Effects of acid compost tea on cotton rhizosphere phosphorus availability and fungi community and function

Acid compost tea (CT) can improve soil physicochemical properties and promote cotton growth, but the response of fungi to rhizosphere nutrient conditions and physicochemical properties is still unclear. In this study, the response mechanism of phosphorus morphology and fungal community structure and function in cotton rhizosphere soil to acid compost tea was investigated. The results showed that the content of Water-P, NaHCO3-P, NaOH-P in rhizosphere soil was significantly increased after CT application, and the absorption and accumulation of nutrients by cotton increased. The diversity of rhizosphere fungi decreased, but the species formed a more complex and stable interaction relationship, and the relative abundance of oligotrophic species, such as Basidiomycota, decreased. Correlation analysis and random forest distribution showed that the main driving factors of species composition change were soil pH and the increasing proportion of medium and high active phosphorus in rhizosphere soil, which directly affected the abundance of species with different nutrient modes. Structural equation model shows that the main factor of cotton dry matter accumulation and yield increase is the increase of phosphorus availability. This study revealed the changes and driving factors of acid compost tea on phosphorus morphology and fungal community in rhizosphere soil, and evaluated the interaction between efficient utilization of phosphorus in calcareous soil and rhizosphere fungal microecology.