Special TECHNICAL Submissions REPORTS
Emissions of Ammonia, Methane, Carbon Dioxide, and Nitrous Oxide from Dairy Cattle Housing and Manure Management Systems April B. Leytem,* Robert S. Dungan, David L. Bjorneberg, and Anita C. Koehn USDA–ARS Concentrated animal feeding operations emit trace gases such as ammonia (NH3), methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). The implementation of air quality regulations in livestock-producing states increases the need for accurate on-farm determination of emission rates. The objective of this study was to determine the emission rates of NH3, CH4, CO2, and N2O from three source areas (open lots, wastewater pond, compost) on a commercial dairy located in southern Idaho. Gas concentrations and wind statistics were measured each month and used with an inverse dispersion model to calculate emission rates. Average emissions per cow per day from the open lots were 0.13 kg NH3, 0.49 kg CH4, 28.1 kg CO2, and 0.01 kg N2O. Average emissions from the wastewater pond (g m-2 d-1) were 2.0 g NH3, 103 g CH4, 637 g CO2, and 0.49 g N2O. Average emissions from the compost facility (g m-2 d-1) were 1.6 g NH3, 13.5 g CH4, 516 g CO2, and 0.90 g N2O. The combined emissions of NH3, CH4, CO2, and N2O from the lots, wastewater pond and compost averaged 0.15, 1.4, 30.0, and 0.02 kg cow-1 d-1, respectively. The open lot areas generated the greatest emissions of NH3, CO2, and N2O, contributing 78, 80, and 57%, respectively, to total farm emissions. Methane emissions were greatest from the lots in the spring (74% of total), after which the wastewater pond became the largest source of emissions (55% of total) for the remainder of the year. Data from this study can be used to develop trace gas emissions factors from open-lot dairies in southern Idaho and potentially other open-lot production systems in similar climatic regions.
Copyright © 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. J. Environ. Qual. doi:10.2134/jeq2009.0515 Published online 15 June 2010. Received 23 Dec. 2009. *Corresponding author (
[email protected]). © ASA, CSSA, SSSA 5585 Guilford Rd., Madison, WI 53711 USA
T
he state of Idaho has experienced rapid growth of the dairy industry in the past decade, with the number of milk cows increasing approximately 88% and milk production increasing 114% (USDA National Agricultural Statistics Service, 2007). In 2006, there were 477,193 milking cows in Idaho, with 71% of these being located in the Magic Valley region of southern Idaho (UDI, 2007). Although this region has benefited economically from the growth of the dairy industry, there is concern regarding the impact of concentrated dairy production facilities on the environment, particularly emissions of ammonia (NH3), methane (CH4), and nitrous oxide (N2O). In the atmosphere, NH3 primarily reacts to form ammonium sulfate and ammonium nitrate aerosols, which contribute to particulate matter with an aerodynamic diameter
