[Succession of Bacterial Community on the Surface of Biodegradable Mulch Films During Farmland Burial]

With the rapid advancement of agricultural modernization, biodegradable mulch （BDM） in farmland has become increasingly prevalent. However, little is known about the effects of BDM buried in soil on bacterial communities. In this study, a burial experiment was conducted on farmland using BDM （PBAT+PLA）. The bacterial communities on the surface of the BDM （H8） at different burial stages were analyzed through Illumina NovaSeq high-throughput sequencing technology. The landfill experiment was carried out for a total of 75 days. The results revealed that the bacterial α-diversity in BDM was significantly lower than that in the control soil, with a notable decrease in soil bacterial α-diversity on the BDM surface in the later stages of burial compared to that in the early stages （P<0.05）. The bacterial community of control soil was significantly different from that of BDM （P<0.01）. The relative abundance of the Proteobacteria phylum in the BDM was significantly higher than that in the control soil （P<0.05）. LEfSe analysis revealed significant differences in taxa between the buried BDM and the control group across burial stages. During the early stage, Pseudarthrobacter and Acidovorax showed significant differences. Variovorax and Mycobacterium exhibited differences in the mid-stage, whereas Hydrogenophaga and Chryseolinea differed significantly in the late stage. These taxa served as indicator species for their corresponding burial stages. Functional analysis of bacterial communities revealed an enhancement of carbon metabolism-related functions in the bacterial community on the BDM surface during the early and middle stages. Moreover, network analysis revealed that, compared to that in the control soil, BDM exhibited a simpler network structure of the bacterial community, higher modularity values, and more negative correlation connections. These findings collectively provide a scientific foundation for a comprehensive understanding of the impact of BDM on the soil microecological environment.