See more from this Session: Emissions From Confined Animal Feeding Operations
In agricultural emissions work, process-based models have been most widely applied to ammonia where important processes include urea hydrolysis, dissociation, diffusion, aqueous-gas partitioning, and mass transport to the atmosphere. Similar process models are now being applied to hydrogen sulfide and volatile organic compounds. Greenhouse gas emissions are often controlled by formation rather than emission processes. Enteric fermentation, nitrification, denitrification, and other microbial processes are modeled to predict the formation and release of methane and nitrous oxide.
Process-based models are being refined and made available in software tools for estimating emissions and evaluating mitigation strategies in animal production. Tools such as DeNitrifcation-DeComposition (DNDC) and Dairy Gas Emission Model (DairyGEM) focus on the emission of important compounds. The Integrated Farm System Model (IFSM) provides a more comprehensive model for estimating emissions along with leaching and runoff losses and farm economics. As these software tools develop, process-based modeling provides effective research and educational aids for guiding us toward more sustainable animal production systems.