Agrivoltaic cultivation of pears under semi-transparent panels reduces yield consistently and maintains fruit quality in Belgium

Abstract

Transitioning to a fossil fuel free society requires an increase in solar energy production. However, expanding solar power to farmland competes with food production. Additionally, climate change threatens food security and leads increasingly to yield losses. Agrivoltaic systems produce solar energy and food on the same field, while sheltering crops. In agrivoltaic systems, crops grow in a protected environment with reduced solar irradiance, a modified microclimate, and a potential physical cover protecting against hail damage. The agrivoltaic system may help safeguard crop yields from extreme weather events such as frost during flowering or sunburn during heat waves. Studies on agrivoltaic fruit production have previously focused on raspberry or apple. However, multiyear field trials are often lacking, and no study has described agrivoltaic pear cultivation. This research describes the multiyear effect of agrivoltaics on pear fruit, revealing that a predictable fruit yield and quality can be attained under solar panels in a temperate maritime climate. Tree rows were fitted with semi-transparent monofacial c-Si photovoltaic modules at a ground coverage ratio of 25.45%. Across three growing seasons, we recorded a 24% light reduction at canopy level. Agrivoltaic pear trees yielded 15% less than the reference control plots in 3 consecutive years. Flowering and fruit-set were unchanged, while agrivoltaics reduced leaf flavonoid levels. The leaf photosynthetic performance was identical, yet delayed leaf senescence under agrivoltaics suggests an adaptation to the modified environment. Agrivoltaics impacted fruit shape, as there was an increase in the number of bottle-shaped pears and a reduction in caliber. Other fruit quality traits were unaffected, including postharvest ethylene production. A land equivalent ratio of 1.44 was reached in the agrivoltaics orchard. This study demonstrates that agrivoltaics hold potential for pear production under temperate climates and highlights how pear productivity and quality is predictable when compared with conventional cultivation methods.