农田施氮对冬小麦产量、根-冠氮素积累及其利用效率的影响

为探讨施氮对冬小麦产量、根-冠氮素积累及其利用效率的影响，通过定位试验，在河南省许昌设置0、180、240和300 kg·hm^-24个施氮水平，利用2015-2018年三个小麦生长季的试验数据，分析了不同氮素供应条件下冬小麦产量、根-冠氮素积累以及氮肥利用特征。结果表明，在三个生长季中，施氮均可显著提高小麦株高、产量、穗数和穗粒数，促进根系、地上部干物质和氮素积累，增加籽粒氮素含量和积累量。氮肥农学利用效率和偏生产力随着施氮量的增加而降低，施氮对氮素利用效率和百千克籽粒吸氮量分别有负向和正向效应。综合来看，各指标在三个施氮处理间差异相对较小，多数未达到0.05显著水平，因此认为在河南中高产麦田施氮180 kg·hm^-2既可保证高产，也有利于氮肥高效利用。

Effect of Nitrogen Application on Yield,Nitrogen Accumulation and Use Efficiency in Root-Shoot of Winter Wheat

In order to study the effect of nitrogen application on grain yield,nitrogen accumulation and use efficiency of winter wheat,four nitrogen levels of 0,180,240 and 300 kg·hm^-2 were set in Xuchang,Henan province by a positioning test with a randomized block design. The yield,root-shoot nitrogen accumulation and nitrogen utilization characteristics of winter wheat under different nitrogen supply conditions were analyzed by using the experimental data of three growing seasons in 2015-2018. The results showed that the plant height,yield,ear number and grain number per ear were significantly increased by nitrogen application in the three years,and the accumulation of dry matter and nitrogen in root and shoot system can be promoted,and the nitrogen content and accumulation of grain were increased. The utilization and partial productivity of nitrogen fertilizer decreased with the increase of nitrogen application,and nitrogen application had negative and positive effects on nitrogen utilization efficiency and nitrogen uptake per 100 kg grain,respectively. Taken together,the differences among the three nitrogen treatments are relatively small,most of which are not significant. Therefore,it is believed that applying 180 kg·hm^-2 in the middle and high yield wheat fields in Henan can not only guarantee high yield,but also improve the high-efficiency utilization of nitrogen.