Submitted to: American Society of Agronomy Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2009
Publication Date: 2/1/2009
Citation: Nyakatawa, E., Mays, D., Way, T.R., Watts, D.B., Torbert Iii, H.A., Smith, D.R. 2009. Tillage and Fertilizer Effects on Soil Methane and Nitrous Oxide Emissions. In: Agronomy Abstracts, Southern Branch ASA, Madison, Wisconsin. CDROM.
Technical Abstract: Agricultural soil is a source of greenhouse gases such as methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2). An experiment was conducted to determine effects of tillage system, fertilizer type, and fertilizer application method on emissions of these three gases. Corn was grown on a silt loam soil in north-central Alabama and the two tillage systems were conventional tillage (CT) and no-till (NT) which included growing a wheat cover crop. The two fertilizer treatments were poultry litter (PL) and ammonium nitrate fertilizer (AN), and the two levels of fertilizer were 0 and 150 kg N/ha. The three methods of applying fertilizer were broadcast surface application (SA), subsurface band application (BA), and soil incorporation (SI). Greenhouse gas fluxes were measured from April through July, 2008. Net positive soil methane fluxes were found in conventional tillage plots with soil incorporation of ammonium nitrate fertilizer (CT-AN-SI) and in no-till plots with surface application of poultry litter (NT-PL-SA). Net positive soil nitrous oxide fluxes were obtained in plots under NT-PL-BA, CT-AN-SI, CT-AN-SA, CT-PL-SI, NT-AN-SA, and CT-PL-SA treatments. All treatments were net emitters of soil carbon dioxide and the top three fluxes were in plots under NT-PL-BA, CT-PL-BA, and NT-PL-SA treatments. The three treatments with the lowest soil carbon dioxide fluxes were in grass fallow, NT-0-0, and CT-AN-SA plots. These results are expected to be useful in developing soil, crop, and animal waste management strategies to minimize greenhouse gas emissions.