The underappreciated role of agricultural soil nitrogen oxide emissions in ozone pollution regulation in North China

• Published in: Nature communications Vol. 12; no. 1; pp. 5021 - 9
• Main Authors: Lu, Xiao, Ye, Xingpei, Zhou, Mi, Zhao, Yuanhong, Weng, Hongjian, Kong, Hao, Li, Ke, Gao, Meng, Zheng, Bo, Lin, Jintai, Zhou, Feng, Zhang, Qiang, Wu, Dianming, Zhang, Lin, Zhang, Yuanhang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.08.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 704/172/169/824; 704/172/4081; Agricultural land; Air pollution; Air quality; Anthropogenic factors; Atmospheric chemistry; Atmospheric models; Combustion; Emissions; Emissions control; Environmental regulations; Fertilizer application; Fuel combustion; Humanities and Social Sciences; Intensive farming; Life Sciences; multidisciplinary; Nitrogen; Nitrogen oxides; Outdoor air quality; Ozone; Parameterization; Photochemicals; Pollutants; Pollution control; Science; Science (multidisciplinary); Sciences of the Universe; Soil investigations; Soil pollution; Soils; China
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-25147-9

Intensive agricultural activities in the North China Plain (NCP) lead to substantial emissions of nitrogen oxides (NO x ) from soil, while the role of this source on local severe ozone pollution is unknown. Here we use a mechanistic parameterization of soil NO x emissions combined with two atmospheric chemistry models to investigate the issue. We find that the presence of soil NO x emissions in the NCP significantly reduces the sensitivity of ozone to anthropogenic emissions. The maximum ozone air quality improvements in July 2017, as can be achieved by controlling all domestic anthropogenic emissions of air pollutants, decrease by 30% due to the presence of soil NO x . This effect causes an emission control penalty such that large additional emission reductions are required to achieve ozone regulation targets. As NO x emissions from fuel combustion are being controlled, the soil emission penalty would become increasingly prominent and shall be considered in emission control strategies. Summertime ozone air pollution in North China remains severe. Here the authors find large biogenic emissions of nitrogen oxides in North China, mainly driven by fertilizer application, challenge the mitigation of ozone pollution by only reducing combustion induced ozone precursors’ emissions.