Soil bacterial community composition and diversity can be an important bioindicator for assessing ecosystem stability, and photovoltaic (PV) shading is a key factor influencing soil bacterial communities in rocky desertification areas; however, how the composition and diversity of soil bacterial communities change with PV operation duration remains unclear. Focusing on the experimental demonstration site of Shilin ecological photovoltaic (PV) power plant in Yunnan Province, we compared soil properties under PV arrays and non-PV control areas with different operation durations (7 and 13 years). The results showed that long-term PV operation significantly increased soil TN and TK content compared to CK, while increasing Ure and ALP activities, but inhibiting CAT activity and decreasing soil moisture, pH, SOC, and TP. High-throughput sequencing revealed stable dominant bacterial phyla (e.g., Aspergillus, Acidobacteriota) and beneficial genera (e.g., RB41, Sphingomonas), with an increase in relative abundance of Bacillota-like phyla but a decrease in Acidobacterium. The α-diversity (ACE, Chao1 index) and β-diversity of soil bacteria greatly increased with years of PV operation, reaching a maximum in the 13-year PV operation area. Correlation analyses showed that differences in soil bacterial communities in regions with different years of PV operation were mainly influenced by differences in PH and enzyme activities.

Soil nutrient loss and infertility in rocky desertification areas severely constrain ecological restoration. Exploring the impacts of external field remediation technologies on soil quality in these regions may offer novel strategies for soil enhancement and ecosystem recovery. This study conducted a three-month experiment to investigate the impact of continuous electric (ET, 20 V) and magnetic (MT, 200 mT) field treatments on soil nutrients, enzyme activities, and bacterial communities in simulated moderate and severe rocky desertification soils. Results showed that although an overall declining trends in total contents of key soil nutrients (Total nitrogen, total phosphorus, and total potassium), both electric and magnetic field treatments effectively mitigated the decreases of total nitrogen and potassium content (with the exception of total phosphorus) in rocky desertification soils, while improving their available contents compared to the control (CK). Electric field application significantly reduced the pH of moderate and severe rocky desertification soils through electrolysis, shifting the soil from alkaline (pH 7.69 and 7.73, respectively) to slightly acidic (pH 6.71 and 6.37, respectively); Both electric and magnetic field treatments enhanced urease and sucrase activities in moderately and severely rocky desertified soils. Compared to the CK, the increases were 21.92%, 4.46%, 5.70%, and 66.43% in moderately rocky desertified soil, and 10.06%, 42.15%, 20.66%, and 0.93% in severely rocky desertified soil, respectively. Their effects on phosphatase and catalase activities varied with the degree of rocky desertification. However, in severely rocky desertified soil, both treatments significantly increased phosphatase and catalase activities by 19.55%, 24.63%, 61.07%, and 38.05% compared to the CK, respectively. Furthermore, both electric and magnetic treatments significantly reduced bacterial α-diversity (chao1, ACE, Shannon, Simpson, and Pielou J indices) but optimized community structure by enriching dominant phyla with specific ecological functions, such as Pseudomonadota (7.63–41.10%), Bacteroidota (13.52–69.29%), and Verrucomicrobiota (38.26–104.81%). Functional prediction revealed that the abundances of dominant pathways (such as chemoheterotrophy, aerobic chemoheterotrophy, and nitrogen fixation) was enhanced following both treatments. Mantel analysis further indicated strengthened correlations among soil nutrients, enzyme activities, and bacterial communities, particularly under magnetic field treatment. These findings demonstrate that electric and magnetic field applications effectively facilitate nutrient cycling, stimulate enzyme activities, and optimize microbial community structure, thereby improving soil ecological functions and overall quality in rocky desertification regions, highlighting their potential for ecological restoration in karst areas.