Degradation of Four Commonly Used Pesticides in Malaysian Agricultural Soils

First-order kinetics were observed for the degradation of 2,4-D, lindane, paraquat, and glyphosate in sandy loam and muck soils, with the exception of glyphosate degradation in an anaerobic muck. Short half-lives were observed for 2,4-D in aerobic (3.4 days) and anaerobic (9.3 days) muck soils, while longer half-lives were found for glyphosate (19.2 days) and 2,4-D (35.9 days) in the sandy loam. Long half-lives were observed for lindane (1.0−1.7 years) and paraquat (1.4−7.2 years) in the soils. The results of the laboratory studies on the degradation of the pesticides in the Malaysian soils showed little difference from the results reported in soils from other parts of the world.