Solute Transport During Absorption and Infiltration: A Comparison of Analytical Approximations

Abstract Several analytical solutions of one‐dimensional solute transport during infiltration have been reported. This study links these solutions by starting with the exact integral solution, followed by successive approximations in order to arrive at the simplest approximate solution. A number of planes of separation are defined and the physical significance of these planes is discussed using model soil‐water profiles. The retardation effect of adsorbed chemicals, such as many fertilizers and pesticides, can easily be included in the analysis when the partition coefficient is known. Experimental and predicted absorption and infiltration profiles of KCl into Brookston silty clay loam [Orthic Humic Gleysol (Can.), Typic Haplaquolls (USA)] compared favorably using the simplest (field applicable) approximation.