Abatement of greenhouse gas and ammonia emissions from storage and land application of dairy manure.

摘要

Manure management contributes 8.4% of anthropogenic methane emissions (USEPA, 2015). It is extremely likely that greenhouse gas emissions including methane are correlated to an increase in global temperatures and sea level over the past century. Additionally, livestock contributes and estimated 71% of ammonia emissions and ammonia is a precursor to particulate matter which can decrease visibility and affect human health (Roe, Spivey, Lindquist, Thesing, & Strait, 2004). Therefore, to reduce future long term environmental and health complications it crucial that gaseous emissions from the production dairy are reduced. Experiments were conducted to evaluate potential mitigation strategies to reduce greenhouse gas (GHG) and ammonia (NH3) emissions from dairy manure. Results from the first experiment on the impacts of manure processing on GHG and NH3 from the storage and land application of dairy manure revealed that anaerobic digestion (AD) and solid liquid separation (SLS) significantly reduce GHG emissions. AD and SLS reduced GHG from untreated manure slurries by 34% and 22%, respectively; however, AD increases NH 3 emissions by 81%. A second experiment quantified the impacts of manure additives, including More Than Manure(TM) (MTM(TM)), Pro-Act, and biochar, on manure solids, gaseous nitrogen losses, and GHG emissions. No treatments were able to reduce manure solids or gaseous nitrogen losses. Biochar was the only manure treatment to impact any manure characteristics, where the total ammonical nitrogen (TAN) was significantly greater than the control at day 14 (p=0.012). In a third experiment, raw wood (white birch, Betula papyrifera), steam treated wood, wood biochar, and corn cob biochar were investigated for their potential to reduce NH3 emissions from digested manure storages. In order to guide application strategies and better understand the mechanisms for mitigation, treatments were incorporated in the manure or applied as a cover and the TAN sorption was measured using extraction techniques. All biomass treatments reduced emissions of NH 3 from the control by 40% to 96%. The highest NH3 emissions reductions were achieved with the wood biochar cover due to its ability to effectively cover the manure. Sorption results indicate that only a very small portion of the biomass mitigation potential was due to sorption and the main mechanism for NH3 reduction was the ability to act as a physical barrier. Future research should assess the GHG and NH3 reduction potential of coupling AD, SLS, and a biochar cover in a long term field trial.