覆盖种植方式和施氮对甘肃庆阳冬小麦产量和水分利用的影响

Cultivation and Nitrogen Application Affect Yield and Water Use Efficiency of Winter Wheat in Qingyang of Gansu Province

通过连续2 a田间试验,研究了覆盖种植方式和施氮对庆阳地区冬小麦土壤水分动态变化和产量及水分生产效率的影响。结果表明,不同栽培模式下各土层含水率在不同生育期变化趋势基本一致。垄沟、覆膜和覆草在小麦生育前期具有很好的保墒集水作用,水分主要集中在0~60 cm土层,并且在小麦生育前期效果显著。2 a间不同种植模式对小麦产量的影响不同,2 a中覆膜种植冬小麦籽粒产量均最高,而不同年度间覆草、垄沟种植模式表现出不同效果;与常规模式相比,2009年覆草和垄沟种植模式均减产,其中覆草模式减产幅度最大,较常规栽培减产10.4%;而2010年这几种种植模式的冬小麦籽粒产量较常规模式均有所增加,增产幅度平均在4.5%~6.9%之间。合理的氮肥施用量能显著提高水分生产效率,施氮120和240 kg/hm^2的水分生产效率分别比不施氮肥高1.1和2.0 kg/(hm^2·mm)。不同种植模式的水分利用效率差异显著,覆膜处理和垄沟处理具有较高的水分生产效率。

A two-year field experiment was conducted in Gansu Province aimed to investigate the effect of cultivation on soil moisture dynamics and water use efficiency （WUE） of winter wheat under different nitrogen applications. The results showed that the temporal change of soil moisture was approximately the same under different treatments. Raised-bed planting and mulching with straw or plastic film could keep root zone （0-60 cm） moistened, especially in the early stage of the wheat growth.The impact of cultivation on yield varied. Mulching with plastic film gave the highest yield, while the yield under mulching with strawandraised-bed planting varied in the two years. Compared with the control, mulching with straw andraised-bed planting reduced the yield in 2009 by up to 10.4%, but increased the yield in 2010 by 4.5% to 6.9%. Nitrogen application also impacted water use efficiency （WUE）. With nitrogen application rate of 120 kg/hm2 and 240 kg/hm2, the WUE increased by 1.1 and 2.0 kg/hm2 mm, respectively, compared with the control （without nitrogen application）. Plastic-film mulching and raised-bed planting were shown to have increased WUE.