Impacts of Fertilization and Soil Amendments on Rhizosphere Microbiota and Growth of <i>Panax</i>: A Meta-Analysis

Panax species are globally recognized for their high medicinal and economic value, yet large-scale cultivation is constrained by high production costs, progressive soil acidification, and persistent soil-borne diseases. Although various soil improvement strategies have been tested, a comprehensive synthesis of their comparative effectiveness has been lacking. Here, we conducted a meta-analysis of 1381 observations from 54 independent studies to evaluate the effects of conventional fertilizers, microbial fertilizers, organic amendments, and inorganic amendments on Panax cultivation. Our results demonstrate that microbial fertilizers, organic amendments, and inorganic amendments significantly increased soil pH, thereby ameliorating soil acidification. Among them, organic amendments significantly enhanced the content of soil organic carbon, available nitrogen, and available phosphorus, alongside a notable increase in microbial diversity (Chao1 and ACE indices, which increased by 9% and 17%, respectively). Moreover, our analysis revealed that while microbial fertilizers, organic amendments, and inorganic amendments (except conventional fertilizers) reduced the disease index of Panax plants, organic amendments demonstrated absolute superiority in promoting plant height, root dry weight, root fresh weight, and root length. By quantitatively integrating multi-source evidence, this study provides novel mechanistic insights and practical recommendations that extend beyond local practices, offering guidance for sustainable ginseng cultivation and broader medicinal plant production systems worldwide.