A screening technique for assessing effects of pesticides on population and activities of non-target soil microorganisms.

A simplified technique for assessing the effect of pesticides on non-target soil microorganisms was developed. Changes in microbial population determined by the dilution plate method, in nitrification by the soil perfusion technique, and in oxygen consumption using a differential respirometer are the only measurements required. A comparison of the effects observed for three pesticides, dieldrin, chlorpyrifos and Vorlex, in three soil types with those produced by an antibiotic, a fungicide, a nitrification inhibitor and steam pasteurization of the soil clearly demonstrate the effectiveness of the simple technique.