Soil Degradation by Erosion in Sloping Land in Southern Jiangsu Province, China

As soil erosion can accelerate soil degradation, some natural soilsand cultivated soils on sloping land in Southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intensity was investigated using 137Cs tracer method. Soil particle-size distribution, soil organic matter (OM) content, total nitrogen (TN) and total phosphorus (TP) measured and the effects of erosion on soil physical and chemical properties wereanalyzed with statistic software SYSTAT8.0. The results indicated that soil erosion intensity for cultivated soils was greater than that of natural soils, suggesting that cultivation increased soil loss. Soil erosion also led to an increase of coarser soil particle proportion, especially in natural soils. In addition,we also found that silt (0.05～0.005 mm) was the primary soil particle lost due to the erosion. However, in cultivated fields, coarser soil particles over time were attributed not only by soil erosion but also by mechanical eluviation as a result of farming activities. Moreover, erosion caused a decrease in soil OM, TN and TP as well as thinning of soil layer.