中文摘要：

以2012—2013年田间对比试验为基础,深入探讨了不同覆盖耕作模式对春玉米根冠比、根系时空分布、地上生物量、产量及水分利用效率的调控效应。试验设置4个覆盖处理（浅松覆盖、条带覆盖、残茬覆盖、免耕全覆盖）及对照传统耕作处理,分别在拔节期和收获期取样观测,并采用SPSS统计软件对数据进行显著性分析。结果表明：各覆盖耕作模式对根系、地上生物量及根冠比具有前控后助效应,且拔节前期影响显著。此外拔节前期免耕全覆盖长势不如对照,但拔节后期4种覆盖模式地上生物量平均高于对照1.56%-5.48%;根质量密度平均高于对照15.10%-32.36%,根冠比平均高于对照10.38%-32.74%。产量与水分利用效率分别平均高于对照3.79%-12.40%和4.22%-12.31%。其中浅松覆盖处理在玉米根系形成、增产及水分利用效率等方面效果最佳,适宜北方寒旱地区推广。

英文摘要：

The object of this study was to explore the high quality and yield cultivation mode for maize in the north drought region. The impacts of different straw mulching modes in different growth stages on maize root-shoot ratio,root temporal and spatial distribution,surface biomass,yield and water use efficiency were analyzed through field contrast experiments from 2012 to 2013. There were a conventional tillage and four straw mulching modes in the experiments,which were surface tillage with straw mulching,no-tillage with straw mulching on furrow,no-tillage with stubble mulching,and no-tillage with straw mulching on ridge and furrow. SPSS statistics software was adopted to conduct significance analysis for data of jointing stage and harvesting stage respectively. The results showed that different straw mulching farming modes had significant effect on the control and support in root,root-shoot ratio and earth surface biomass,obvious effect in the early jointing stage. In addition,no-tillage with straw mulching on ridge and furrow was inferior to conventional tillage. But the other four kinds mulching models were better than comparison for 1. 56% - 5. 48% in growth of earth surface biomass,higher than comparison for 15. 10% -32. 36% in root weight density,and higher than comparison CK for 10. 38% - 32. 74% in root-shoot ratio. The yield and utilization efficiency of water were respectively higher than comparison for 10. 38% -32. 74% and 4. 22% - 12. 31%. Surface tillage with straw mulching was an ideal cultivation method for cold and arid regions of North China,which had significantly advantages in growth of root formation,yield increase and water availability.