Biodegradation of pesticides in soil: Rapid induction of carbamate degrading factors after carbofuran treatment

Abstract
Degradation rates of carbofuran were greatly increased by a single 10 ppm carbofuran pretreatment of a sandy loam soil with no previous history of pesticide use. Thorough mixing was required to homogeneously distribute the active agent(s). Numbers of bacteria and fungi were not affected by pretreatment, but the drastic reduction in activity produced by heat sterilization, freezing or drying suggested that soil microorganisms were the active agents. Increased degradation rates for a variety of aryl- and oximinomethyl carbamates were observed in carbofuran-activated soil but this soil did not affect the degradation rates of the thiolcarbamate, butylate, phenylcarbamate, chlorpropham or the organophosphorus insecticide, phorate.