The co-allocation of photovoltaic arrays with crops presents a promising strategy to mitigate the conflict between photovoltaics and agricultural land. However, there is a notable lack of quantitative research on the impact of agrivoltaic system on land quality in fragile areas. In this study, peanuts (Arachis hypogaea) and ryegrass (Lolium perenne) were cultivated in photovoltaic array in the dry–hot valley of southwest China, with an off-site native land serving as the control. Sixteen soil physicochemical and biochemical parameters were measured in the gap and under-panel and control area. Results demonstrated that the agrivoltaic system significantly enhanced soil moisture, organic carbon, nitrogen–phosphorus–potassium nutrients, microbial biomass, and urease activity. It also led to varying degrees of increase in soil pH and electrical conductivity, along with reduced soil sucrase and phosphatase activity. In comparison to the control, the agrivoltaic system notably improved soil quality and multifunctionality. Specially, gap cultivation had a more pronounced positive impact on soil quality than under-panel cultivation, and the cultivation of peanuts had a greater effect on soil quality and multifunctionality improvement than ryegrass. This study provides fundamental data to support the improvement of land quality in photovoltaic developed regions, and to alleviate the conflict between photovoltaics and agricultural land.

Solar photovoltaic (PV) power generation is a major carbon reduction technology that is rapidly developing worldwide. However, the impact of PV plant construction on subsurface microecosystems is currently understudied. We conducted a systematic investigation into the effects of small-scale light stress caused by shading of PV panels and sampling depth on the composition, diversity, survival strategy, and key driving factors of soil bacterial communities (SBCs) under two vegetation restoration modes, i.e., Euryops pectinatus (EP) and Loropetalum chinense var. rubrum (LC). The study revealed that light stress had a greater impact on rare species with relative abundances below 0.01% than on high-abundance species, regardless of the vegetation restoration pattern. Additionally, PV shadowing increased SBCs’ biomass by 20–30% but had varying negative effects on the numbers of Operational Taxonomic Unit (OTU), Shannon diversity, abundance-based coverage estimator (ACE), and Chao1 richness index. Co-occurrence and correlation network analysis revealed that symbiotic relationships dominated the key SBCs in the LC sample plots, with Chloroflexi and Actinobacteriota being the most ecologically important. In contrast, competitive relationships were significantly increased in the EP sample plots, with Actinobacteriota having the most ecological importance. In the EP sample plot, SBCs were found to be more tightly linked and had more stable ecological networks. This suggests that EP is more conducive to the stability and health of underground ecosystems in vulnerable areas when compared with LC. These findings offer new insights into the effects of small-scale light stress on subsurface microorganisms under different vegetation restoration patterns. Moreover, they may provide a reference for optimizing ecological restoration patterns in fragile areas.

Agro-photovoltaics (APV) or agrivoltaic systems integrate crop cultivation with solar energy production, offering a promising solution through the dual-use of land. This two-year study (2023 and 2024) examined the effects of an APV system on rice production. The results indicated that APV arrays created spatially variable light environments, with shadow lengths following predictable solar azimuth patterns and cloudy conditions mitigating shading effects through enhanced diffuse light. Compared with CK (non-shadow area), inter-panel plots (BP) maintained 77% photosynthetic efficiency and 85.4% plant height, whereas the areas beneath the panel showed a significant decrease in the relative chlorophyll content (SPAD values), photosynthesis rates, and yield. BP plots preserved a 78% fruiting rate through adaptive stomatal regulation, whereas LP zones (directly under the low eave) exhibited 35% higher intercellular CO₂ because of the limited assimilation in shading. Rice yield losses were correlated with shading intensity, driven by reduced panicles and grain filling. Moreover, the APV system achieved a high land equivalent ratio of 148–149% by combining 65–66% rice yield with 82.5% photovoltaics output. Based on the microenvironment created by the APV system, optimal crop types and fertilisation are essential for enhancing agricultural yields and improving land use efficiency.

Hydropower is a clean and renewable energy source, and cascade hydropower stations have been developed to enhance water energy utilization efficiency. While small hydropower stations have a smaller scale and environmental impact compared to large ones, the cumulative effects of cascade development on river ecosystems should not be overlooked. In this study, flow cytometry was used to classify picoplankton from water samples collected at four small cascade hydropower stations on a Pearl River tributary into six microbial groups: Virus, LNA (Low Nucleic Acid), HNA (High Nucleic Acid), Cyanobacteria, Algae, and Fungi. Four ecological assessment indices were calculated: Photosynthetic Autotrophic Capacity (PAC), Bacterial Activity Index (BAI), Virus Regulatory Capacity (VRC), and Fungal Metabolic Capacity (FMC). By analyzing trends in microbial abundance and ecological indices and their correlations with environmental factors, the results showed that along the small cascade hydropower stations, dissolved oxygen (DO) and electrical conductivity (EC) increased from 5.71 mg/L and 49.87 μS/cm upstream to 6.80 mg/L and 56.18 μS/cm downstream, respectively. In contrast, oxidation-reduction potential (ORP) and total organic carbon (TOC) concentrations decreased from 3.81 mV and 1.59 mg/L to −8.05 mV and 1.08 mg/L, respectively. Among the microbial groups, the abundance of Virus, LNA, and Fungi decreased by 30.9%, 30.5%, and 34.9%, respectively, along the cascade system. EC, TOC, and NO₃⁻-N were identified as key drivers of changes in the abundance of the Virus, LNA, and Fungi groups. The concentrations of carbon and nitrogen nutrients significantly influenced the ecological assessment indices. Cascade hydropower stations had a significant impact on PAC, BAI, and VRC, while their influence on FMC was relatively small. The VRC showed a decreasing trend, suggesting a weakening effect of the stations on VRC. This study offers new perspectives and methods that facilitate the rapid and quantitative assessment of the ecological impacts of cascade hydropower stations.

Agrophotovoltaic (APV) or agrivoltaic (AV) systems, which combine the crop cultivation with solar energy production, emerge as a promising solution by leveraging the dual use of land. This two-year study (2023 and 2024) investigated APV system impacts on rice production. The findings indicated that APV arrays created spatially variable light envi-ronments, with shadow lengths following predictable solar azimuth patterns, cloudy conditions mitigated shading effects via enhanced diffuse light. Compared to CK (non shadow area), inter-panel plots (BP) maintained 77% photosynthetic efficiency and 85.4 % plant height, while beneath panel areas showed significant declines of SPAD values, photosynthesis rate and yield. BP plots preserved 78% fruiting rate through adaptive sto-matal regulation, while LP zones (directly under the low eave) showed 35% higher inter-cellular CO₂ due to limited assimilation in shading. Rice yield losses correlated with shading intensity, driven by reduced panicles and grain filling. In addition, the APV sys-tem achieved high land equivalent ratio of 1.48–1.49, which was combining 65-66 % rice yield with 82.5 % photovoltaic output. Based on the microenvironment created by the APV system, an optimal crop types and fertilization management are essential to enhance ag-ricultural yields and to improve land use efficiency.