Planting American ginseng (Panax quinquefolius L.) caused soil acidification and bacterial and fungal communities changes

Abstract Background：American ginseng is an important herb crop and is widely cultivated in China. However, continuous cropping obstacles seriously affect the production of American ginseng, and the reason is still unclear and needs more research. We analyzed the soil microbial alpha diversity and community composition as well as soil physicochemical properties, in bulk soils to assess the changes in soil associated with planting American ginseng. Results：The cultivation of American ginseng resulted in a significant decrease in soil pH. The alpha diversity of soil bacteria and fungi was significantly reduced with the increase of American ginseng planting years. Planting American ginseng also largely altered the community and functional composition of soil bacteria and fungi, in particularly, increased the relative abundance of the pathogenic fungus Fusarium, and readuced the relative abundance of some beneficial microorganisms, such as KD4-96, RB41 and Sphingomonas. Conclusions：Soil acidification, reduction of beneficial taxa and accumulation of fungal pathogens, therefore, may lead to the replantation problem of American ginseng.