23/06 6/2/06 6/12/06 6/22/06 7/2/06

Date

0

5

10

15

20

25

30

35

40

45

50

55

60

Soi

l Wta

ter C

onte

nt (%

)

Depth 10 cm20 cm3O cm40 cm50 cm60 cm80 cm100 cm

M1L1 M1L2 M1L3 M1L4 M2L1 M2L2 M2L3 M2L4 M3L1 M3L2 M3L3 M3L4

Irrigation Treatments

0

2

4

6

8

10

12

14

16

18

20

22

Yiel

d (M

g/ha

)

0

1

2

3

4

5

6

7

8

9

10

Bulb w

eight (kg/100)

YieldBulb weight

Flood

SD

SSD

Market Yield, total weight, cull weight Market Yield, total weight, cull weight an soluble solids by irrigation levelan soluble solids by irrigation level

Irrigation Irrigation Level Level % ET% ETcc

Market YieldMarket Yield(Mg/ha)(Mg/ha)

Total WeightTotal Weight(Mg/ha)(Mg/ha)

Cull WtCull Wt(Mg/ha)(Mg/ha)

Soluble SolidsSoluble Solids(%)(%)

5050 13.15*13.15* 20.16*20.16* 1.29*1.29* 36.61*36.61*

7575 16.70*16.70* 23.76*23.76* 1.09*1.09* 36.63*36.63*

100100 19.8019.80 26.9526.95 0.80.8 35.8635.86

125125 20.1720.17 27.6527.65 0.870.87 35.1235.12

SESE 488488 0.570.57 0.060.06 0.2130.213

*Significantly < 100% ETc by Dunnett’s one tailed test (p<0.05)

Soluble Solids and Bulb Weight by SystemSoluble Solids and Bulb Weight by System

Irrigation TypeIrrigation Type Soluble Solids Soluble Solids (%)(%)MeanMean

100 Bulb Weight 100 Bulb Weight (kg) Mean(kg) Mean

SE (bulb weight)SE (bulb weight)

FloodFlood 35.94a35.94a 4.82a4.82a 0.310.31

Surface DripSurface Drip 35.58a35.58a 4.98ab4.98ab 0.440.44

Subsurface dripSubsurface drip 36.89b36.89b 5.22b5.22b 0.310.31

SE (SS%)SE (SS%) 0.180.18

Means not followed by the same letter are significantly different (p<0.5) by Tukey’s multiple range test

2/22/06 3/4/06 3/14/06 3/24/06 4/3/06 4/13/06 4/23/06 5/3/06 5/13/06 5/23/06Date

0

1

2

3

4

5

6

7

8

9

10

11

12

ET

(mm

/day

)

ETo- CIMISETo- GrassRain

0

2

4

6

8

10

12

14

16

18

20

22

24

Rainfall D

epth (mm

)

2/22/06 3/4/06 3/14/06 3/24/06 4/3/06 4/13/06 4/23/06 5/3/06 5/13/06 5/23/06

Date

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

ET (m

m/d

ay)

ETc- Crop LysimeterRain

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

Rainfall D

epth (mm

)

2/22/06 3/4/06 3/14/06 3/24/06 4/3/06 4/13/06 4/23/06 5/3/06 5/13/06 5/23/06 6/2/06

Date

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

Cro

p co

effic

ient

(Kc)

kC-CIMISKc -Grass ReferenceCrop cover

ConclusionsConclusions

Water requirement for garlic 425 mm (16 Water requirement for garlic 425 mm (16 – 17 inches)– 17 inches)

No difference in yield between 100 and No difference in yield between 100 and 125% Et125% Etcc

Significant difference below 100% EtcSignificant difference below 100% Etc Peak KPeak Kcc – 1.3 – 1.3

AcknowledgementsAcknowledgements

Mr. Jim GartungMr. Jim Gartung California Department of Water ResourcesCalifornia Department of Water Resources California State University, Fresno – California State University, Fresno –

Agricultural Research InitiativeAgricultural Research Initiative