Subsurface Drip Irrigation for Row Crops Chad Lee Extension Grain Crops University of Kentucky

Agronomy Agronomy Agronomy Biosystems & Agricultural Engineering Agronomy Agronomy Agronomy Biosystems & Agricultural Engineering Agronomy Agronomy Agronomy Biosystems & Agricultural Engineering Agronomy Agronomy Agronomy Biosystems & Agricultural Engineering Project SDI - Team Investigators Scott Shearer Chad Lee Greg Schwab Mike Collins Bob Pearce Mike Montross Dennis Hancock Key Contributors Mike Peters Bill Peterson Steve Higgins John Fulton Tracy Hamilton James Dollarhide Rob Prewitt BAE Engineers

Subsurface Drip Irrigation  Increased Efficiency  Ease of Use  Competitive Cost  Especially for smaller acreage  Low pressure Advantages

Subsurface Drip Irrigation  Increased Efficiency  Ease of Use  Competitive Cost  Especially for smaller acreage  Low pressure AdvantagesDisadvantages  Stationary  Difficult/Laborious Installation

Tape Specifications T-Tape ( ) 15 mil thick, 15 mil thick, 4,100 ft/reel, 4,100 ft/reel, 8-10 psi 8-10 psi 8” spacing, 8” spacing, gpm/100ft gpm/100ft

Installation Specifications

Installation

Installation

Installation

Installation

Installation

Location University of Kentucky Animal Research Center, Woodford County University of Kentucky Animal Research Center, Woodford County About 300 acres of corn grown for livestock About 300 acres of corn grown for livestock About 7.5 acres in SDI Study About 7.5 acres in SDI Study Maury silt loam soil Maury silt loam soil

Crop Rotations  Corn, Continuous  Corn – Soybean  Corn – Tobacco  Tobacco – Corn  Alfalfa

SDI Installation and Plot Preparation Drip Tape Installed in April Drip Tape Installed in April Installer was pulled through rainfed plots as well Installer was pulled through rainfed plots as well Field was disked 3 times Field was disked 3 times Finished twice Finished twice Will be no-till next year Will be no-till next year

2003: SDI Questions Will subsurface drip irrigation Improve establishment?Improve establishment? Improve 2 nd cutting yields?Improve 2 nd cutting yields?Alfalfa

Will subsurface drip irrigation Improve establishment?Improve establishment? Improve 2 nd cutting yields?Improve 2 nd cutting yields?Alfalfa 2003: SDI Questions Corn Will subsurface drip irrigation increase corn yields?increase corn yields? increase N requirements?increase N requirements?

SDI in Alfalfa

Just add water Approximately 4 inches of water was applied to alfalfa from July through August. Approximately 4 inches of water was applied to alfalfa from July through August. Month Rain (inches) Average (inches) Diff. (inches) June July August Total

2003: Alfalfa Results Irrigated vs. Rainfed – (August 27, 2003) −Second Cutting of Establishment Year Yield (tons/acre) Irrigated1.24 Rainfed1.14 Difference0.10 * * P=0.08

2003: SDI in Corn Pioneer 31R88 (CRM 120) Pioneer 31R88 (CRM 120) 27,000 seeds/A 27,000 seeds/A 5 gal of liquid 28% 5 gal of liquid 28% 5 gal Starter 5 gal Starter

SDI in Corn: Weed Control First Application (sprayed at V3) Spirit 1 oz/a Basagran 1.5 pt/a COC 1 % v/v 28 % N 1 qt/a Second Application (spot sprayed at V5) Exceed 1 oz Accent 0.33 oz COC 1 qt/a

Nitrogen Application Sidedress N (lbs N/acre)

Just add water Approximately 4 inches of water was applied to corn from V6 to VT Approximately 4 inches of water was applied to corn from V6 to VT Month Rain (inches) Average (inches) Diff. (inches) June July August Total

Corn Yields (Averaged Across N Rates) Water Yield (Bu/A) Irrigated178 Rainfed181 ns

N Effect on Corn Yield a a a ab ab b c d d

N Use Efficiency (lbs N recovered / lbs N applied)

2003: SDI Lessons Establishment was improved based on improved yields of 2 nd cutting hay.Establishment was improved based on improved yields of 2 nd cutting hay. What will happen in a year that is dry?What will happen in a year that is dry?Alfalfa

2003: SDI Lessons Establishment was improved based on improved yields of 2 nd cutting hay.Establishment was improved based on improved yields of 2 nd cutting hay. What will happen in a year that is dry?What will happen in a year that is dry?Alfalfa Corn  Corn yields were not increased in a year when water was adequate.  If water was needed, it would have been before installation was complete.  Sidedress rate of 160 lbs N / acre was sufficient for maximum yield in a wet year.

2004 Plans No-Till (even tobacco) No-Till (even tobacco) Corn (2 nd year of continuous corn plots) Corn (2 nd year of continuous corn plots) Corn (following tobacco) Corn (following tobacco) Soybeans (following corn) Soybeans (following corn) Tobacco (following corn) Tobacco (following corn)

Alfalfa Future Plans Yield K Fertility Taproot Reserves Remote Sensing Yield Monitor for Forages

Corn Future Plans Yield Nitrogen Population Hybrids

SDI: Future Plans Economic analysis Increasing yields is great, but we need to be able to pay for it!! After three of four years of research.

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