摘要

The cultivation of Sanqi ginseng (Panax notoginseng) plants is terribly hindered by replant disease and crop rotation is an effective agriculture practice to overcome this issue. In this study, microbial abundance, activity, diversity, and community structure were examined in a Sanqi ginseng monoculture system (SGMS) and maize-Sanqi ginseng system (MSGS) in Wenshan County, Yunnan Province. MSGS significantly increased soil microbial activity, resulting in a 2.6 times higher than in SGMS. The abundance of bacteria, fungi, and Fusarium oxysporum considerably increased in the MSGS, while the ratio of F. oxysporum/fungi was remarkably reduced when compared to the SGMS. Moreover, maize cultivation resulted in significantly greater bacterial diversity and evenness of community composition, but lower fungal richness. We suggest that maize plants are capable to restructure the soil microenvironment allowing exploitation by bacteria rather than fungi, thus shifting the microbial consortium from a fungi to bacteria dominated microflora, especially for the increase of beneficial microorganisms such as Bacillus. Surprisingly, the Acinetobacter (8 times lower) and Fusarium (3 times lower) genera dramatically decreased in MSGS, and contributed 26.91% and 12.87% of Bray-Curtis dissimilarity of bacterial and fungal communities, respectively. Taken together, we suggest that maize cultivation could enhance the soil microenvironment for the growth of more abundant, diverse, and stable soil microbial communities, that include beneficial microorganisms rather than F. oxysporum, to improve soil functions and may ultimately play an important role in overcoming the replant problem of Sanqi ginseng.