CONSUMPTION OF METHANE BY SOILS

Measurements of the methane flux and methane concentration profiles in soil air are presented. The flux of methane from the soil is calculat ed by two methods: a) Direct by placing a static open chamber at the s oil surface. b) Indirect, using the Rn-222 concentrations profile and the Rn-222 flux in the soil surface in parallel with the methane conce ntration (Rn-222 calibrated fluxes). The methane flux has been determi ned in two kinds of soils (sandy and loamy) in the surroundings of Mal aga (SPAIN). The directly measured methane fluxes at all investigated sites is higher than methane fluxes derived from ''Rn calibrated fluxe s''. Atmospheric methane is consumed by soils, mean direct flux to the atmosphere were - 0.33 g m-2yr-1. The direct methane flux is the same within the measuring error in sandy and loamy soils. The influence of the soil parameters on the methane flux indicates that microbial deco mposition of methane is primarily controlled by the transport of metha ne.