Do I Need to Schedule Irrigation on Peanuts? Wesley M. Porter - PowerPoint PPT Presentation

Do I Need to Schedule Irrigation on Peanuts? Wesley M. Porter Extension Precision Ag & Irrigation Specialist University of Georgia South Carolina State Peanut Meeting January 28, 2016

Irrigation Scheduling • A technique that involves: – Determining how much water is needed – When to apply it to the field to meet crop demands. • Main purpose is: – To increase the profitability and/or quality of the crop by increasing the efficiency of using water and energy or by increasing crop productivity.

What to Consider for Irrigation • Irrigation type-efficiency of system (60-95%) • Soil water holding capacity (0.6-1.8 inches/foot) • Crop Growth Stage • Utilization of Sensors for more precise estimation of soil moisture: • Split apply weekly rates if possible

Irrigation Cost (2015) • Average Irrigation cost ~ $9/ac-in applied: – ~$6/ac-in for electric – ~$12/ac-in for diesel • So for 1,000 acres of irrigated land @ 10 inches of irrigation: – $90,000

Soil Water Holding Capacity Example • We have a soil with the infiltration rate and soil water holding capacity (SWHC) below, and a rooting depth of 12 inches, how much moisture will we store from a rain event that had a 1.5 in/hr intensity and a two hours duration, i.e. we caught 3 inches of rainfall in our rain gage? – Infiltration rate is 1.0 in/hr – SWHC is 0.8-1.0 in/ft

Soil Water Holding Capacity Example • We have a soil with the infiltration rate and soil water holding capacity (SWHC) below, and a rooting depth of 12 inches, how much moisture will we store from a rain event that had a 1.5 in/hr intensity and a two hours duration, i.e. we caught 3 inches of rainfall in our rain gage? – Infiltration rate is 1.0 in/hr – SWHC is 0.8-1.0 in/ft – We had the ability to infiltrate or “catch” approximately 2.0 inches of the event.

Soil Water Holding Capacity Example • We have a soil with the infiltration rate and soil water holding capacity (SWHC) below, and a rooting depth of 12 inches, how much moisture will we store from a rain event that had a 1.5 in/hr intensity and a two hours duration, i.e. we caught 3 inches of rainfall in our rain gage? – Infiltration rate is 1.0 in/hr – SWHC is 0.8-1.0 in/ft – We had the ability to infiltrate or “catch” approximately 2.0 inches of the event. – With a 12 inch or 1 foot rooting depth, only 1 inch of that was available to our crop.

Soil Water Holding Capacity Example • We have a soil with the infiltration rate and soil water holding capacity (SWHC) below, and a rooting depth of 12 inches, how much moisture will we store from a rain event that had a 1.5 in/hr intensity and a two hours duration, i.e. we caught 3 inches of rainfall in our rain gage? – Infiltration rate is 1.0 in/hr – SWHC is 0.8-1.0 in/ft – We had the ability to infiltrate or “catch” approximately 2.0 inches of the event. – With a 12 inch or 1 foot rooting depth, only 1 inch of that was available to our crop. – This is the problem with using the checkbook method and models that do not account for soil information!

System Performance • The more time I have spent on farms I have realized that many irrigation systems are not up to perfect operating condition: – Poor uniformity – Leaks – Not applying assumed amount – Problems at the pump

System Performance

System Performance

System Performance

System Performance

System Performance

System Performance

Water Requirements: Peanuts • Peanut requires approximately 23 inches of water from planting until harvest. • Approximately 18 of the 23 inches (78%) of water is needed from weeks 10-17 of the 20 week growing season.

Water Requirements: Peanuts • Peanut requires approximately 23 inches of water from planting until harvest. • Approximately 18 of the 23 inches (78%) of water is needed from weeks 10-17 of the 20 week growing season.

Soil Moisture Variability

Soil Moisture Variability

Soil Moisture Variability

Irrigation Scheduling: USDA NASS Irrigation Scheduling Entire United Georgia (%) South Carolina (%) Method States (%) Visible Stress 78 88 90 Feel of Soil 40 40 40 Soil Moisture Sensor 10 9 6 Scheduling Service 8 7 4 Weather Report 8 7 3 Calendar Schedule 21 12 17 When Neighbor Irrigates 6 2 2

2014 Peanut Irrigation Treatments • Irrigation Scheduling Methods: – UGA SSA (weighed average of 40-50 cb range) – SmartCrop – Checkbook – UGA Easy Pan – UF Peanut Farm (http://agronomy.ifas.ufl.edu/peanutfarm/) – Rainfed

Peanut Irrigation Scheduling 2014 Irrigation Irrigation Total Water (in) Yield (lb/ac) Scheduling Method Amount (in) Dryland 0.40 12.73 465.2 UGA SSA 9.40 21.73 6052.3 SmartCrop 6.40 18.73 5642.0 EasyPan 11.65 23.98 5725.0 UGA ET Checkbook 15.02 27.35 5025.5 UF Peanut Farm 7.90 20.23 4802.5 Planted: May 20, 2014 Dug: October 10, 2014 Harvested: October 17, 2014 Rainfall: 12.33 inches

