The Extent of Manure Removal from Storages and Its Impact on Gaseous Emissions
Citation
Ngwabie, N.M., Gordon, R.J., VanderZaag, A., Dunfield, K., Sissoko, A., Wagner-Riddle, C. (2016). The Extent of Manure Removal from Storages and Its Impact on Gaseous Emissions. Journal of Environmental Quality, [online] 45(6), 2023-2029. http://dx.doi.org/10.2134/jeq2016.01.0004
Plain language summary
Oftentimes, when manure is removed from storage for field application there will be a small amount of manure left in storage. This remaining manure can introduce microorganisms to fresh manure loaded into the tank that can possibly kick-start methane (CH4), nitrous oxide (N2O), and ammonia (NH3) emissions. This study investigated the effects of this leftover manure on these emissions. Fresh manure was loaded into concrete tanks that were filled with varying amounts of leftover manure and emissions were monitored from these tanks. CH4 emissions were found to increase with higher levels of leftover manure from 0-20%. The leftover manure did not have any observable effects on N2O and NH3 emissions.
Abstract
Manure remaining in storage due to incomplete removal is a source of microbial inoculum that may affect methane (CH4), nitrous oxide (N2O), and ammonia (NH3) emissions during subsequent storage. Manure removal was studied by loading fresh manure into outdoor concrete tanks (10.6 m3) that contained previously stored manure (inoculum) at six levels (0, 5, 10, 15, 20, and 25%, with 0% representing an empty tank). Emissions were continuously measured for 6-mo storage periods (warm and cold seasons) using flow-through chambers. Fluxes during the warm season (average manure temperature at 80 cm depth, Tm = 17°C) were 25 times higher for CH4, 20 times higher for N2O, and 2.9 times higher for NH3 compared with the cold season (Tm = 4°C). Cumulative CH4 emissions increased linearly with the level of added inoculum in the cold season (r2 = 0.98). A similar linear increase was observed in the warm season from 0 to 20% inoculum (r2 = 0.91), after which a decrease in emissions was observed at 25%. Reducing inoculum from 15 to 5% reduced CH4 emissions by 26% in the warm season and 45% in the cold season. There was no clear effect of inoculum on N2O and NH3 emissions, suggesting that complete manure storage emptying does not alter their emissions.