Factors affecting the fate of dimethoate in soils

Abstract

For a given application of dimethoate, the loss by leaching increased with soil type in the following order: clay < clay loam < loam < sandy clay loam (S.C.L.) < sand. In general, the loss through leaching for a single soil type increased with the amount of dimethoate applied. The degree of retention was greatest in the loam and least in the sand. Retention was thought to be affected by physical forces and hydrogen bonding. The loss of the pesticide through evaporation, degradation and irreversible adsorption increased with the dosage applied. It was in descending order of; clay > clay loam > sand > S.C.L. > loam. However, the loss due to evaporation alone was in the order; sand > S.C.L. > clay loam > loam. Biological degradation of dimethoate was of little importance.