Characteristics of Water and Soil and Nutrients Loss on Sloping Lands in Weibei Highland

The thesis studied the mechanism of soil degradation of slope lands in Weibei highland by field orientation observed and laboratory analysis.The main conclusions were as follows: The slope lands degradation was caused by soil and water erosion which was the several torrential rains within a year.The mean sediment yield of 5°,10° and 15° were 320.9,1 581.1 and 3 819.6 t/(km2·a) and the mean runoff were 13 836.4,46 869.3,53 956.5 m3/(km2·a) respectively within the observation period.The value was impacted by rain intensity and slope.Water and soil erosion resulted in the increase of soil bulk density and the decease of the soil porosity and the lower of the water-holding capacity as well as removing the soil available nutrients which could lead to poor fertility.The content of the total nitrogen and available potassium in sediment were far higher than those of plough layer which took on the enrichment.