Soil microbial community composition and nitrogen enrichment responses to the operation of electric power substation

Abstract The surge in global energy demand mandates a significant expansion of electric power substations. However, the ecological consequences of electric power substation operation on soil microbial communities and nitrogen enrichment have not been addressed. In this study, we collected soil samples from seven distinct sites at varying distances from an electric power substation in Xintang village, southeastern China, and investigated the microbial diversity and community structures employing metagenomic sequencing technique. Key environmental determinants shaping soil microbial communities at both the phylum and genus levels were identified as soil moisture content, pH and electric conductivity. Prominent taxa identified across all sampled soils included Acidobacteria, Proteobacteria, Actinobacteria, Chloroflexi, Basidiomycota, Ascomycota, and Mucoromycota. While the bacterial community exhibited statistically significant differences across the seven distinct sites, fungal communities did not show such variations. Correlation analysis revealed a diminished nitrogen fixation capacity at the site nearest to the substation, characterized by low moisture content, elevated pH, and robust soil electric conductivity. In contrast, heightened nitrification processes were observed at this site compared to others. These findings were substantiated by the relative abundance of key genes associated with ammonium nitrogen and nitrate nitrogen production. This study provides insights into the relationships between soil microbial communities and the enduring operation of electric power substations, thereby contributing fundamental information essential for the rigorous environmental impact assessments of electric power substations.