Simultaneous Solute and Water Transfer for an Unsaturated Soil

The simultaneous transfer of solute and water during infiltration was studied both in the field and numerically. An apparent diffusion coefficient of about 0.07 cm2/min provided maximum solute concentration values agreeable with field data over a 17-hour period. The advance of a solute front introduced as irrigation water is shown to be nearly independent of the initial soil moisture content but highly dependent on the moisture content maintained at the soil surface during infiltration.