A Novel Chamber Method for the Soil CO₂ Flux Measurement Based on the Diffusion Equation

Abstract

A new chamber technique, based on the diffusion equation, is devised to measure gas fluxes emitted from the soil. The top of the chamber is made of a porous material of known diffusivity. We determine the fluxes passing through the porous media by measuring the concentration difference between the inside and outside of the chamber. The proposed method, the diffusion system or the porous-top chamber method, is a steady state method and able to measure the CO₂ fluxes from soil cores in the laboratory within the precision of the CO₂ sensor. Our system may provide a simple and economical means for continuous surface flux measurements in the field.