Do volatile solids from bedding materials increase greenhouse gas emissions for stored dairy manure?
Citation
Riche, E.L.L., Vanderzaag, A.C., Wagner-Riddle, C., Dunfield, K., Sokolov, V.K., Gordon, R. (2016). Do volatile solids from bedding materials increase greenhouse gas emissions for stored dairy manure?. Canadian Journal of Soil Science, [online] 97(3), 512-521. http://dx.doi.org/10.1139/cjss-2016-0119
Plain language summary
Several different types of bedding materials are used for dairy cattle. However, current estimating methods for emissions from liquid manure storages do not take into consideration the bedding material. A comparison between emissions from a sand bedding slurry and a wood bedding slurry was performed to assess the impacts of bedding. The sand bedding slurry did not form a crust and there were higher levels of ammonia volatilization losses. The wood bedding slurry had much higher GHGs emissions compared to the sand bedding slurry. This difference was reduced if only the first 123 days (out of 207 days) of storage was considered, presumably due to the slow degradability of the wood bedding. From these results, bedding choice should be considered when making GHG estimates from liquid manure storages.
Abstract
Current approaches for estimating greenhouse gas (GHG) emissions from manure storages do not consider contributions due to bedding materials. Compared with sand, wood-based bedding has the potential to increase volatile solids and total solids concentrations and favour crust formation in liquid dairy manure. In this study, the GHG emissions from wood and sand bedding slurries were evaluated monitored continuously for 207 d (1 May–24 Nov. 2014) under “warm season” storage conditions. For both slurries, methane (CH4) made up >95% of the GHG emissions. The sand bedding slurry had minimal crust, which also led to more evaporation and higher ammonia volatilization losses when scaled by nitrogen content. The wood bedding slurry emitted 51% more CH4, eight times more nitrous oxide, and 53% more total GHG emissions (CO2 -eqivalents). However, these differences were reduced if only the initial 123 d (1 May–31 Aug. 2014) of storage was considered. This was presumably related to the slower degradability of the wood bedding. Given these differences bedding choice should be considered in GHG emissions estimates.