Persistence and Movement of Endosulfan in Soil in a Supervised Field Trial at Farrukhabad

Persistence and downward movement of endosulfan residues were studied in a sandy loam soil under wheat cultivation at two locations on the bank of river Ganga at Farrukhabad (U.P.). The residues of endosulfan in soil (0–15 cm) persisted for 60 days with half-life of 10.3–10.6 days. β-Endosulfan was more persistent than the α-isomer. Concentration of endosulfan sulphate gradually increased upto 15 d and declined thereafter. Endosulfan residues were detected in soil samples upto 105 cm depth showing accumulation of residues over a period of time from previous sprays.