Abstract
INTRODUCTION: Continuous cropping (CC) poses significant challenges to the yield and quality of Salvia miltiorrhiza, a medicinally important plant with annual market demand of around 20 million kg. Previous studies have explored chemical mitigation methods, but concerns persist regarding environmental pollution and safety issues. METHODS: In this study, we evaluated three strains of the fungus Trichoderma (T. brevicompactum, T. viridescens, and T. velutinum) as ecofriendly alternatives for CC obstacle mitigation in S. miltiorrhiza cultivation. RESULTS: The Trichoderma treatments significantly enhanced the relative abundance of beneficial soil bacteria (Actinobacteria 9.25%-16.88%; Chloroflexi 6.41%-16.73%; Gemmatimonadetes 1.21%-3.16%), while decreasing the abundance of pathogenic Fusarium by 12.67%-31.75%. Soil analysis revealed substantial improvements in total organic carbon (47.35%-65.88%), nitrate nitrogen (91.38%-318.89%), available potassium (4.29%-17.16%), and available phosphorus (1.85%-11.86%) following Trichoderma treatment. T. brevicompactum demonstrated superior performance among the three tested strains, increasing the individual plant fresh weight by 17.79% and the survival rate by 13.33%. This treatment also significantly elevated (p < 0.05) the content of key bioactive compounds in S. miltiorrhiza root: tanshinone IIA (51.16% increase), cryptotanshinone (56.76%), tanshinone I (50.00%), and salvianolic acid B (18.43%). DISCUSSION: Trichoderma can effectively alleviate S. miltiorrhiza CC obstacles by improving the soil nutrient status and modulating the soil microbial community, thereby enhancing plant growth and stress resistance. This study provides a promising ecofriendly strategy for sustainable cultivation of S. miltiorrhiza and other medicinal plants facing similar challenges.