Dynamics and functional roles of fungal communities in Pseudostellaria heterophylla soil under continuous cropping

Notwithstanding the pivotal role of soil microbial communities in sustaining crop health and advancing sustainable agricultural practices, comprehensive investigations into the temporal dynamics and functional attributes of fungal communities under continuous cropping syndrome in P. heterophylla cultivation remain conspicuously limited. This study examined the fungal communities in P. heterophylla soil under continuous cropping through multi-year sampling. A total of 2,496 OTUs were identified, with fungal diversity highest in the first year, declining in the second due to nutrient depletion and pathogen buildup, and partially recovering in the third. Continuous cropping caused soil acidification, nutrient imbalances, and the persistence of harmful fungi like Fusarium, while promoting beneficial fungi such as Mortierella. Network analysis revealed key fungal taxa (e.g., Ascomycota, Chytridiomycota) as central to ecosystem stability. Functional gene predictions suggested strategies to restore soil health by enhancing beneficial fungi and suppressing harmful ones. Mortierella was identified as a keystone genus, critical for organic matter decomposition and nutrient cycling, and a target for microbial remediation. The study also isolated Fusarium oxysporum and Bacillus thuringiensis, providing strategies to improve soil health and crop productivity in medicinal plant cultivation.