reducing economic and environmental associated risks of ......nov 29, 2018 · nutrient management...

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


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


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)



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)


T1 120 Irrigation 100% App and Nitrogen 60%








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


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


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)


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

THANK YOU

?


reducing economic and environmental associated risks of ......nov 29, 2018 · nutrient management...

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