论文部分内容阅读
据文献记载,肥料氮的利用率仅为施氮量的35～60%。有20～40%的肥料氮被土壤固定,1～10%从根系分布层被淋溶,氮素气态损失可达20～40%。目前人们正在采取农业措施和化学方法来减轻肥料氮的损失。化学方法包括应用长效肥料及能抑制硝化和反硝化过程的有机制剂。长效肥料包括尿素同有机物的缩聚物,以及薄膜包衣肥料。这类肥料的共同特点是:开始施用时溶解性弱,氮素被作物吸收量小,经过一段时间,肥料溶解性增强,从而有利于作物逐渐吸收。
According to the literature, fertilizer nitrogen utilization rate of only 35 to 60% of nitrogen. 20% to 40% of fertilizer nitrogen is fixed in the soil, 1% to 10% is leached from the root distribution layer, and the nitrogen gas loss can reach 20% to 40%. At present, people are taking agricultural measures and chemical methods to reduce the loss of fertilizer nitrogen. Chemical methods include the application of long-term fertilizer and can inhibit the nitrification and denitrification process of organic agents. Long-acting fertilizers include polycondensates of urea with organic compounds, and film-coated fertilizers. Common characteristics of these fertilizers are: weak solubility at the beginning of application, small amount of nitrogen absorbed by crops, and over time, the solubility of fertilizers is enhanced, which is conducive to the gradual absorption of crops.