减氮覆膜对黄土旱塬小麦产量构成及水肥利用效率的影响

为明确减氮测控定量施肥技术结合地膜覆盖措施对黄土旱塬冬小麦产量构成及水肥利用效率的影响,为旱地冬小麦减施氮肥及提高产量提供理论依据,于2013—2018年在晋南黄土旱塬冬小麦种植区,设置农户施肥种植模式、减氮测控施肥、减氮测控施肥+垄膜沟播和减氮测控施肥+平膜穴播4种处理,分析了在减氮覆膜条件下连续5年冬小麦产量构成情况、土壤水分和氮、磷、钾肥利用效率。结果表明:(1)减氮测控施肥较农户模式在减少氮肥施用量46.9%,平衡施用磷钾肥的情况下,冬小麦年均籽粒产量、生物产量和公顷穗数分别增加4.4%,4.0%和4.3%,氮肥收获指数和偏生产力分别提高4.3%和120.3%,同时促进了冬小麦地上部分对磷素和钾素的吸收量;(2)在减氮测控施肥基础上进行覆膜种植,地膜覆盖使水分利用效率和生育期耗水量分别增加13.8%~23.9%和7.1%~10.1%,氮肥收获指数提高1.7%~3.5%,偏生产力提高21.7%~41.4%,生理效率降低8.7%~16.8%,磷肥和钾肥的偏生产力分别提高22.4%~39.2%和19.3%~37.1%。地膜覆盖良好的水肥调节作用使垄膜沟播和平膜穴播的籽粒产量、生物产量、公顷穗数和千粒重较不覆膜分别增加21.0%,39.2%,18.2%,4.7%和23.5%,40.3%,27.6%,7.0%。因此,为了实现小麦增产和肥料增效,减氮测控定量施肥技术与地膜覆盖措施相结合的种植方式可以在黄土旱塬冬小麦种植区进行推广应用。

Effects of Nitrogen Reduction and Film Mulching on Wheat Yield Composition and Utilization Efficiency of Water and Fertilizer in the Loess Plateau

To determine the effects of nitrogen reduction combined with film mulching measures on the yield composition and the utilization efficiency of water and fertilizer of winter wheat in the Loess Plateau, and to provide theoretical basis for reducing the application of nitrogen fertilizer and increasing the yield of winter wheat in dry land, in 2013-2018, experiment was conducted in winter wheat growing region of dry highland in Southern Shanxi. In the experiment, four treatment were set up, which were farmer pattern, monitoring fertilization, monitoring fertilization plus ridge mulching-furrow planting and monitoring fertilization plus whole field filming with soil covering and hole-seeding. The yield components, soil moisture and the utilization efficiency of nitrogen, phosphorus and potassium fertilizer were analyzed under the condition of reducing nitrogen and mulching for five consecutive years. The results showed that: (1) Compared with farmer pattern, total nitrogen application in the monitoring fertilization treatments decreased by 46.9%, and under the condition of balanced application of phosphorus and potassium fertilizer, the average annual grain yield, biological yield and panicle number per hectare of winter wheat increased by 4.4%, 4.0% and 4.3%, respectively, the nitrogen harvest index and the partial productivity of nitrogen fertilizer increased by 4.3% and 120.3%, respectively. At the same time, the uptake of phosphorus and potassium by above ground part of winter wheat was promoted. (2) On the basis of monitoring fertilization, plastic film mulching planting increased water use efficiency and water consumption in growth period by 13.8%~23.9% and 7.1%~10.1%, respectively. At the same time, the harvest index of nitrogen fertilizer increased by 1.7%~3.5%, the partial productivity increased by 21.7%~41.4%, the physiological efficiency reduced by 8.7%~16.8%, and the partial productivity of phosphorus fertilizer and potassium fertilizer increased by 22.4%~39.2% and 19.3%~37.1%, respectively. Good water and fertilizer regulation effect of plastic film mulching planting increased the grain yield, the biological yield, the hectares ears and the 1000-grain weight by 21.0%, 39.2%, 18.2% and 4.7% in the treatment of ridge mulching-furrow planting, respectively, and by 23.5%, 40.3%, 27.6% and 7.0% in the treatment of whole field filming with soil covering and hole-seeding, respectively. Therefore, in order to increase wheat yield and fertilizer efficiency, the combination of the nitrogen reduction and control fertilization technology and the ground film covering measures can be applied in the planting area of the Loess Plateau.