Improving Irrigation and Nutrient Management of Central Coast Vegetable and Berry Crops

Michael CahnIrrigation and Water Resources AdvisorUC Cooperative Extension, Monterey County

Collaborators Aziz Baameur, UCCE Santa Clara Co. Andre Biscaro, UCCE Ventura Co. Mark Bolda, UCCE Santa Cruz Co. Surendra Dara, UCCE Santa Barbara Co. Oleg Daugovish, UCCE Ventura Co. Mark Gaskell, UCCE Santa Barbara Co. Tim Hartz, Dept. Plant Sci, UC Davis Cayle Little, Ca. Dept. of Water Resources Richard Smith, UCCE Monterey Co. Rick Snyder, LAWR, UC Davis Dave Krause and Bryon Noel, UCANR CSIT

Acknowledgements

ANR Strategic Initiative Grant (2013) California Department of Food and Agriculture (CDFA),

FREP CDFA Specialty Crop Block Grant California Celery Research Board California Pepper Commission Driscolls Berry Grower participants

Central Coast

The Central Coast is the Salad Bowl Capital of the US

74% of lettuce produced in the US is from California

LettuceBroccoliCeleryCauliflowerBaby greensSpinachMushrooms

ArtichokesCarrotsKaleRadicchioPeasAsparagusOnions (green)

Top vegetables by value:

85% of US Strawberry Production

99% of US Raspberry Production

National Geographic Magazine, 2010

http://ngm.nationalgeographic.com/2010/0

4/water/plumbing-california-animation

Ground Water is the Largest Water Supply on the Central Coast

Salinas Valley Aquifers

Deep Aquifer

122 m Aquifer

55 m Aquifer

Monterey County Water Resource Agency

Nitrate contamination of Ground Water

MCWRA

Harter and Lund, 2012

Nitrogen use reporting started October, 2014

2 to 3 vegetable crops per year

High rates of water and fertilizer applied to

maximize economic returns for yield and

quality

Shallow rooted crops

Why is Managing Agricultural Water Quality

Challenging on the Central Coast?

Approximately half of the

above ground biomass is

removed at harvest

60 to 70 lbs of nitrogen per

acre remains as residue

Field Number

1 3 5 7 9 11 13 15 17 19

Applie

d W

ate

r (%

Cro

p E

T)

0

50

100

150

200

250

300

350

Avg Applied Water = 176% of Crop ET

Applied Water as Percentage of

Crop ET (Lettuce)

Tools for Managing Water and NitrogenFertilizer in Vegetables

Soil nitrate quick test

Weather-based irrigation scheduling

Minimum soil nitrate

threshold for needed for

developmental stages of

crop

N uptake rate (by

development stage)

Total N uptake

Other information needed

for N fertilizer

recommendations:

CIMIS weather network

ETcrop = ETref Kcrop

Kc can vary from 0.1 to 1.2

Converting Reference ET to Crop ET:

Weather-based irrigation scheduling

29 DAP 41 DAP

47 DAP 65 DAP

Goal: Develop guidelines that will assist farmers with

improving nitrogen and water management of vegetable

and berry crops.

1. Determine water and nitrogen needs of coastal vegetable and

berry crops

2. Develop outreach tools to ensure that research results are

used by farmers

Approach: “Many hands make light work”

1. Standard protocols for sampling commercial fields

2. > 50 commercial fields evaluated during 2014

3. Pool data for analysis

4. Extension products: guidelines, expand CropManage, Industry

presentations

Crops evaluated:

Baby LettuceBlackberryBroccoliCabbageCauliflowerCelery

MizunaLeaf LettucePepperRaspberrySpinachStrawberry

Data collected from commercial fields

1. Nitrogen uptake2. Soil Nitrate3. Applied Fertilizer N4. Canopy development5. Rooting depth6. 4

Crop

Number of

Field Sites

Broccoli 6 Monterey, Santa Barbara

Cabbage 5 Monterey

Caneberries 1 Santa Barbara

Cauliflower 6 Monterey, Santa Barbara

Celery 6 Monterey, Ventura

High density leafy greens 13 Monterey

Peppers 7 Monterey, Santa Clara

Strawberry 9 Santa Barbara, Ventura

Total 53

Counties

2014 Commercial Field Sites

Fraction of Crop Cycle

0.0 0.2 0.4 0.6 0.8 1.0

Fra

ctio

n o

f M

axim

um

Can

op

y C

ove

r

0.0

0.2

0.4

0.6

0.8

1.0

Biomass Sampling: Nitrogen Uptake of Raspberry

Fraction of growing season

0.2 0.4 0.6 0.8 1.0

Fra

ction o

f N

upta

ke

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Nitrogen Uptake Pattern of Broccoli

Crop Season a b Xo

N uptake at

harvest (Nmax)

Crop

cycle Sites

lbs N/acre days #

broccoli winter 2.2050 0.1480 1.0274 249 139 4

broccoli summer 1.0835 0.1292 0.6968 337 86 10

cauliflower summer 1.0623 0.1306 0.6519 283 74 6

cauliflower winter 1.5309 0.1446 0.9087 274 127 4

red cabbage summer 1.0346 0.1416 0.6080 386 90 3

green cabbage summer 1.0411 0.1354 0.6429 317 76 7

Nitrogen Uptake Pattern of Cole Crops

Root Depth of Broccoli

Energy Balance approach to measuring Crop ET

Net Radiometer

Thermal couple

Sonic Anemometer

Evaluate Crop Coefficients

Kc = ETa/ETref

Expand CropManage to additional commodities:Web-based Irrigation and N management decision support tool

https://ucanr.edu/cropmanage

The road ahead…

Microsoft .NET Framework

New version of CropManage under development

Dedicated programmer for CM Better user-interface Faster speed More flexibility to support different types of

commodities Web-service for partnering Usage reporting

Summary

We are developing basic information needed for understanding nitrogen and water requirements of coastal vegetable and berry crops

Growers need this information to improve water conservation and minimize nitrate impacts on water supplies.

Team approach has been effective in collecting a lot of data quickly over a large region.