As a major alkaline gas in the atmosphere, NH₃ significantly impacts atmospheric chemistry, ecological environment, and biodiversity. Gridded NH₃ emission inventories can significantly affect the accuracy of model concentrations and play a crucial role in the refinement of mitigation strategies. However, several uncertainties are still associated with existing NH₃ emission inventories in China. Therefore, in this study, we focused on improving fertilizer-application-related NH₃ emission inventories. We comprehensively evaluated the dates and times of fertilizer application to the major crops that are cultivated in China, improved the spatial allocation methods for NH₃ emissions from croplands with different rice types, and established a gridded NH₃ emission inventory for mainland China with a resolution of 5 min × 5 min in 2016. The results showed that the atmospheric NH₃ emissions in mainland China amounted to 12.11 Tg, with livestock waste (44.8 %) and fertilizer application (38.6 %) being the two main NH₃ emission sources in China. Obvious spatial variability in NH₃ emissions was also identified, and high emissions were predominantly concentrated in North China. Further, NH₃ emissions tended to be high in summer and low in winter, and the ratio for the July–January period was 3.08. Furthermore, maize and rice fertilization in summer was primarily responsible for the increase in NH₃ emissions in China, and the evaluation of the spatial and temporal accuracy of the NH₃ emission inventory established in this study using the WRF-Chem and ground-station- and satellite-based observations showed that it was more accurate than other inventories.