The impact of surface ozone on agricultural yields in the Ciuc Basin

Tropospheric ozone can affect agricultural productivity, particularly in geographically enclosed regions such as the Ciuc Basin, where air pollutants tend to accumulate. Ozone adversely affects plants by reducing photosynthetic efficiency and impairing stomatal function, ultimately resulting in reduced growth and lower yields. The objective of the present study was to investigate the relationship between ozone concentration and agricultural yield during the period 2008-2023. Descriptive and trend-based statistical analyses, as well as mathematical exposure-response models, were applied, incorporating hourly, daily, monthly, and annual variations in ozone concentrations, along with the effects of solar radiation and air temperature. The findings indicate that the annual mean ozone concentration exhibited a slight upward trend, accompanied by an increase in solar radiation intensity. During the vegetation period (April-September), elevated ozone levels (> 40 µg/m³), in combination with high solar radiation (> 2500 W/m²/day), could negatively affect crop performance. To quantify the effects of ozone, the AOT40 indicator was applied, representing the accumulated exposure to concentrations above the critical threshold. Based on Relative Yield Loss estimates, the most sensitive crops were maize (0.93%), barley (0.92%), and potato (0.85%), while wheat was moderately affected (0.58%). Over the study period, the total economic loss attributable to ozone-induced yield reductions was estimated at €5.72 million, with potato incurring the largest financial impact (€4.84 million), followed by wheat (€465,529), barley (€212,853), and maize (€201,151). The results suggest that tropospheric ozone can negatively impact agricultural productivity in the Ciuc Basin. Consequently, the promotion of ozone-tolerant crop varieties, the reduction of air pollution, and the encouragement of sustainable agricultural practices among local producers are of particular importance.