黄土高原旱塬区不同覆盖模式下冬小麦耗水特征及根系生长规律研究

Characteristics of Water Consumption and Root Growth of Winter Wheat under Different Covering Modes in Arid Tableland of the Loess Plateau

为探究黄土高原旱塬区不同覆盖模式对冬小麦耗水及根系生长的影响,采用微根管动态监测技术,连续两年对比分析平作不覆盖(T0)、秸秆覆盖平作(T1)、半膜覆盖垄作(T2)和垄上覆膜沟覆秸秆(T3)4种处理下冬小麦不同生育时期0~130cm土层根系密度及土壤水分的变化。结果表明,与T0处理相比,T1、T2和T3处理对冬小麦耗水总量无显著影响,T1、T2和T3处理的水分利用效率分别提高25.42%、9.68%和20.13%。T1、T2和T3处理均会减小冬小麦根系富集深度,使根系分布深度上移,根系富集区离地表深度表现为T2<T3<T1≤T0。与T0处理相比,T1、T2和T3处理分别增产23.10%、12.24%和20.70%。由此可知,T1、T2和T3处理在减小冬小麦根系富集深度及提高水分利用效率和产量方面均优于传统平作不覆盖种植模式,其中以T1处理最优。

Field experiment was conducted to explore the effects of different covering modes on characteristics of water consumption and root growth of winter wheat in arid tableland of the Loess Plateau.Minirhizotron root monitoring system was used to study the root length density and soil moisture in a0-130 cm soil profile at different growth stages for two years.There were four treatments：flat plot without mulching（T0）,flat plot with straw mulching（T1）,plastic mulching on soil ridges（T2）,and plastic mulching on soil ridges and straw mulching in furrows（T3）.The results showed that T1,T2 and T3 had no significant effect on total water consumption in comparison with T0.However,water use efficiency of T1,T2 and T3 was increased by 25.42%,9.68%and 20.13%,respectively.T1,T2 and T3 also reduced the depth of root enrichment zone,and shallowed depth of root enrichment zone in the order of T2〈T3〈T1≤T0.Moreover,the average yield of T1,T2 and T3 was increased by23.10%,12.24%and 20.70%,respectively,compared with T0.Therefore,all covering modes could reduce the depth of root enrichment zone,increase water use efficiency and yield of winter wheat,compared with traditional non-mulching treatments,and flat plot with straw mulching is the best mode.