ABSTRACT
Field studies were begun in the fall of 1984 to determine optimum fall and spring tillage requirements for cotton grown in the Coastal Plain area of Alabama. The test was conducted for two years at the E.V. Smith Research Center on a Norfolk sandy loam soil. Treatments consisted of three primary tillage systems (subsoiling, turn plowing and chiseling) in combination with two secondary tillage operations (bedding and disking) done either in the fall or spring. Additional treatments included chiseling, turn plowing and in-row subsoiling in a rye cover crop. Soil bulk density, soil moisture and seed cotton yields were measured. In both years the lowest bulk density resulted from fall subsoiling followed by fall bedding. The poorest tillage practice proved to be the in-row subsoiler in the rye cover. In 1985 bulk density values were generally lower from spring primary tillage than fall tillage. Soil moisture content was greatest from the treatment occurring in the rye cover crop. Yields were maximized by turn plowing in the spring followed by bedding. In all three primary tillage systems yields were drastically reduced when disking followed the operation as compared to bedding. In 1986 bulk density values were higher than in 1985, reflecting an extremely dry spring. The highest bulk density and lowest soil moisture content were recorded in the in-row subsoiled plots. The highest yield resulted from spring turning and disking. In all three tillage systems yields were reduced when bedding followed spring primary tillage than disking. Turning and chiseling in the rye cover proved to be as effective as the same treatments in the fallow area.
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