Effects of Photovoltaic Power Station Construction on Soil Bacterial Community Structure and Function in Saline-Alkaline Land

This study systematically investigates the impact of photovoltaic (PV) power station construction on the soil physicochemical properties, microbial community structure, and function in the special habitat of saline-alkali land, taking the 200 MW PV power generation base in Hongshagang, Minqin County, Gansu Province, China as the research object. By measuring the physicochemical properties of surface soil (0~20 cm) from different locations within the PV station-namely between panels (IP), at the front edge of panels (FP), and under panels (UP)-and comparing them with an external control area undisturbed by human activity (CK), and by conducting high-throughput sequencing and functional prediction analysis based on 16S rDNA, this research reveals the regulatory effects of PV station construction on the soil environment and microbial structure in saline-alkali land. The results indicate that: (1) PV station construction significantly improved soil moisture and nutrient conditions in the saline-alkali land, with the UP position showing the most pronounced improvement, where soil water content, organic carbon, total nitrogen, and total potassium contents were 2.32, 2.71, 2.81, and 3.09 times that of CK, respectively; (2) Soil microbial diversity within the PV station was significantly higher than in the external control area, with the OTU richness and Shannon index in UP increasing by 26.28% and 15.56% compared to CK; (3) PV station construction induced significant changes in the bacterial community structure of the saline-alkali soil. Compared with CK, the relative abundances of the phyla Gemmatimonadetes, Bacteroidetes, and Planctomycetes in IP, FP, and UP were significantly increased. At the genus level, the relative abundances of Halomonas in FP and Truepera in UP increased significantly, being 28.83 times and 152 times that of CK, respectively; (4) Mantel analysis showed that soil pH, electrical conductivity, water content, and total nitrogen were the key environmental factors driving changes in the soil microbial community; (5) Functional prediction results indicated that the primary function of soil bacteria in the saline-alkali land was metabolism, with pathways such as carbohydrate metabolism and amino acid metabolism being significantly enhanced within the PV station compared to CK. This study provides a theoretical basis for understanding the ecological response of soil microorganisms in saline-alkali lands under the context of photovoltaic power generation and offers valuable insights for ecological restoration and sustainable soil use in arid regions.