COVER CROPS AND TILLAGE EFFECTS ON COTTON

Cotton (Gossypium hirsutum L.) is one of the most erosive row crops grown in the southeastern USA and with the implementation of the 1985 Food Security Act, producers may have to use no-till or cover crops in order to remain in compliance. A 3-yr field experiment examined cover crop (crimson clover [Trifolium incarnatum L.], hairy vetch [Vicia villosa L.], wheat [Triticum aestivum L.], and cool season weeds) and tillage (no-till [NT] and conventional [CT]) effects on cotton. Wheat produced more canopy cover during the winter and higher dry matter (DM) yields during 2 of 3 yr than the other winter vegetation. Seedcotton yields for NT cotton were significantly higher than for CT cotton during 1 yr of this study. Generally, plant height and population were unaffected by cover crops or tillage treatments. Stem, leaf, and total plant weights were significantly higher for NT cotton in 1 of 2 yr. Cone index readings at the 6-in. depth were significantly greater for NT cotton at in-row and traffic middle sites. Soil pH and organic matter percentage were generally unaffected by cover crops or tillage systems. Extractable P levels (0- to 3-in. depth) tended to be higher for NT cotton while extractable K amounts (0- to 3-in. depth) tended to be higher for CT cotton. Total production expenses across cover crops were lower for NT cotton than for CT cotton. Of the planted cover crops, wheat was the least expensive to establish. No-till cotton, therefore, could be used to reduce soil erosion while maintaining high cotton yields.