[Emission Inventory and Distribution Characteristics of Anthropogenic Ammonia in Quzhou County, North China Plain]

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.