Irrigation Management Technologies

Irrigation Management Technologies Nicholas Kenny, P.E. Texas AgriLife Extension Service Amarillo Crop Production Clinic Goodwell, Oklahoma; 8 March 2012 Improving Lives. Improving Texas.

Programs Supported By Texas AgriLIFE Extension Service Ogallala Aquifer Initiative North Plains GCD

North Plains EPIC Efficient Profitable Irrigation in Corn www.everydaycitizen.com

Corn Yield and Returns Per Unit of Water 225 $700 200 $600 175 $500 Grain YIield (Bushels / Acre (Blue, smooth line) 150 125 100 75 Maximum physiological yield is expected to occur at 34 of total water. Maximum economic return is expected to occur at 29 of total water. $400 $300 $200 Net Residual Returns per acre (Green, marked line) 50 25 $100 0 $- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Total Seasonal Water (Inches) Irrigation + Soil Storage + Precipitation

E.P.I.C Project Goals 2011 Protocol 1. Maintain or Improve Grain Yield 2. Reduce Irrigation by 1 4

Management Technologies Employed

2011 EPIC Field Parameters County Plot Acres Tillage Method GPM GPM / Acre Variety Plant Population Planting Date Previous Crop Dallam 1 Legacy 120 No-till LESA 650 5.42 Pioneer Y74 24-30,000 VR 2-May Wheat 2 Hartley Legacy 120 Strip LESA 700 5.83 Pioneer 33D49 32,425 27-Apr Corn EPIC 120 Strip LESA 700 5.83 Pioneer 1395AM1 31,200 27-Apr Corn Hutchinson Legacy 10.25 No-till SDI 57 5.60 Syngenta N72F 36,000 18-Apr Cotton EPIC 11.6 No-till SDI 65 5.60 Syngenta N72F 36,000 18-Apr Cotton Ochiltree 1 Legacy 90 Conv. LESA 707 7.85 Pioneer 1395AM1 32,000 30-Apr Wheat EPIC 50 Conv. LESA 393 7.85 Pioneer 1395AM2 32,000 30-Apr Wheat Sherman Legacy 120 Strip LESA 650 5.42 Channel 214-14 25-Apr Corn EPIC 120 Strip LESA 600 5.00 Channel 214-14 26-Apr Corn 1 Dallam and Ochiltree County cooperators employed a split-pivot. The Ochiltree acreages are estimated based on the North - South divider line. 2 The Dallam County plot was prepared with a spray-killed wheat cover crop, following the 2010 grain corn crop.

2011 EPIC Field Results Water (Inches) Location Plot Irrigation Soil 3 Precipitation Total Yield (Bu/ Acre) WUE 4 Dallam Co. 1 Legacy 29.1 2.71 0.97 32.8 207.5 6.3 Hartley Co. Legacy 34.6 0.12 1.97 36.7 241.0 6.6 EPIC 31.4 (0.35) 1.97 33.1 241.0 7.3 Hutchinson Co. 2 Legacy 20.0 4.32 2.57 26.9 180.1 6.7 EPIC 17.4 3.10 2.57 23.1 190.2 8.2 Ochiltree Co. Sherman Co. Legacy 31.2 (0.66) 2.30 32.8 168.0 5.1 EPIC 30.0 0.39 2.30 32.6 188.0 5.8 Legacy 28.6 4.40 2.11 35.1 140.8 4.0 EPIC 25.6 2.12 1.67 29.4 171.0 5.8 1 Irrigation application was not able to be reduced on the Dallam County field due to the severe 2011 weather conditions. 2 The Hutchinson County plots utilized subsurface drip irrigation (SDI). The Legacy plot (10.25-acres) reached physiologically maturity earlier than the EPIC plot (11.6-acres) and the remainder of the field (total of approximately 65-acres). The field average yield was 184- bushels, including the two test plots. 3 Soil water content was measured early and late in the season using gravimetric sampling, except the Dallam field which is modeled by AquaPlanner. Negative values indicate seasonal soil moisture accumulation and were evidenced in multiple fields due to dry residual early soil conditions. 4 WUE refers to water use efficiency defined as bushels of corn per inch of TOTAL water (bu/ inch)

