Film warming indirectly increases the yield of Allium chinense G. Don via recruitment of growth-promoting rhizosphere microorganisms

Film warming is a common agricultural practice that induces soil warming, alters soil water balance and heat flow, and improves farmland productivity. However, the effect of film warming on rhizosphere microecology and its underlying mechanisms of correlation with the yield of Allium chinense G. Don remain unclear. We conducted high-throughput sequencing to analyze the bacterial, fungal, and protists communities in the rhizosphere soil. Compared with the control group, both film warming treatments significantly decreased the richness index of rhizosphere microbial communities (Bacteria: 23.4% and 24.2%; Fungi: 8.9% and 17.0%; Protists: 18.4% and 32.2%) in Allium chinense G. Don. Notably, enhanced connections within the sub-network centered on Aspergillus highlight its pivotal role in regulating microbial community interactions under temperature change. Structural equation modeling (SEM) and network analyses identified the genus Aspergillus as the key contributor of crop yield. Aspergillus terreus and Aspergillus aculeatus were isolated and demonstrated various plant growth-promoting traits in laboratory and greenhouse experiments, and significantly enhanced the yield of pot-planted Allium chinense G. Don up to 31.3% and 22.9%, respectively. This study elucidated the mechanisms by which microorganisms promote crop growth under the context of film warming and identified the specific categories of rhizosphere growth-promoting fungi. Additionally, the experiment offers a new insight into how film warming can indirectly enhance crop yield by recruiting beneficial rhizosphere microorganisms.