Grassland Productivity Responds Unexpectedly to Dynamic Light and Soil Water Environments Induced by Photovoltaic Array

In this article, researchers evaluated seasonal patterns of soil moisture (SM) and diurnal variation in incident sunlight (photosynthetic photon flux density [PPFD]) in a single-axis-tracking agrivoltaic system established in a formerly managed semiarid C3 grassland in Colorado. Their goals were to (1) quantify dynamic patterns of PPFD and SM within a 1.2 MW photovoltaic array in a perennial grassland, and (2) determine how aboveground net primary production (ANPP) and photosynthetic parameters responded to the resource patterns created by the photovoltaic array. Investigators found relatively weak relationships between SM and ANPP despite significant spatial variability in both. Further, there was little evidence that light-saturated photosynthesis and quantum yield of CO2 assimilation differed for plants growing directly beneath (lowest PPFD) versus between (highest PPFD) PV panels. Overall, the AV system established in this semiarid managed grassland did not alter patterns of ANPP in ways predictable from past studies of controls of ANPP in open grasslands.