title: Sorption and degradation of fipronil in flooded anaerobic rice soils.
abstract: The fate of fipronil in flooded, reductive rice soils was modeled using a conceptual model. Rate constants for the various sorption and degradation processes were calculated from experimental studies involving intact soil cores, and the reductive degradation constant was used to calculate half-lives for fipronil on each soil. The data predicted that fipronil was subject to rapid, reductive degradation or immediate sorption to the soil and any sorbed fipronil desorbed was reductively degraded. The reductive metabolite, fipronil sulfide, accumulated over the 184 day duration of the experiment and sorbed rapidly to the soil, where it accumulated and did not appear to degrade. Neither fipronil nor fipronil sulfide was found beyond the top 1 cm of soil in Yanco soil, while a small amount of each chemical was found up to 4 cm deep in the Coleambally soil profile.
authors.affiliation: Cooperative Research Centre for Sustainable Rice Production, Farrer Centre, School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga 2678, New South Wales, Australia. gdoran@csu.edu.au
authors.forename: Gregory
authors.initials: G
authors.lastname: Doran
authors.forename: Philip
authors.initials: P
authors.lastname: Eberbach
authors.forename: Stuart
authors.initials: S
authors.lastname: Helliwell
mesh_terms: D000327:Adsorption; D000693:Anaerobiosis; D055868:Floods; D007306:Insecticides / Q000737:chemistry*; D012275:Oryza; D011720:Pyrazoles / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D007306:Insecticides; D011720:Pyrazoles; D012989:Soil Pollutants; C082360:fipronil