An Emission Model for Regional Biogenic Oxygenated Volatile Organic Compounds from Crops

Biogenic oxygenated volatile organic compounds (BOVOCs), including methanol (CH₃OH), are mainly released from vegetation and soil microbes in terrestrial ecosystems. Cropland is an important emission source of methanol to the environment. Wheat, as one of the large-methanol-emitters among fast-growing crops in Canada, was selected for this study. There are still few studies on modelling regional BOVOC emissions from crops using empirical models. An emission model was updated to estimate the net methanol emission from wheat in Saskatchewan in this study. Overall, the mean methanol emission rates were 52 μg m⁻² h⁻¹. They have no obvious spatial variations but significantly changed among different months. These spatial and temporal differences are closely correlated with air temperature, solar radiation, and leaf development. This study seeks to evaluate methanol emissions during different wheat developmental stages. The results can be used to develop an appropriate strategy for regional emission management, such as crop selection considering the ratio of leaf biomass to VOC emission.