前氮后移及有机肥替代对油菜产量和氮吸收利用的影响
Effects of postponing nitrogen application and organic fertilizer substitution on yield, nitrogen uptake and utilization in rapeseed
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摘要:
为探究油菜高产稳产的优化施氮技术,采用田间小区试验,对比分析了不施肥(CK)、常规施肥(CF:氮肥基肥、越冬肥和蕾薹肥比例为6∶2∶2)、前氮后移(CR:氮肥基肥、越冬肥和蕾薹肥比例为5∶3∶2)和前氮后移+有机肥替代30%(CRM)对油菜产量和氮吸收利用的影响。结果表明:不施肥处理油菜籽粒产量仅为施肥条件下的30%~36%;施肥条件下,CR、CRM较CF处理降低株高、有效分枝点高和单株主序有效角果数,但增加油菜的茎粗、二次有效分枝数、单株二次有效角果数及千粒重,油菜籽粒产量显著增产23.8%和11.7%;CR、CRM分别较CF处理氮累积吸收量增加25.0%和20.9%,氮肥吸收利用率提升27.9%~33.6%,氮肥农学利用率提高14.6%~37.0%。前氮后移以及有机肥替代有助于油菜的矮壮生长,能够促进油菜二次分枝发育,增加油菜分支角果数量,提高氮吸收利用,进而影响产量,是油菜优化施肥的有效途径。
Abstract:In order to explore the optimal nitrogen application for high and stable yield of rapeseed, a field experiment was conducted to analyze no fertilizer (CK), conventional fertilizer (CF: the ratio of nitrogen-based fertilizer, overwintering fertilizer and bolting fertilizer is 6∶2∶2), postponing nitrogen application (CR: The ratio of nitrogen-base fertilizer, overwintering fertilizer and fleecing fertilizer was 5∶3∶2) and postponing nitrogen application+organic fertilizer replacement 30% (CRM) on rapeseed yield and nitrogen uptake and utilization.The results showed that the rapeseed grain yield under no fertilization only maintained 30%~36% of that under fertilization.Under fertilization, compared with CF treatment, CR and CRM treatments reduced plant height, productive branch height and productive number of horns per plant in the main sequence, but increased stem thickness, productive number of secondary branches, productive number of primary horns per plant, productive number of secondary horns per plant and 1 000-grain weight of rape.CR and CRM treatments significantly increased grain yield by 23.8% and 11.7%, enhannced cumulative N uptake by 25.0% and 20.8%, improved N uptake efficiency by 27.9%~33.6%, and increased N agronomic efficiency by 14.6%~37.0%, respectively.It is an effective way to optimize fertilization for rapeseed, which can promote the growth of rapeseed secondary branches, increase the number of branch siliques, and increase nitrogen uptake and utilization.