夏休闲期复种油菜对旱地土壤水分和小麦产量的影响

以冬小麦收获后高留茬休闲地为对照，连续4年在陇东黄土旱塬设6个油菜播种期，研究了休闲期作物覆盖对土壤水分及后作冬小麦产量与水分利用效率的影响.结果表明：不同播种期夏休闲期土壤贮水量差异显著(P＜0.05)，其中8月5日播种油菜的土壤蓄水效率为58.5%,产量和水分利用效率较对照提高7.5%和5.9%.平均而言，夏休闲期复种油菜后作小麦干旱年份增产16.1%，平水年份增产6.8%.夏休闲期复种油菜是西北旱地小麦抗旱增产的有益途径.

Effects of rape cropping in summer fallow period on dryland soil moisture content and winter wheat yield.

Taking the fallow land with wheat stubble after harvesting as the control, a 4-year field experiment was conducted in a dryland of east Gansu, Northwest China to investigate the effects of rape cropping in summer fallow period on the soil moisture content, wheat yield, and water use efficiency (WUE). The rape was sown at 6 dates. There was a significant difference (P<0.05) in the soil moisture content in summer fallow period when the rape was sown at different dates. When the rape was sown on August 5, the soil water storage efficiency was 58.5%, and the wheat yield and WUE were increased by 7.5% and 5.9%, respectively, as compared with the control. Averagely, cropping rape in fallow period could increase the wheat yield by 16.1% in dry year and 6.8% in normal year. It was suggested that rape cropping in summer fallow period would benefit the wheat yield and drought resistance of drylands in Northwest China.