Cultivation of Panax notoginseng in forestland alters the soil microbial community

Abstract:

[Background] The knownledge is limited about the effects of Panax notoginseng cultivation in forestland on the physicochemical properties of the soil and the structure and function of the soil microbial community. Studying such effects will be of great significance in guiding the cultivation of P. notoginseng in forestland. [Objective] To analyze the soil microbial communities in the forestland cultivated with P. notoginseng for different years during the rainy and dry seasons, and to elucidate the response patterns of soil microbial communities to the P. notoginseng cultivation process as well as the key influencing factors. [Methods] The natural forestland soil without P. notoginseng cultivation was taken as the control. High-throughput sequencing and biochemical tests were carried out to reveal the dynamics of soil microbial communities in the soil of the forestland with P. notoginseng cultivation. Based on the results, the redundancy analysis was then performed to clarify the drivers of the microbial community changes. [Results] The dominant bacteria and fungi in the soil of the forestland with and without P. notoginseng cultivation were Proteobacteria and Basidiomycota, respectively. The abundance of beneficial microbial phyla and genera showed an increasing trend. The number of unique genera of fungi and bacteria in soil was the lowest in the control, while it was the highest in the forestland with two-year P. notoginseng cultivation. The Chao1 and ACE indexes were the highest in the forestland with three-year P. notoginseng cultivation. The results of the principal coordinate analysis showed that the microbial distribution area in the forestland with P. notoginseng cultivation shifted and shrank with the increase in cultivation years. The soil microbial community composition was more similar among different groups in the dry season than in the rainy season. The redundancy analysis showed that total phosphorus and acid phosphatase were the main soil factors driving the changes of soil microbial communities in the forestland with P. notoginseng cultivation. [Conclusion] P. notoginseng cultivation in the forestland significantly changed the microbial community composition in the soil, and the microbial distribution presented a gradual shift and contraction with the increase in cultivation years. The alternation of rainy and dry seasons accelerated the composition and structure differentiation of the soil microbial communities in the forestland with P. notoginseng cultivation. Total phosphorus and acid phosphatase were the main environmental factors affecting the soil microbial communities.