适宜的施肥时期和施肥方法是合理、经济施用氮素化肥的重要内容。在华北地区,对小麦施用拔节肥的效果是一致肯定的,但对其它时期施用氮素化肥的增产效果却存在不同看法。为了进一步探讨不同时期和不同方法施用氮素化肥的增产效果及氮素利用等情况,1981—1983年我们用~(15)N 标记化肥进行了这方面的盆栽试验,各次试验所用土壤均为褐色草甸土,其主要农业性状见表1。 Appropriate fertilization period and fertilization method is an important and economical application of nitrogen fertilizers. In North China, the effect of applying jointing fertilizer to wheat is unanimously affirmed, but there are different opinions on the yield increasing effect of applying nitrogenous fertilizer in other periods. In order to further explore the different periods and different methods of application of nitrogen fertilizer yield and nitrogen utilization, etc., 1981-1983, we used ~ (15) N labeled fertilizer in this area pot experiments, the soil used in each test were Brown meadow soil, the main agricultural traits in Table 1.