Water-Conserving Irrigation Systems for
Furrow Irrigated Soybean and Rice
Grown in the Mississippi Delta
Joe Massey
Department of Plant & Soil Sciences
Mississippi State University
Acknowledgements
Collaborators
• Justin Dulaney
(Coahoma Co.)
• Earl Kline
(Bolivar Co.)
• Collier Tillman
(Leflore Co.)
• Buddy Allen
(Tunica Co.)
• Kirk Satterfield
(Bolivar Co.)
• Tim Walker
(MS DREC)
• Shane Powers
(YMD)
• Lyle Pringle
(MSU DREC)
• Jim Thomas
(MSU ABE ret.)
• Tom Eubank
(MSU DREC)
Support
• MAFES
• MS Rice Promotion
Board
• MS Water Resources
Research Institute
• MS Soybean
Promotion Board
• YMD
Soybean-Rice Rotation
• Common rotations are 2:1 or 1:1
soybean:rice.
• 2008 crop value: ~$430 million (soybean) and
~$208 million (rice) for the Mississippi Delta.
Crop Acres in MS Delta
USDA NASS (2011)
Harvested Acres (thousands)
1600
1400
Soybean Acres (Delta only)
1200
1000
800
600
400
Rice Acres
200
0
1998
2000
2002
2004
2006
Year
2008
2010
2012
Avg. Irrigation Water Use (A-ft/A)
Average Irrigation Water Use (A-ft/A)
(YMD, 2010)
4
9-yr rice avg = ~3.07 A-ft/A
3.5
3
2.5
2
1.5
9-yr soybean avg = ~0.76 A-ft/A
1
0.5
0
2000
2002
2004
2006
Year
2008
2010
2012
Estimated Irrigation Water Use (A-ft/A)
247,000 A rice @ 100% flood irrigated x 3.07 A-ft/A =
~758,000 A-ft water/yr (rice crop)
1,054,000 A soybean @ 65% irrigated x 0.76 A-ft/A =
~520,000 A-ft water/yr (soybean crop)
Estimated combined rice-soy water use: ~1.3 million A-ft/yr
YMD total water use in 2010: ~2.5 million A-ft/yr
2011 Soybean Phaucet-Optimzed
Furrow Irrigation Results
Tillman Farm
Homeplace
Fields A and B
Conventional
Design
(33.8 A)
Phaucet
+ Timer
(40.6 A)
Savings
(%)
16.8
13.7
22.6
4
4
---
Energy Use
(gal/A) (est.)
11.8
9.6
20
Total Pumping
Time (hrs)
NA
NA
NA
Soybean
Yield (bu/A)
33.8
42.6
21
Water Use
(A-inches)
# of Irrigations
Potential Water Savings in FurrowIrrigated Soybean (A-ft/A)
1,054,000 A soybean @ 65% irrigated x 0.76 A-ft/A =
~520,000 A-ft water/yr (soybean crop)
@ 22% savings via Phaucet = up to ~100,000 A-ft
YMD estimated average overdraft: ~300,000 A-ft/yr
Soybean Phaucet-Optimzed
Furrow Irrigation Results
Comments:
MSU Phaucet trials have been conducted
on rectangular, relatively ‘uniform’
fields…savings could be greater than
22% on hard-to-water, irregularly-shaped
fields, but such fields are hard to study.
Phaucet Comments:
Pump timers may be important to securing
savings unless someone will be present to
shut-off well when field waters out.
Murphy Switch Brand
~$280 each
Grainger Brand Switch
~$30 each
Potential Water & Energy Savings in Rice
Pringle (1994)
How much water does rice actually need?
Depending on soil and cultivar, rice needs ~14 to 25
inches water (1.1 to 2.1 A-ft/A) per 80-day flood in
Mississippi.
Avg. Deep
Percolation Losses
Soil
Inches per
80-d Flood
Sharkey
1.2
Alligator
1.2
Forestdale
3.3
Brittain
3.6
1991 rainfall was 66.5% of avg.
