Drip Irrigation Research in Arkansas

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Drip Irrigation Research in Arkansas

• Earl Vories
• University of Arkansas
• Northeast Research Extension Center
• Keiser, Arkansas

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Center Pivot and Furrow Irrigation Common in the
Mid-South
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Blytheville
Leachville
Satellite Image of NE Ark. Aug., 99
Manila
Osceola
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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).

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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.
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Change in Water Use With Crop Age
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Computerized Irrigation Scheduler
Distributed by University of Arkansas Cooperative
Extension Service (www.uaex.edu)
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Computerized Irrigation Scheduler
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Computerized Irrigation Scheduler
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Reference Evapotranspiration (Etr)
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Crop Coefficient Function - Cotton
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Crop Coefficient Function - Corn
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As you would expect, many differences between the
drip irrigation systems on a production-field
scale and a small-plot research scale.
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Field Scale
System Controls
Small Plot
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Injector Pumps for Water Conditioners (generally
required for groundwater) Fertilizers, Soil
Conditioners, etc.
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Filter Bank for Groundwater
Field Scale
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RPZ Valve and Screen for Municipal Water
Small Plot
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Solenoids for Controlling Water
Small Plot
Field Scale
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Lateral Lines Feeding Individual Drip Lines
Small Plot
Field Scale
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Much of 2001 growing season spent installing and
testing irrigation/control/monitoring systems,
probably reducing potential responses.
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Estimated Soil Water Deficits - Corn
No Irr.
Irrigation System Began Operation
75 ET
125 ET
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Corn Yields (bu/acre)
Yields not significantly affected by water
treatments.
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Later season allowed more observations in cotton
study, more treatment differences observed.
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Estimated Soil Water Deficits - Cotton
Irrigation System Began Operation
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Watermark sensor
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Output from Watermark Sensors - Cotton
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Crop Response to Water
No Irrigation
100 ET
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Physiological Cutout (NAWF5, DAP)
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Mean Maturity (DAP)
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Seedcotton Yields (lb/acre)
Yields not significantly affected by water
treatments.
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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.

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Acknowledgment

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