湖南省慈利县坡耕地占总耕地面积的56％以上,其成土母质多为紫色砂页岩和泥质页岩,易风化,土壤粘结力差,抗蚀力弱,多被侵蚀切割为低丘,加之人口密度大,暴雨多,耕垦活动频繁,水土流失严重,年侵蚀模数3000～4000t/km~2,最高达万吨以上,为水土流失的主要来源地.由于坡地严重水土流失,造成土壤瘠薄、产量低,阻碍了农业生产 Cultivated land in Cili County, Hunan Province, accounts for over 56% of the total cultivated area. Its parent soil is mostly purple sandstone and shale, weathering, poor soil adhesion, weak erosion resistance, For the low hill, combined with the population density, heavy rain, frequent reclamation activities, serious soil erosion, the annual erosion modulus 3000 ~ 4000t / km ~ 2, up to 10,000 tons or more, as the main source of water and soil loss due to severe slope Soil and water loss, resulting in infertile soil, low yield, hinder agricultural production