1993 rainfall was 97.9% of avg.
Avg. EvapoTranspiration Losses
Variety
Measured
ET (inches)
Rosemont
12.8 ± 3.0
Maybelle
13.6 ± 1.7
Newbonnet
15.7 ± 2.2
Lemont
16.7 ± 2.1
ET was linearly-related to biomass
production
YMD (2009)
(A-in/A)
6-yr average water use in Mississippi rice production
55
50
45
40
35
30
25
20
15
10
5
0
44
38
38
31
Total H2O Requirements (ET + Soil Percolation) = ~14 to 25 A-in/A
20
9
9
Coutour
Levees
Straight SL + Side
Levee
Inlet
(SL)
Zero
Grade
Pringle (1994): Water Use Requirements for Rice in the MS Delta
Seasonal
Rainfall
Estimated Adoption Rates for Rice
Irrigation Systems in MS (2009)
Sources: MSU Extension Service grower surveys; rice consultant surveys; YMD permitting data.
Zero-Grade Rice Irrigation
Agronomic Issues Limit Adoption
Drawbacks of Zero-Grade Systems:
1. Water-logging of rotational crops,
leading to continuous rice systems
Conversion of 0-Grade to “Ridge-Irrigation” in Tunica Co.
which can result in
Farmers creating crest in center of 0-grade 40-acre fields to
2. Pest management issues
have 0.3-ft fall:
(weed resistance; herbicide carryover) and
• Rice irrigated as normal for 0-grade.
3. Loss of yield bump associated with
•Soybean irrigated with tubing placed on ridge down center of
Soy-Rice Rotation
field.
Estimated Adoption Rates for Rice
Irrigation Systems in MS (2009)
Sources: MSU Extension Service grower surveys; rice consultant surveys; YMD permitting data.
Multiple-Inlet Irrigation
in Straight-Levee Systems
Straight-Levee System
Riser
Multiple-Inlet Irrigation
in Straight-Levee Systems
MAFES Publication No. 2338
Thomas et al. (2004)
Advantages of Side-Inlets:
• More rapid flood establishment.
• Reduced nitrogen loss.
• Improved herbicide activation.
•Greater control of flood.
• Facilitates adoption of other
water-saving practices.
Tacker (2010): Approximate cost = $12/A (tubing + labor)
Estimated Energy Used By Groundwater-Based
Irrigation Systems per A-in Water Delivered
State
Diesel
(gallons)
Electric
(kWh)
per Acre-in water pumped
AR
1
38
(Tacker)
LA
(Sheffield)
MO
42 water not pumped,
For 1.1
every inch of
at least 0.7 gallon/A diesel fuel saved.
0.8
30
0.7
27
0.9 gal
34 kWh
(Vories)
MS
(Thomas)
Avg.
