Federal researchers say a new study—conducted in Idaho—has quantified for the first time just how much ammonia, methane and nitrous oxide are released into the atmosphere from dairy operations.
The study, published by the University of Idaho, focused on three dairies, varying in size, animal housing and manure handling systems. One of the facilities was a small open-lot dairy (700 cows), another was a large open-lot dairy (10,000 cows) and a third was a large open-freestall dairy (10,000 cows) with an anaerobic digester.
The study says "the impact of these production systems on regional air quality and potential impacts on climate change via greenhouse gas emissions has become a concern."
As expected, the researcher found that emissions increased throughout the day as temperature, wind speed and animal activity increased. Ammonia emissions from the animal housing areas were greatest when temperatures were rising and lot conditions were wetter.
The researchers say their next step is to identify management strategies to reduce on-farm emissions.