利用~(15)N研究氮肥对土壤及植物内硝酸盐的影响

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。

INFLUENCE OF NITROGEN FERTILIZER ON NO_3 N IN BOTH SOIL AND PLANTS

The nitrificaion of nitrogen fertilizer in soil as well as its metabolism and transform in plants was studied by using 15 N. The results showed that the amount of NO - 3 N in soil and plants increased with the increase of nitrogen fertilizer amount, but decreased gradually with the growth of plants. Over application of N fertilizer as 300kg N/hm\+2 caused higher residual NO - 3 N in soil, which not noly harms soil but also pollutes groundwater by drip washing.In order to gain high production and alleviate pollution, a simple procedure was suggested to determine optimum amount of N fertilizer.