Study on Surface Runoff and Sediment Yield of Different Tillage for Red Soil hilly Region

摘要

To study effects of different tillage on soil and water conservation (SWC) for red-soil hilly region in south China. field experiments including three tillage measures(contour strip intercropping, downslope strip intercropping and clean tillage) and a check were performed on the representative area named Jiangxi Eco-science Park of SWC. The surface runoff and sediment yield of each treatment and natural rainfall were investigated from 2001-2005. The results indicated that, (a) seasonal and annual precipitations of the study area were uneven， and the rainfall in rainy season nearly accounted for 68.72% of the whole year. At the same time. seasonal and annual rainfall erosivity of the study area was also uneven. and the rainfall erosivity in Apr.-Sept. nearly accounted for 91.66% of the whole year; (b) compared with the check. surface runoff reduction rates of the three farming practices were among 21.16%～75.32%, and their sediment reduction rates were among 38.08%～80.57%; (c) these farming practices have great benefits to preserving water and soil and stands ranked in the descendant order of contour strip intercropping, downslope strip intercropping and clean tillage. Meanwhile. contour strip intercropping has the greatest benefits of soil and water conservation and can be applied widely to agricultural exploitations in red-soil hilly region.