| Abstract: | This study documents the erosivity of rainfall, the high erodibility of soils, and reduction in annualand storm soil loss rates by conservation tillage at Holly Springs, Mississippi. Holly Springs is innorthern Mississippi in the Midsouth United States. Rainfall characteristic data and runoff dare wereexarmined for single storms and for cultivated fallow conditions for Loring (Typic Fragiudalfs) andLexington (Typic Paleudlfs) soils during 1963 through 1968 using data from 135 single storm events.Rainfall erosion index (EI) was the best single estimator among those rainfall characteristics studied to estimatC siol loss during the storms. Soil losses from a cultivated fallow plot were greater than 20 imaduring each of 10 storms. Average annual rainfall of 1314 mm and rainfall erosion index of 6315 MJmm (ha h)-1 during 1958 to 1976 for the 303-square kilometer Pigeon Roost Watershed near HollySprings, Mississippi illustrated the high erosivity of rainfall. Conservation tillage cropping systems forcom (grain and silage), soybean, cotton, and sorghum from 1974 to 1990 at Holly Springs effectivelycontrolled erosion, especially as compared to conventional-till. Soil losses from agricultural landpreviously under conventional-till were dramatically reduced. Cropping and management factor (SLR)values derived from selected large storms provided good estimates of annual SLR values for use in theuniversal soil loss equation. |
