Gas emission flux rates from dairy sources using sand bedding

Total reduced sulfur (TRS), hydrogen sulfide (H₂S) and ammonia (NH₃) flux rates from four to six sources on eight dairy operations using sand bedding were measured three times using a wind-tunnel. Emissions flux rates and emissions rates for TRS, H₂S and NH₃ varied from source to source and farm to farm. TRS and H₂S flux rates were the highest from intermittent and continuous flow sand lanes and the reception pits at the ends of the continuous flow sand lanes. Cow manure alleys and piles of recycled sand consistently had the lowest TRS and H₂S flux rates. Sources with NH₃ emissions flux rates greater than 15 μg/m ²s included the solids and liquids manure basins on farms that did not recycle sand, liquid manure basins on farms with continuous flow sand lanes and manure basins on farms with intermittent sand lanes. Manure storages were generally the sources with the largest emissions rates of TRS, H₂S and NH₃. These sources usually had low flux rates but they often had the largest emitting surface areas. Both the continuous flow and intermittent flow sand lanes were important sources of TRS and H₂S emissions. They had small emitting surface area compared to other sources but larger flux rates. Cow manure alleys were important sources of NH₃ emissions.