农业生态系统中氮素造成的非点源污染

Non_point pollution of nitrogen in agricultural eco_system.

施入农业生态系统（土壤）中的氮素，除一部分被作物吸收外，其余大部分经径流、淋溶、农田排水等形式流失。畜禽养殖场所排废水中的氮素也主要进入地表水和地下水中。氮素流入对水域的污染为非点源污染，主要导致地表水的富营养化、地下水硝酸盐含量过高等。解决途径是确定合理施肥量和平衡施肥，并对畜禽粪便进行处理利用。

The nitrogen in fertilizers applied to agricultural ecosystem(soil) is partially adsorpted by crops, its marjority is lost through runoff,leaching,drainage,etc..The nitrogen in waste water from animal farms mainly goes into ground water. Nitrogen may cause non_point pollution in water in forms of eutrophication in surface waters and high nitrate concentration in ground water. The solutions include rational and balancing application of nitrogen fertilizers and treatment of the waste water from animal farms.