4. Prof. Ferran Garcia-Pichel

Interventions to restore soils to their pristine state through inoculation of impacted areas with biocrusts or biocrust organisms are currently widely pursued. Current technologies can only be implemented effectively in small, high-importance settings, but not at the landscape scale that is needed for impactful ecological restoration. One potential avenue to overcome the scaling problem is to make use of existing, extensive photovoltaic energy generating installations as ad hoc biocrust nurseries, as such installations provide a greenhouse-like setting similar to those proven to work well in the production of biocrust inoculum, an approach we call crustivoltaics. Such dual use would not be without benefits for solar projects, diminishing fugitive dust deposition on PV panels, and its costly cleaning costs. Compared to agrivoltaics, on-site additional disturbance by the secondary use should be minimal. In order to probe the feasibility of crustivoltaics and to provide some initial guidance to develop best practices, we carried out minimally invasive, 2-year long pilot experiment of soil inoculation and monitoring with a variety of approaches to reconstitute the cyanobacterial biocrusts typical of pristine soils in the lower Sonoran Desert, sourced from remnant biocrusts in the immediately surrounding areas of a local solar farm. We provide evidence that the approach is feasible and useful in terms of fugitive dust suppression.