秸秆还田下氮肥管理对低中产田水稻产量和氮素吸收利用影响的研究

探究氮肥运筹管理对湖北中低产田水稻产量及氮素利用率的影响，为中低产田水稻生产提供合理的施肥技术措施。本研究在秸秆还田和总氮（180 kg/hm2）控制的条件下，以水稻两优培九为材料，研究不同基、 蘖、 穗氮肥配比对中低产田水稻产量及其构成因子、不同时期叶片SPAD值、 氮含量、 地上部氮素累积量及其氮利用效率的影响。结果表明， 在2011年和2012年两年大田试验的4个基、 蘖、 穗氮肥配比处理中，各试验点水稻产量均以40-30-30的处理最高， 其中在田块A与田块C中比80-0-20处理增产15.9%和8.6%，在田块B与田块D中比60-20-20处理增产6.7%和5.5%。同时40-30-30处理的氮素收获指数（NHI）和氮肥偏生产力（PFPN）也最高，优化基、 蘖、 穗肥比可以提高氮素收获指数（NHI）和氮肥偏生产力（PFPN）。综上研究结果，各中低产田中不同基、 蘖、 穗氮肥配比处理的水稻产量依次为40-30-3050-20-3060-20-2080-0-20，结合产量构成因子、SPAD值、氮肥利用率等因素综合考虑，40-30-30是湖北中低产水稻田氮肥配比的合理运筹模式。

Effect of nitrogen fertilizer managements on rice yield and nitrogen uptake in medium and low yield fields under the conditions of straw turnover

A field experiment was carried out to study the effect of different nitrogen fertilizer ratios of basal∶dressing in tillering-panicle period of rice in Hubei Province in 2011 and 2012 on the yield and nitrogen uptake in the experiment. Rice cultivar, Liangyoupei 9, was used as material. The rice straw were completely turnover into paddy fields after harvest and the total nitrogen input was N 180 kg/ha for all the treatments in both the medium and low yield paddy fields, and the yield and yield components, leaf SPAD, nitrogen uptake and utilization were determined. The results show that the highest rice yield in both low and medium yield fields are achieved in the N application ratio of 40-30-30 for basal-tillering-panicle among the four treatments, the yield is increased by 15.9%-8. 6% compared with the ratio of 80-0-20, and 6.7%-5.5% with the ratio of 60-20-20. Meanwhile, higher nitrogen harvest index and partial fertilizer productivity of nitrogen are also obtained in the ratio of 40-30-30. The descant order of the yield in both the low and medium yield fields is 40-30-30>50-20-30>60-20-20>80-0-20. Comprehensively considering the yield and its components, SPAD value, nitrogen uptake and utilization, we conclude that the application ratio of 40-30-30 for nitrogen fertilizer used at basal, tillering and heading stage in rice is a reasonable N fertilization management in medium\| and low\| yield fields.