Influence of a commercial formulation of tridemorph on methane production and oxidation in a tropical rice soil

Abstract

In a laboratory incubation study, application of a commercial formulation of tridemorph to a tropical rice soil under flooded condition significantly stimulated CH₄ production at low levels (5, 10 and 20 μg.g^-1) but inhibited the process at higher levels of 50 and 100 μg.g^-1. Oxidation of CH₄, however, was progressively inhibited with increasing concentrations of the fungicide. Increase in CH₄ production in tridemorph-amended soil was attributed to a hastening in the soil reduction, increase in the K₂SO₄-extractable C content and an increase in the population of methanogenic bacteria. Inhibitory effect of the fungicide on the oxidation of CH₄, on the other hand, was related to the inhibition in the population of methanotrophic bacteria.