Sheep Grazing Impacts on Soil Health and Pasture Quality at Commercial Solar Sites in Northeastern USA

Abstract

As solar sheep grazing continues to gain traction, it is important to emphasize soil health and pasture quality. Therefore, this study was performed to collect in-field data from 28 grazed and 3 non-grazed commercial solar sites to determine how grazing influences solar site health, associated ecosystem health, forage nutritive quality, and pasture conditions at Northeastern United States of America solar sites from 2022-2024. The majority of the selected sites were previously cropland. Construction of sites was between 2015-2020 with local graziers later joining the operation to create agrivoltaic systems. Sites were selected by their ability to contribute to the knowledge base over the duration of the study, provide relevant information about innovative co-location strategies and the willingness of all parties involved in the solar site maintenance to share information. Solar grazed sites tended to (p=0.06) have higher soil organic matter than non-grazed sites, with values of 4.14% and 3.70% respectively. Soil pH was significantly higher (p=0.01) in grazed sites, with an average of 6.20 compared to 5.81 in non-grazed sites, demonstrating the potential for solar grazing to improve solar site soil health. Crude protein was consistently significantly higher (p<0.001) in under panel areas for all seasons and years, while better digestibility was seen in under panel areas in Fall 2023. While not statistically significant (p=0.07), pasture condition scores increased between 2022 and 2023, suggesting that sheep grazing may have the potential to improve solar site pasture quality over time. Overall, solar sheep grazing helps to create a beneficial dual-use environment.