氮肥后移对江汉平原小麦籽粒产量及氮肥偏生产力的影响

以中筋小麦品种郑麦9023为试验材料，研究了氮肥后移对小麦籽粒产量、收获指数及氮肥偏生产力的影响。结果表明，底追比例为7：3，追肥时期由起身期后移至拔节期，籽粒产量及氮肥偏生产力均显著提高；底追比例为5：5，追肥时期由拔节期后移至旗叶露尖期，籽粒产量及氮肥偏生产力均显著降低，表明拔节期是追施氮肥的适宜时期。追肥时期同为拔节期，底追比例由3：7 调整至5：5，由5：5则调整至7：3，籽粒产量、收获指数、氮肥偏生产力均显著升高。总之，在本试验条件下，总施氮量为180kg•hm-2，底追比例为3：7、拔节期追肥的处理，成熟期籽粒产量最高，收获指数和氮肥偏生产力亦显著大于其他处理，是氮肥运筹的最优处理。

Effects of Postponing N Application on Grain Yield and Partial Factor Productivity of wheat in Jianghan Plain

The study was conducted to investigate the effects of postponing nitrogen application on wheat grain yield, harvest index and partial factor productivity (PFP), with the high-yield-cultivar Zhengmai 9023. Research was initiated in the fall of 2008 and continued through 2009 at the Experiment station of Yangtze University, China. The results indicated that, when the ratio of basal dressing nitrogen fertilizer to topdressing fertilizer (B:T) was 7:3, grain yield and PFP increased significantly with the postponing of topdressing fertilizer from reviving stage to jointing stage. When the ratio was 5:5, grain yield and PFP decreased significantly with the postponing of topdressing fertilizer from jointing stage to flag-leaf-emerging stage. When topdressing fertilizer was applied at jointing stage, grain yield, harvest index, and PFP increased significantly with the ratio changing from 7:3 to 5:5, or from 5:5 to 3:7. On the basis of the above result, the treatment with the B:T as 3:7 and topdressing at jointing stage, gained the highest grain yield, harvest index and PFP and was the optimum treatment in this experiment.