利用15N研究了肥料氮在土壤中的转化以及作物吸收的氮在体内的代谢、积累的变化。结果表明 :施氮量越大 ,土壤及植物体内的硝态氮量越高 ;但随着作物的生长 ,硝态氮的含量又逐渐减少 ;过量施氮肥会造成土壤残留的硝态氮过高 ,不但对土壤造成污染 ,而且还会通过淋溶作用对地下水造成污染。 15N was used to study the transformation of fertilizer nitrogen in the soil and the changes in the metabolism and accumulation of nitrogen absorbed by crops in the body. The results showed that the higher the amount of nitrogen application was, the higher the content of nitrate nitrogen was in the soil and plants. However, with the growth of the crop, the content of nitrate nitrogen decreased gradually. Excessive application of nitrogen fertilizers resulted in excessive nitrate nitrogen , Not only pollutes the soil, but also pollutes the groundwater through leaching.