EFFECT OF ANNUAL, BIENNIAL, AND TRIENNIAL IN-ROW SUBSOILING ON SOIL COMPACTION AND COTTON YIELD IN SOUTHEASTERN U.S. SILT LOAM SOILS

For those soils that require deep tillage to alleviate soil compaction, subsoiling can be an expensive and time-consuming tillage event. Alternative tillage methods are needed which conserve natural resources without sacrificing cotton yields. An experiment was conducted in the Tennessee Valley region of north Alabama to determine how frequently deep tillage is needed to alleviate soil compaction problems in these soils. Three different subsoilers (an in-row subsoiler and two bentleg subsoilers) were tested against a no-till treatment to determine if differences in crop productivity or soil condition could be detected. Annual subsoiling resulted in reduced bulk density compared to biennial subsoiling, triennial subsoiling, or no subsoiling. Reductions in draft force were also found for annual subsoiling. However, cotton yield results over a two-year period from tillage three-years previous, two-years previous, and one year previous found no differences.