Decline in atmospheric nitrogen deposition in China between 2010 and 2020

Abstract

The deposition of atmospheric nitrogen sourced from emissions has broad environmental consequences, but long-term measurements of recent air pollution control and nitrogen management effectiveness in China are rare. Here we report measurements from a ground-based monitoring network that show a 14% decline in the rate of nitrogen deposition over China from 2010 to 2020, including a 34% decrease in oxidized nitrogen (mainly industrial) and a 10% decline in reduced nitrogen (mostly agricultural) with larger declines over eastern China. The increasing ratio of reduced to oxidized nitrogen deposition (from 1.5 to 2.0 between 2010 and 2020) underscores the need for effective agricultural nitrogen management. Nitrogen deposition in China decreased by 14% between 2010 and 2020, with greater declines in nitrogen from industrial than agricultural sources, according to decadal observations of atmospheric deposition of different forms of reactive nitrogen.