Predicting Freundlich adsorption isotherm of atrazine on Japanese soils

It was possible to predict the amounts of atrazine adsorption on Japanese soils by deriving predicting equations from the value of the initial concentration of atrazine applied to the soils containing less than 70 g kg(-1) carbon. The equations predicted the values of Freundlich isotherm coefficients, log K-F and 1/n. Using the linear correlation between log K-F and 1/n for atrazine adsorption, Freundlich adsorption isotherm could be represented by using log K-F as a parameter. Predicting equations for log K-F were derived from the soil physicochemical properties by multivariate analyses. Direct and indirect regressions to derive the predicting equations for log K-F were examined on the analyses. The better predicting equations were as follows; 1/n=-0.16Xlog K-F + 0.99, log K-F=0.51 + 0.31 X OM + 0.08 X TE + 0.06 X XA + 0.04 X XC, where OM, TE, XA, and XC denote the organic matter factor, the texture factor, the exchangeable acidity factor, and the exchangeable cations factor, respectively. These predicting equations estimated well experimental values of log K-F and 1/n.