Submitted to: Proceedings of the Workshop on Agricultural Air Quality: State of the Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2006
Publication Date: 11/9/2006
Citation: Roberson, T., Nyakatawa, E.Z., Reddy, K.C., Raper, R.L. 2006. Carbon Dioxide Efflux From Poultry Litter Applied Soils under Conservation Tillage Systems in North Alabama. Proceedings of the Workshop on Agricultural Air Quality, June 5-8, 2006, Washington, D.C. p.1057-1058. Interpretive Summary:
Technical Abstract: Increased carbon dioxide release from soils resulting from agricultural practices such as tillage and application of poultry litter in cotton production systems has generated concerns about contributions to global warming which negatively impacts natural ecosystems, weather patterns, and food production. We conducted a study in north Alabama in 2003 and 2004 to measure carbon dioxide efflux and carbon storage in long-term tilled and non-tilled cotton plots receiving poultry litter and ammonium nitrate as nitrogen sources. Treatments were established in 1996 on a Decatur silt loam and consisted of conventional-tillage, mulch-tillage, and no-tillage systems with winter rye cover cropping and ammonium nitrate and poultry litter sources of nitrogen. In 2003, carbon dioxide efflux in conventional tillage plots averaged from May through October 16% and 63% significantly higher than in mulch tillage and no-tillage, respectively. Also, in 2004, carbon dioxide efflux in mulch-tillage averaged 14% and 33% greater than conventional tillage and no-tillage, respectively. At the conclusion of this study, soil carbon content was 10% and 7% higher in no-tillage than in conventional tillage and mulch-tillage plots, respectively. On average, no-tillage can reduce soil carbon dioxide emissions by when compared to conventional tillage systems during the cotton growing season of about 165 days. Our study suggests that no-tillage conservation tillage systems along with application of poultry litter at the rate of 100 or 200 kg N ha-1 promotes carbon storage in soil and thus reduces atmospheric carbon dioxide increases.