Irrigation and Nitrogen Management Web‐Based Software for Lettuce ProductionWeb Based Software for Lettuce Production
Michael CahnIrrigation and Water Resources AdvisorUniversity of California, Cooperative, Monterey Co
Acknowledgements
California Department of Food and AgricultureCalifornia Department of Food and Agriculture, Fertilizer Research and Education ProgramUC ANR Communication ServicesUC ANR Communication ServicesGrower participantsChiquita FreshExpressChiquita FreshExpress
Nitrate is part of CA Central Coast Agricultural Water Quality Regulations
regulatory compliance will require management changesregulatory compliance will require management changesuse nitrogen fertilizer more efficientlyaccount for all sources contributing to crop uptake of Nimprove irrigation managementrecord keeping and reportingdocument improvements in water qualitydocument improvements in water quality
Tools for Managing Water and Nitrogen F ili i LFertilizer in Lettuce
Quick nitrate soil test (20 NO N 70 80 lb f N/ /f )(20 ppm NO3‐N = 70 to 80 lbs of N/acre/ft)
Weather‐based irrigation scheduling
Commercial Lettuce Nitrogen Fertilizer Trials
300
Standard BMP
200
250
Lbs N/A212
Difference 66 lbs/A
150lbs
N/A
146
66 lbs/A
@ 0.60/lb N$40/A
50
100=$40/A
0
50
1 2 3 4 5 6 Ave1 2 3 4 5 6 AveField
Commercial Yield
1000
1200
97% of G
800
1000
e
Grower
600
xes/
Acr
e
GRBMP
200
400
Box
BMP
01 2 3 4 5 Avg
FieldField
Applied Water as Percentage of Crop ET (Lettuce)
) 300
350Crop ET (Lettuce)
Cro
p ET
)
250
300 Avg Applied Water = 176% of Crop ET
ater
(% C
150
200
pplie
d W
a
100
150
Ap
0
50
Field Number
1 3 5 7 9 11 13 15 17 19
I i ti T i l i L ttIrrigation Trials in Lettuce
WeatherStandard BMP
Estimated Crop ETc
Irrigation
requirement 1 Water use reduction Total Applied Water
- based
Trial Sitep
(inches)q(inches) (%)
King City 17.7 14.7 10.1 13.4 17S. Salinas 9.9 8.7 7.6 8.9 12
pp(inches)
San Ardo 19.4 11.9 6.7 8.7 39N. Salinas 10.7 10.4 7.0 8.4 3S. Salinas 2 10.9 10.1 6.1 7.6 7
Average 13.7 11.2 7.5 9.4 16
1. Irrigation requirement = ETc/distribution uniformity
Weather‐based Irrigation Scheduling
Converting 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 Lettuceie
nt (K
c)
0 6
0.8
47 DAP 65 DAP
op C
oeffi
c
0.4
0.6
SprinklerDrip
Cro
0.0
0.2 Average Kc = 0.33 during germination with sprinklers
Days after Planting
0 20 40 60 80
Other factors for determining an irrigation g gschedule:
Soil water holding capacityCrop rooting depthIrrigation system application rateIrrigation system application uniformity
hi f i ( li i )Leaching fraction (water salinity)Crop development stage
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 makersmakers One farm manager may be responsible for >200 fields during a seasonfields during a seasonOther responsibilities besides water and fertilizer N managementN management
Web‐based Irrigation and N management software for lettuce
https://ucanr.org/cropmanage
CropManage Web‐based Tool:Assist growers in making decisions on irrigation and nitrogen fertilizer management
Intuitive, simple, quick to use.Accessible from smart phone, tablet computer,Accessible from smart phone, tablet computer, desktop computerGuide irrigation schedules using CIMIS weatherGuide irrigation schedules using CIMIS weather data. Guide nitrogen fertilization decisions using quickGuide nitrogen fertilization decisions using quick nitrate test data.Maintain and share irrigation, fertilizer, and soilMaintain and share irrigation, fertilizer, and soil test records for multiple fields and farms.
Integrate information from multiple sources
Soil and Ranch base info Crop ET model Watering Recommendation
Database driven web
CIMIS EToCrop N model
Recommendation
N fertilizer
applicationSoil nitrate test
Recom‐mendation
Record display and data export
Field sensors
data export
Decision support using crop models
How is N fertilizer rate determinedHow is N fertilizer rate determined from the quick nitrate test?
Future Crop N uptakeFertilizer N Rate = Future Crop N uptake
– (Quick Test N ‐ threshold NO3‐N)
Fertilizer N Rate
– predicted soil mineralization N
– predicted plant residue N
100100Iceberg lettuce canopy cover
over
(%)
60
80
over
(%)
60
80
Can
opy
Co
20
40
Can
opy
Co
20
40
Days after Planting
0 10 20 30 40 50 60 700
Days after Planting
0 10 20 30 40 50 60 700
%)
100
Canopy b = 1 01 x Canopy d 0 69%)
100
Canopy b = 1 01 x Canopy d 0 69
anop
y C
over
(%60
80 Canopyobs = 1.01 x Canopypred - 0.69
R2=0.99an
opy
Cov
er (%
60
80 Canopyobs = 1.01 x Canopypred - 0.69
R2=0.99O
bser
ved
Ca
20
40
Obs
erve
d C
a
20
40
Predicted Canopy Cover (%)
0 20 40 60 80 1000
Predicted Canopy Cover (%)
0 20 40 60 80 1000
Available moisture depends on soil type and rooting depthg p
0Rooting Depth of Lettuce(in
ches
)
10
otin
g D
epth
20
Roo
30
Days after Planting0 10 20 30 40 50 60 70 80
Spatial CIMIS ETo Reporting
How much water was applied?
Evaluate and document water management
s) 12
water managementr (
inch
es
10
12
CropManage RecommendationGrower Application
ed W
ater
6
8
ve A
pplie
4
6
Cum
ulat
iv
0
2
Days after Planting
0 10 20 30 40 50 60
C
Soil Summary
Fertilizer Summary
Watering Summary Table
Field Validation of CropManage
TreatmentApplied N Fertilizer
Commercial Yield
lb ‐‐‐‐‐‐‐ lbs per acre ‐‐‐‐‐‐‐‐CropManage 149 18760Grower Standard 211 19114Grower Standard 211 19114
The road ahead…
Interface with UCD online Soil Survey Tool
Soil moisture monitoring
s)
0
sion
(cba
rs10
oist
ure
tens
20
8 inches
soil
mo 30
40
8 inches18 inches
Date
9-16 9-18 9-20 9-22 9-24 9-26 9-28 9-30 40
Final Thoughts
Web‐based applications can integrate complex data and models into simple to use decision support tools
CropManage is not just for growers. It is a potential tool for crop consultants to use in assisting growers withfor crop consultants to use in assisting growers with water and N management decisions.
We will offer training workshops on CropManage beginning March 2013.