Methane and carbon dioxide fluxes in soils evaluated by 222Rn flux and soil air concentration profiles

Measurements of methane and carbon dioxide fluxes from diverse soils in the surroundings of Málaga (Spain) were made. Methane and carbon dioxide fluxes were carried out by an indirect method from simultaneous measurements of 222Rn flux from the soil surface in parallel with concentration profile measurements of 222Rn, methane and carbon dioxide in the air of soil. Correlations found between fluxes and soil permeability are better than correlations between fluxes and soil temperature. The permeability is daily evaluated from soil parameters as tortuosity and soil moisture content and the molecular diffusion coefficient in air. Atmospheric methane is consumed by soils and mean flux to atmosphere evaluated by this method was −1.3 μmol m−2 h−1. Carbon dioxide emitted by soils showed a mean flux to the atmosphere of 4.6 mmol m−2 h−1.