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在美国南部大平原地区，由于周期性强烈降雨及大面积的易侵蚀土壤的存在，引起了强烈的沟蚀。在俄克拉荷马州的ＬｉｔｔｌｅｗａｓｈｉｔａＲｉｖｅｒ流域选取了两个毗邻的普遍发生沟蚀（４级侵蚀）并长有当地草类的小流域，坡度均为５％，面积分别为３．８、５．７ｈｍ２，同时对径流中的土壤沉积物、氨、磷的流失量进行了长达１３年的测试研究（１９８０～１９９２），１９８３年，对试验流域的冲沟进行了治理，种植了米德兰狗牙根，并修建了１个蓄水池。治理前，沉积物、氮和磷的流失量远大于对照流域的流失量。治理后，年土壤流失量只有４９００ｋｇ／ｈｍ２，氮、磷流失量分别为３，１ｋｇ／ｈｍ２、１．６ｋｇ／ｈｍ２，而对照小流域年土壤流失量为２７５００ｋｇ／ｈｍ２，氮、磷流失ｈ量分别为７．１ｋｇ／ｈｍ２、４．６ｋｇ／ｈｍ２。根据径流与土壤相互作用的主要层次的土壤特性，利用动力学与丰度法。预测出治理区和对照区径流中氨、磷的流失量。根据心土层特性预测出对照区径流中氮、磷的释放量及迁移量：在治理区，也作出同样精确的预测。此后１０年效益结果为：用在冲沟治理上的每投入１美元可减少土壤流失量２１０ｋｇ，减少氮、磷流失量为５ｇ、３ｇ。关键词
In the southern Great Plains of the United States, intense gully erosion is caused by the intense rains and large areas of erodable soils. In the Littlewashita River Valley, Oklahoma, two adjacent small watersheds with gully erosion (Grade 4 erosion) and long grasslands are selected, each with a slope of 5% and an area of 3.8 and 5.7hm2, respectively , And at the same time conducted a 13-year study on the runoff sediment, ammonia and phosphorus losses (1980-1992). In 1983, the gully of the pilot basin was controlled and Midland dogs Roots, and built a reservoir. Before the treatment, sediment, nitrogen and phosphorus loss is much larger than the control basin loss. After the treatment, annual soil loss was only 4900kg / hm2, nitrogen and phosphorus losses were 3,1kg / hm2, and 1.6kg / hm2, respectively. Compared with the control, annual soil loss was 27,500kg / hm2, nitrogen and phosphorus loss h Respectively 7.1kg / hm2, 4.6kg / hm2. Based on the major levels of soil properties of the interaction between runoff and soil, kinetic and abundance methods are used. Predict the runoff and runoff ammonia and phosphorus loss. According to the characteristics of the soil layer, the release of nitrogen and phosphorus and the amount of migration of nitrogen and phosphorus in the control area were predicted: in the control area, the same exact prediction was also made. The result of the following 10 years’ benefit is as follows: For every US $ 1 invested in gully management, it can reduce 210kg of soil loss and 5g, 3g of loss of nitrogen and phosphorus. Key words