Responses of soil nutrients and rhizosphere microbial communities of a medicinal plant Pinelliaternata to vermicompost.

Abstract

Vermicomposting is an important strategy for restoring soil function and fertility. However, information on the effects of vermicompost application in intensive Pinellia ternata planting systems has rarely been reported. Here, we focus on the effects of different vermicompost levels and chemical fertilizer (CF) strategies on soil chemical properties, soil enzymes, and soil rhizosphere microbial communities (bacteria and fungi) in a field experiment. Compared to no added fertilizers (CK), vermicompost was more effective than the CF treatment in increasing P. ternata yield. We found that the 5 t ha-1 vermicompost treatment (VC2) significantly increased the tuber yield by 44.43% and 6.55% compared to the CK and CF treatment, respectively, and water-soluble exudates by 6.56% and 9.63% (P < 0.05). The vermicompost and CF treatments significantly increased the total phosphorus (TP), urease (Ure), and soil catalase (Cat) contents (P < 0.05). Compared to the vermicompost and CK treatments, the CF treatment significantly decreased soil organic carbon (SOC), C/N ratio, and soil acid phosphatase (Pac) (P < 0.05). Redundancy analysis (RDA) showed that Ure and total potassium (TK) were the major drivers in the bacterial community, whereas TP, total nitrogen (TN), Pac, and TK were the major drivers in the fungal community. We also found a positive correlation between soil enzyme activities, including between Ure and bacterial genera (Clostridium, Pseudoclavibacter, Stella, Hyphomicrobium, Mesorhizobium, and Adlercreutzia). In summary, vermicompost application promotes P. ternata soil microecosystems and improves soil fertility, soil enzyme activities, and rhizosphere microbial structure and function. Vermicomposting is a novel and promising approach to sustainable ecological cultivation of Chinese herbs via the promotion of soil properties and beneficial organisms.