Winter Cover and Tillage Influences on Coastal Plain otton Production

摘要

Winter cover crops and conservation tillage can be used by southeastern Coastal Plain cotton (Gossypium hirsutum L.) growers to meet soil erosion control requirements of the 1985 Food Security Act. Our objective was to determine whether these production practices influence cotton productivity and quality. The study was conducted on a Norfolk loamy sand soil (fine-loamy, siliceous, thermic Ty pic Kandiudult) near Florence, SC, in 1991 and 1992. Treatments were winter annual cover crops, tillage, and timing of cover crop incorporation or desiccation before cotton planting. Cover crop treatments were crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth.), rye (Secale cereale L.), and winter fallow. Tillage systems were conventional(annual disking and bedding with in-row subsoiling) and conservation (in-row subsoiling only). Soil strength was measured during the spring in the fallow plots in both tillage systems. Incorporation (conventional tillage) or desiccation (conservation tillage) of the winter cover was done 5 or 15 d before cotton planting. Winter legume dry matter production was <1800 Ib/acre per yr. Rye dry matter production was approximately 2200 Ib/acre per year. Soil and crop variables studied were not affected by timing of the cover crop incorporation or desiccation. Soil strength was lower in the top 12 in. with conventional tillage. In conservation tillage, soil strength was the same both years. Conservation tillage had lower lint yield than conventional tillageby 267 Ib/acre following clover and by 259 Ib/acre following vetch [LSD_((0.05) = 221 Ib/acre]. Within winter cover treatments following fallow and rye, tillage systems did not differ in yield, but lint yield for conservation tillage following rye was 292 Ib/acre greater than yield for that tillage system following fallow. Fiber properties were not greatly influenced by tillage system or winter cover, but micronaire was 0.1 units lower for cotton following rye than cotton following legumes. Including arye winter cover crop may better insure successful conversion to conservation tillage cotton production systems on Coastal Plain soils.