Agrivoltaics is the simultaneous production of both solar energy and crops on the same land. The success of crops grown underneath the panels depends on the crop type, soil composition, regional climate conditions, and panel configuration (height, row spacing, tilt angle, and tracking system). There is a need for more research-based guidance on the trade-offs between energy and crop production in agrivoltaics systems. The objective of this study was to compare the microclimate conditions and crop performance within a solar array to the control (without a solar array). The on-farm agrivoltaics study was conducted from July to September 2023 in Grafton, MA, using two contrasting crops: butternut squash (sun-loving) and Boston lettuce (shade tolerant). Microclimate variables such as photosynthetically active radiation (PAR), air temperatures, soil temperatures, soil moisture, and relative humidity were monitored at different transect positions within the solar array [BP 1 (under leading panels), BP 2 and BP 3 (between two panels), and BP 4 (under the back panel)] and control. Data were analyzed in R statistical software using an independent sample t-test to compare control to array and test and one-way ANOVA to compare each bed position within the array only. Preliminary findings showed higher mean and maximum PAR in control than in BP 1, BP 2, and BP 4 within the array. Air temperature (mean and maximum) was found to be higher in control than in the array. Mean and maximum soil temperature was highest in control when compared to BP 1 and BP 2 under the array. Similarly, mean relative humidity was found to be significantly higher in the control than in the array. The chlorophyll index of butternut squash showed a positive correlation with decreasing PAR, suggesting potential adaptive responses to varying light conditions. Butternut squash fruit yield was similar across the four different bed positions under the array, and lettuce yield under the array was similar to that of the control area. Further continuation of this study in 2024 provides insights for growers about the successful production of butternut squash and lettuce production under the agrivoltaics system.
