Work

Low solar grazing densities support beneficial insects in agrivoltaic systems

Year: 2026

Type: article

Abstract: Solar grazing—the co-location of livestock grazing and photovoltaic energy production—is rapidly expanding globally to mitigate land-use conflicts. Solar facilities are increasingly sited on agricultural land, where both sheep grazing and the promotion of agriculturally beneficial insects are recognized as facilitators of multi-functional agroecosystems, yet how stocking rate shapes beneficial insect communities remains poorly understood. We conducted a replicated, three-year experiment testing six stocking rates (0–10 sheep ha −1 ) at an operational 18 MW solar facility, sampling bees and lady beetles across three years and four grazing rotations per year. Light grazing at 2 sheep ha −1 supported 38% greater beneficial insect abundance than ungrazed controls, driven primarily by an 83% increase in honey bees. High stocking rates (⩾8 sheep ha −1 ) reduced bee abundance by 42%–68% and significantly changed insect community composition. A companion study identified 8 sheep ha −1 as the agrotechnological optimum, but our results identify 2 sheep ha −1 as the agroecological optimum in our study region, where beneficial insect abundance and flock health are maximized. These optima did not coincide, indicating a clear tradeoff between ecological and operational objectives. However, at 4 sheep ha −1 , beneficial insect communities remained statistically indistinguishable from ungrazed controls while vegetation management effectiveness was greater than at 2 sheep ha −1 . Together these results define a synergy–tradeoff boundary with direct implications for targeting agroecological outcomes via the operations and maintenance of solar grazing facilities.

Source: Environmental Research Letters

DOI: 10.1088/1748-9326/aeb145