ABSTRACT
Reduced tillage and winter legume cover crops could increase the yield of cotton grown on clay soil in the lower Mississippi River Valley. Field studies were conducted from 1987 through 1993 to evaluate tillage regimes of no-till, ridge-till and conventional-till with and without a winter vetch cover crop for cotton planted on Sharkey clay. In 1993, N rates of 0, 45, 90 and 135 pounds per acre were added as a third treatment variable. There was little effect of tillage on cotton yield from 1988 through 1992. In 1993, no-till produced higher yields than ridge-till or conventional-till. The vetch cover crop increased seedcotton yield an average of 390 pounds per acre compared with native cover crop vegetation . The optimum N rate without a vetch cover crop in 1993 was 90 pounds per acre, which produced a yield of 800 pounds of lint per acre. With a vetch cover crop, 45 pounds of N per acre produced optimum lint yield of 1100 pounds per acre. A combination of no-till and vetch cover crop substantially increased cotton yield, improved crop growth rate and reduced the amount of fertilizer N needed for cotton production on clay soil.
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