2011 EPIC Economics Summary County Irr Reduction (inches) Yield (Bushels / acre) Profit ($ / Acre) Dallam 0 0 $ - Hartley 3.2 0 $ 16.00 Hutchinson 2.6 10.0 $ 78.08 Ochiltree 1.3 20.0 $ 136.25 Sherman 3.0 30.2 $ 211.65

Why Plants Use Water Provides Plant Structure Temperature Regulation Move Nutrients (Drink, not Eat!!) Salinitymanagement.org

Evapotranspiration - ET Meteorological model to estimate crop water use. Wind is the most influential factor Heat is the second most influential factor Vegetation Mass / Plant size

AquaPlanner: Irrigation Modeling

2011 EPIC: Ochiltree Co.

Cotton: Daily ET & Irrigation Demand: 1 June PD 0.30 0.25 14-year Average (1995-2008) North Plains Research Field - Etter, Texas Cotton Daily ET (inches) Average Daily Irrigation Demand 0.20 3 GPM / Acre Daily ET, Inchs 0.15 0.10 0.05 0.00 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov

AquaPlanner Summary Cost: ~$1 per acre Uses Local weather data corrected for Ag. ET Use Email of daily / weekly ET info Helpful in pre-season crop water use projections Would be beneficial on EVERY ACRE Pat Scarth: (806) 674-4120 email: pat@aquaplanner.net

Capacitance Probe: Soil Water Monitoring aquaspy.com Dave Sloane: (314) 825-4777 $2,200 per Unit - Lease Probe Install Data

Capacitance Probe: Soil Water Monitoring cropsense.com Keith Patterson: (901) 237-0415 $2,500 per Unit - Lease Probe Install Data

Capacitance Probe: Soil Water Monitoring aquacheck.co.za Available through Eco-Drip $3,200 per Unit - Purchase Sensor Logger Install

2010: Probe Water Response 1.32.25.9.67 1.22 1.64 i i i 2.19 i.4 i i i i i i i i 11 irrigations, ~1.2 Rain event Unit lost power

Lessons from Ochiltree Co. Legacy: 168 Bushels 32.8 Total

Lessons from Ochiltree Co. EPIC: 188 Bushels 32.6 Total

EPIC 2011: Ochiltree County Legacy: 168 Bushels 32.8 Total EPIC: 188 Bushels 32.6 Total

EPIC 2011: Sherman County Legacy: 141 Bushels 28.6 Irr EPIC: 171 Bushels 25.6 Irr

Can t Manage what you Can t Measure

CropMetrics Irrigation Prescriptions

EM Survey with RTK Elevation Data EM38 Sensor

Process EM Data and Calculate Field Variability Uniform Application: 12.8% (estimate 12.8% yield opportunity) Sector Application: 6.4% (anticipate 6.4% yield improvement) Zone Application: 1.6% (anticipate 11.2% yield improvement)

Example Custom VRI Prescriptions

CropMetrics Service Cost: ~$8 / acre + 1x Set-up Costs (Varis @ $6 / acre) Yield Map Fertility Map Topography Map Valley, Wilbur-Ellis (North) Kevin Abts (402) 650-9380

Aerial / Satellite Photography Images Courtesy of Olan Moore High Plains Consulting, Inc.

Gypsum Block: Soil Water Monitoring

Gypsum Block: Soil Water Monitoring ~$750 per unit 4+ Sensors ~$30 per sensor

Gypsum Block: Soil Water Monitoring

Electro Tensiometers: Irr. Triggers Irrometer Tensiometer Talgil TensioMarker

Portable Soil Moisture Meters Watchdog: FieldScout TDR Campbell Scientific: CWS655 (Volumetric)

Nicholas Kenny, P.E. Irrigation Specialist Agricultural Engineer Amarillo Research and Extension Center 6500 Amarillo Blvd. West Amarillo, TX 79106 806.677.5600 NPKenny@ag.tamu.edu YouTube Channel: NPKTexasAgriLIFE Web Site: http://amarillo.tamu.edu/people/kenny

Efficiency A measure of how well an input is converted to a desired output Miles / Gallon Energy / Pumped Water

Measures of Irrigation Efficiency Application Efficiency Water that reaches the soil Transpiration Efficiency Water available to the Plant (Application Eff. minus evaporation and run-off) Water Use Efficiency - Yield / Acre-inch total water (Applied or Final Water)

