Mechanisms of yield improvement in dryland wheat under plastic film mulching: Insights from soil fungal communities and function.

Plastic film (PF) mulching is an important method for winter wheat cultivation. In this study, the effects of PF mulching on wheat yield were analysed. Compared with non-mulched control, grain yield increased by 70% in PF treatment. Soil available phosphorus (AP) and electrical conductivity (EC) increased by 104.70% and 5.55%, respectively. PF mulching was associated with shifts in the relative abundance of several fungal taxa, including increases in Talaromyces, Trichoderma, and Schizothecium. The overall abundance of taxa classified as potential plant pathogens decreased by 37.73%. However, some taxa that include known plant pathogens, such as Didymella and Bipolaris, showed increased abundance, suggesting the need for careful disease management under mulching conditions. Co-occurrence network analysis indicated that fungal interactions became less complex in PF treatment, accompanied by an increased proportion of positive correlations. Redundancy analysis showed that soil EC and AP were significantly associated with wheat yield and with the relative abundance of specific fungal taxa. PF mulching was associated with changes in soil properties and fungal community structure, which may contribute to improved wheat yield. It provides insights into the potential role of fungal communities in mulching systems and highlights the importance of considering pathogen risks in wheat production.