College of Ecology and Environment,Southwest Forestry University
[Objective] To examine the impact of contoured reverse-slope terrace (CRT) on the microecological features of the rhizosphere in maize continuous cropping and maize-kidney bean rotation systems. [Method] Four treatments that were established comprise of continuous cropping on undisturbed sloping farmland (CK1), continuous cropping on contoured reverse-slope terrace (CRT1), rotational cropping on undisturbed sloping farmland (CK2), and rotational cropping on contoured reverse-slope terrace (CRT2). The maize-kidney bean rotation wheel was used as the research object, and the maize continuous cropping was used as the control. A combination of field in situ monitoring sampling and indoor experimental analysis was used. The crop root exudates and soil microbial community composition and structural characteristics of were analysed by GC-MS and high-throughput sequencing techniques. To reveal the effects of contoured reverse-slope terrace (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. [Result] The results of the study showed that, (1) the changes in the relative content of root exudates were more prominent on CRT measures and more significant in the maize-kidney bean rotation. (2) The effect of CRT2 treatment on increasing the number, richness and diversity of soil microbial communities was more significant. (3) The correlation of root exudates, soil microbial community, and soil environmental factors was more significant in the CRT2 treatment than others, that under root exudates-soil microbial community interactions. [Conclusion] Contoured reverse-slope terrace changed the root exudates content of maize continuous cropping and maize-kidney bean rotation, and increased the number, diversity and richness of soil microbial community. And the enhancement effect of this measure in combination with maize-kidney bean rotation was better, and the improvement of root-soil microbial community was more significant. To provide a theoretical basis for growing crops on sloping arable land, choosing farming methods and improving the soil microenvironment and comprehensive management of soil erosion.