中国是世界上第一大化肥生产国和消费国。每年进入长江、黄河的氮素中,分别有92%和88%来自于农业。2002年中国有7个省份农业面源污染处于高风险水平,起因是农民施用过多化肥。过量使用化肥造成土壤肥力下降,农民为维护生产能力更加依赖于增施化肥,形成恶性循环,导致土壤生态环 China is the world’s largest fertilizer producer and consumer. Of the nitrogen entering the Yangtze River and the Yellow River each year, 92% and 88% respectively come from agriculture. In 2002, the agricultural non-point pollution in seven provinces of China was at a high level of risk due to excessive use of fertilizers by farmers. Excessive use of fertilizers caused soil fertility decline, farmers in order to maintain production capacity is more dependent on the application of fertilizers, forming a vicious circle, leading to soil ecological ring