化肥对我国水环境安全的影响及过量施用的成因分析

我国是世界上化肥施用量最大的国家，化肥施用强度高且利用率低。统计我国化肥施用量与施用强度的数据，与主要发达国家的情况进行对比分析，结果表明：我国农用化肥施用折纯量近30年来增长了3.4倍，氮、磷肥施用强度是发达国家的3～5倍，化肥施用利用效率不到发达国家的50%。化肥过量施用导致地表水富营养化和地下水硝酸盐污染等水环境问题。农业生产对化肥的过度依赖和面源污染法律制度约束的缺失是造成化肥过量施用并成为面源污染的主要成因。建议通过建立环境质量与国家农业支持保护补贴、土地承包权和经营权挂钩的制度约束，控制化肥过量施用；同时引导大众参与，促进消费升级，由市场需求倒逼农业生产者采取环保措施，减少农业面源污染，从而实现粮食安全与水环境安全的协调发展。 China is the largest consumer of chemical fertilizer in the world,with high application intensity and low utilization efficiency.In this study,we analyzed the data of China′s chemical fertilizer consumption amount and application intensity,and compared them with the situation of major developed countries.The results are as follows:In the recent 30 years, the amount of agricultural fertilizer applied in China increased by 3.4 times,and the application intensity of nitrogen and phosphorus fertilizer was 3-5 times of that in developed countries,but the utilization efficiency of chemical fertilizer was less than 50% of that in developed countries.The overuse of chemical fertilizer has caused water environment problems such as eutrophication of surface water and nitrate contamination of groundwater.The excessive use of chemical fertilizer has led to non-point source pollution.Its main causes are the over reliance of agricultural production on chemical fertilizer and the lack of legal constraints on non-point source pollution.We recommend that the excessive application of chemical fertilizer be controlled by the establishment of a system that encompasses subsides on environmental quality and national agricultural support and protection and linking of land contracting rights to management rights.Public participation should be encouraged to promote consumption upgrading,so that market demands will force agricultural producers to adopt environmental measures and reduce agricultural non-point source pollution;thus,coordinated development of food security and water environment security will be achieved. 深圳市技术创新计划技术攻关项目（JCYJ20180504165440088）