Soil Science · 1973 · 104 citations · 0 references
AgricultureMicrobiologySoil SciencesSoil ChemistrySoil Organic MatterSoil ScienceHerbicide Residue ChemistryHerbicide ScienceMineral-organic InteractionsPesticide ChemistrySoil Contaminant ChemistrySoil Organic Matter ChemistryHerbicide Binding MechanismsHerbicide Retention In SoilHerbicide Soil ResiduesPesticide Residues In SoilPolymerization ReactionsSandy LoamSoil BindingSoil Herbicide Residues
Herbicide-derived chloroaniline residues are immobilized by physical absorption to both the organic and the inorganic fraction of the soil and, in addition, by chemical binding to the soil organic matter. In contrast to the polymerization reactions, the binding of the chloroanilines is strictly a physicochemical process; microbial activity is involved only in the liberation of the chloroanilines from the parent herbicides. The chemical attachment of chloroanilines to humic substances occurs by at least two mechanisms, in a hydrolyzable (probably anil and anilinoquinone) and in a nonhydrolyzable (probably heterocyclic rings and ether bonds) manner. In the test soil (Nixon sandy loam) these two types of bonds immobilized roughly equal amounts of chloroanilines. Free radicals have little or no role in these reactions. The binding of chloroanilines to the soil organic matter greatly increases the persistence of these herbicide-derived residues in the environment.