Agricultural greenhouse gas (GHG) fluxes are often measured using chamber-based methods. However, comparisons among chamber-based methods are limited. This study compared the effects of chamber type and GHG concentration measurement method on GHG fluxes, emissions, global warming potential (GWP), and reduced two-gas GWP (GWP*) in conventionally tilled soybean (Glycine max L. Merr) on a silt-loam soil (Aeric Epiaqualfs) in southeast Arkansas. Carbon dioxide (CO2) fluxes measured by optical feedback-cavity enhanced absorption spectroscopy (OF-CEAS, FT-LICOR) were greater (p 0.05) between FT-LICOR and NFT-GC methods for the 0–15, 0–30, and 0–60 min intervals. Results suggest that differences in GHG flux, emissions, and GWP estimates reflect the combined influence of measurement methods rather than individual system components (i.e., chamber design, analyzer type, or closure time), which should be considered when designing and executing field studies.
Ortiz et al. (Wed,) studied this question.