Hashimoto S, Suzuki M. 2002. Vertical distributions of carbon dioxide diffusion coefficients and production rates in forest soils. Soil Science Society of America Journal 66: 1151-1158.
These authors inverted the usual soil-gas measurement approach of inserting probes into soil: they inserted soil into their apparatus. “Undisturbed” soil samples approximately 20cm in diameter and 40cm long were collected from a research forest in Japan, dried for up to 17 days, and then placed into the laboratory apparatus. This consists of a sample cylinder big enough to take the soil samples, with chambers above and below that allow control of boundary conditions. Sample ports through the side of the cylinder allow measurement of CO2 concentrations at various positions in the sample. A set of pumps, valves, and tubes allow control of soil water conditions, including manipulation of water potential.
The point of this device is to measure CO2 diffusion in large soil samples, and control for water and temperature effects. Theories of soil gas diffusion can be tested using this apparatus.
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