氮肥是作物增产的顶梁柱,但并非越多越好。近年来,我省化学氮肥施用量急剧增加,平均年施用量在380万吨左右,居全国使用量之首。施入土壤中的氮肥只有30％～50％为作物吸收利用,大部分从土壤中淋失流入水体和挥发到大气中。因此,对氮肥的不合理施用,不仅会造成很大的经济损失,而且会严重污染农业环境, Nitrogen fertilizer is the mainstay of crop production, but not the better. In recent years, chemical nitrogen fertilizer application in our province increased sharply, with an average annual application of 3.8 million tons, ranking first in the national usage. Only 30% to 50% of nitrogen applied to the soil is absorbed by the crop, most of which is leached from the soil into the water and volatilized into the atmosphere. Therefore, irrational application of nitrogen fertilizer will not only cause great economic losses, but also seriously pollute the agricultural environment,