红壤小流域不同利用方式氮磷流失特征研究

从红壤小流域坡地资源合理利用和保护的角度研究了不同利用方式土壤氮、磷流失的特征，结果表明：恢复保护性植被的试验区3，由于其水土流失量最低，氮、磷流失量最小。侵蚀严重的试验区5，由于水土失量最大，磷的流失量最大，但其有效磷、水溶性磷及氮素流失量低于不注重水土资源保持经营利用的试验区1、注重水土保持措施的试验区2和试验区4。由于采用了水土保持综合农林措施，有效地减轻了水土流失，试验区2和试验区4的土壤氮、磷流失量明显小于试验区1土壤氮、磷流失量，红壤小流域不同利用方式中水土保持综合措施能有效地控制土壤养分流失。2000年不同试验区土壤氮、磷的流失主要集中于5、6及8月份，其流失量占全年氮、磷流失量的90％以上，这与当地的降雨季节性分配特征有关。土壤氮、磷的坡面流失方式为推移质流失和径流流失，磷的流失形态主要为泥砂结合态，约占总磷流失量的70％以上。除试验区3以外，其它试验区泥沙结合态氮素的流失量大于水溶态氮素流失量。

Losses of nitrogen and phosphorus under different land use patterns in small red soil watershed

Soil erosion is very significantly serious throughout China, which covers 1.80 million km2. In red soil region of southern China, soil erosion also occurred seriously with area of 0.80 million km2. Soil erosion, which causes river silted, floods, nutrient loss, water pollution, soil and land productivity degradation, has negatively impacted on sustainable agriculture development. A lot of reports on soil erosion were presented focusing on simulation based on single factor treatment. Soil erosion research on...