Maize Irrigation Study, 1983, Georgia Coastal Plain

Yield Comparisons:
Study:

Research Objectives:

    1. Evaluate the effects of varying soil moisture conditions on yield.
    2. Measure leaf temperature changes resulting from drought periods.
    3. Create conditions of subsoil dewatering to evaluate their effect on yield.
Treatments:
 1. Control - 30cb vary full season, full replacement
 2. 30cb vary except weeks 1-7, full replacement
 3. 30cb vary except weeks 6-10, full replacement
 4. 30cb vary except weeks 9-13, full replacement
 5. 30cb vary except weeks 12-16, full replacement
 6. 30cb shallow 2/3 replacement topsoil only
 7. Fixed two irrigations - pretassel emergence, late pollination
 8. 30cb deep 2/3 replacement topsoil and subsoil
 9. No irrigation

Basic Crop Management: PLANTED - 23 Mar 1983 (rows 0.6m apart); HARVEST - 19-20 Jul 1983 (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 - 30cb vary full season, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 8.70; Induvidual plots - 8.71, 9.24, 9.88, 7.45, 8.21 Text File
Treatment 2:
  30cb vary except weeks 1-7, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 10.45; Individual plots - 11.24, 10.85, 9.91, 10.20, 10.03 Text File
Treatment 3:
  30cb vary except weeks 6-10, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture. T/ha: Average - 9.60; Individual plots - 10.02, 10.63, 8.13, 9.93, 9.27 Text File
Treatment 4:
  30cb vary except weeks 9-13, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 7.29; Individual plots - 7.42, 6.35, 4.83, 7.95, 9.92 Text File
Treatment 5:
  30cb vary except weeks 12-16, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 8.37; Individual plots - 8.46, 9.54, 7.94, 6.56, 9.37 Text File
Treatment 6:
  30cb shallow 2/3 replacement topsoil only
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 9.41; Individual plots - 10.45, 9.31, 7.10, 10.54, 9.63 Text File
Treatment 7:
  Fixed two irrigations - pretassel emergence, late pollination
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 9.37; Individual plots - 10.00, 8.85, 10.54, 8.78, 8.69 Text File
Treatment 8:
  30cb deep 2/3 replacement topsoil and subsoil
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 8.01; Individual plots - 9.21, 8.75, 7.27, 4.56, 10.25 Text File
Treatment 9:
  No irrigation
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04-05 Apr 1983; Pollination (R2) - ; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 7.08; Individual plots - 7.82, 8.74, 5.91, 8.10, 4.81 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.