title: Pesticide soil sorption parameters: theory, measurement, uses, limitations and reliability.
abstract: The soil sorption coefficient Kd and the soil organic carbon sorption coefficient KOC of pesticides are basic parameters used by environmental scientists and regulatory agencies worldwide in describing the environmental fate and behavior of pesticides. They are a measure of the strength of sorption of pesticides to soils and other geosorbent surfaces at the water/solid interface, and are thus directly related to both environmental mobility and persistence. KOC is regarded as a 'universal' parameter related to the hydrophobicity of the pesticide molecule, which applies to a given pesticide in all soils. This assumption is known to be inexact, but it is used in this way in modeling and estimating risk for pesticide leaching and runoff. In this report we examine the theory, uses, measurement or estimation, limitations and reliability of these parameters and provide some 'rules of thumb' for the use of these parameters in describing the behavior and fate of pesticides in the environment, especially in analysis by modeling.
authors: US Department of Agriculture-Agricultural Research Service, PO Box 748, Tifton, GA 31794, USA. don@tifton.cpes.peachnet.edu
authors: R Don
authors: RD
authors: Wauchope
authors: Simon
authors: S
authors: Yeh
authors: Jan B H J
authors: JB
authors: Linders
authors: Regina
authors: R
authors: Kloskowski
authors: Keiji
authors: K
authors: Tanaka
authors: Baruch
authors: B
authors: Rubin
authors: Arata
authors: A
authors: Katayama
authors: Werner
authors: W
authors: Kördel
authors: Zev
authors: Z
authors: Gerstl
authors: Michael
authors: M
authors: Lane
authors: John B
authors: JB
authors: Unsworth
mesh_terms: D000327:Adsorption; D000465:Algorithms; D001578:Benzopyrans / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002855:Chromatography, Thin Layer / Q000379:methods; D006812:Humic Substances / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D010575:Pesticides / Q000378:metabolism*; D015203:Reproducibility of Results; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000378:metabolism*; D014867:Water / Q000378:metabolism; D014872:Water Movements
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D014867:Water; D002244:Carbon; C005023:fulvic acid