Irrigation System Application Efficiency Surface 50-80% Common Flood 50% Land Leveled 60% Row 65% Alternate Furrow 70% Surge 80% Center Pivot 70-92% LESA 85% LEPA 90% Drag Hoses 92% Drip 90-95% Above Ground 92% Subsurface (SDI) 95%

Calculating Application Depth Consider: 500 GPM Center pivot with Sprays (90% eff.) 120 Acres

Why Plants Use Water Provides Plant Structure Temperature Regulation Move Nutrients (Drink, not Eat!!) Salinitymanagement.org

Evapotranspiration - ET Meteorological model to estimate crop water use. Wind is the most influential factor Heat is the second most influential factor Vegetation Mass / Plant size

Reference Evapotranspiration ET o 17-year Average (1995-2011) TXHPET Weather Station - Etter, Texas 0.40 0.35 Daily Evapotranspiration (Inches) 0.30 0.25 0.20 0.15 0.10 0.05 0.00 1 Apr 1 May 31 May 30 Jun 30 Jul 29 Aug 28 Sep 28 Oct

Grain Corn Daily Evapotranspiration for Multiple Planting Dates 17-year Average (1995-2011) TXHPET Weather Station - Etter, Texas Daily Evapotranspiration (Inches) 0.40 0.35 0.30 0.25 0.20 0.15 1 April PD - FS Corn 15 April PD - FS Corn 1 May PD - FS Corn 15 May PD - SS Corn 1 June PD - SS Corn 5 June PD - SS Corn 15 June PD - SS Corn Reference ET 0.10 0.05 0.00 1 Apr 1 May 31 May 30 Jun 30 Jul 29 Aug 28 Sep 28 Oct

Grain Corn Physiology MATURES based on HEAT & GROWS based on TIME!! Start Fast to maximize Photosynthesis Finish Slow to maximize Grain Fill

Grain Corn Daily Evapotranspiration for Multiple Planting Dates 17-year Average (1995-2011) TXHPET Weather Station - Etter, Texas Daily Evapotranspiration (Inches) 0.40 0.35 0.30 0.25 0.20 0.15 15 April PD - FS Corn 15 May PD - SS Corn 5 June PD - SS Corn 1 June PD - Cotton Reference ET 0.10 0.05 0.00 1 Apr 1 May 31 May 30 Jun 30 Jul 29 Aug 28 Sep 28 Oct

Grain Corn Accumulative Evapotranspiration for Multiple Planting Dates 17-year Average (1995-2011) TXHPET Weather Station - Etter, Texas 40 35 30 Accumulated Evapotranspiration (Inches) 25 20 1 April FS Corn 15 April FS Corn 15 1 May FS Corn 15 May FS Corn 1 April SS Corn 10 15 April SS Corn 1 May SS Corn 15 May SS Corn 5 1 June SS Corn 5 June SS Corn 15 June SS Corn 0 1 Apr 1 May 31 May 30 Jun 30 Jul 29 Aug 28 Sep 28 Oct

Grain Corn Heat Units after Planting (HUAP) for Multiple Planting Dates 17-year Average (1995-2011) TXHPET Weather Station - Etter, Texas 4,000 3,750 3,500 3,250 2,800 HUAP - Mature Grain Corn Accumulated Heat Units After Planting (F) 3,000 2,750 2,500 2,250 2,000 1,750 1,500 1,250 1,000 750 500 250 1 April Corn HUAP 15 April Corn HUAP 1 May Corn HUAP 15 May Corn HUAP 1 June Corn HUAP 5 June Corn HUAP 15 June Corn HUAP 0 1 Apr 1 May 31 May 30 Jun 30 Jul 29 Aug 28 Sep 28 Oct

Direct Planting into trash

1999-2001 Preplant Irrigation Study

1999-2001 Estimated Reduction of Profile SW as a Percentage of Rain and Applied Water During PP Irrigation Period System 1999 2000 2001 Average Spray 60% 58% 83% 67% LEPA 43% 61% 76% 60% SDI 29% 55% 57% 47%

