川中紫色土区磷素年非点源的输出负荷

为了探讨磷素的农业非点源输出规律，于2002年4月至2003年4月，对中国科学院盐亭农业生态站进行了为期1a的定期监测。试验通过采集不同时期不同耕作处理(平作、顺坡、垄作)的农田径流水样、水田田面水并分析不同形态磷素，根据全年降雨量预测出其产流量．结合平均浓度法，计算出了旱地径流场非点源磷的年污染负荷为94．56g／hm^2，水田的非点源磷素年输出负荷为107.4g／hm^2，为该区进行大面积农业面源污染负荷的研究提供了一定的依据。

Load of Phosphorous from Purple Soil in Mid- Sichuan by Way of Non -point Sources

A periodical survey was carried out at Yanting agricultural ecology station in order to find out the rule of phosphorous transfer in purple soil agricultural area of mid-Sichuan from Apr. 2002 to Apr. 2003. Different cultivation manner sections were designed, including ridge tillage (RT), flat tillage (FT), and down slope tillage (DT). Runoff from different sections and water in paddy field were collected, and phosphorous forms were analyzed. On the base of rainfall in the whole year, the total runoff amount in a year was figured out. Combine with equilibration concentration designed by Li Huaien, the burthen of P from cropland the whole year as well as the load of TP from paddy-field was calculated in non-point source ways, which were 94.56 g/hm 2 and 107.4 g/hm 2, respectively. The result could provide a certain basis for further study on the load in large areas.