High-resolution inventory of emissions of atmospheric PM 10 from agricultural tillage and harvesting operations in China: historical trend, spatio-temporality, and optimization methodology

Atmospheric particulate matter (PM) from agricultural activities aggravates global, regional, and local air pollution. The detailed emission evaluation for major crops can be used to understand, predict, and control the release of atmospheric PM from or in agriculture. However, previous studies on sources of emissions from agricultural activities have tended to focus only on straw burning, livestock or fertilizer, etc. at a macro scale, such that there is a lack of spatial–temporal and high-resolution quantitative data on particulate emissions generated from typical farming and harvesting activities. In this study, we developed high-resolution emission inventory of atmospheric PM 10 generated as a result of tilling and harvesting in China using a crop emission factor–based approach, combining agricultural, meteorological, and soil information. Temporal, spatial, and historical features of agricultural PM 10 emission in China were analyzed, and an optimization methodology was proposed. The historical trends (1978–2015) for agricultural emissions have been increasing with rate of 4.3% per year for the period. The annual emissions from all agricultural operations were estimated to be 986.8kt in 2015. The contribution rate for tilling (51.0%) was higher than that for harvesting (39.0%) and planting (10.0%). The PM 10 emissions at the county level were all higher by 30.5% than those at the high-resolution scale. After correction, the decreases of M2 (optimization of soil texture), M3 (optimization of soil texture and moisture), and M4 (optimization of soil texture, soil moisture, and wind speed) were 52.3%, 82.5%, and 89.6%, respectively. These results indicate the soil texture and moisture are the main factors for the decrease of emissions. The high-resolution inventory of emissions of PM 10 due to farming practices and harvesting is helpful for assessing the impact of agricultural activities on regional air quality in China and providing a scientific basis for the development of pollution control measures in agriculture.