Drip Irrigation Research in Arkansas Earl Vories University

Drip Irrigation Research in Arkansas Earl Vories University of Arkansas Northeast Research & Extension Center Keiser, Arkansas

Center Pivot and Furrow Irrigation Common in the Mid-South

Blytheville Leachville Satellite Image of NE Ark. Aug. , 99 Manila Osceola

Drip Irrigation Getting Interest • Earlier use in arid areas (AZ, west TX, Israel). • Efficient use of limited water. • Allows injection of fertilizers/other products in root zone. • More recently being investigated in humid areas (southeast, mid-south).

Current research efforts in Arkansas using precise water control possible with drip irrigation to investigate irrigation scheduling, rather than investigating the optimal drip irrigated production system.

Change in Water Use With Crop Age

Computerized Irrigation Scheduler Distributed by University of Arkansas Cooperative Extension Service (www. uaex. edu)

Computerized Irrigation Scheduler

Computerized Irrigation Scheduler

Reference Evapotranspiration (Etr)

Crop Coefficient Function - Cotton

Crop Coefficient Function - Corn

As you would expect, many differences between the drip irrigation systems on a production-field scale and a small -plot research scale.

Field Scale System Controls Small Plot

Injector Pumps for Water Conditioners (generally required for groundwater) Fertilizers, Soil Conditioners, etc.

Filter Bank for Groundwater Field Scale

RPZ Valve and Screen for Municipal Water Small Plot

Solenoids for Controlling Water Field Scale Small Plot

Lateral Lines Feeding Individual Drip Lines Small Plot Field Scale

Much of 2001 growing season spent installing and testing irrigation/control/monitoring systems, probably reducing potential responses.

Estimated Soil Water Deficits - Corn No Irrigation System Began Operation 75% ET 125% ET

Corn Yields (bu/acre) Yields not significantly affected by water treatments.

Later season allowed more observations in cotton study, more treatment differences observed.

Estimated Soil Water Deficits - Cotton Irrigation System Began Operation

Watermark sensor

Output from Watermark Sensors - Cotton

Crop Response to Water 100% ET No Irrigation

Physiological Cutout (NAWF=5, DAP)

Mean Maturity (DAP)

Seedcotton Yields (lb/acre) Yields not significantly affected by water treatments.

Conclusions from 2001 • System/equipment functioning well. • Installation of drip tubing (subsoiling every row) in spring, as well as delays in planting and irrigating due to installation probably affected responses in initial season. • Drip irrigation system appears to provide desired water control for studying irrigation scheduling.

Acknowledgment Research supported by Arkansas corn and cotton producers through checkoff programs.