CH4 oxidation, expressed in terms of the decrease in the
concentration of CH4 in the headspace of the serum
bottles, proceeded very rapidly in unamended alluvial soil
held at 60% MHC and was more intense during the initial
5 days of incubation. Application of heavy metals at
20 mg.g71 differentially affected CH4 oxidation in the
alluvial soil held at 60% MHC (Table 2). Among the
different heavy metals tested, Ni and Cd effected marginal
inhibition of CH4 oxidation, while Cr exerted a highly
significant inhibition. CH4 oxidation was significantly low
and the resultant half-life (t1/2) value was high in soil
amended with Cr. Cu amendment resulted in the stimulation
of CH4 oxidation, while Zn did not affect the
methanotrophic activity of the soil.