Carbon and air pollutant emission characteristics and cleanliness improvement measures for agricultural machinery in Beijing, 2022

Fuel-fired agricultural machinery is a significant source of carbon and pollutant emissions, and improving its cleanliness level is crucial for emissions reduction. We quantified the carbon and air pollutant emissions of agricultural machinery in Beijing in 2022 using the power-based emission factor method. We further applied the established cleanliness evaluation framework to assess the degree of agricultural machinery cleanliness, and finally put forward some optimization suggestions. The findings indicated that the emissions of VOCs, CO, NO_x, particulate matter (PM), and CO₂ from agricultural machinery in Beijing in 2022 were 220.8, 4 620.2, 1 228.5, 112.7 t, and 57.6 kt, respectively. Emissions exhibited strong seasonal variations, peaking during spring tillage (April-June) and autumn harvest (August-October) due to increased machinery usage. Spatially, emissions were concentrated in Daxing, Shunyi, Yanqing, Tongzhou, and Fangshan districts, accounting for over 71% of total emissions. The current cleanliness index of Beijing's agricultural machinery was 73, with outdated equipment comprising 45%, highlighting significant potential for improvement. To enhance the cleanliness level of agricultural machinery in Beijing, efforts should focus on accelerating the retirement of outdated machinery and promoting new energy-powered agricultural equipment through economic incentives. Scenario analysis suggested that under carbon neutrality goals, these measures could reduce carbon and pollutant emissions by 70%-84%. The results provide a scientific basis for the green transition of agricultural machinery in Beijing.