Fig. 1. Sorption kinetics of herbicides ([a] metolachlor and atrazine, [b] 2,4-D and picloram) on the natural and PAM-treated Linne clay loam. The PAM application rate was 80 mg kg^-1, and initial herbicide concentration was 40 µmol L^-1. Each data point is the mean of three replicates and the error bar is its standard deviation.