为了解决当前农业生产过程中氮磷损失量计算过程中存在的不确定性问题,该文结合硝酸盐、铵盐与土壤颗粒结合类型的差异,从氮循环的角度定量评价降雨径流作用下的土壤氮损失量;结合磷元素的运移与土壤类型密切相关的特性,通过对土壤中的溶解态、颗粒态磷质量分数进行计算,确定农田径流量对应下的土壤磷损失量。永定河流域化学肥料施用量过大,致使土壤总氮损失量为96kg/hm2,总磷损失量为9kg/hm2,研究区内部的氮磷损失量数值差异较大。由于流域氮磷损失量计算方法充分考虑了流域土壤及施肥特性,因此,计算结果具有一定的合理性和适用性。本研究为土壤氮磷损失计算以及流域农业生产面源污染的源头控制提供依据。
To solve the uncertain problem of calculation of nitrogen and phosphorus loss in the soils, considering the difference of combination type between nitrate, ammonium and soil particle, quantitative evaluation method of nitrogen losses based on nitrogen cycle was established for calculating the Yongding River Basin soil nitrogen and phosphorus loss. Combined with the characteristics of closely relationship between the movement of phosphorus and soil styles, phosphorus loss based on farmland runoff was determined by computing the content of dissolved phosphorus and particulate phosphorus. Amount of nitrogen and phosphorus loss in Yongding River Basin were 96 kg/hma and 9 kg/hm2, respectively; the differences of which among the basin was significant. The soil and characteristics of chemical fertilization application were considered in the method of calculation of nitrogen and phosphrus loss amout, so the results of calculation was reasonable and suitable for the study area. The study provides a reference for calculation of nitrogen and phosphrus loss and agricultural point source pollution control.