Persistence of Chlorpyrifos in Acid Soils

The persistence of chlorpyrifos in three different acidic soils of Kerala was studied under two moisture levels at 1,10 and 100 μg g−1 levels. The persistence of chlorpyrifos was maximum in sandy loam soil followed by laterite and red loam soil. Degradation of chlorpyrifos was comparatively faster in flooded condition than at field capacity moisture conditions in all the three soils. There was an increase in the persistence with increase in the concentration. The persistence in soil was dependent on pH, type of clay, organic matter and the concentration of chlorpyrifos used for treatment.