Impact of Photovoltaic Panels on Soil Aggregate‐Associated Organic Carbon Varies With Grassland Type

ABSTRACT Soil aggregates serve as pivotal pools for organic carbon storage, with their associated organic carbon distribution being essential to the soil's long‐term carbon sequestration capacity. Solar power, an essential form of renewable energy, is increasingly being harnessed through the construction of photovoltaic power stations (PVPs). However, the consequences of PVPs construction on the composition of soil aggregate‐associated organic carbon, especially across diverse grassland ecosystems, remain inadequately explored. This study selected seven utility‐scale PVPs across two distinct grassland types (steppe and meadow) in western China, and conducted a comparative analysis of organic carbon content within different size fractions of soil aggregates under various conditions: outside the PVPs (control), beneath the photovoltaic (PV) panels (under), and between the aligned PV panels (between). The objective was to assess the effects of PVPs on the aggregate‐associated organic carbon content, which is indicative of the soil's potential for long‐term carbon storage. The findings revealed that while PVPs did not markedly affect the total soil organic carbon (SOC) density, they did influence the composition of soil aggregate‐associated organic carbon density, with variations observed between grassland types. In meadows, the organic carbon density in small macroaggregates and silt + clay fractions beneath the PV panels increased by 43.2% and 76.2%, respectively, compared to the control. Conversely, in steppes, the organic carbon density in the silt + clay fraction between the aligned PV panels decreased by 51.4% relative to the control. This suggests that PVP construction may enhance SOC stability in meadows but could diminish it in steppes, highlighting the contrasting impacts of PVPs on soil aggregate composition and stability between the two grassland types. Our results emphasize the complex potential impact of PVPs on SOC over the long term and stress the necessity of considering site‐specific conditions in PV construction to coordinate renewable energy development with ecological conservation efforts.