丘陵坡地地表径流中磷的形态及其影响因素

 土壤磷随地表径流进入水体是导致水域富营养化的重要因素，研究地表径流中磷的形态有助于了解农业活动对流域水质的影响.本研究在2年内测定了浙江北部排溪冲小流域6种坡地利用方式的径流中各种磷的形态浓度及其影响因素．结果表明，对于己开发利用的坡地（尤其是新开荒的坡地）泥沙结合态磷（PP）是地表径流中P存在的主要形态，PP占总磷（TP）比例在49．39％～87．72％,径流中可溶性磷（DP）占生物可利用磷（BAP）的50％以上；径流中的DP和BAP明显受施肥状况和土壤中磷含量的影响，磷肥施用后遇降雨和高的土壤含磷量是导致径流中DP和BAP浓度高的主要原因.

Phosphorus forms in surface runoff and its affecting factors in hilly upland

The transport of soil phosphorus through surface runoff into water body is an important factors leading the eutrophication of the receiving water body. Study of P forms in surface runoff will help understand the impacts of agricultural activities on the water quality of the watershed. The concentration of various phosphorus forms and its affecting factors were determined over a 2-year period in the runoff from six land use patterns in Pai-xi-chong micro-watershed in the north of Zhejiang Province. The results show that particulate P (PP) is the main form of phosphorus accounting for 49.39%~87.72% of total P (TP) in the runoff from 6 kinds of used land. Dissolved P (DP) contributes more than 50% of bioavaifable P (BAP) in the runoff DP and BAP are influenced significantly by P fertilizing and P content in soil. Fertilizing of P in rainy season and high content of P in soil are the main causes of high DP and BAP in the runoff.