Sustainable Agrivoltaic Farming: The Role of Mycorrhiza in Promoting Mint Cultivation and High-Quality Essential Oil Production

Agriphotovoltaic (Agri-PV) systems are a dual-purpose solution for resolving land utilization conflicts through combining agricultural practices and photovoltaic power generation. However, the reduced light intensities and altered microclimatic conditions under PV modules may have negative effects on the productivity of crops. This study investigated whether incorporating arbuscular mycorrhizal fungi (AMF) inoculation into Agri-PV systems could mitigate such limitations for mint cultivation (Mentha arvensis and Mentha × piperita). A field trial was conducted in Bandırma, Türkiye, where both mint species were grown under and between PV panels, with and without AMF. The photosynthetically active radiation (PAR), temperature, fresh biomass, nutrient uptake, and essential oil content were evaluated. PAR was reduced by more than 90% under panels, while air temperatures were 1.0–1.6 °C lower than those in the between-panel areas. AMF inoculation significantly improved the yield and quality. In Mentha arvensis, the fresh herb yield increased by 43.4% (from 10,620 to 15,230 kg ha−1), and the essential oil content reached 10.08% under between-panel mycorrhizal conditions. For Mentha × piperita, the highest menthol concentration (30.38%) was observed exclusively in between-panel plots with AMF. In contrast, the highest oil content (4.50%) was achieved under shaded, mycorrhizal conditions, indicating that both light exposure and microbial interactions shape biochemical responses. This is the first study to demonstrate the synergistic impact of AMF inoculation and agrivoltaic shading on essential oil crops. This paper presents a novel and sustainable model that enhances crop productivity and biochemical quality in solar-integrated agriculture.