我国是一个农业大国,农村人口占总人口的70%,能够很好地利用有限的土地是我国发展经济的重要途径。另外我国还是个用肥大国,尤其是氮肥,近几年平均用量在2100万吨左右(纯养分),位居世界前列;我国的氮肥质量不高,低浓度的氮肥占50%左右。依据我国现有的使用状况和施肥技术,氮肥 As a big agricultural country in our country, the rural population accounts for 70% of the total population. To be able to make good use of the limited land is an important way for our country’s economic development. In addition, China is still a big country with fertilizer, especially nitrogenous fertilizer. In recent years, the average dosage is about 21 million tons (pure nutrients), ranking the highest in the world. The quality of nitrogenous fertilizers in China is not high, and the low concentration of nitrogenous fertilizers accounts for about 50%. According to China’s existing conditions of use and fertilization technology, nitrogen fertilizer