三峡库区紫色土坡地的模拟降雨实验表明 ,香根草 (Vetiverzizanioides)等高植物篱—农作系统能有效地控制坡面土壤侵蚀。单纯等高植物篱处理小区的侵蚀量仅为在相近雨强及雨量条件下对照坡耕地的 37 71%。植物篱截短坡长 ,防止细沟侵蚀产生和发展是侵蚀量明显减少的一个主要原因。等高植物篱—农作系统带间覆盖和施用有机或无机肥能进一步将小区侵蚀量减少至对照坡耕地的 0 18%～ 0 19%。植物篱能有效拦截流失的土壤大颗粒 ,使侵蚀泥沙中粒径 <0 0 2mm的细粒比例增加 ,多数养分有明显富集。土壤细颗粒的损失对土壤有效钾影响最大。植物篱—农作系统建成初期和单纯农作系统氮、磷养分流失途径以侵蚀泥沙的携带为主。植物篱完全蔽合 ,篱前淤积带形成后 ,由于植物篱和覆盖物的阻滞 ,径流与土壤的更充分分作用 ,使植物篱—农作系统的径流中钾含量提高 ,径流成为有效钾损失的主要途径 Simulated rainfall experiments on purple soil slopes in the Three Gorges Reservoir Area show that contour hedgerows and cropping systems such as Vetiverzizanioides can effectively control soil erosion on slope. The erosion of plots of pure contour hedgerows was only 37 71% of the control plots under similar rainfall intensity and rainfall conditions. Truncation of hedgerow length, to prevent the occurrence of rill erosion and development is a significant reduction in erosion is a major reason. Contour hedgerows - Intercropping with farming systems and application of organic or inorganic fertilizers further reduced erosion in the community to 0 18% to 0 19% of the control sloping farmland. Plant hedgerows can effectively intercept large soil particles lost so that the proportion of fine particles with particle size <0 0 2mm in the sediment to be eroded increases, and most nutrients are significantly enriched. Soil loss of fine particles has the greatest effect on soil available potassium. Hedgerow-farming system was mainly carried by erosion sediment in the early stage of farming system and the way of nitrogen and phosphorus loss in simple farming system. When the hedgerows were fully masked and silt straps were formed in front of the hedgerows, the potassium content in the runoff of the hedgerow-cropping system increased due to the blockage of hedgerows and coverings and the fuller effect of runoff and soil, and the runoff became a valid potassium The main way to lose