Antagonistic effect of multifunctional actinomycete strain Act12 on soil-borne pathogenic fungi and its identification Effects of soil amendments on rhizosphere microbial number, soil enzyme activity and yield of continuous cropped American ginseng Soil microbial diversity analysis after different years of Panax notoginseng harvest Comprehensive evaluation of reduced obstacles of continuous cropping of Panax notoginseng using TOPSIS-RSR analysis