title: Influence of dissolved humic substances on the leaching of MCPA in a soil column experiment.
abstract: The influence of dissolved humic substances on the transport of (4-chloro-2-methylphenoxy) acetic acid (MCPA) in a sandy soil with a low organic carbon content was studied in a column experiment. Soil columns were eluted with aqueous solutions containing different fractions of humic substances. More than 70% of the applied compound was found in the leachate in all sandy soil experiments, but distinct differences were obtained depending on the composition of the eluent. The addition of both humic and fulvic acids to the eluent affected the leaching behaviour of MCPA. While the presence of humic acids increased and accelerated the movement of MCPA in the investigated sandy soil, fulvic acids caused the opposite effect: increased retention was observed relative to the control. We concluded that a possible carrier transport or retention strongly depends on the composition of the dissolved organic matter. Thus, changes in the composition of dissolved organic matter may affect MCPA movement into deeper soil layers.
authors.affiliation: Department of Environmental Research, Austrian Research Center, A-2444 Seibersdorf, Austria. georg.haberhauer@arcs.ac.at
authors.forename: Georg
authors.initials: G
authors.lastname: Haberhauer
authors.forename: Brigitta
authors.initials: B
authors.lastname: Temmel
authors.forename: Martin H
authors.initials: MH
authors.lastname: Gerzabek
mesh_terms: D008456:2-Methyl-4-chlorophenoxyacetic Acid / Q000737:chemistry*; D001578:Benzopyrans / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry*; D006812:Humic Substances / Q000737:chemistry*; D009930:Organic Chemicals; D012989:Soil Pollutants; D012995:Solubility; D014872:Water Movements
chemical_list: D001578:Benzopyrans; D006540:Herbicides; D006812:Humic Substances; D009930:Organic Chemicals; D012989:Soil Pollutants; D008456:2-Methyl-4-chlorophenoxyacetic Acid; C005023:fulvic acid