Ammonia (NH₃) discharged from agricultural activities to the atmosphere plays a crucial role in the formation of secondary inorganic aerosols. This study analyzed the temporal-spatial development of agricultural NH₃ emissions from 2000 to 2018 in the Beijing–Tianjin–Hebei (BTH) region and assessed the effects of reducing PM_2.5 by removing agricultural NH₃ using an air quality model. The results showed that the interannual agricultural NH₃ emissions in the BTH region exhibited a stairs trend from 2000 to 2018, with an average of 971.63 Gg. In particular, agricultural NH₃ emissions in the BTH region reached a maximum in summer when the temperature was high and were more concentrated in the southern plains compared to the northern areas. Under the reduction scenario (RS), the agricultural NH₃ emissions in the BTH region in 2015, 2016, 2017, and 2018 were reduced by 2.95%, 4.10%, 18.75%, and 10.21%, resulting in a reduction of 0.5%, 0.5%, 2.5%, and 1.2% of annual mean PM_2.5 concentration, respectively, compared with the baseline scenario (BS). Furthermore, agricultural NH₃ emissions contributed 12.6, 12.1, 11.9, and 11.3 μg m⁻³ to PM_2.5 concentrations in 2015, 2016, 2017, and 2018 under the zero-emission scenario (ZS), respectively. However, the contribution rates exhibited a slightly increasing trend from 20.5% in 2015 to 24.6% in 2018. These findings could provide a new understanding of agricultural NH₃ emission trends and their impacts on PM_2.5 concentration based on actual NH₃ mitigation ratios in recent years, thereby guiding the formulation of future control strategies.

从农业活动中排放到大气中的氨 (NH ₃ ) 在二次无机气溶胶的形成中起着至关重要的作用。本研究分析了2000 年至 2018 年京津冀 (BTH) 地区农业 NH ₃排放的时空变化，并使用空气质量模型评估了通过去除农业 NH ₃来减少 PM _2.5的效果。结果表明，2000-2018年京津冀地区农业NH ₃年际排放量呈阶梯状变化，平均为971.63 Gg。特别是，农业 NH ₃京津冀地区的排放在夏季高温时达到最大值，与北部地区相比，更集中在南部平原。在减排情景（RS）下，京津冀地区2015年、2016年、2017年和2018年的农业NH ₃排放量分别减少了2.95%、4.10%、18.75%和10.21%，从而减少了0.5%，与基线情景 (BS) 相比，年平均 PM _2.5浓度分别为0.5%、2.5% 和 1.2% 。此外，农业 NH ₃排放对PM _2.5贡献了 12.6、12.1、11.9 和 11.3 μg m ^-32015 年、2016 年、2017 年和 2018 年零排放情景（ZS）下的浓度。然而，贡献率呈现出从 2015 年的 20.5% 到 2018 年的 24.6% 的小幅上升趋势。这些发现可以提供对农业 NH ₃排放趋势及其对 PM _2.5浓度影响的新认识，基于最近的实际 NH ₃缓解率年，从而指导未来控制策略的制定。