秸秆覆盖对沟灌夏玉米根系分布及产量影响

【目的】探究夏玉米根系分布、水分利用效率及产量对沟灌种植下不同秸秆覆盖方式的动态响应。【方法】在河套灌区开展不同耕作模式的小区试验,试验设常规垄覆膜沟灌(FM)、垄覆秸秆沟灌(FLJ)、沟覆秸秆沟灌(FGJ)、垄沟覆秸秆沟灌(FLGJ)4个处理。研究了夏玉米各土层的根长密度、作物耗水量、产量及其相关指标,【结果】沟灌种植模式下不同秸秆覆盖方式显著(P<0.05)影响夏玉米根系分布、产量和水分利用效率,通过沟覆秸秆沟灌可改善夏玉米根系分布,提高水分利用效率,达到高产。沟覆秸秆促进了垄上大于40 cm土层根系发育,根长密度较FM处理增加128.1%,显著提高沟里大于20 cm土层根长密度,促进对深层土壤水分养分吸收利用,提高产量。与FM处理相比,FGJ和FLGJ处理的水分利用效率显著提高了51.9%和54.3%,增产9.3%和9.0%,但FGJ处理的收获指数显著高于其他处理(P<0.05),为0.48。【结论】沟灌种植模式下沟覆秸秆FGJ处理改善深层根系分布效果较好,显著提高夏玉米水分利用效率及产量。

The Effect of Straw Mulching Coupled with Furrow Irrigation on Root Distribution and Yield of Summer Maize

【Objective】Root growth and its consequence for yield is modulated by water and nutrient distribution in soil,as well as soil resistance for roots to grow.The objective of this paper is to explore how straw mulching and furrow irrigation combine to affect root growth,as well as the ultimate yield and water use efficiency of summer maize【.Method】The experiments were conducted at a field in Hetao irrigation district,Inner Mongolia(China),with the site ridge tilled.It consisted of four treatments:furrow irrigation coupled with film mulching(FM),furrow irrigation with the ridge-top mulched by straws(FLJ),furrow irrigation with the depression mulched by straws,and furrow irrigation with both ridge top and depression mulched by straws(FLGJ).For each treatment,we measured root length,water consumption,yield and traits of the summer maize.【Result】Straw mulching had a significant impact on root distribution,yield and water use efficiency.Mulching the depression with straws improved root distribution,water use efficiency and the yield as it increased root growth into soil deeper than 40 cm in the ridge top by 128.1%compared with FM,and root density in soil deeper than 20 cm in the depression.Compared with FM,FGJ and FLGJ increased water use efficiency by 51.9%and 54.3%respectively,and yield by 9.3%and 9.0%respectively,despite that the harvest index of FGJ was 0.48,significantly higher than that of other treatments.【Conclusion】Integrating furrow irrigation with straw mulching of the depression in ridge tillage was most efficient for promoting deep roots growth,thereby increasing water use efficiency and yield of summer maize.It can be used as a cultivation method to improve water use efficiency of summer maize in the Hetao irrigation district and its adjacent regions.