Quzhou county is a county in the North China Plain with intensive agricultural production. Based on data collected on the local anthropogenic activity level and the ammonia (NH3) emission factor, the anthropogenic NH3 emission inventory in Quzhou county from 2002 to 2019 was established using the emission factor method, and the NH3 emission inventory in 2019 was optimized using the locally measured nitrogen (N) fertilizer application NH3 emission factor and activity data from farmer surveys. We found that the total NH3 emission in Quzhou county showed a bimodal pattern: it increased from 6682.9 t in 2002 to 7195.0 t in 2004 and then decreased to 5872.0 t in 2008. The second peak occurred in 2015 (7010.5 t) and then gradually decreased to 5636.3 t in 2018. Livestock husbandry (61%-75%) and N fertilizer application (14%-28%) were the primary NH3 emission sources. In 2019, the total NH3 emission in Quzhou county was 6559.7 t, of which N fertilizer application and livestock husbandry contributed 28% and 61%, respectively. Wheat planting contributed the highest NH3 emissions, accounting for 40% of the total NH3 emission of crop production. Laying hens had the largest NH3 emission in livestock production, contributing 40% of the total emissions. NH3 emissions were higher in the south than those in the north at the county level, with the average NH3 emission intensity reaching 13.5 t·km-2. Nanliyue and Baizhai towns were hot spots of NH3 emission. Taken together NH3 emission reduction in wheat production and layer hen breeding will help to control atmospheric NH3 pollution in the North China Plain.
Keywords: Quzhou county; air pollution; ammonia; emission factor; emission inventory.