Phosphorus is a “life element” for crop growth. However, about one-third of agricultural soils in China and globally are facing a shortage of bioavailable phosphorus. On the one hand, the current-season utilization rate of phosphate fertilizer is extremely low, and a large amount of applied phosphorus is “locked” by soil, forming “legacy phosphorus” that is difficult for crops to use. On the other hand, long-term dependence on phosphate fertilizer has become a potential threat to national food security and ecological security. Vermicompost, as an organic amendment rich in beneficial microorganisms, has been proven to effectively activate soil phosphorus, but the specific microbial mechanisms involved have not yet been systematically revealed.
The team led by Jun ZHOU at the Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, in collaboration with the team led by Hongtao ZHONG at the College of Environment and Ecology, Xiamen University, published a review paper titled “Microbial mechanisms enhancing soil phosphorus bioavailability through vermicompost application for sustainable agriculture” in ENGINEERING Agriculture (DOI: 10.15302/J-FASE-2026672). The article systematically analyzed three core mechanisms by which vermicompost-derived microorganisms activate soil “legacy phosphorus,” laying a theoretical foundation for the development of green and efficient biological phosphate fertilizers.
Traditional studies have mostly focused on the activation of phosphorus by biochemical substances such as phosphatases directly introduced by vermicompost. However, understanding remains limited regarding deeper mechanisms: how the microbial communities it carries colonize soil, how they interact with native microorganisms (synergistically or competitively), and how phosphorus in microbial cells is released and cycled after microbial death and lysis. As a result, the scientific community currently knows only the surface phenomenon of “phosphorus activation” but has not fully elucidated the underlying microbial driving mechanisms and ecological processes. Therefore, systematically revealing the microbiological mechanisms by which vermicompost regulates soil phosphorus cycling is a core issue urgently needing breakthrough in current agricultural microbial ecology research.
To address these issues, this article systematically elucidated three core microbial mechanisms by which vermicompost improves soil phosphorus availability, constructing a complete theoretical framework. The study first clarified that microorganisms derived from vermicompost can directly secrete protons, carboxylates, and siderophores. These metabolites effectively dissolve sparingly soluble inorganic phosphorus in soil by acidifying the environment or competitively binding metal ions. Second, phosphatases secreted by these microorganisms can mineralize organic phosphorus in soil into inorganic phosphorus that plants can absorb. Particularly noteworthy is the study’s new insight of “two-step mineralization”: carboxylates first dissociate organic phosphorus fixed by metal ions, and then phosphatases enzymatically hydrolyze it, thereby significantly improving phosphorus release efficiency.
The input of vermicompost not only introduces exogenous microorganisms, but its rich organic carbon and nitrogen sources also significantly activate the native soil microbial community. These activated native microorganisms also participate in secreting phosphorus-solubilizing substances and phosphatases, jointly enhancing soil phosphorus availability. More critically, the study revealed the important contribution of microbial cell lysis: vermicompost promotes rapid growth of microbial populations, and when some microorganisms die and lyse, the phosphorus stored within their cells (microbial biomass phosphorus) is released into the soil solution, forming dynamic phosphorus turnover and release. In addition, changes in soil physicochemical properties caused by vermicompost input, such as altered soil pH and carbon-to-nitrogen ratio, further regulate the above microbial processes.
Microorganisms do not exist in isolation in soil. Complex ecological interactions exist between vermicompost-derived microorganisms and native microorganisms, including competition for ecological niches and resources, as well as potential complementary cooperation. Such community-level interactions determine the persistence and stability of phosphorus activation functions. In the future, using synthetic microbial community approaches to directionally construct efficient and stable phosphate-solubilizing microbial communities will be an important direction for achieving precision phosphorus application in agriculture.
This study not only achieved a systematic theoretical breakthrough but also provided a practical and feasible technical path for the green transformation of China’s agriculture. In terms of ensuring food security, by activating “legacy phosphorus” accumulated in soil, it can effectively alleviate dependence on imported phosphate rock resources, while enhancing arable land productivity and reducing agricultural input costs. In terms of ecological environmental protection, improving soil phosphorus use efficiency can significantly reduce phosphorus loss through runoff, curbing environmental problems such as water eutrophication and cyanobacteria blooms at the source. Looking ahead, this study points the direction for developing efficient “synthetic microbial agents,” which is highly consistent with the national strategic plans for “fertilizer reduction and efficiency enhancement” and the “bioeconomy,” and will strongly promote the transformation of China’s agriculture toward a resource-saving and environmentally friendly sustainable development model.
DOI: 10.15302/J-FASE-2026672