(A-in/A)
Approximate water and fuel savings
for adoption of side-inlet in straight-levee system
55
50
45
40
35
30
25
20
15
10
5
0
38
38
38 - 31 in = 7-in water savings (22%)
@ 0.7 gal diesel/in = 5 gal diesel/A
@ $3/gal = ~ $15/A
31
Less ~$12/A cost of tubing
and labor = ~ $2/A net savings
9
9
Coutour
Levees
Straight SL + Side
Levee
Inlet
(SL)
Zero
Grade
Seasonal
Rainfall
(A-in/A)
Approximate water and fuel savings
for adoption of side-inlet in straight-levee system
with 25 A-in/A target
55
50
45
40
35
30
25
20
15
10
5
0
38 - 25-in = 13-in water savings (52%)
@ 0.7 gal diesel/in = 9 gal diesel/A saved
@ $3/gal diesel = ~$27/A
38
less tubing + labor = $15/A (net)
38
31
Total H2O Requirements (ET + Soil Percolation) = ~14 to 25 A-in/A
9
9
Coutour
Levees
Straight SL + Side
Levee
Inlet
(SL)
Zero
Grade
Seasonal
Rainfall
Estimated Irrigation Water Use (A-ft/A)
247,000 A rice x 0.45 = 112,500 A straight-levee rice
x ~ 1-ft/A water savings (38 A-in  25-A-in) =
~100,000 A-ft savings
saved by adoption of multiple-inlet irrigation on
existing straight-levee fields
Phaucet-optimized savings in soy: Up to 100,000 A-ft
Multiple-inlet rice irrigation savings: Up to 100,000 A-ft
= ~ 2/3 of 300,000 A-ft annual overdraft (potential)
(A-in/A)
Average Water Use by Different MS Rice Irrigation Systems
55
50
45
40
35
30
25
20
15
10
5
0
9-yr average @ Dulaney Seed
44
38
31
22
Coutour
Levees
20
+ Side Inlet Zero
Straight SL + Side SL
Intermittent
+(Dulaney)
Intermittent Grade
Levee (SL)
Inlet
Seasonal
Rainfall
(A-in/A)
Average Water Use by Different MS Rice Irrigation Systems
55
50
45
40
35
30
25
20
15
10
5
0
4-yr average @ Kline Farms
44
38
31
21
Coutour
Levees
20
+ Side Inlet Zero
Straight SL + Side SL
Intermittent
+(Dulaney)
Intermittent Grade
Levee (SL)
Inlet
Seasonal
Rainfall
Farmers Extend Savings of
Multiple-Inlet Rice Irrigation by:
• Managing flood to increase rainfall capture
and to reduce over-pumping.
• Very shallow flooding.
• Managing each paddy as separate production
unit.
Flood Management within Each Paddy
Top of
Levee
Top of
Levee
Emergency Overflow
Top of Gate
~12-in
4-in Freeboard for Rain Capture
4-in Controlled Flood
• Irrigate each paddy as needed, not on a schedule.
• Prevent water movement from one paddy to next.
• Keep levels low to capture rainfall.
Multiple-Inlet Irrigation
in Straight-Levee Systems
Tacker (2010): Approximate cost = $12/A (tubing + labor)
2011 Rice Irrigation Trials
Kline 38-A field, clay soil
(A-in/A)
Total H2O Use = 7.6-in (rainfall) + 18-in (irrigation) = 25.6-in
55
50
45
40
35
30
25
20
15
10
5
0
44
38
31
20
9
Coutour
Levees
Straight SL + Side
Levee
Inlet
(SL)
Zero
Grade
Seasonal
Rainfall
Depth Gauges Used to Aid in
Flood Management
• Allows rapid determination
of flood status.
• Tillman constructed 200
in an afternoon.
Flow Meters used as Management Tool
Permanently Installed Saddle-Type
Flow Meters used as Management Tool
Portable flow meter
Tools & Methods to Efficiently Lay Tubing
Tools & Methods to Efficiently Lay Tubing
Tools & Methods to Efficiently Lay Tubing
Takes a 3-person crew ~1 hour to lay one roll of 10 mil x 15-in
tubing, install gates, punch air holes, and begin initial flood.
Summary
Multiple (Side) Inlet
Irrigation is:
A proven, cost-effective flood
management tool currently
available to MS growers.
Serves as a ‘foundation’ on
which greater water and
energy savings can be
achieved by managing
flood to capture rainfall
and reduce over-pumping.
2010 tubing + labor costs: ~$12/A
(Tacker, 2010)
Takes a 3-person crew ~1 hour to
install one roll of tubing incl. gates
(E. Kline; J. Dulaney, 2011)
Summary
Phaucet-optimized savings in soy: Up to 100,000 A-ft
Multiple-inlet rice irrigation savings: Up to 100,000 A-ft
= ~ 2/3 of 300,000 A-ft annual overdraft (potential)
Systematic Approach to Water and Energy
Conservation in Irrigation of Row Crops
Crop
Breeding
Agronomic
Management
Managing shortEconomics
vs. longer-term risks
State/Federal
Regulations
Irrigation
Technology