【摘要】 土壤侵蚀是坡耕地土壤退化的主要影响因子之一。在金沙江干热河谷区坡耕地的实验表明， 沿坡耕地等高线种植高密度高固氮植物篱并合理经营，可有效防治土壤侵蚀。１９９７ 年植物篱处理的土壤侵蚀量减少到对照的１４ ．５ ％ ～２３ ．９ ％ ，１９９８ 年侵蚀量仅为对照的１ ％ ～３ ％ 。坡耕地土壤侵蚀集中发生在雨季中期。土壤侵蚀过程也是土壤养分加速流失的过程，分析表明流失土壤中全氮和有机质在侵蚀土壤中含量分别是表土平均含量的２ ．３ 倍和２ ．４７ 倍以上。在培植等高植物篱系统后，经过４ ～７ ａ 的正常耕作，坡耕地可形成以植物篱为地埂的梯地。更多还原

【Abstract】 Soil erosion is one of the major factors for land degradation in mountains. Contour hedgerow system, consisting of thickly planted double or single hedgerows of nitrogen fixing trees or shrubs, shows great potential in soil conservation of cultivated slope lands in the tropics. On farm research was carried out in Ningnan county of southwest China to assess the effect of hedgerows on soil erosion control in the subtropical region. The research consists of four treatments with three replicates. The results showed that more than 70% soil erosion occurred in the mid term of monsoon under the traditional cultivation. The 4～7 year old hedgerows of L. leucocephala and T. candida reduced soil loss to be 1%～3% of the control. The erosion is also an accelerating nutrient loss procedure. The contents of total nitrogen and organic matter in the sediments were more than 2.3 and 2.47 times of those in eroded topsoil. Maintenance of hedgerows can also lead to formation of terrace after normal cultivating in the alleys for several years.更多还原