Reducing Economic and Environmental Associated Risks of Tomato Production Using Irrigation and Nutrient BMP
I.T. Ayankojo & K.T. MorganNov 29, 2018
Photo credit: I.T. Ayankojo
Introduction
▪ Nutrient management is a key aspect of vegetable production
▪ Efficient nutrient management can improve yield and fruit quality
▪ Irrigation scheduling methods and/or irrigation application rate are critical for an efficient nutrient management
▪ Excessive irrigation application may result in negative economic and environmental consequences
Objectives
➢Overall goal is to reduce both economic (yield factor) and environmental (water, nutrient factors) associated risks in tomato production using best management practices (BMP).
▪ Evaluate an alternative irrigation scheduling method (SmartIrrigation Veg. App) in tomato production
▪ Evaluate the effects of combined irrigation and nitrogen rates on general crop performance
▪ Determine the impact of modified irrigation and nitrogen timing in tomato production
▪ Evaluate an alternative bedding system for both nutrient and water conservation in tomato crop.
What is SI Vegetable App?
Other SI Apps available for use
Joint efforts by
• UF/IFAS
• USDA NIFA
• University of Georgia
For more information please visit<http://smartirrigationapps.org/>
Any of these Apps can be downloaded for free on your smartphone from both iOS and Android platforms
Study location
All the experiments
in this presentation were
conducted
at SWFREC, Immokalee
experimental fieldSWFREC
Immokalee
Materials and Methods: Pre- and post-planting practices
Photo credit: I.T. Ayankojo
All pre- and post-planting operations followed the growers standard• Fumigation• Bedding and bed size• Planting and planting density• Crop protection and harvesting
• Nutrient and irrigation management may change for different studies
• Drip irrigation was used during all studies
Photo credit: I.T. Ayankojo
Study #1: Irrigation Scheduling Methods (Fall ‘15 & Spring ‘16)
Treatment ID Total N (lb A-1) Detail
T1 200 Irrigation 100% IFAS (HI, Grower Standard)
T2 200 Irrigation 66% App (66% SI)
T3 200 Irrigation 100% App (100% SI)
T4 200 Irrigation 150% App (150% SI)
Study #1: Result water use
Grower’s standard (HI) vs SmartIrrigation Veg. App (SI)
Weeks After Transplanting
5 6 7 8 9 10 11 12 13 14 15 16
Cu
mm
ula
tive
Irr
iga
tio
n D
ep
th (
mm
)
0
50
100
150
200
250
300 100% HI
66% SI
100% SI
150% SI
Weeks After Transplanting
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Cu
mm
ula
tive I
rrig
ati
on
Dep
th (
mm
)
0
100
200
300
400
500
600
100% HI
66% SI
100% SI
150% SI
Water Use: Fall 2015 Water Use: Spring 2016
• Water use was 20% (fall) and 17% (spring) lower for 100% SI compared to 100% HI• This may translate in reduction in water pumping cost
Results: Yield
Production Seasons
Fall 2015 Spring 2016
Tot
al M
arke
tabl
e Y
ield
(bo
x/ac
re)
0
1000
2000
3000
4000100% IFAS 66% App 100% App 150% App
▪ All treatments received 200 lb per acre N
▪ SI Veg. App increase tomato yield compared to the growers standard irrigation method
▪ Irrigation at 100% App rates maintained nutrient at tomato root zone hence reduce nutrient leaching
Study #2: Combined irrigation and nitrogen rates (Fall ‘16 & Spring ‘17)
Treatment ID Total N (lb A-1) Detail
T1 120 Irrigation 100% App and Nitrogen 60%
T2 160 Irrigation 100% App and Nitrogen 80%
T3 200 Irrigation 100% App and Nitrogen 100%
T4 240 Irrigation 100% App and Nitrogen 120%
T5 120 Irrigation 66% App and Nitrogen 60%
T6 160 Irrigation 66% App and Nitrogen 80%
T7 200 Irrigation 66% App and Nitrogen 100%
T8 240 Irrigation 66% App and Nitrogen 120%
Results: Yield – Nitrogen rates
▪ N application rate above 160 lb/A does not increase tomato yield under an efficient irrigation management
▪ Lower but efficient N application can reduce production cost
▪ High N application rate can increase leaching and reduce N use efficiency
Production Seasons
Fall 2016 Spring 2017
To
tal M
arke
tab
le Y
ield
(b
ox/
acre
)
0
500
1000
1500
2000
2500
3000120 lb/A - N160 lb/A - N200 lb/A - N240 lb/A - N
Results: Yield – Irrigation rates
Production Seasons
Fall 2016 Spring 2017
To
tal M
arke
tab
le Y
ield
(b
ox/
acre
)
0
500
1000
1500
2000
2500
3000100% App66% App
▪ Irrigation rates at 100% App increase tomato yield irrespective of N application rate
▪ Low irrigation application rate throughout the production season can cause plant stress and reduce tomato yield especially during the spring season
Study #3: Modified irrigation and N timing (Spring ‘18 & Fall ‘18)
Treatment ID Total N (lb A-1) Detail
T1 200 Irrigation 100% App and Bottom mix
T2 200 Irrigation 100% App and No bottom mix
