China is a country with a large population, and grain production plays an important role in the development of agricultural production. Generally, the way to increase grain production is to expand the area of cultivated land or increase the yield per unit area. According to China's national conditions, there is little potential to continue to expand the area of cultivated land. Although China still has a lot of uncultivated land, most of them have problems of large investment and great difficulty. This determines that China's grain production must take the way of increasing the output per unit area.

Fertilization can not only improve soil fertility, but also is an important measure to improve crop yield per unit area. Chemical fertilizer is the most basic and important material input in agricultural production. According to the statistics of the food and Agriculture Organization of the United Nations (FAO), chemical fertilizer accounts for about 40% - 60% of the total share of crop production. China can feed 22% of the world's population with 7% of the world's arable land. It can be said that chemical fertilizer plays a decisive role.