Soil-water content changes under three tillage systems used for cotton

Cotton (Gossypium hirsutum L.) was grown on Deca-tur silty clay loam (clayey, kaolinitic, thermic Typic Paleudults) at the Tennessee Valley Substation of the Alabama Agricultural Experiment Station. Treatments included conventional tillage, reduced tillage with a winter wheat (Tritium aestivum L.) as a cover crop, and reduced tillage with no cover crop. Soil water was measured biweekly by the neutron scatter method at 20-, 40- 60-, 80-, and 100-cm depths in the soil profile during the 1987 growing season (May 1-September 30) immediately after 2 years of the same treatments. At the 20-cm depth, soil-water content was the highest for reduced tillage with cover crop, but this treatment had lower soil-water contents at depths below 40-cm than those of reduced tillage with no cover crop. Soil-water contents at the measured soil depths were lowest with conventional tillage throughout the growing season.