Maize Irrigation Study, 1997, Georgia Coastal Plain

Yield Comparisons:
Study:

Research Objective:

    1. Develop irrigation management systems for consistent high yield and quality corn for loamy sand soils.
    2. Establish soil water requirements needed for consistent growth and grain development.
    3. Validate corn irrigation models and scheduling equipment for the Georgia Coastal Plain.
Treatments:
 1.Control - Soil water content scheduling - when the average soil water content in the 10-45 cm depth exceeds 35 kPa schedule an irrigation for the same day (Full - on time).
 2.Irrigate as 1. above except wait until one day after triggering, unless intervening rain (see below) (Full - 1 day late).
 3.Irrigate as 1. above except apply only 2.0 cm on the same day as triggered (Deficit - on time).
 4.Irrigate as 1. above except wait until two days after triggering, unless intervening rain (see below) (Full - 2 days late).
 5.Irrigate as 1. above except wait until three days after triggering, unless intervening rain (see below) (Full - 3 days late).
 6.No irrigation
    Intervening rain exceeding 2.5 cm total cancels a delayed irrigation.
    Intervening rain totaling <2.5 cm and>1.5 cm, apply 1.5 cm on the delayed treatments.
    Intervening rain totaling less than 1.5 cm, irrigate as though no rain.

    Basic Crop Management: PLANTED - 11 Mar 1997; HARVEST - 30-31 Jul 1997 (2-row grain combine); 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 - Full - on time
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 11.17; Individual plots - 10.46, 11.20, 9.38, 11.77, 13.03 Text File
Treatment 2:
 Full - one day late
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 10.96; Individual plots - 12.25, 10.76, 11.48, 10.81, 9.51 Text File
Treatment 3:
 Deficit - on time
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 11.01; Individual plots - 11.46, 11.13, 11.30, 9.78, 11.39 Text File
Treatment 4:
 Full - two days late
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 10.27; Individual plots - 11.09, 9.33, 9.61, 9.16, 12.14 Text File
Treatment 5:
 Full - three days late
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 10.80; Individual plots - 11.15, 11.36, 10.68, 9.60, 11.20 Text File
Treatment 6:
 No irrigation
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 24 Mar 1997; Pollination (R2) - 27 May 1997; Maturity (Black layer) - 07 Jul 1997
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 9.23; Individual plots - 10.26, 10.22, 9.38, 7.09, 9.19 Text File
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.