Abstract:
Protective management of arable slope land plays an important role in protection of land resource and aquatic environment in Three Gorges region, China. Base on the regional natural conditions and the utilization of the arable slope land, four tillage modes with H1 (rotation of wheat and maize, wheat intercropped with horse bean, less tillage and ridge cultivation), H2 (rotation of wheat and maize, with Vetiveria ziz anioides contour hedges intercropped at slop length interval of 5m), H3 (rotation of wheat and maize, with alfalfa contour hedges intercropped at slop length interval of 5m), H4 (rotation of wheat and maize, conventional management) were conducted from Oct. 2009 to Oct. 2011. The differences of apparent recovery efficiency and Agronomic efficiency of applied nitrogen and phosphorus between treatments were discussed, as well as nitrogen and phosphorus losses through slope land surface runoff were analyzed. The results showed that compared with H4, H1 increased phosphorus use efficiency by 0.06 kg/kg. No significant difference of biological and economic production, apparent recovery efficiency and agronomic efficiency of applied nitrogen and phosphorus was observed among H2、H3 and H4, which showed intercropping with Vetiveria ziz anioides or alfalfa contour hedges wouldn't lead to the reduction of production. Furthermore significant effects on reducing soil erosion and sediment phosphorus loss were observed for H1、H2 and H3. Compared with H4, and sediment losses for H1, H2 and H3 decreased by 48.46%, 52.26% and 58.59% respectively, and sediment phosphorus losses decreased by 30.58%, 47.70% and 44.58% respectively.