1 of pre-plant irrigation = <0.50 July - Aug irrigation

Pre-Water Considerations Avoid unless very dry and Late Planting Dates Consider: 360 GPM on 120-acres 3 GPM / acre 4.3 in 30-days with 90% Efficiency May 15 PD with 1.3 30-day ET In- season irrigation Possible gain of 3 early In 2011 Driest starting soil tested had 3.5 PAW

Pre-Water Considerations Irrigation when water is the most valuable Regulatory Limits Capacity Limits (well depletion not based on calendar days) Think of a soil like a bucket It can only hold so much Defer as long as possible to allow for rainfall accumulation Plant is very small early, not much water demand Residue / Surface Cover is always a good option

Cotton: Daily ET & Irrigation Demand: 1 June PD 14-year Average (1995-2008) North Plains Research Field - Etter, Texas 0.30 0.25 5 GPM / Acre Most Valuable Water Cotton Daily ET (inches) Average Daily Irrigation Demand 4 GPM / Acre 0.20 3 GPM / Acre Daily ET, Inchs 0.15 0.10 Necessary for vigor Damaging Water 0.05 0.00 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov

Soil Management Considerations http://www.blogdivvy.com/growing-vegetables/what-is-soil.htm

Plant Available Water In Soil Inches of Water (3' Root Zone) Coarse Sand 1.50 Fine Sand 2.75 Loamy Sand 3.50 Sandy Loam 4.00 Fine Sandy Loam 5.25 Silt Loam 6.75 Silty Clay Loam 5.75 Silty Clay 5.00 Clay 4.00

Seasonal Soil Water Levels (Hypothetical) 100.0% SAT - Saturation 90.0% 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% Plant Available Water 2 5.5 FC Field Capacity RAW Readily Available Water MAD Management Allowable Depletion PWP Permanent Wilting Point 10.0% 0.0% Jun Jul Aug Sep Oct Nov

Understanding Evapotranspiration Evaporation + Transpiration Water Provides: Plant Structure Temperature Regulation Nutrient Update Salinitymanagement.org

Understanding Evapotranspiration Evaporation + Transpiration Water Provides: Plant Structure Temperature Regulation Nutrient Update Transpiration Yield Evaporation Wasted Water Salinitymanagement.org

Soil Surface Evaporation Post Application 100% 90% Percent of Evapotranspiration 80% 70% 60% 50% 40% 30% 20% 10% 0% Clay Silt Loam Loamy Sand 0 1 2 3 4 5 6 7 8 9 10 Days after Surface Wetting

Irrigation Frequency Slow Down in Drought / Deficit Conditions Image Courtesy of Olan Moore High Plains Consulting, Inc.

Pivot Speed Considerations Specific VOLUME of water lost per application (up to ¼ ) More applications More evaporative loss Consider: 550 GPM on 120-acres.25 per day capacity Assume.20 evap. loss per application 3-day lap leads to 1.84 over 10 days 5-day lap leads to 2.1 over 10 days 90-day Season 2.34 reduction in effective water.

Application Rate vs. Runoff / Percolation Derrel L. Martin, et al: University of Nebraska - Lincoln ASABE Proceedings IRR10-9282

Windshield Wiper Pivots #1 Compromise: Sprinkler Opposite of where it needs to be. Don t get too complicated in Management: Water volume = Water Volume Match application to infiltration in the corners ( <2 in one day) 5 GPM / Acre 7-8 day round trip (.95-1.10 ) 6 GPM / Acre 6-7 day round trip (1 1.15 ) 7 GPM / Acre 5-6 day round trip (.95 1.15 ) DO NOT dead-head back!!! (Except for rain or shut-down)

Windshield Wiper Pivots #2 Very deep application (1.5 2 ) from centerline in. Dead-head back to centerline (<.10 ).10 1.5

Daytime and Nighttime Variation

Plugged / Worn-out Nozzles

How frequently to change nozzles?? Re-Nozzle when: Flow changes by 25-50 GPM (be Honest!!!) Add or Remove regulators Replace nozzles with wear, check annually: Infinite lifespan with clean water Maybe annually with sand, salt, grit

Altered Drop Heights Pressure Change 2.31 Elevation = 1 PSI

Spray vs. Bubble Increased Efficiency Uniform Germination

Dealing with Air in Pipelines Used with permission from Nelson Irrigation.