Irrigation and Nitrogen Management Web Based Software for Lettuce ProductionWeb‐Based Software for Lettuce Production

Michael CahnMichael CahnIrrigation and Water Resources AdvisorU i it f C lif i C ti M t CUniversity of California, Cooperative, Monterey Co

Acknowledgements

Tim Hartz, Richard SmithCalifornia Department of Food and Agriculture, p g ,Fertilizer Research and Education ProgramUC ANR Communication Services Bryon NoelUC ANR Communication Services, Bryon NoelLee Johnson and Forrest Melton, CSUMB/NASAG ti i tGrower participantsChiquita FreshExpressTanimura and Antle

Lower Salinas Nutrient TMDLSalinas Valley Basin Plan

Ag OrderSWRCB SBX2 1

Tools for Managing Water and Nitrogen Fertilizer in Lettuce

Soil nitrate quick testSoil nitrate quick test  (20 ppm NO3‐N = 70 to 80 lbs of  N/acre/ft) 

Weather‐based irrigation schedulingWeather based irrigation scheduling

Commercial Lettuce Nitrogen Fertilizer Trials

300

Standard BMP

250

150

200

bs N

/A

100

lb

Standard = 212 lbs N/acreBMP = 146 lbs N/acre

Difference = 66 lbs N/Acre

50

BMP = 146 lbs N/acre 66 lbs N/Acre

0

1 2 3 4 5 6 AveFieldField

Weather‐based irrigation scheduling

Converting Reference ET toConverting Reference ET to Crop ET:

ETcrop = ETref Kcrop

Kc can vary from 0.1 to 1.2

CIMIS weather networkCIMIS weather network

29 DAP 41 DAP

1 0sprinkler irrigation events

Estimated Kc of Lettuce(K

c) 0.8

1.0oe

ffici

ent

0.6

Sprinkler47 DAP 65 DAP

Cro

p C

o

0.2

0.4SprinklerDrip

Average Kc = 0.33 during germination with sprinklers

0 20 40 60 800.0

Days after Planting

0 20 40 60 80

Other information needs to be consideredI i ti S t U if it dIrrigation System Uniformity and 

Application RateRooting Depth

S li it f W t SS il T Salinity of Water SourceSoil Type

How can water and N management tools be useful for large vegetable growing operations?useful for large vegetable growing operations?

Large growing operations have multiple decision makers One farm manager may be responsible for >100One farm manager may be responsible for >100 fields during a seasonOther responsibilities besides water and fertilizerOther responsibilities besides water and fertilizer N management

Web‐based Irrigation and N management  software for lettucesoftware for lettuce

https://ucanr.edu/cropmanage

Integrate information from multiple sources

Crop ET modelWatering R d i

Soil and Ranch

Database 

Crop ET model Recommendation

Driven Web Application

N fertilizer RecommendationCIMIS ETo

Crop N model

lSoil nitrate testDisplay and export water and fertilizer records

Field sensorsSoil nitrate test

Decision support using crop models

Current crops supportedCurrent crops supported 

Romaine, 40‐inch wide beds (2 plant rows)Romaine, 80‐inch wide beds (5 to 6 plant rows) , ( p )Iceberg, 40‐inch wide beds (2 plant rows)Iceberg 80‐inch wide beds (5 to 6 plant rows)Iceberg, 80 inch wide beds (5 to 6 plant rows)

Steps to Using CropManageSteps to Using CropManage

1. Establish user login2 S h2. Set up a ranch3. Add new plantings to ranch4. Enter soil tests, fertilizer, or 

irrigation events for plantingsgat o e e ts o p a t gs

How is N fertilizer rate determinedHow is N fertilizer rate determined from the quick nitrate test?

Recommended F ili N Future Crop N uptake

( )

Fertilizer N =

– (Quick Test N  ‐ threshold NO3‐N) 

l l– Soil mineralization N 

l d– Plant residue N

N uptake rate by head lettuce (40 i h id b d )(40 inch‐wide beds)

ptak

e

1.0

1.2

mum

N u

p

0.8

of m

axim

0.4

0.6

Frac

tion

0.2

Fraction of crop growth period

0.0 0.2 0.4 0.6 0.8 1.00.0

Fraction of crop growth period

100100Iceberg lettuce canopy cover

ver (

%)

60

80

ver (

%)

60

80

Can

opy

Co

20

40

Can

opy

Co

20

40

0 10 20 30 40 50 60 700

20

0 10 20 30 40 50 60 700

20

Days after PlantingDays after Planting

Spatial CIMIS ETo Reporting

Interface with UCD SoilWeb Tool 

Irrigation System Application Rate (inches/hr)

User Support: CropManage Blog

How much water was applied?

Evaluate and Document Water Management

nche

s)

10

12

CropManage Recommendationnche

s)

14

16

CropManage RecommendationGrower Application

Wat

er (i

8

10 p gGrower Application

Wat

er (i

10

12Grower Application

pplie

d W

6

App

lied

W

6

8

lativ

e A

2

4

lativ

e A

2

4

6

0 10 20 30 40 50 60

Cum

ul

0

2

0 10 20 30 40 50 60

Cum

u

0

2

Days after Planting

0 10 20 30 40 50 60Days after Planting

0 10 20 30 40 50 60

Field Validation of CropManagep g

Applied water Commercial Treatment sprinkler drip1

lbs/acreinchesYield

Grower Standard 4.1 4.9 17935CropManage 4.1 3.8 183891 comparison was on last 7 irrigations

Applied N CommercialTreatment

Applied N Fertilizer

Commercial Yield

lbs per acre ------- lbs per acre --------Grower Standard 211 19114CropManage 149 18760CropManage 149 18760

Summary of Commercial Lettuce Strip Trials (2012‐2013)ow

er)

120

140Grower CropManage

% o

f Gro

80

100

e Yi

eld

(%

60

80

33% (57 lbs N/Ac) less N applied

arke

tabl

e

20

4033%  (57 lbs N/Ac) less N applied following CropManage

1 2 3 4 5 6 AVG

Ma

0

20

Trial

Replicated Irrigation Trial for Iceberg Lettuce

CFR1

Treatment untrimmed trimmed untrimmed trimmed yieldhead wt carton yield

Treatment untrimmed trimmed untrimmed trimmed yield lbs/head

Grower standard (150% ETc) 2.73 1.60 73903 43221 41070 --------- lbs/acre ----------

CropManage (100% ETc) 2.76 1.61 75623 44109 39579LSD0.05 ns ns ns ns ns1. Cored for region

Grower interest

> 350 users> 350 users> 100 Ranches3500 i i CM> 3500 visits to CM 

blog since Jan 2013g

The road ahead…

N contribution from irrigation water?g

Final Thoughts

Web applications can be useful for repackaging research lt i t i l t d i i t t lresults into simple to use decision support tools

W b l h l t k th i ti dWeb apps can also help growers track their practices and demonstrate they are managing nutrients and water ffi i tlefficiently

C M i t ti l t l f lt t dCropManage is a potential tool for crop consultants and advisers to use in assisting growers with water and N 

t d i imanagement decisions.

Questions?