The researchers studied how different amounts of nitrogen fertilizer and water nitrogen content in paddy fields affect the release of ammonia gas. They found that higher nitrogen fertilizer application led to more ammonia gas being released, with the most being released in the first few days after fertilization. The amount of ammonia gas released increased with higher nitrogen application rates. The nitrogen loss through ammonia gas ranged from 29.4% to 38.0% of the applied fertilizer. The levels of different nitrogen forms in the field water were closely related to the amount of ammonia gas released. To reduce ammonia gas emissions, better fertilizer techniques like using organic materials and controlled-release fertilizers are needed in purple soil hilly districts.