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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #329115
Title: Greenhouse gas and ammonia emissions from digested and separated dairy manure during storage and after land application

Author
item Holly, Michael
item LARSON, REBECCA - University Of Wisconsin
item Powell, Joseph
item RUARK, MATTHEW - University Of Wisconsin
item AGUIRRE-VILLEGAS, HORACIO - University Of Wisconsin

Submitted to: Agriculture Ecosystems and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2017
Publication Date: 2/13/2017
Citation: Holly, M.A., Larson, R.A., Powell, J.M., Ruark, M.D., Aguirre-Villegas, H. 2017. Greenhouse gas and ammonia emissions from digested and separated dairy manure during storage and after land application. Agriculture Ecosystems and the Environment. 239:410-419.

Interpretive Summary: Some manure management methods have a strong potential for reducing greenhouse gas and ammonia emissions from dairy farms. Most manure on large-scale dairy farms is stored in lagoons or separated into liquids and solids prior to land application. Some farms also use anaerobic digestion which captures manure gases and creates energy. This study evaluated the effects of anaerobic digestion, solid-liquid separation, and the two combined on gas emissions during manure storage through land application. Compared to untreated manure, anaerobic digestion and solid-liquid separation reduced methane and carbon dioxide emissions by 34% and 22%, respectively. However anaerobic digestion increased ammonia emissions by 181% during storage. The two methods combined decreased methane emissions by 66%, but increased nitrous oxide emissions by 330% during storage. If manure is incorporated during land application, anaerobic digestion and solid-liquid separation greatly reduce gas emissions from storage through land application. This information is useful to dairy producers, service providers and policy makers when assessing the relative benefits and tradeoffs in manure management systems.

Technical Abstract: Manure management at dairy production facilities, including anaerobic digestion (AD) and solid-liquid separation (SLS), has a strong potential for the abatement of greenhouse gas (GHG) and ammonia (NH3) emissions. This study evaluated the effects of AD, SLS, and AD+SLS on GHG and NH3 emissions during manure storage through land application over nine months. AD and SLS significantly (P < 0.05) reduced GHG emissions, mostly in the form of methane (CH4) and carbon dioxide (CO2), compared to untreated manure slurries by 34% and 22%, respectively. AD resulted in a gas emission tradeoff as it increased NH3 emissions by 181% during storage. Digested manure with subsequent separation decreased CH4 emissions from 3.9 g CO2-eq to 1.3 g CO2-eq, but increased emissions of nitrous oxide (N2O) from 0.6 g CO2-eq to 2.0 g CO2-eq during storage. Results indicate that if manure is incorporated during land application, integrating AD or SLS in manure systems at dairy operations greatly reduces GHG contributions from storage through land application.