Dual use of solar power plants as biocrust nurseries for large-scale arid soil restoration

Arid soils are currently under substantial anthropogenic stress and are globally degrading. Co-operating photovoltaic plants with biocrust nurseries has potential to restore soil health alongside renewable energy production. Large portions of global arid lands are under severe, increasing anthropogenic stress, their soils progressively degrading or already degraded. The interventional regeneration of the natural cover of these soils-photosynthetic communities known as biocrusts that armour them against erosion and fertilize them-is currently regarded as promising for dryland restoration and sustainability. Technologies for biocrust restoration developed during the past decades are, however, invariably of high effort and low capacity, constraining application to small spatial scales. We tested the notion that crustivoltaics, where solar power plants are used as ad hoc biocrusts nurseries, can break this scaling barrier. We show experimentally that solar plants indeed promote the formation of biocrust over neighbouring soils, doubling biocrust biomass and tripling biocrust cover, and that after biocrust harvesting, recovery is swift particularly if re-inoculated. Our results point to a mode of continuous dual operation that is not only effective and socioeconomically attractive but can also increase capacity by orders of magnitude to reach regional scales.

Automated summary

Arid soils are degrading globally due to anthropogenic stress. Co-operating photovoltaic plants with biocrust nurseries has the potential to restore soil health alongside renewable energy production. The use of solar power plants as ad hoc biocrust nurseries, known as crustivoltaics, can break the scaling barrier of current biocrust restoration technologies, allowing for large-scale restoration.