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

Measurements of methane and carbon dioxide fluxes from diverse soils in the surroundings of Malaga (Spain) were made. Methane and carbon dioxide fluxe s were carried out by an indirect method from simultaneous measurements of Rn-222 flux from the soil surface in parallel with concentration profile me asurements of Rn-222, methane and carbon dioxide in the air of soil. Correl ations found between fluxes and soil permeability are better than correlati ons between fluxes and soil temperature. The permeability is daily evaluate d from soil parameters as tortuosity and soil moisture content and the mole cular diffusion coefficient in air. Atmospheric methane is consumed by soil s and mean flux to atmosphere evaluated by this method was -1.3 mu mol m(-2 ) h(-1). Carbon dioxide emitted by soils showed a mean flux to the atmosphe re of 4.6 mmol m(-2) h(-1). (C) 1999 Elsevier Science Ltd. All rights reser ved.