通过田间试验研究了玉米的氮肥适宜施用量对玉米生长发育和产量的影响。结果表明，氮肥不同施用量对玉米生育期及经济性状的影响不同，施N 144.0、172.5 kg/hm2时拔节期、大喇叭口期较不施氮处理和减氮处理提前1～3 d；全生育期也最长，为145 d，较其它施氮处理延长2～3 d。施N 172.5 kg/hm2和144.0 kg/hm2时株高、秃顶长、行粒数、千粒重均优于其它处理，穗长、穗粗和穗行数处理间并无差异。施N144.0～172.5 kg/hm2时玉米籽粒产量为 11 578.05～11 818.2 kg/hm2，较不施氮肥处理(8 764.35 kg/hm2)增产32.10%～34.84%，不施氮肥处理与施氮处理的差异均达极显著水平。氮肥贡献率随着施氮量的增加呈递增趋势，氮肥贡献率的变幅为15.48%～25.84%，施N 172.5 kg/hm2的氮肥贡献率最高，为25.84%，从氮肥的农学利用效率和氮肥偏生产力看，不同施氮量之间存在差异，随着施氮量的增加都呈递减趋势，氮肥农学利用效率变幅为19.54～46.53 kg/kg，氮肥偏生产力变幅为65.81～300.57 kg/kg，而高施氮量的农学效益和偏生产力低下，不利于资源节约和环境友好，所以在保证玉米籽粒产量的基础上，氮肥的农学利用效率为17.70～19.54 kg/kg，偏生产力为68.51～80.40 kg/kg。

The effect of suitable application amount of nitrogen fertilizer on the growth and development of corn was studied by field experiment. The results showed that the effects of different nitrogen application rates on corn growth and economic shape are different. When 144 kg/hm2 and 172.5 kg/hm2 are applied , jointing stage and bell mouth stage are 1～3 days earlier than those without nitrogen application and nitrogen reduction treatment. The longest growth period is 145 days, which is 2～3 days longer than other nitrogen treatments. It is superior to other treatments in plant height, bald top length, grain number per row and 1000-grain weight when applying nitrogen fertilizer 172.5 kg/hm2 and 144 kg/hm2, but there are no differences in panicle length, panicle diameter and row number per panicle. When applying nitrogen fertilizer144.0～172.5 kg/hm2. The corn grain yield was 11 578.05～11 818.2 kg/hm2, 32.10%～34.84% higher than that at without nitrogen fertilizer (8 764.35 kg/hm2)， and the difference between the treatment without nitrogen fertilizer and other nitrogen treatments is very significant. The contribution rate of nitrogen fertilizer increased with the increase of nitrogen application. The variation range of contribution rate of nitrogen fertilizer is 15.48%～25.84%, and the highest contribution rate of nitrogen fertilizer is 25.84% at 172.5 kg/hm2. According to the agronomic use efficiency and partial productivity of nitrogen fertilizer, there are differences among different nitrogen application rates， which decrease with the increase of nitrogen application. The agronomic use efficiency range from 19.54 kg/kg to 46.53 kg/kg, and the partial productivity of nitrogen fertilizer range from 65.81 kg/kg to 300.57 kg/kg. However， the low agronomic benefit and partial productivity of high nitrogen application are not conducive to resource conservation and environmental friendliness. Therefore, on the basis of ensuring corn grain yield， the agricultural use efficiency of nitrogen fertilizer is 17.70～19.54 kg/kg, and the partial productivity is 68.51～80.40 kg/kg.

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国家科技支撑计划项目(2012BAD05B06)； 公益性行业(农业)科研专项(201203030)。