water use and economic impacts of furrow irrigation
TRANSCRIPT
Water Use and Economic Impacts of Furrow Irrigation Initiation Delays in
Mid-South Soybean Production Systems
C.R. Stark, Jr. ([email protected])
Presented at the Soil & Water Conservation Society 70th International Annual Conference
Greensboro, North Carolina, July 26-29, 2015
P.B. Francis ([email protected])
Soybean in Arkansas
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 20152.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.033.11
2.85
3.3
3.42
3.19
3.33
3.23.27 3.24
3.3
Total Acres Planted(Million Acres)
Soybean in Arkansas
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 20150.0
0.5
1.0
1.5
2.0
2.5
3.0
1.9632.18 2.125
2.48 2.5652.348
2.627 2.532.68 2.65
Total Irrigated Acres Planted(Million Acres)
Soybean in Arkansas
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 20150.0
10.0
20.0
30.0
40.0
50.0
60.0
34.0 35.0 36.030.0
37.5 35.038.5
43.5 43.550.0
Statewide Annual Average Yield(Bushels/Acre)
Soybean in Arkansas
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 20150.0
10.0
20.0
30.0
40.0
50.0
60.0
39.0 39.0 40.0 41.0 39.0 39.542.2
48.3 46.452.5
Irrigated Annual Average Yield(Bushels/Acre)
Study Questions1. Are there agronomic and economic effects of delaying
initiation of soybean irrigation?2. What magnitude of water
savings could come from delaying initiation of soybean irrigation?
Background Literature Review– Economic impacts of furrow irrigation termination for
determinate soybean (Heatherly & Spurlock, 1993)
– If irrigation water is limiting, withholding at R2 may be acceptable (Froud, Saindon & Mundel, 1993)
– Irrigation at growth stages can influence yield, but improvements may not justify the practice (Sweeney, Long & Kirkham, 2003)
– Irrigation management significantly affects yield. Supplemental irrigation may be an alternative for full season irrigation (Bellaloui & Mengistu, 2007)
– Irrigation at different times increased yield over no irrigation (Amin, Jahan & Hasanuzzaman 2009)
– Economics of water limiting irrigation scheduling needed due to yield reduction (Candogan, et al. 2013)
Research Design• Soybean Irrigation Initiation Study – Sharkey Silty Clay soil, Southeast Research Station, Rohwer,
Arkansas, 2008-2010, following soybean, – Randomized Complete Block design with 4 replications.
Research Design• Soybean Irrigation Initiation Study – Watered from well with 80’ water table, pumped from
approx. 100’, by 3-stage electric pump (100 acre capacity).– Irrigation timing was based on the AR Irrigation Scheduler
computer program developed by UA-CES.
Research Design• Soybean Irrigation Initiation Study – Fertilization was applied according to annual soil tests.– Management practices followed UA-CES recommendations
for weed, insect, and disease control.
Soybean Varieties Utilized
• 2008 - PIONEER 94M71 – MG 4
• 2009 – HB 5525 – MG 5
• 2010 – HB 5525 – MG 5
Irrigation Initiation Treatments– 0 Days – Began irrigation at normal time
indicated by Irrigation Scheduler program.– 5 Days – Began irrigation after five days under
the soil moisture deficit level.– 10 Days - Began irrigation after ten days under
the soil moisture deficit level.– 15 Days - Began irrigation after fifteen days
under the soil moisture deficit level. Note: Rain events within each delay period were incorporated into
the program until full delay period was reached.
• Partial Budget approach used 2015 UA Division of Agriculture interactive enterprise budgets.
• Market Prices were annual AR statewide average cash market soybean prices for 2008-10.
Economic Research Methods
• Inputs by year were actual products & quantities.• Input prices taken from UA Division of Agriculture &
Mississippi State Budget Generator 2015 lists.• Profit Estimates were made for each replication.• Statistical analyses by SAS GLM procedure.
Economic Research Methods
Actual Irrigation Event NumbersYEAR DELAY TREATMENTS (Days)
0 5 10 152008 4 3 2 1
2009 6 5 4 2
2010 5 4 3 2
Average Actual Water UsagesYEAR DELAY TREATMENTS (Days)
0 5 10 152008 4 3 2 1
2009 6 5 4 2
2010 5 4 3 2
Avrg. # 5.00 4.00 3.00 1.67
Volume(acre-inches) 10.00 8.00 6.00 3.34
Average Actual Water UsagesYEAR DELAY TREATMENTS (Days)
0 5 10 152008 4 3 2 1
2009 6 5 4 2
2010 5 4 3 2
Avrg. # 5.00 4.00 3.00 1.67
Volume(acre-inches) 10.00 8.00 6.00 3.34Savings 2.00 4.00 6.66
Yield Results By Year/Treatment
YEARTREATMENT 2008 2009 2010
0 Delay 56.70 54.46 55.705 Day Delay 55.88 50.40 54.45
10 Day Delay 55.80 41.77 57.5515 Day Delay 55.35 40.82 52.38
(Bushels/Acre)
Economic Results By Year/Treatment
YEARTREATMENT 2008 2009 2010
0 Delay 362.27 a 247.25 a 392.66 ab5 Day Delay 359.00 a 215.71 ab 384.03 a
10 Day Delay 363.64 a 142.59 b 424.35 ab15 Day Delay 364.33 a 144.79 b 371.56 b
(Net Returns in Dollars/Acre)
Means with the same letter are not significantly different.
Conclusions1. Delaying Irrigation Initiation reduced total
irrigations approximately 1 event/year.
2. Delaying Irrigation Initiation reduced total water usage approximately 2 acre-inches for each 5 days delayed.
3. Delaying Irrigation Initiation consistently reduced Yield in only 1 of 3 years [2009].
4. Delaying Irrigation Initiation consistently reduced Net Returns Per Acre in only 1 of 3 years [2009].
Possible Contributing Factor
YEARGROWTH
STAGE2008 2009 2010
V5 to R1 9 76 64R1 to R3 17 127 47R3 to R5 91 19 144V5 to R5 117 222 255
RAINFALL TOTALS (mm)
Acknowledgments Arkansas Soybean Promotion Board.
Research Station Director Larry Earnest
Mr. Scott Hayes & Mr. Randy Spurlock
Southeast Research Station, Rohwer, AR.
Dr. Kelly Bryant, Dean UAM School of Agriculture
Director, UA Southeast Research & Extension Center
Monticello, AR.
Questions??