/AnMtgsAbsts2009.53933 Impact of Various Biochars On Greenhouse Gas Production Potentials.

Wednesday, November 4, 2009: 3:15 PM
Convention Center, Room 335, Third Floor

Kurt Spokas, Soil and Water Management Research, USDA-ARS, St. Paul, MN and Donald Reicosky, USDA-ARS, Morris, MN
A potential abatement strategy to increasing atmospheric levels of carbon dioxide (CO2) is to sequester atmospheric CO2 into a more stable form through the use of pyrolysis. Biomass feed stocks are used to generate a more stable carbon form (biochar) that then can be returned to the soil sequestering atmospheric carbon into a slower cycling pool.  We evaluated the impacts of 16 different biochars from different processes and feed stock materials (corn stover, peanut hulls, algae, wood chips, and turkey manure plus wood chips) as well as an activated coconut shell charcoal on net CO2, methane (CH4) and nitrous oxide (N2O) production potentials through 100 day laboratory incubations with three differing soils at a variety of soil moisture contents.  There was CO2 production from all the biochars, which is highly variable across the various materials and production processes.  This production needs to be accounted for determining the impact of the soil+biochar system.  There was no observable sorption, degradation, oxidation or production of CH4 or N2O during the 100 day incubation of solely the biochar with and without water additions.  Following correction for the CO2 production from the biochar alone, biochar additions in soil generally suppress CO2 and N2O production (5-100% reduction in N2O production).  Biochar amendments universally suppressed CH4 oxidation capacities (25 to 100% reduction) in laboratory incubations across various soil types.  The impacts on reductions in N2O production are moisture dependent, with greater reduction being observed at higher moisture contents. However, there is still significant suppression in the production of N2O at field capacity from biochar additions.