等高反坡台阶整地对不同耕作系统根土微生态的影响

[目的] 为探究坡耕地等高反坡台阶整地对玉米连作和玉米—芸豆轮作系统根土微生态特征的影响。[方法] 以玉米—芸豆轮作为研究对象,玉米连作为对照,采用野外原位监测采样和室内试验分析相结合的方法,通过GC-MS和高通量测序技术分析作物根系分泌物和土壤微生物群落组成、结构特征,揭示坡耕地等高反坡台阶整地对玉米连作和玉米-芸豆轮作根系分泌物种类、含量和土壤微生物群落组成及多样性的影响。[结果] (1)根系分泌物相对含量变化在CRT措施上更为突出,在轮作模式中更为显著。(2) CRT2处理提高土壤微生物群落数量、丰富度和多样性效果更显著。(3)在根系分泌物与土壤微生物互作下,根系分泌物、土壤微生物、土壤环境因子的两两相关性在CRT2处理下更显著。[结论] 坡耕地等高反坡台阶整地通过改变玉米连作和玉米—芸豆轮作的根系分泌物含量,使作物根土微生态环境发生变化,提高土壤微生物数量、多样性及丰富度,且该措施与玉米—芸豆轮作结合的提升效果更佳,对根土微生态的改善作用更显著。研究结果为坡耕地作物种植、耕作方式选择及改善土壤微环境和水土流失综合治理提供理论基础。

Effects of Contour Reverse-Slope Terrace on the Microecology of Rhizosphere in Different Farming Systems

[Objective] To study the effect of contour reverse-slope terrace (CRT) on micro-ecological characteristics of rhizosphere soil in maize continuous cropping and maize-kidney bean rotation system. [Methods] With corn bean wheel as the study object and corn bean joint as the control, the crop root exudates and soil microbial community composition and structural characteristics of were analysed by GC-MS and high-throughput sequencing technology by combining field in-situ monitoring and sampling with laboratory analysis. To study the effects of CRT on the species and content of root exudates and the composition and diversity of soil microbial community in maize continuous cropping and maize-kidney bean rotation. [Results] (1) The relative content change of root exudates was more prominent in CRT measures and more significant in crop rotation mode. (2) CRT2 treatment had a more significant effect on improving the quantity, richness and diversity of soil microbial community. (3) Under the interaction between root exudates and soil microorganisms, the pair-based correlation between root exudates, soil microorganisms, and soil environmental factors was more significant under CRT2 treatment. [Conclusion] CRT changed the root soil microecological environment of crops by changing the root secretion content of maize continuous cropping and maize-kidney bean rotation, and improved the number, diversity and richness of soil microorganisms. Moreover, the combination of this measure and corn-kidney bean rotation can improve the micro-ecology of root soil more significantly. The research results provide theoretical basis for crop planting, cultivation method selection, soil microenvironment improvement and soil erosion control.