T3 200 Modified irrigation and Bottom mix
T4 200 Modified irrigation and No bottom mix
T5 200 Irrigation 66% App and Bottom mix
T6 200 Irrigation 66% App and No bottom mix
Note: Modified irrigation = 66% App early in the season and 100% App from about 6 weeks after transplanting (6 WAT)
Results: Total Root Length at Crop Growth Stage 3
▪ Lower irrigation rate early in the production season increase tomato root production
▪ Increase in root production does not reduce plant biomass production
▪ Greater root production can improve water and nutrient uptake hence, yield increase
0
20
40
60
80
100
120
140
BM No BM BM No BM BM No BM
100% App Modified 66% App
Tota
l Ro
ot
Len
gth
(cm
)
BM = Bottom mixNo BM = No bottom mix
Results: Total root length at crop growth stage 3 (6 WAT)
Full water rate (100% App) Low water rate (66% App)
Tomato root production increased under 66% App (lower irrigation) compared to 100% App early in the season
Results: Yield (Box/Acre)
▪ Modified irrigation (66% App early and 100% App from 6 WAT) and N timing improve crop performance and increase tomato yield
▪ Increase in yield can result in higher economic return per unit area
0
500
1000
1500
2000
2500
BM No BM BM No BM BM No BM
100% App Modified 66% App
Yie
ld (
Bo
x/h
a)
Total Seasonal N Application (200 lb per A)
Study #4: Alternative bedding system (H2Grow System)
Alternative bedding system: Potential advantage & challenges
Potential advantages
▪ Can eliminate nutrient leaching
▪ Reduce irrigation-water pumping cost
▪ Can eliminate nematode infection
▪ Can reduce production cost*
Potential challenges
▪ May increase initial cost
▪ Appropriate fumigant
▪ Overall management – Under investigation
Result: Tomato growth curve
▪ H2Grow system consistently increase tomato growth compared to the conv. system
▪ Increase in biomass production can reduce sun damage and increase marketable yield
▪ Greater biomass may increase CO2 use efficiency hence yield increase
0
200
400
600
800
1000
1200
Conv. H2Grow Conv. H2Grow Conv. H2Grow
Stage 1 Stage 2 Stage 3
Tota
l Bio
mas
s (l
b/A
)
Conv. = Conventional bedding system (open bottom)
H2Grow = New bedding system with closed bottom
Result: Yield (First harvest, X-large only)
223.61
283.14
0.00
50.00
100.00
150.00
200.00
250.00
300.00
Conv. Bed H2Grow
Yie
ld (
bo
x/A
)
Bed Type
▪ Preliminary data shows that H2grow bed can potentially increase tomato yield up to 20% compared to the conv. bed
▪ Up to 60 boxes increase for extra-large fruit category at first harvest
▪ Increase in crop yield can potentially increase crop economic return
Result: Water Use (First 10 weeks after transplant)
▪ H2Grow bed reduce water up to 62% compared to conventional bedding system
▪ This implies a saving of up to 62% reduction in irrigation cost (Fuel price)
▪ H2Grow system can potentially eliminate negative environmental consequences of tomato production (nutrient leaching) especially on sandy soils.0
20000
40000
60000
80000
100000
120000
Conv. FullWater
Conv. LowWater
H2Grow
wat
er
Use
(G
al/A
)
Conclusions
▪ Irrigation water use was lower for SI App compare to the recommended growers standard
▪ SI App increase tomato yield
▪ N application rate above 160 lb/A–N may not increase tomato yield
▪ Modified irrigation and N application timing increase tomato yield
▪ H2Grow system can significantly reduce production cost, nutrient-based pollution and maintained tomato yield
▪ Efficient irrigation and N management can reduce contamination and production cost with no reduction in yield and fruit quality
Conclusions
▪ Irrigation water use was lower for SI App compare to the recommended growers standard
▪ SI App increase tomato yield
▪ N application rate above 160 lb/A–N may not increase tomato yield
▪ Modified irrigation and N application timing increase tomato yield
▪ H2Grow system can significantly reduce production cost, nutrient-based pollution and maintained tomato yield
▪ Efficient irrigation and N management can reduce contamination and production cost with no reduction in yield and fruit quality
Conclusions
▪ Irrigation water use was lower for SI App compare to the recommended growers standard
▪ SI App increase tomato yield
▪ N application rate above 160 lb/A–N may not increase tomato yield
▪ Modified irrigation and N application timing increase tomato yield
▪ H2Grow system can significantly reduce production cost, nutrient-based pollution and maintained tomato yield
▪ Efficient irrigation and N management can reduce contamination and production cost with no reduction in yield and fruit quality
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Photo credit: I.T. Ayankojo