Driving forces of agricultural ammonia emissions in semi-arid areas of China: a spatial econometric approach

Abstract

Ammonia emissions contribute to PM_2.5 formation, posing significant threats to public health, including respiratory and cardiovascular diseases, and causing various ecological issues, such as soil and water acidification. This study investigates ammonia emissions in the semi-arid region of central Gansu Province, China, by establishing a county-level agricultural ammonia emission inventory for 2014–2020 using the emission factor method. A spatial econometric model, integrated with the STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) model, is employed to identify key drivers of emissions. This approach is crucial because it accounts for the spatial dependencies of emissions across regions and incorporates socio-economic factors, providing a more comprehensive understanding of emission patterns. Results indicate that livestock and poultry farming (58.76%) and nitrogen fertilizer application (37.73%) are major contributors to ammonia emissions. Regional agricultural ammonia emissions are concentrated in the east, river basins, and parts of the southwest. The study also reveals positive spatial clustering and spillover effects of ammonia emissions. In the central region of Gansu Province, a 1% increase in per capita GDP, population, agricultural structure, and rural electricity consumption leads to changes in agricultural ammonia emissions of 0.059%, -1.181%, -0.109%, and 0.133%, respectively. Rural electricity consumption, population dynamics, and agricultural structure improvements influence not only locally but also across neighboring regions. The findings emphasize the need for targeted, collaborative regional strategies to mitigate emissions and underscore the importance of considering spatial interactions in emission reduction policies.