This research had the aim to evaluate the influence of temperature and moisture on fipronil degradation under laboratory conditions of two soils at Mato Grosso do Sul State. Soil samples (0-30 and 50-70cm) were incubated at temperatures of 30 and 40°C and soil moistures of 50 and 80% field capacity. Soil samples for fipronil residue analysis were collected at 0, 3, 10, 17, 24, 34, and 44 days after application and remaining amount data as a function of time were fitted to first-order kinetic and biphasic models. Temperature and soil moisture increase did improve fipronil degradation for both soils. First-order kinetics model did show a better performance than biphasic model to describe fipronil degradation with half-life values between 19 and 74 days.
pesticide; persistence; half-life
