冬油菜施氮的增产和养分吸收效应及氮肥利用率研究

 【目的】分析当前生产条件下长江流域冬油菜施氮增产效应及氮肥利用率,为冬油菜进一步增产和提高氮肥利用率提供依据。【方法】总结2004—2006年在长江流域10个省的73个油菜肥效田间试验数据,通过增产量、增产率、偏生产力、农学效率、生理利用率及表观利用率等指标分析长江流域冬油菜施氮增产效应及氮肥利用率。【结果】长江流域油菜施氮增产效果显著,当氮肥用量为180 kg?hm-2 时,平均增产油菜籽1 109 kg?hm-2,增产率为71.7%,地上部生物总量增加72.7%,但施氮对油菜收获指数无明显影响;施氮处理收获期地上部氮、磷和钾养分吸收量分别比不施氮处理增加90.0%、55.4%和59.8%,氮素收获指数随氮肥的施用而明显下降,磷及钾素收获指数则呈现上升趋势;氮肥偏生产力、农学效率、生理利用率及表观利用率分别为14.7 kg?kg-1、6.2 kg?kg-1、18.5 kg?kg-1和34.6%。【结论】在磷、钾及硼肥基础上施用氮肥,能明显提高油菜地上部生物量及氮、磷、钾养分吸收量,从而显著增加了油菜籽产量;油菜生产的氮肥利用率还不高,改进技术措施提高利用率的空间还很大。

Study on Yield Increasing and Nutrient Uptake Effect by Nitrogen Application and Nitrogen Use Efficiency for Winter Rapeseed

【Objective】Field experiments were carried out to study the effect of nitrogen application on winter rapeseed (Brassica napus L.) in the Yangtze River Valley and further to explore approaches of increasing rapeseed yield and improving nitrogen use efficiency. 【Method】The indices, such as yield increment, increase rate, partial factor productivity (PFP), agronomic efficiency (AE), physiological efficiency (PE) and apparent recovery efficiency (RE) were calculated based on the data from 73 field experiments in 10 main rapeseed production provinces in the valley during 2004-2006, and the rapeseed yield increase from nitrogen application and nitrogen use efficiency were analyzed in the valley. 【Result】Application of N fertilizer increased winter rapeseed yield significantly, the average grain yield increment resulting from 180 kg N?hm-2 application was 1 109 kg?hm-2, and the increase rate was 71.7%. Although N application had little effect on harvest index, the shoot biomass of rapeseed was increased by 72.7%. Compared to the CK (no N) treatment, nitrogen, phosphorus and potassium uptake of +N treatment at harvest were increased by 90.0%, 55.4% and 59.8%, respectively. Nitrogen harvest index declined significantly and P and K harvest index were on the rise with N application. The results also showed that PFPN, AEN, PEN and REN of winter rapeseed were 14.7 kg?kg-1, 6.2 kg?kg-1, 18.5 kg?kg-1 and 34.6%, respectively. 【Conclusion】The combination of nitrogen with phosphorus, potassium and boron fertilizers could obviously improve the shoot biomass and nitrogen, phosphorus and potassium uptake, and thus increase the grain yield of winter rapeseed significantly. Nitrogen use efficiency for rapeseed production is still quite low, and it has a great potential for growth by improving the technology.