Microbial Fertilizer: A Sustainable Strategy for Medicinal Plants Production

Medicinal plants have aroused considerable interest as an alternative to chemical drugs due to the beneficial effects of their active secondary metabolites. However, the extensive use of chemical fertilizers and pesticides in pursuit of yield has caused serious pollution to the environment, which is not conducive to sustainable development in the field of medicinal plants. Microbial fertilizers are a type of "green fertilizer" containing specific microorganisms that can improve the soil microbial structure, enhance plant resistance to biological and abiotic stresses, and increase the yield of medicinal plants. The root exudates of medicinal plants attract different microorganisms to the rhizosphere, which then migrate further to the plant tissues. These microbes can increase the levels of soil nutrients, and improve the physical and chemical properties of soil through nitrogen fixation, and phosphorus and potassium solubilization. In addition, soil microbes can promote the synthesis of hormones that increase plant growth and the accumulation of active compounds, eventually improving the quality of medicinal plants. In 2022, the total value of the global microbial fertilizer market was $4.6 billion and is estimated to reach $10.36 billion by 2030. In this review, we have summarized the types of microbial fertilizers, the colonization and migration of microorganisms to plant tissues, and the beneficial effects of microbial fertilizers. In addition, the prospects of developing microbial fertilizers and their application for medicinal plants have also been discussed. It aims to provide a reference for the rational application of microbial fertilizers in the field of medicinal plants and the green and sustainable development of medicinal plant resources.