Author
GACENGO, C - AUBURN UNIVERSITY | |
WOOD, C - AUBURN UNIVERSITY | |
SHAW, J - AUBURN UNIVERSITY | |
RAPER, RANDY | |
Balkcom, Kipling |
Submitted to: Soil Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/4/2009 Publication Date: 4/1/2009 Citation: Gacengo, C.N., Wood, C.W., Shaw, J.N., Raper, R.L., Balkcom, K.S. 2009. Agroecosystem management effects on greenhouse gas emissions across a Coastal Plain Catena. Soil Science. 174(4):229-237. Interpretive Summary: Landscape variability affects soil properties that influence soil respiration and subsequent trace gas emissions, but limited data exists on greenhouse gas emissions as influenced by landscape variability and agroecosystem management in southeastern US. Scientists from Auburn Univ. in cooperation with scientists from USDA-ARS located at the National Soil Dynamics Laboratory in Auburn, AL initiated a study to evaluate effects of landscape variability and agroecosystem management on methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions on a Coastal Plain catena in AL. Agroecosytem management strategies consisted of 1) conventional tillage (CT), 2) conservation tillage (CsT), 3) CT with dairy manure (CTM) and 4) CsT with dairy manure (CsTM) on a corn-cotton rotation replicated on the summit, sideslope and drainageway landscape position. Generally, gas fluxes were more influenced by management strategies than terrain attributes. Technical Abstract: Landscape variability influences soil properties that influence soil respiration and subsequent trace gas emissions. Scarcity of data on greenhouse gas emissions as influenced by landscape variability and agroecosystem management in southeastern US necessitates study. The objective of this study was to evaluate effects of landscape variability and agroecosystem management on methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) emissions on a Coastal Plain catena (Typic, Oxyaquic, and Aquic Paleudults) in AL. Soil management strategies included 1) conventional tillage (CT), 2) conservation tillage (CsT), 3) CT with dairy manure (CTM) and 4) CsT with dairy manure (CsTM) on a corn (Zea mays L.)-cotton (Gossypium hirsutum L.) rotation. Each soil management treatment was replicated on summit, sideslope and the drainageway landscape position. Gas measurements were conducted using a closed chamber method. The drainageway emitted 46, 251, 59, and 185mg CH4-C ha-1 h-1 from CT, CTM, CsT and CsTM treatments, respectively. The summit position had fluxes of -59 and -90 mg CH4-C ha-1 h-1 on CT and CsT treatments, respectively. However, dairy manure application converted the summit landscape to a CH4 emitter, with 8 and 311 mg CH4-C ha-1h-1 from CT and CsT, respectively. Averaged across seasons, CT and CsT N2O fluxes were similar (547 and 437 mg N2O-N ha-1 h-1, respectively) in the drainageway landscape position. Winter 2005 CO2 emission from CsT treatments (averaged across landscape positions) was 1304 g CO2-C, compared to 227 g ha-1 h-1 CO2-C from CT treatments. Generally, gas fluxes were more influenced by tillage than terrain attributes. |