Trichoderma consortium compost corncob promotes the growth of Pseudostellaria heterophylla and alleviates its diseases incidence via reshaping the soil microbiome and improving the soil nutrients under continuous monocropping conditions

The continuous monocropping obstacle, resulting from imbalance of nutrients and soil microorganisms, is the main factor limiting the productivity and quality of Pseudostellaria heterophylla (Miq.) Pax ex Pax et Hoffm. However, few agricultural methods and products are available to increase the productivity and quality of P. heterophylla by regulation the soil nutrients and microorganisms in continuous monocropping fields. In this study, Trichoderma consortium compost corncob (TCCC) was applied to P. heterophylla under continuous monocropping conditions to investigate its effects on growth, productivity, quality, disease incidence and to explore its impact on the soil nutrients and microbial communities. TCCC significantly enhanced the number of fibrous roots, the number of tuberous roots, the weight of 50 tuberous roots, the yield, and the drying rate of tuberous roots by 93.78–186.68%, 48.48–51.52%, 22.05–39.69%, 40.26–117.41%, and 4.23–6.67%, respectively. In addition, it significantly enhanced the crude polysaccharides content by 22.08–30.17% in P. heterophylla, whereas it significantly decreased the total saponin content by 20.00–22.50%. TCCC significantly lowered the incidence of leaf spot and root rot diseases by 69.71–73.86% and 18.64–53.25%, respectively. Moreover, applying TCCC significantly enhanced organic matter (OM), total nitrogen (TN), available nitrogen (AN), and total phosphorus (TP). Finally, the microbial analysis showed that TCCC significantly increased the relative abundance of beneficial microbiota (i.e., Trichoderma, Gaiella, and Chaetomium), while the relative abundances of pathogens such as Fusarium, Gibberella, Clonostachys, and Neocosmospora significantly decreased. Correlation analysis and structural equation model demonstrated that TCCC may promote the growth and productivity of P. heterophylla and alleviate its disease incidence under continuous monocropping conditions via reshaping the soil microbial community and enhancing soil nutrients. The present findings suggest that applying TCCC represents an innovative approach for alleviating continuous monocropping obstacles to improve P. heterophylla productivity and quality.