Predicting soil erosion in conservation tillage cotton production systems using the revised universal soil loss equation (RUSLE)

Despite being one of the most profitable crops for the southeastern USA, cotton (Gossypium hirsutum L.) is considered to create a greater soil erosion hazard than other annual crops such as corn (Zen mays L.) and soybeans (Glycine max (L.) Merr.). Reduced tillage systems and cover cropping can reduce soil erosion and leaching of nutrients into ground water. The objectives of this study, which was conducted in north Alabama from 1996 to 1998, were to assess the impact of no-till and mulch-till systems with a winter rye (Secale cereale L.) cover crop and poultry litter on soil erosion estimates in cotton plots using the revised universal soil loss equation (RUSLE). Soil erosion estimates in conventional till plots with or without a winter rye cover crop and ammonium nitrate fertilizer were double the 11 t ha(-1) yr(-1) tolerance level for the Decatur series soils. However, using poultry litter as the N source (100 kg N ha(-1)) gave soil erosion estimates about 50% below the tolerance level under conventional till. Doubling the N rate through poultry litter to 200 kg N ha(-1) under no-till system gave the lowest soil erosion estimate level. No-till and mulch-till gave erosion estimates which were about 50% of the tolerance level with or without cover cropping or N fertilization This study shows that no-till and mulch-till systems with cover cropping and poultry litter can reduce soil erosion in addition to increasing cotton growth and lint yields, and thus improve sustainability of cotton soils in the southeastern USA. (C) 2001 Published by Elsevier Science B.V.