Premium
Methane Oxidation in Slurry Storage Surface Crusts
Author(s) -
Petersen S⊘ren O.,
Amon Barbara,
Gattinger Andreas
Publication year - 2005
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.455
Subject(s) - slurry , methane , crust , manure , environmental chemistry , liquid manure , organic matter , anaerobic oxidation of methane , chemistry , biogas , incubation , geology , environmental science , environmental engineering , agronomy , geochemistry , ecology , biology , biochemistry , organic chemistry
Livestock manure is a significant source of atmospheric methane (CH 4 ), especially during liquid storage. In liquid manure (slurry) storages a surface crust may form naturally, or an artificial surface crust can be established. We investigated whether there is a potential for CH 4 oxidation in this environment. Surface crust materials were sampled from experimental storages with cattle slurry (with natural crust) or anaerobically digested cattle slurry (with straw layer) that had been stored with or without a wooden cover. Extracts of surface crust material were incubated with 5.6% CH 4 in the headspace, and methanotrophic activity was demonstrated in all four treatments following a 4‐ to 10‐d lag phase. Subsequent incubation of field‐moist surface crust material with 350 μL L −1 CH 4 also showed CH 4 oxidation, indicating a potential for CH 4 removal under practical storage conditions. There was no CH 4 oxidation activity during incubation of autoclaved samples. Methane oxidation rates were 0.1 to 0.5 mg kg −1 organic matter (OM) h −1 , which is comparable with the activity in wetlands and rice paddies. Partial drying increased CH 4 oxidation to 0.2 to 1.4 mg kg −1 OM h −1 , probably as a result of improved diffusivity within the surface crust. Rewetting reversed the stimulation of methanotrophic activity in some treatments, but not in others, possibly due to a decline in CH 4 production in anaerobic volumes, or to growth of methanotrophs during incubation. This study presents direct evidence for methanotrophic activity in slurry storages. Measures to ensure crust formation with or without a solid cover appear to be a cost‐effective greenhouse gas mitigation option.