The Power of Planting Less: How China’s Farm Rules Cut Two Big Polluters

China has been working hard to lower two harmful gases from farms: ammonia (NH₃) and nitrous oxide (N₂O). These gases hurt the air we breathe and speed up climate change. Scientists built a new model that blends detailed data on farm emissions with real policy plans to see how well China’s rules are working from 2000 to 2022. The results show a clear win. Both gases hit their highest levels around 2015, then dropped by 16 % for ammonia and 30 % for nitrous oxide by 2022. The biggest reason for this drop is the country’s focus on cutting fertilizer use. Those policies now account for about nine‑tenths of all emissions reductions and have made the combined effect of cutting both gases almost six times stronger than before.Other ideas, like better handling of animal poop or turning leftover straw into useful products, did not make a big difference overall. In some areas that are not mainly livestock farms, these measures started to help both gases at the same time after 2015. Still, the overall impact of these extra measures is small compared to fertilizer cuts. If farmers adopt a complete system that looks at every step of animal production—from feeding to manure storage—China could flip the small negative trade‑offs into a big positive. In short, smarter livestock management can reach the same level of joint success as cutting fertilizer use. The study highlights that China’s farm policies are not just about one gas. By thinking about both ammonia and nitrous oxide together, the country can make its air cleaner faster while staying on track with climate goals.