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New research from the United States shows that agrivoltaic plants in grasslands can not only maintain grass productivity, but also increase forage quality. The scientists made their measurements at Jacks Solar Garden (JSG), an elevated, south-facing agrivoltaic research facility using single-axis tracking systems near Longmont, Colorado.
Researchers at Colorado State University in the United States have studied the impact of an agrivoltaic system on semi-arid grasslands previously managed for hay production. The team investigated, in particular, how the grasslands responded to different simulated grazing management strategies within the agrivoltaic array.
“This is the first study to test how forage quantity and quality respond to simulated grazing in the semiarid climate of Colorado,” Matthew Sturchio, corresponding author of the research, explains to pv magazine . “The ability of plants to regrow at different stages of the growing season, when environmental conditions become warmer and drier, is important in determining best practices for grazing management in grassland agrovoltaic systems.”
The scientists conducted their measurements at Jacks Solar Garden (JSG), an elevated, south-facing agrivoltaic research and learning facility using single-axis tracking systems near Longmont, Colorado. They quantified how the timing of grazing alters overall productivity and whether forage quality changes throughout the growing season.
Their analysis took into account air temperature and relative humidity throughout the growing season, from May to September 2022. This data was then used to calculate the vapor pressure deficit (VPD). ), which is the difference between the amount of moisture that is actually in the air and the amount of moisture that the air could contain at saturation.
The main objective was to evaluate how photovoltaic panels altered forage production patterns, technically known as above-ground net primary production (APP), and forage quality. “Above-ground net primary production of grasslands is a valuable ecosystem service important to the grazing economy as an agricultural land use,” explain the researchers, who compare the results of the simulated ungrazed grasslands under the panels with those of a reference area without grazing and without photovoltaic modules.
Measurements showed that the agrivoltaic system had no significant impact on end-of-season ANPP totals in the absence of simulated grazing activity.
“More importantly, regrowth after simulated grazing produced ANPP equal to or greater than ungrazed sites at all microenvironmental locations in the ensemble,” the team states. “This finding indicates that a previously managed low-diversity semiarid grassland can maintain productivity within an agrovoltaic array and that the timing of grazing is unlikely to greatly affect total annual productivity.”
Overall, results indicated that forage quality in semi-arid regions can even increase later in the growing season with grazing under solar panels.
The group presented its conclusions in the study “ Agrivoltaic arrays can maintain semi-arid grassland productivity and extend the seasonality of forage quality ”, published at Applied Energy.
Another research group at Colorado State University last year investigated how agrivoltaic systems mounted on single-axis trackers affect precipitation and light redistribution at a 1.2 MW facility in Boulder Prairie. This team believes that their knowledge of the effects of single-axis agrivoltaic systems on rainfall and light redistribution and their subsequent impacts on crop productivity can help reclaim lands degraded by overgrazing, agricultural practices and water scarcity. |
