氮素化肥是增加农作物产量的重要因素,施用氮素化肥在广大农村是人人尽知的事情。但是人们对氮素化肥在土壤中的肥效持续时间却仍然是一个未知数。据研究当季作物对所施的氮素化肥的吸收利用率一般在30—40%。其残留部分究竟在土壤中存在多长时间?对下茬,乃至下下茬作物有无作用,作用有多大,对连效氮素化肥的经济效益如何评价较为合理?为此,我们应用 N~(15)示踪技术,定位测量进行了氮素化肥肥效持续期的 Nitrogen fertilizers are an important factor in increasing crop yields. Applying nitrogenous fertilizers is a well-known thing in the vast rural areas. However, the duration of the fertilizer effect on nitrogenous fertilizers in the soil is still unknown. According to the study of seasonal crops on the application of nitrogen fertilizer absorption and utilization are generally 30-40%. How long does the residual part exist in the soil? Does it have any effect on the stubble and even the stubble crop? How to evaluate the economic benefit of the nitrogen-linked fertilizer? For this reason, we use N ~ (15) tracer technology, positioning measurement of nitrogen fertilizer duration