坡地土壤氮素径流损失表现为两种形式 ,溶解于径流中的矿质氮随径流液流失 ,吸附于泥沙颗粒表面以无机态和以有机质形式存在的氮素。坡地土壤氮素流失过程实际上是表层土壤氮素与降雨、径流相互作用的过程 ,土壤氮素流失的多少主要受相互作用的限制。从分析土壤与降雨、径流相互作用入手 ,分析了土壤氮素与降雨、径流相互作用过程及机理 ,并对相互作用模型进行探讨。

Soil N loss by erosion on slope land is affected by soil mineral N loss mainly by runoff and organic N loss mostly by sediment. The process of soil nitrogen loss by erosion is restricted by interaction of soil nitrogen with rainfall and runoff. The interacting process of soil N with rainfall is divided into two stages: under rainfall conditions, soil N releasing process from soil to rain drops and soil N (mostly nitrite N) infiltrating process from top soil to deep soil in soil profile. Meanwhile, interacting process model of soil N with runoff is divided into three types, i.e. the mixed depth model of interacting process of soil N with runoff, the releasing and transporting model of soil N from topsoil to runoff and from upper slope to down slope, and process model of soil N loss by erosion. Based on analysis on interaction of soil with rainfall and runoff on slope land, the interacting models and mechanisms of soil nitrogen with rainfall and runoff are discussed to provide research methods and thoughts for further study on soil N loss by erosion.