Assessment Of O-3-Induced Crop Yield Losses In Northern China During 2013-2018 Using High-Resolution Air Quality Reanalysis Data

Long-term exposure of food crops to high concentrations of ambient ozone (O3) can cause significant yield reductions. O3-induced crop loss studies are limited in China, especially in the North China Plain (NCP) where agricultural resources are abundant and O3 concentrations are high. In this study, we quantify the O3-induced adverse impacts on wheat and maize over the NCP and Shanxi province during 2013-2018 through the use of high-resolution air quality reanalysis dataset and land-use dataset. Results show that the accumulated hourly O3 concentration above 40 ppb (AOT40) in croplands experienced an upward trend, with an annual increase of 2.2 ppm h (18.1%) during the wheat growing period and 1.5 ppm h (10.9%) during the maize growing period from 2013 to 2018. O3-induced relative yield losses grew from 17.9% in 2013 to 38.6% in 2018 for wheat, and ranged from 7.5 to 11.9% for maize. The estimated crop production losses also increased over time. Shandong and Hebei provinces are the hot spots of crop losses and priorities should be given to them for O3 pollution prevention. Comparison with previous studies shows that uncertainties still exist in crop loss estimations. More rural O3 measurements and localized crop exposure-response experiments should be performed for better assessments.