Landscape-scale greenhouse gas emissions and their key controlling factors in conservation and standard till agroecosystems. (6089)
Authors:
J. Lee* - UC Davis J. Six - UC Davis A.E. Patrick - UC Davis J. Evatt - UC Davis D.E. Rolston - UC Davis C. Van Kessel - UC Davis
Abstract:
We determined the singular and interactive effects of soil texture, soil moisture and tillage on the flux of CO2, N2O, and CH4 in order to understand differences in greenhouse gas emissions at different spatial scales under conservation and standard tillage systems. We quantified the spatial variability of controlling factors on GHG emissions across a farmer’s fields. In 2004, 40 soil cores were taken to a depth of 0-15 cm at regular spatial intervals along two 360-m transects which represented a range of variation in soil texture and moisture. The cores were incubated at 25ºC at field moist state for 15 days, and then were brought up to 60% of water holding capacity and incubated again for additional 15 days.
During the incubation, all three biogenic GHGs (CO2, N2O, and CH4) were measured. Before and after the incubation, the cores were analyzed for soil C and N associated with particulate organic matter fractions and other soil properties.
Speaker Information: Juhwan Lee, UC Davis, 410 Russell Park #3, Davis, CA 95616; Phone:
530-752-3457; E-mail: [email protected]
Session Information: Wednesday, November 3, 2004, 10:00 AM-12:00 PM Presentation Start: 10:00 AM (Poster Board Number: 1855)
Keywords: greenhouse gas emissions; tillage; carbon and nitrogen sequestration; agroecosystem