缓释型配方肥在晚稻套播油菜上的施用效果研究

油菜套播是利用双季稻区冬闲田的有效手段,为探究缓释型配方肥（N-P₂O₅-K₂O：25-7-8,及5%的中微量元素）在晚稻套播油菜上的施用效果,设置一次性基施缓释型配方肥与分次施常规肥效果对比试验和配方肥施用量试验,调查油菜产量形成、肥料利用率及经济效益。结果表明,在减少肥料养分投入且一次性基施的情况下,缓释型配方肥仍能达到甚至优于常规肥分次施用的效果。菜籽产量与缓释型配方肥用量呈线性加平台关系,适宜施肥量可保证较大的收获密度并产生较多的每株角果数和每角粒数,同时维持较高的肥料利用率,从而提高籽粒产量和经济效益。根据本试验结果推算出晚稻套播油菜的目标产量为1 500~1 800kg/hm²时,缓释型配方肥的适宜用量为645~715kg/hm²。

Application Effect of Slow-Released Formulated Fertilizer on Oilseed Rape (Brassica napus L.) under Late Sowing Rice

The rapeseed undersowing rice cultivation model is effective for double cropping rice in the winter fallow field. Field experiments covering two rape seasons (2016-2017 and 2017-2018) were conducted to explore the yields, fertilizer use efficiency and economic benefit affected by slow-released formulated fertilizer (N 25%, P₂O₅ 7%, K₂O 8%, and other mid-nutrient and micro-nutrient 5%, respectively) on rapeseed undersowing late rice, and thus to provide a reference for simplified fertilization of intercropping rapeseed. The results showed that both the application of formulated fertilizer and conventional fertilizer on rapeseed undersowing late rice with residues retention could significantly increase the yield and economic benefits. Compared with conventional fertilizer application, one-off base fertilization application of formulated fertilizer technology could ensure stable or increase seed yield and improved economic benefit, while reduced the total amount of nutrients significantly. Significant linear plus platform correlations had been shown between seed yield and slow-released formula quantity. Proper fertilizer increased yield and economic benefits significantly, with high fertilizer use efficiency due to higher plant density and sufficient pod number. On the whole, it could be calculated that the optimal quantity of slow-released formulated fertilizer for rapeseed undersowing late rice was 645 to 715kg/hm² to target yield of 1 500 to 1 800kg/hm².