秸秆还田与氮磷钾化肥配施对直播冬油菜产量及其构成因子的影响

Effects of straw incorporation with nitrogen,phosphate and potassium fertilization on yield and yield components of direct-sown winter oilseed rape

明确化肥施用和秸秆还田对直播冬油菜产量及其构成因子、群体密度以及养分吸收与利用的影响,为油菜轻简化种植提供理论依据和技术支持。试验于2014-2015年在湖北省武汉市开展,以甘蓝型油菜品种华油杂62为材料,设置对照（ CK）、施氮磷钾肥（ F）、秸秆还田（ S）和氮磷钾肥配合秸秆还田（ F＋S）4个处理。结果显示,4个处理的油菜籽产量分别为32、1468、102和1843 kg/hm2,不施肥处理产量极低,施肥和秸秆还田均能显著提高油菜籽产量,且施肥与秸秆还田具有正交互作用。分析产量构成因子可知,化肥施用显著提高收获密度、单株角果数和每角粒数,而秸秆还田显著提高收获密度。单株角果数对产量直接影响最大,在收获密度〈55万株/hm2范围内,随密度的增大而增加,收获密度和单株角果数与产量相关程度最高。直播油菜群体密度随生育期推进逐渐降低, CK处理密度降幅最大,其次是S处理, F＋S和F处理降低最少,最终收获密度F≈F＋S〉S〉CK。结果还表明,施肥配合秸秆还田显著促进了油菜对养分的吸收积累。施化肥提高了氮磷收获指数,秸秆还田显著降低氮磷钾素收获指数,但可以提高肥料农学利用率。研究结果说明,秸秆还田和氮磷钾肥配施利于构建良好的产量构成因子,保障收获密度,提高直播冬油菜产量,促进油菜养分吸收和利用。

Field experiment was conducted in Wuhan, Hubei province during 2014-2015, using cultivar Huayouza 62 （Brassi-ca napus L） as material to study the effects of chemical fertilization and straw incorporation on rapeseed yield and yield compo-nents, plant density, nutrient uptake and utilization of winter oilseed rape and to provide theoretical basis and technical support for the simplified cultivation of oilseed rapeseed. Four treatments were set as below： control （CK）, nitrogen, phosphate and potassium fertilizer applying treatment （ F） , straw incorporation treatment （ S） and straw incorporation with nitrogen, phosphate and potassium fertilizer treatment （F＋S）. Results showed that the rapeseed yield of CK, F, S and F＋S treatments were 32, 1 468, 102 and 1 843 kg/hm2 , respectively. Rapeseed yield was extremely low in the treatments of no fertilization. Both fertili-zation and straw incorporation improved the yield significantly, and showed positive interactions between them. After analyzing the yield components, it was found that applying chemical fertilizer increased plant density, pod number per plant and seed num-ber per pod significantly, while straw incorporation improved plant density. Pod number per plant had the greatest direct influ-ence on yield, which was improved with the increasing of plant density （ plant density〈55 ＆#215; 104 plant/hm2 ） . The correlation be-tween harvest density and pod number per plant and yield were highest. With oilseed rape growth advancing, plant density de-creased. The density of CK treatment decreased most largely, followed by the S treatment, and then the F＋S and F treatments, i. e. F≈F＋S〉S〉CK. Fertilizer applying and straw incorporation increased nutrient uptake significantly. Nitrogen and phos-phorus harvest index were increased by applying fertilizer. While straw incorporation decreased nitrogen, phosphate and potassi-um harvest index, but improved the agronomic efficiency of fertilizer. It suggested that straw incorporation with fertilizer applying could help to establish good yield components and guarantee harvest density to improve yield and nutrient uptake and utilization of oilseed rape.