Cotton Irrigation Study, 1997, Georgia Coastal Plain

Yield Comparisons:
Study:

Research Objectives:

    1. Develop irrigation management systems for consistent high yield and quality cotton for loamy sand soils.
    2. Establish water requirements needed for consistent growth and boll development.
    3. Validate cotton irrigation models and scheduling equipment for the Georgia Coastal Plain.
    4. Determine the relationship between canopy stress signals measured with a 4-band multi-spectral reflectrometer and soil water pressure during dry-down periods.
Treatments:
 1. Control - Soil water content scheduling - when the average soil water content in the 10 to 45 cm depth exceeds 35 kPa schedule an irrigation for the next day (1 day late)
 2.Apply water according to the Extension service checkbook scheduling, replacing needed water once each week
 3.Irrigation scheduled as treatment 1 except no irrigation beginning at first square (approx. June 15) for up to 30 days
 4.Irrigation scheduled as treatment 1 except no irrigation beginning at first full sized boll (approx. July 5) for up to 30 days
 5.Irrigation scheduled by evaporation pan
 6.No irrigation

Basic Crop Management: PLANTED - 24 Apr 1997 (placed 2 cm deep, seed rate 10 seeds/m ); HARVEST - ; TILLAGE - Moldboard Plow (30 cm deep plus smoothing and bed shaping), wheel traffic controlled at 1.2 m centers; FERTILIZATION - Typical Extension Recommended Rate; WEED & PEST CONTROL: Typical Extension Recommendations.
Chronological Treatment and Observation Details

Observations and data sets for individual treatments (crop years) follow:
Treatment 1:
  Control - Soil water content scheduling - when the average soil water content in the 10 to 45 cm depth exceeds 35 kPa schedule an irrigation for the next day (1 day late)
Treatment 2:
  Apply water according to the Extension service checkbook scheduling, replacing needed water once each week
 Treatment 3:
  Irrigation scheduled as treatment 1 except no irrigation beginning at first square (approx. June 15) for up to 30 days
 Treatment 4:
  Irrigation scheduled as treatment 1 except no irrigation beginning at first full sized boll (approx. July 5) for up to 30 days
 Treatment 5:
  Irrigation scheduled by evaporation pan
 Treatment 6:
  No irrigation
For more information on the study and its interpretation contact:
Dr. Jim Hook Professor, Soil and Water Management
Crop and Soil Sciences Department and NESPAL
The University of Georgia, College of Agricultural and Environmental Sciences
P.O. Box 748, Tifton, GA 31793-0748
e-mail: jimhook@tifton.cpes.peachnet.edu

Page developed by James E. Hook, Amanda Richards, and Linsey Forlow.
Last Modified on 29 June 2000.