Irrigation Scheduling Profitability Irrigation Total Cost/ac of Cost/ac of Profit/ac from Profit/ac from Yield Scheduling Irrigation Electric @ Diesel @ Electric Irrigation Diesel Irrigation (lb/ac) Method (in) $6/ac-in $18/ac-in Only @ $0.21/lb Only @ $0.21/lb Dryland 0.40 $2.40 $7.20 465.2 $93.43 $88.63 UGA SSA 9.40 $56.40 $169.20 6052.3 $1190.37 $1077.57 SmartCrop 6.40 $38.40 $115.20 5642.0 $1123.85 $1047.05 EasyPan 11.65 $69.90 $209.70 5725.0 $1109.45 $969.65 UGA Checkbook 15.02 $90.12 $270.36 5025.5 $945.13 $764.89 UF Peanut Farm 7.90 $47.40 $142.20 4802.5 $941.92 $847.12

Peanut Irrigation Scheduling: Varieties Georgia 06G Irrigation Treatment Irrigation Amount (in.) Yield (lbs/ac) Dryland 0.40 481.3 UGA SSA 9.40 6662.5 SmartCrop 6.40 5926.8 UGA EasyPan 11.65 6255.5 UGA Checkbook 15.02 5509.8 UF Peanut Farm 7.90 4988.8 Georgia 12Y Irrigation Treatment Irrigation Amount (in.) Yield 0.40 498.3 Dryland UGA SSA 9.40 5833.0 6.40 5344.5 SmartCrop UGA EasyPan 11.65 5698.5 UGA Checkbook 15.02 5345.3 7.90 4418.5 UF Peanut Farm Planted: May 20, 2014 Dug: October 10, 2014 Harvested: October 17, 2014 Rainfall: 12.33 inches

Peanut Irrigation Scheduling: Varieties TUFRunner 511 Irrigation Treatment Irrigation Amount (in.) Yield Dryland 0.40 413.3 UGA SSA 9.40 6261.5 SmartCrop 6.40 6276.5 11.65 5842.5 UGA EasyPan UGA Checkbook 15.02 4867.5 UF Peanut Farm 7.90 5184.8 TUFRunner 727 Irrigation Treatment Irrigation Amount (in.) Yield 0.40 468.0 Dryland UGA SSA 9.40 5452.3 SmartCrop 6.40 5020.3 11.65 5103.5 UGA EasyPan UGA Checkbook 15.02 4379.5 UF Peanut Farm 7.90 4618.0 Planted: May 20, 2014 Dug: October 10, 2014 Harvested: October 17, 2014 Rainfall: 12.33 inches

Peanut Irrigation Scheduling 2015 Irrigation Scheduling Irrigation Total Water (in) Yield (lb/ac) Method Amount (in) Dryland 0.50 23.30 5193.6 UGA SSA 4.45 27.25 5478.6 CWSI 3.55 26.35 5172.8 UGA ET Checkbook 12.50 35.30 5313.4 UGA EasyPan 5.20 28.00 5404.9 UF PeanutFarm 5.20 28.00 5327.3 IrrigatorPro 2.80 25.60 5542.6 50% Checkbook 6.76 29.56 5176.1 Planted: May 18, 2015 Dug: October 5, 2015 Harvested: October 12, 2015 Rainfall: 22.65 inches

Irrigation Scheduling Profitability Irrigation Total Cost/ac of Cost/ac of Profit/ac from Profit/ac from Yield Scheduling Irrigation Electric @ Diesel @ Electric Irrigation Diesel Irrigation (lb/ac) Method (in) $6/ac-in $12/ac-in Only @ $0.19/lb Only @ $0.19/lb Dryland 0.50 $3.90 $7.80 5193.6 $995.87 $991.97 UGA SSA 4.45 $27.60 $55.20 5478.6 $1027.03 $999.43 CWSI 3.55 $22.20 $44.40 5172.8 $973.56 $951.36 UGA Checkbook 12.50 $75.90 $151.80 5313.4 $946.93 $871.03 UGA EasyPan 5.20 $32.10 $64.20 5404.9 $1008.34 $976.24 UF Peanut Farm 5.20 $32.10 $64.20 5327.3 $993.41 $961.31 IrrigatorPro 2.80 $17.70 $35.40 5542.6 $1049.25 $1031.55 50% Checkbook 6.76 $41.46 $82.92 5176.1 $954.94 $913.48

50% Checkbook IrrigatorPro UF PeanutFarm UGA EasyPan UGA Checkbook Rainfall (in) CWSI UGA SSA

Peanut Irrigation Scheduling: Varieties GA-06G Irrigation Treatment Irrigation Amount (in.) Total Water (in.) Yield (lbs/ac) Dryland 0.5 23.30 5268.7 UGA SSA 4.45 27.25 5700.2 SmartCrop CWSI 3.55 26.35 5729.7 UGA Checkbook 12.50 35.30 5829.1 UGA EasyPan 5.20 28.00 5769.8 UF PeanutFarm 5.20 28.00 5533.1 IrrigatorPro 2.80 25.60 5439.9 50% Checkbook 6.76 29.56 5937.0 GA-12Y Irrigation Treatment Irrigation Amount (in.) Total Water (in.) Yield (lbs/ac) Dryland 0.5 23.30 5030.1 UGA SSA 4.45 27.25 5829.3 SmartCrop CWSI 3.55 26.35 5076.9 UGA Checkbook 12.50 35.30 4879.4 UGA EasyPan 5.20 28.00 5456.1 UF PeanutFarm 5.20 28.00 5456.1 IrrigatorPro 2.80 25.60 5620.9 50% Checkbook 6.76 29.56 4479.1 Planted: May 18, 2015 Dug: October 5, 2015 Harvested: October 12, 2015 Rainfall: 22.65 inches