农业非点源氮磷流失规律研究

Research on Loss of Nitrogen and Phosphorus in Watershed

以北京密云县高岭乡石匣实验小区为研究对象,通过监测分析降雨后的径流样研究实验小区氮磷流失特征, 结果表明:土地利用方式的差异对径流中氮磷的浓度有径流中总磷浓度变化趋势:果园>标准小区>农地>荒草坡>林地;总氮浓度变化趋势:林果地>荒草坡>农地>标准小区>林地。这表明果园由于施肥的影响造成径流中氮磷浓度偏高;免耕种植、梯田种植、鱼鳞坑造林等耕作方式会明显减少农田土壤的侵蚀。植被覆盖明显减少径流量和泥沙量,从而有效地控制农田氮磷污染物的流失;径流中氮、磷主要以颗粒态存在。

Loss of nitrogen and phosphorus in soil and runoff of Shixia experimental area was studied in this paper. The results show that: the sequence of the concentration of total phosphorus and total nitrogen is: orchard >standard spot >tillage > grass land >woodland and orchard >grassland> tillage> standard spot > woodland; no tillage has an obvious control on the soil erosion; there is a remarkable linear relativity between flow and bedload . vegetation can prevent soil erosion effectively , in this way decrease the loss of nitrogen and phosphorus.