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

Degradation rates of carbofuran were greatly increased by a single 10 ppm carbofuran pre‐treatment 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 the pre‐treatment, but the drastic reduction in activity produced by heat sterilization, freezing or drying suggests soil microorganisms are the active agents. Increased degradation rates for a variety of aryl‐ and oximino‐ methyl carbamates were observed in carbofuran‐activate'd soil but this soil did not affect the degradation rates of the thiolcarbamate, butylate, the phenylcarbamate, chlorpropham or the organophosphorus insecticide, phorate.