ARS | Publication request: REDUCING IN-BARN AMMONIA EMISSIONS TO CONSERVE THE FERTILIZER NITROGEN VALUE OF DAIRY MANURE.

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 20, 2005
Publication Date: January 17, 2006
Citation: Powell, J.M., Misselbrook, T.H. 2006. Reducing in-barn ammonia emissions to conserve the fertilizer nitrogen value of dairy manure. In: Proceedings of the 2006 Wisconsin Fertilizer, Aglime & Pest Management Conference, January 17-19, 2006, Madison, Wisconsin. p. 211-215.

Technical Abstract: Only approximately 20 to 35% of the N (protein) fed to dairy cows is converted into milk. The remaining N is excreted in urine and feces. About three-fourths of the N in urine is in the form of urea. Urease enzymes, which are present in feces and soil, rapidly convert urea to ammonium. Ammonium can be transformed quickly into ammonia gas which can have detrimental impacts on natural ecosystems and human health. This paper provides an overview of several factors that impact ammonia losses from dairy barns, such as the type and amount of protein fed to dairy cows and the bedding used in tie-stalls, as well as the impact of ammonia loss on plant availability of manure N. Removal of excess protein from the cow's diet, selection of bedding (e.g. sand, straw) that separate feces and urine, covering manure storage, and incorporating manure in the field could potentially reduce ammonia N loss from about 115 to 30-40 lbs/cow/yr, a 65-70% reduction. This means an additional 70-80 lbs. N per cow would be available annually for application to field crops.