20世纪40年代工业化学肥料的问世,使农作物的产量得到了大幅度的提高。为了获得更高的产量,人们在最大限度地施用化学肥料。同时也带来了高投入、低产出、化肥利用率低、农产品质量下降、污染环境、盐类聚集造成土壤板结等,反过来制约农业的发展。我国化学肥料的利用率一般在35%左右,低于发达国家约20个百分点,化肥的回报率呈逐年下降的趋势。就氮肥而言,由于其肥效短,必须采用多次 The advent of industrial chemical fertilizers in the 1940s led to a dramatic increase in crop yields. In order to obtain higher yields, people are maximizing the use of chemical fertilizers. At the same time, it also brings about problems such as high input and low output, low utilization rate of chemical fertilizers, declining quality of agricultural products, environmental pollution and salt compaction, which in turn restrict the development of agriculture. The utilization rate of chemical fertilizers in China is generally about 35%, which is about 20% lower than that of developed countries. The rate of return of chemical fertilizers shows a declining trend year by year. As far as nitrogenous fertilizer is concerned, it must be used several times because of its short fertilizer efficiency