CROP_PLANTING FACTOR OF SOIL EROSION OF SLOPING CULTIVATED LAND IN THE NORTHEAST MOUNTAIN REGION OF YUNNAN PROVINCE

By means of setting up experimental spots of the influences of four representative crop_planting types maize,potato,soybean and maize_soybean intercrop on rainfall erosion,and measuring continuously three years in the northeast mountain region of Yunnan province,the C value of crop_planting factor was analysed and calculated.The results showed:1.the conserving effect of crops on the soil of slopeland increases with the growth of crops,i.e.the higher the covering rate of ground is,the lower the C value is.2.in four crop_planting types,the maximum conserving effect on the soil of slopeland is maize_soybean intercrop,its C value is 0 1990,the C values of other crops are respectively:maize 0 3517,soybean 0 3551,potato 0 3721.