Author(s)

Alden D. Smartt¹, Kristofor R. Brye^1*, Christopher W. Rogers², Richard J. Norman¹, Edward E. Gbur³, Jarrod T. Hardke⁴, Trent L. Roberts¹

¹Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Fayetteville, USA.
²Department of Plant, Soil, and Entomological Sciences, University of Idaho, Aberdeen, USA.
³Agricultural Statistics Laboratory, University of Arkansas, Fayetteville, USA.
⁴Department of Crop, Soil, and Environmental Sciences, University of Arkansas, Stuttgart, USA.

Quantifying methane (CH₄) emissions from cultivated rice (Oryza sativa L.) production in the field has received increased attention recently due to methane’s importance as a greenhouse gas. The enclosed-headspace chamber technique is the standard methodology for field assessments of trace gas emissions. However, to our knowledge, no direct comparisons of measured CH₄ fluxes and emissions from field-grown rice among differing chamber sizes have been reported. Therefore, the objective of this study was to evaluate the effect of chamber size [15.2- and 30.4-cm inside diameter (id)] on CH₄ fluxes and season-long emissions from rice grown on a clay soil in Arkansas. Chamber size did not affect (P > 0.05) CH₄ fluxes on 10 sampling dates during the flooded portion of the rice growing season and only affected fluxes on one of four sampling dates after flood release. Total season-long CH₄ emissions from optimally N-fertilized rice were 32.6 and 35.6 kg CH₄-C ha^-1·season^-1, which did not differ, and from bare clay soil were 0.74 and 1.75 kg CH₄-C ha^-1·season^-1, which also did not differ, from the 15.2- and 30.4-cm chambers, respectively. Chamber size (i.e., 15.2- or 30.4-cm id) did not result in differences in cumulative CH₄ emissions from this flooded-rice study that was conducted on a Sharkey clay soil in northeast Arkansas. Results indicate that both 15.2- and 30.4-cm diameter chambers were similarly adequate for measuring CH₄ fluxes and emissions from the clay soil investigated. The similarity in emissions results between chamber sizes also indicates that the 15.2-cm diameter chambers adequately facilitated the quantification of CH₄ emissions in this study.

Methane Emissions, Rice Production, Clay Soil, Arkansas

Smartt, A. , Brye, K. , Rogers, C. , Norman, R. , Gbur, E. , Hardke, J. and Roberts, T. (2015) Chamber Size Effects on Methane Emissions from Rice Production. Open Journal of Soil Science, 5, 227-235. doi: 10.4236/ojss.2015.510022.