Impacts of Agro-photovoltaic Systems on Soil Properties and Fungal Biodiversity

Soils play a central role in agricultural activity, supporting plant growth while maintaining in balance the whole ecosystem. Life on Earth strongly depends on the soils’ ability to promote food and feed production, host and preserve biotic reserves, regulate water flux, store organic matter, release nutrients and filter pollutants. In recent years the need to adopt sustainable practices aimed to safeguard the soil system has grown, with particular attention to soil quality and soil health. Following this perspective, agrivoltaic systems purposed to combine solar energy production with agricultural practices, enhancing land use efficiency, preserving soil biodiversity, while responding to the increasing global energy demand. Although the installation of agrivoltaics has been rapidly spreading, there is a lack of information about the effect of photovoltaic panels on soil ecosystems. This work quantitatively assesses the impact of agrivoltaic REM Tec 3D horizontal trackers - by varying Ground Coverage Ratios (GCR) - on soil health, analysing chemical-physical characteristics and fungal diversity. Physico-chemical analysis, ionome profiling, total DNA extraction and ITS metabarcoding were employed to achieve a complete insight about soil properties and fungal communities’ response. Field experiments were conducted in a wheat-cultivated field using three shading configurations: standard (STV1, GCR = 13%) and extended (STV2, GCR = 41%) trackers, compared to a full-sun control (CI). Shading from solar panels led to significant changes (p < 0.05) in soil characteristics: soils covered by extended panels resulted enriched in fertility-key elements such as organic carbon, total nitrogen and available phosphorus, while exhibited higher concentration of macro- and micro-nutrients. Molecular analysis revealed increased total DNA content and a distinct enrichment of fungal genera in soils under the same conditions, suggesting shifts in microbial community structure and function. These findings highlight a significant effect of agrivoltaic systems in soil quality, providing a foundation for future research. Long-term studies should be implemented to assess effects across multiple seasons to optimize panel configurations aimed to balance energy production, crop growth and soil health.