紫云英翻压条件下氮肥运筹对双季稻产量和肥料利用率的影响

在早稻-晚稻-紫云英轮作模式下，研究连续3年（2011-2013年）紫云英翻压还田下氮肥运筹对水稻增产效果、肥料利用率及经济效益的影响。本研究通过田间小区试验分析比较了紫云英翻压（G）下5种不同施氮模式（氮肥按照基肥/蘖肥/穗肥比例100/0/0、70/30/0、70/0/30、50/50/0、50/30/20分别设置G₁、G₂、G₃、G₄、G₅处理）及单施化肥配合氮肥运筹50/30/20比例（F₁）和不施肥处理（CK）共7种处理，对早、晚稻产量、产量稳定性及肥料利用率的影响。试验结果表明，在早稻施肥处理中，相同氮肥运筹G₅的早稻产量、产量稳定性和可持续性比F₁分别提高7.77%、33.47%和3.89%。在不同氮肥运筹之间，G₅和G₃均具有较高的早稻产量及产量稳定性。在晚稻中，G₅晚稻产量显著高于F₁，但产量稳定性和可持续性较差；对比5个氮肥运筹，G₅具有较高的晚稻产量和产量稳定性。相同氮肥运筹下，G₅的化肥偏生产力和化肥农学效率均高于F₁，整个轮作周期里分别提高9.35%和22.60%。折算经济效益，早稻各个处理之间经济收益相差不大，晚稻在G₅的施肥方式下经济效益最高。综合水稻产量、产量稳定性以及肥料利用率，在紫云英翻压条件下G₃和G₅分别是早稻和晚稻的最佳施肥方式。

Effects of nitrogen managements with incorporation of Chinese milk vetch on the yield of double cropping rice and fertilizer use efficiency

This three-year study was aimed to investigate the effects of nitrogen managements with the incorporation of Chinese milk vetch on rice yield of double cropping rice, fertilizer use efficiency and economic benefits. There were seven treatments including five modes of nitrogen managements combined with the Chinese milk vetch(G), the chemical fertilizer only with one mode of nitrogen management(F₁), and the control(CK, no fertilizer applied). Five modes of nitrogen managements were designed with N fertilizer applied percentages in basal/tillering/heading stages, namely G₁, G₂, G₃, G₄, G₅. The results showed that the yield of early season rice, the coefficient of variation of the yield(CV) and sustainable yield index(SYI) of G₅ were higher than that of F₁, which increased by 7.77%, 33.47%, and 3.89% respectively. For early season rice, the yield of rice and the stability of rice yield of G₅ and G₃ were both higher among all the treatments with nitrogen managements. For late season rice, the yield of rice in G₅ was significantly higher than that of F₁, yet the SYI value and the stability of rice yield of G₅ were both lower among the five different treatments of nitrogen management. For the whole rotation cycle, the partial factor productivity(PFD) and the agronomic efficiency(AE) of fertilizer of G₅ were higher than that of F₁, which increased by 9.35% and 22.60%, respectively. For the economic benefit, there was no significant difference among all the treatments for early season rice, whereas the economic benefit of G₅ was the highest for late season rice. Took the yield of rice, the stability of yield and the fertilizer use efficiency into account, G₃ and G₅ was the best fertilizing mode for early and late season rice, respectively.