|Todd, Richard - Rick|
Submitted to: Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)
Publication Type: Proceedings
Publication Acceptance Date: 6/1/2008
Publication Date: 6/29/2008
Citation: Rhoades, M., Auvermann, B., Cole, N.A., Todd, R.W., Parker, D., Caraway, E., Shuster, G., Spears, J. 2008. Ammonia concentration and modeled emission rates from a beef cattle feedyard. In: Proceedings of 2008 Annual International Meeting of the American Society of Agricultural and Biological Engineers International, June 29-July 2, 2008, Providence, Rhode Island. Meeting Presentation Paper Number 084445.
Interpretive Summary: Emissions of ammonia (NH3) from agriculture and industry can potentially have adverse effects on air quality. Because of the large quantities of nitrogen excreted in urine and feces, livestock feeding operations may emit significant quantities of ammonia. However, the quantities emitted, and the effects of environmental factors on these emissions, have not been studied extensively. In this study ambient NH3 concentrations were measured at a 25,000 head beef cattle feedyard during the spring and summer months of 2007. Ammonia concentrations were measured near the center of the feedyard at a sample height of 3.3 m using a chemiluminescence analyzer. Ammonia and weather data were entered into a computer model (backward Lagrangian Stochastic model: Windtrax 126.96.36.199), and emission rates were estimated. Mean ambient ammonia concentrations ranged from 0.498 to 0.702 and tended to be higher in summer than spring. Average daily ammonia flux ranged from 57.8 to 123.1 ug m**-2 sec**-1 (1,387 to 2,955 kg per day) and were similar in summer and spring. These emissions were 31 to 65% of total nitrogen fed. These flux estimates tend to agree with other data and indicate that environmental factors can affect ammonia emissions from feedyards.
Technical Abstract: Ambient NH3 concentrations were measured at a beef cattle feedyard during the spring and summer months of 2007. Concentrations were measured every five minutes, 24-hours per day at a sample intake height of 3.3 m using a chemiluminescence analyzer. On site weather data was collected concurrently. Applicable data were entered into a backward Lagrangian Stochastic model (Windtrax 188.8.131.52), and emission rates were estimated. Mean ambient concentrations for spring were 0.498, 0.597 and 0.568 ppm for March, April and May, respectively. Corresponding fluxes for March, April and May were 57.76, 123.10 and 86.34 ug m**-2 sec**-1, respectively. Summer mean concentrations were 0.684, 0.702 and 0.568 ppm for June, July and August, respectively. Summer fluxes were 85.27, 75.06 and 71.56 ug m**-2 sec**-1 for June, July and August, respectively.