|Sauer, Thomas - Tom|
|HERNANDEZ RAMIREZ, GUILLERMO|
Submitted to: Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2009
Publication Date: 7/1/2009
Citation: Sauer, T.J., Compston, S.R., West, C.P., Hernandez Ramirez, G., Gbur, E.E., Parkin, T.B. 2009. Nitrous Oxide Emissions from a Bermudagrass Pasture in Arkansas: Poultry Litter and Interseeded Winter Rye. Soil Biology and Biochemistry. 41(7):1417-1424.
Interpretive Summary: Increasing concentrations of greenhouse gases in the atmosphere may be causing global warming effect, which is an important environmental problem. It is known that agricultural soils can release greenhouse gases such as nitrous oxide depending on the management practices in place. In this study, gas samples were collected in a bermudagrass pasture planted to rye in the fall and receiving poultry litter in Arkansas during two years. The gas samples were analyzed for nitrous oxide. We observed different responses in the two years. In general, nitrous oxide emissions were higher after poultry litter applications and lower when pasture was planted to rye in the fall. To combine both poultry litter applications and winter rye in the same pasture can be done in order to both enhance forage productivity and reduce nitrous oxide emissions. This research is important to growers, scientists, and policy-makers interested in management practices that can reduce the contribution of soils and pasture systems to global warming effect.
Technical Abstract: The impact of poultry litter applications and interseeded winter rye on nitrous oxide (N2O) emissions from pasture is not well documented. This study was conducted to estimate soil surface N2O fluxes as affect by poultry litter applications and interseeded winter rye as well as weather and soil variables. Gas fluxes were measured by vented chambers in Tonti soil series during two years evaluating bermudagrass pasture with and without both turkey litter applications and interseeded winter annual rye (Secale cereale L.). The N2O fluxes were correlated with soil NO3- (r: up to 0.82*), soil temperature (r: 0.49*), and water-filled pore space (r: 0.56*). In the spring 2000, soil receiving turkey litter increased 1.5 fold seasonal cumulative N2O emissions (P= 0.04), which was related to a consistent increase in soil NO3- in both years (P= 0.09). In the spring 2001, soils planted to rye showed a pronounced effect in mitigating N2O emissions (P= 0.04). Rye also had a significant impact on decreasing both soil NO3- (P= 0.08) and WFPS (P= 0.06) during winter and early spring, which might partially account for the lower N2O emissions in the spring. Maximum N2O flux means were respectively 263 and 290 µg N m-2 h-1 in 2000 and 2001, and they occurred shortly after large accumulated rainfalls of 91 and 32 mm within 6 days prior sampling dates. Since poultry litter applications and interseeded winter rye showed contrasting effects on N2O emissions, to combine both management practices may have an overall beneficial impact in pasture systems.