氮肥运筹对冬小麦灌浆动态和氮素利用效率的影响

his study was conducted from 2012 to 2014 in Gaocheng Liu Guzhuang experimental station of Hebei Agricultural University . One cultivars shimai 18 (SM18) was used as the experimental material. Design of the experiment use 4 nitrogen application rates, 12 treatments in all. Main results were as follows: Low nitrogen treatment (N0 and N1) has the nutrient deficiency so that groups are relatively small, leaf area index is relatively small, and spiking rate is relatively low, as the same time, the leaf senescence accelerated , and the SPAD values decreased obviously, which is not conducive to photosynthesis. High nitrogen treatment (N3), although there is a higher group, but invalid more tillers, too much in decline before and after jointing stage, the development of leaf area index was suppressed, and SPAD values is relatively low, so that spiking rate is low. Nitrogen treatment (N2) ensures high spiking rate in a relatively large, both leaf area index and SPAD values at a higher level at the same time. N2 treatment can significantly extend the grain-filling active period and the ultimate growth of grains, reduce the number of days when reaching the maximum grouting rate. N2 treatment can significantly improve the winter wheat ear grain number and grain and yield. N application processing results show that the n uptake efficiency and n use efficiency of N2 treatment were at a higher level. Comprehensive this study, on the basis of the guarantee of soil moisture, winter wheat applied pure nitrogen 225 kg hm-2can satisfy the demand of water and nitrogen of high yield of winter wheat and obtain the ideal grain yield in the whole stages.