Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/26/2006
Publication Date: 6/27/2006
Citation: Gacengo, C.N., Wood, C.W., Shaw, J.N., Balkcom, K.S., Raper, R.L. 2006. Effect of Soil Management and Landscape Position on CH4, N2O, and CO2 Fluxes. In: Schwartz, R.C., Baumhardt, R.L., and Bell, J.M., editors. Proceedings of the 28th Southern Conservation Systems Conference, June 26-28, 2006, Amarillo, Texas. USDA-ARS Conservation and Production Research Laboratory, Report No. 06-1, Bushland, Texas. p. 132.
Technical Abstract: Knowledge of interactive effects of agricultural soil management and landscape variability on greenhouse gas emissions is necessary for soil organic carbon sequestration efforts. This study evaluates the effects of tillage, dairy manure and landscape position on nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2) emissions from a corn (Zea may L.)-cotton (Gossypium hirsutum L.) rotation. Gas samples were collected seasonally using a closed chamber method on a field-scale experiment near Shorter, AL, in spring 2004 through winter 2005. Treatments included conservation tillage (CsT) and conventional tillage (CT) with or without dairy manure (DM) application distributed over three landscape positions: drainageway, sideslope, and upland. In spring 2004, tillage, landscape variability, and DM significantly influenced total methane emission (p=0.0361), with DM increasing total methane emission on sideslopes by 20%. Mean CO2 fluxes were significantly different among treatments (p= 0.0255). Dairy manure decreased CO2 flux on upland CT and sideslopes CsT treatments by 10% and 20% respectively, while it increased the flux on concave CsT treatment by 20%. In winter 2005, CO2 flux was in the order upland>sideslope>drainageway. Nitrous oxide flux was significantly different among treatments only in spring 2004 (p= 0.0001). Dairy manure increased N2O flux on upland CT treatment by 10%. Nitrous oxide flux was in the order upland>drainageway>sideslope. Adopting CsT in spring through fall can decrease CO2 and N2O emissions in these agricultural systems; however, CsT may increase winter CO2 fluxes. It is apparent that soil management and landscape position interact to control greenhouse gas emissions from agricultural fields. [GRACEnet Publication]