The Process, Significance and Factors of Soil Nitrogen Cycle

Nitrogen Cycle is one of the most significant biogeochemical cycles, which plays a key role in soil science. The nitrogen in air enters into soil by the effect of microorganism and transforms as ammonia and nitrate or other forms to be absorbed by plants,and it returns to air through microorganism to complete a cycle. The cycle can improve the soil fertility, which not only promote the growth of plant, but also increase the crop productivity. Furthermore, it is of great influence to maintain healthy soil and agricultural productivity, and protect environment. This paper summarized the basic process of nitrogen cycle, and analyzed the relationship between the cycle and modern agricultural production as well as the factors that impacts the whole cycle in soil. It would provide the theory support for achieving sustainable agriculture and natural environment protection when utilizing and maintaining the nitrogen cycle in soil.