A solution of the convection-dispersion equation is used to describe the solute breakthrough curves generated in the demonstrations in the companion paper. Estimation of the best fit model parameters (solute velocity, dispersion, and retardation) is illustrated using the method of moments for an example data set. (Author/MDH)

Presents the general theory to explain chemical movement in soil. Describes classroom demonstrations with visually stimulating results that show the effects of soil structure, soil texture, soil pH, and soluble organic matter on that movement. (MDH)