ABSTRACT
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 K[OC] 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; K[OC] values were 1086.00, 1288.46, 1191.14, 771.71 and Rvalues were 9.05, 33.5, 20.02 and 36.66 from Alfisot 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 half-life of anilofos in topsoil from Alfisol: T[1]- 3.17 days and T[2] 3.67 days and in Inceptisol: T[1]-3.91 days and T[2]- 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 [t[1/2]- soil] and organic carbon based sorption [K[oc]] 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