Nitrite and nitrous oxide accumulation during denitrification in the presence of pesticide derivatives.

Temporary accumulation of nitrite and nitrous oxide was observed in soil incubated under anaerobic conditions when derivatives of the insecticide chlordimeform [(N-4-chloro-o-tolyl)-N',N' -dimethylformamidine] were added. Chlordimeform did not affect the denitrification process, but N-formyl-4-chloro-o-toluidine and 4-chloro-o-toluidine caused an inhibition as determined by the accumulation of nitrite and nitrous oxide. A simultaneous application of the insecticide and its derivatives resulted in a stronger inhibitory effect than the application of each compound separately. Aniline intermediates of other pesticides also inhibited denitrification in soil, and they proved to be more effective than their parent compound.