Total ammonia nitrogen (TAN) as a tool for estimating NH3 emissions in manure management of dairy herds

Abstract

Livestock farming is one of the human activities with the greatest environmental impact due to the significant contribution of greenhouse gases (GHG) throughout its production chain. Although the main GHG emitted are carbon dioxide, methane, and nitrous oxide, ammonia (NH₃) plays a crucial role in climate change as the primary gas that acidifies precipitation and damages various ecosystems. One of the main sources of this gas is cattle manure, which is why annual emissions were estimated in five different herds using the European Environment Agency (EEA) methodology. The contribution of ammonia-nitrogen (NH₃-N) was calculated at each stage of manure management evaluated. The results show considerable differences in the amount of NH₃ emitted per herd, mainly due to the amount of nitrogen (N) provided in the feed. On the other hand, soil application was identified as the most significant source of NH₃ emissions among the evaluated manure management stages, contributing over 50% of the total emissions across all analyzed herds. In conclusion, these values ​​provide insight into NH₃ emissions in the different herds, their relationship to feed nitrogen, and the contribution of manure management stages to atmospheric emissions.