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 - Tensiometer - 30 cb vary full season, full replacement
 2.Tensiometer - 30 cb vary except weeks 1-7, full replacement
 3.Tensiometer - 30 cb 2 day delay/rainfall throughout weeks 1-7, full replacement
 4.Tensiometer - 30 cb vary except weeks 9-13, full replacement
 5.Tensiometer - 30 cb vary except weeks 12-16, full replacement
 6.Tensiometer - 30 cb shallow 2/3 replacement topsoil only
 7.Tensiometer - Fixed two irrigations-pretassel emergence, late pollination
 8.Tensiometer - 30 cb deep 2/3 replacement topsoil and subsoil
 9.No irrigation

Basic Crop Management: PLANTED - 23 Mar 1983 (rows 0.6m apart); HARVEST - 09 Aug 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 - Tensiometer - 30 cb vary full season, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 7.00; Individual plots - 6.59, 6.41, 8.06, 7.52, 6.38 Text File
Treatment 2:
 Tensiometer - 30 cb vary except weeks 1-7, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 6.96; Individual plots - 6.50, 5.99, 6.75, 8.56, 6.99 Text File
Treatment 3:
 Tensiometer - 30 cb 2 day delay/rainfall throughout weeks 1-7, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 5.67; Individual plots - 6.16, 4.72, 4.99, 5.86, 6.64 Text File
Treatment 4:
 Tensiometer - 30 cb vary except weeks 9-13, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 3.33; Individual plots - 3.73, 1.74, 4.12, 3.97, 3.07 Text File
Treatment 5:
 Tensiometer - 30 cb vary except weeks 12-16, full replacement
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 2.45; Individual plots - 4.36, 1.56, 2.16, 2.24, 1.93 Text File
Treatment 6:
 Tensiometer - 30 cb shallow 2/3 replacement topsoil only
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 7.39; Individual plots - 8.06, 6.93, 5.96, 8.81, 7.14 Text File
Treatment 7:
 Fixed two irrigations-pretassel emergence, late pollination
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 5.43; Individual plots - 5.61, 5.63, 4.41, 5.78, 5.70 Text File
Treatment 8:
 Tensiometer - 30 cb deep 2/3 replacement topsoil and subsoil
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 5.65; Individual - 6.19, 5.29, 5.76, 5.54, 5.48 Text File
Treatment 9:
 No irrigation
  • Irrigation Dates and Amounts: Text Format;
  • Phenology: Emergence - 04 Apr 1983; Pollination (R2) - 15 Jun 1983; Maturity (Black layer) - 11 Jul 1983
  • Stand Count:
  • Soil Water Pressure Observations: Tensiometer & Gypsum Block
  • Yield Corn Grain, 15.5% moisture, T/ha: Average - 2.71; Individual plots - 2.87, 2.63, 3.59, 2.33, 2.08 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.