Effect of hexachlorocyclohexane on metel4ne production and emission from flooded rice soil

Application of commercial formulation (an isomeric mixture) of hmachlorocyelohexane (HCH) to flooded rise fields planted to cv. Ran at 1 kg active ingredient.ha−1 significantly inhibited mute emission. Negative P oxafed between methane emission from HCH-treated fields and root oxidise activity (in tents of α-naphthylamine oxidised). Under laboratory condaition, the addition of technical grade α-, β-, γ- and δ-isomers (99.1% purity) of HM individually at 20 μg.g−1 soil at flooding, effected a distinct inhibition of methane production. Evidence suggests that the inhibitory effect of all the four isomers on methane production only until 20–25 days after their application was related to their persistence in flooded soil.