Agrivoltaic arrays can maintain semi-arid grassland productivity and extend the seasonality of forage quality

The co-location of photovoltaic energy generation and agricultural land use (Agrivoltaics, AV) has become increasingly popular in recent years. Although the benefits of AV in croplands have great promise, the development of AV systems has primarily occurred in former grasslands and sites now managed as grasslands, because of their relatively flat topography and consistently high solar irradiation. Evidence is accumulating that grassland productivity can be maintained within solar arrays, but how grassland productivity responds to grazing within solar arrays is largely unknown, despite the prevalence of grazing as a vegetation management option. Here, we report the results of a study aimed at quantifying how a semi-arid C3 grassland growing beneath an AV system in Colorado (USA) responded to simulated grazing treatments (canopy removal in June or July). In the absence of simulated grazing, there were no differences between aboveground primary production in the AV grassland vs. an adjacent control grassland. However, simulated grazing in June and July had a compensatory effect and, in some cases, annual productivity exceeded that in the control grassland. Additionally, we found that simulated grazing increased forage protein content later into the growing season compared to un-grazed AV and control sites. Overall, our results indicate that grazing within a grassland AV array is unlikely to negatively impact forage production, and that forage quality in this semi-arid region may even be increased later into the growing season with grazing.