Methane emissions from stored liquid dairy manure in a cold climate

• Published in: Animal feed science and technology 2011-06, Vol.166, p.581-589
• Main Authors: VanderZaag, A.C, Wagner-Riddle, C, Park, K.-H, Gordon, R.J
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; carbon dioxide; cold zones; dairy manure; Emission factor; emissions; Feed and pet food industries; feeds; Food industries; foods; Fundamental and applied biological sciences. Psychology; global warming; greenhouse gases; Liquid dairy manure; manure storage; Methane; Micrometeorological mass balance; thawing
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/j.anifeedsci.2011.04.041

Climate change has been linked to increasing concentrations of greenhouse gases including CH₄, which has a global warming potential 25 times greater than CO₂. Stored liquid animal manure is an important emissions source of CH₄ globally and in Canada. As part of ongoing efforts to mitigate CH₄ emissions, it may be beneficial to obtain field scale flux estimates which can be used to verify CH₄ emission factors. The objective of this study was to measure CH₄ fluxes from a liquid dairy manure storage tank and compare measured fluxes with predicted values using US EPA methodology. Fluxes were measured from a circular concrete tank 11.25m in diameter storing liquid dairy manure in Bright, Ontario, Canada. Measurements were conducted semi-continuously from January through July 2003, using a tunable diode laser and the non-interfering micrometeorological mass balance method. Monthly average CH₄ flux ranged from 11μg/m²/s in June after the tank had been emptied, to 153μg/m²/s in July. Large bubble flux events occurred in February and March that coincided with surface thawing. Predicted emissions using the US EPA approach with carryover of volatile solids showed overestimation unless a substantial correction factor was used. In contrast, if volatile solids were not carried over, predicted fluxes had acceptable agreement with measurements. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture - Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors: K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.