三峡库区坡耕地土壤养分流失的实验研究

采用室内模拟降雨装置研究了三峡库区坡耕地土壤养分流失规律。无论是紫色土还是黄色石灰土,坡耕地表层土壤养分含量在人工降雨后发生衰减,并表现出随雨强增大,雨后表土各养分含量衰减幅度加大的趋势,但径流和流失泥沙的养分含量与雨强无关;径流中养分含量虽低于泥沙养分含量,但养分含量的差异主要体现在全量养分含量上,而速效养分含量的差异则相对较小。对三峡库区坡耕地土壤养分流失而言,紫色土坡耕地土壤养分流失主要以流失泥沙为载体,而黄色石灰土坡耕地土壤养分流失则由流失泥沙和径流共同携带。

Research on Nutrient Loss from Slope Land in Three Gorges Reservoir Area

The pattern of soil nutrient loss from slope land was studied in Three Gorges Reservoir Area by means of simulated rainfall equipment.For purple soil and terra gialla soil,the nutrient content of surface soil of slope land declined and the declining extent of surface soil was increasing with rainfall intensities increasing,but the nutrient content of runoff and sediment was irrelative to rainfall intensities.The nutrient content of runoff was lower than that of sediment,but the discrepancy was mainly lied in the total nutrient and the discrepancy of the available nutrient was slight.For nutrient loss from slope land in Three Gorges Reservoir Area,the nutrient loss form purple soil was mainly caused by sediment,but that form terra gialla soil was caused by runoff and sediment.