Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 4, 2004
Publication Date: October 5, 2004
Citation: Todd, R.W., Cole, N.A., Harper, L.A., Flesch, T.K., Clark, R.N. 2004. Flux-gradient estimates of ammonia emissions from a beef cattle feedyard [abstract]. Agronomy Abstracts, ASA-CSSA-SSSA Annual Meeting, Seattle, Washington. 2004 CDROM. Technical Abstract: The Panhandle of Texas is a major cattle-feeding region, producing almost a third of U.S. fed cattle. These concentrated feeding operations are a source of ammonia to the atmosphere, but the magnitude of emissions is uncertain. Fugitive ammonia can negatively impact sensitive terrestrial and aquatic ecosystems, and understanding its source contributions and strengths is needed to control or regulate emissions. The objective of this study was to determine the magnitude and seasonal variation of ammonia emissions from a commercial beef cattle feedyard. Research was conducted during two winter and two summer campaigns. Profiles of windspeed, air temperature, and ammonia concentration were measured. The flux-gradient method was used to estimate emissions. Winter emissions averaged 1030 +/- 110 kg ND3-N/d in 2003 and 3430 +/- 1200 kg NH3-N/d in 2004. Summer emissions averaged 2100 +/- 260 kg NH3-N/d in 2002 and 5020 +/- 925 kg NH3-N/d in 2004. Daily mean flux ranged from 15 to 82 ug/m2/s during the winter, and from 30 to 106 ug/m2/s during the summer.