Document Type : Original Research Paper
International Institute of Biotechnology and Toxicology, Department of Analytical Chemistry, Padappai, Chennai 601 301, Tamil Nadu, India
Adsorption of anilofos was studied in four soils (topsoil from alfisol, inceptisol, oxisol and
vertisol). The order of adsorption of anilofos was Vertisol > Oxisol > Alfisol > Inceptisol. The soil sorption coefficient K and the soil organic carbon sorption coefficient Koc are the basic parameters used for describing the environmental fate of the herbicides. In top soil the calculated K values were 5.43, 3.35, 9.41, 11.73; Koc values were 1086.00, 1288.46, 1191.14, 771.71 and Kc values were 9.05, 33.5, 20.02 and 36.66 from Alfisol, Inceptisol, Oxisol and Vertisol respectively. Field experimental plots with no previous history of anilofos were selected and studied the degradation of anilofos in top soil collected from Alfisol and Inceptisol. The halflife of anilofos in topsoil from Alfisol : T1- 3.17 days and T2 3.67 days and in Inceptisol: T1-3.91 days and T2 - 4.55 days . The degradation of anilofos followed first order kinetics. Anilofos persisted for a longer duration
in Inceptisol than in Alfisol. The combination of degradation data (t1/2- soil) and organic carbon based sorption (Koc) data of herbicides have been used to assess the pesticide environmental impact in soils through Gustafson Ubiquity Score (GUS). The GUS values were found to be 0.48 in top soil from alfisol and 0.53 in inceptisol.