Managed sheep grazing can improve soil quality and carbon sequestration
at solar photovoltaic sites
Abstract
Solar energy development is land intensive and recent studies have
demonstrated the negative impacts of large-scale solar deployment on
vegetation and soil. Co-locating vegetation with managed grazing on
utility scale solar PV sites could provide a sustainable solution to
meeting the growing food and energy demands, along with providing
several co-benefits. However, the impacts of introducing grazing on soil
properties at vegetated solar PV sites are not well understood. To
address this knowledge gap, we investigated the impacts of episodic
sheep grazing on soil properties (micro and macro nutrients, carbon
storage, soil grain size distribution) at six commercial solar PV sites
(MN, USA) and compared that to undisturbed control sites. Results
indicate that implementing managed sheep grazing significantly increased
total carbon storage (10-80%) and available nutrients, and the
magnitude of change correlated with the grazing frequency (1-5 years) at
the study sites. Furthermore, it was found that sites that experienced
consecutive annual grazing treatments benefitted more than
intermittently grazed sites. The findings will help in designing
resource conserving integrated solar energy and food/fodder systems,
along with increasing soil quality and carbon sequestration.