Influência do sistema de manejo na retenção e mobilidade da atrazina em amostras de solos

Abstract

Atrazine is one of the most used pesticides in Brazil, however, its dynamic in soils is still unknown, specially regarding different management systems. Thus, the aim of this work was to evaluate the sorption and leaching of atrazine in a dystroferric Red Latosol cultivated under no-till or conventional till management system. Sorption was evaluated using the "batch" method and the miscible displacement method, using undisturbed soil columns from 0-20 cm layer. Results were expressed by Freundlich isotherm and the elution curves were to the dispersive-convective model in order to obtain the retardation factor (R) and the hydrodynamic dispersion coefficient (D). No significant difference of the the Freundlich coefficient (Kf) was found in the soil samples under no-till or conventional till management systems. The retardation factor was higher and the hydrodynamic dispersion coefficient was lower in the samples under conventional till system, showing evidences of a higher leaching potential in soils under no-till system.