The influence of variable B horizon thickness (tonguing) on solute transport through undisturbed soil columns

Dadfar, Humaira
Journal Title
Journal ISSN
Volume Title
University of Guelph

All soils have distinct horizons with different transport properties, which will affect the movement of the non-reactive and reactive solutes during their transport to groundwater. Therefore, the major objective of this study was to obtain a quantitative description of solute transport and reaction in unsaturated layered soil. Nine undisturbed Fox sand columns with approximately equal A horizon, and variable B horizon thicknesses (ranging from 27 cm to 126 cm) were used for a one-dimensional unsaturated solute transport experiment. At steady state, a spike of LiCl was released at the top of each column, and the transport of the Cl\sp− and Li\sp+ ions were monitored at every 10 cm depth increment using TDR probes, and solution samplers. The average Li\sp+ retardation factor for the entire length of the A horizon for the nine columns was 4.3. Whereas, the average Li\sp+ retardation factor for the entire length of the B horizon of the nine columns was 7.9. The retardation factor in the B horizon was independent of the thickness of the B horizon.

soils, horizons, transport properties, solute transport, reaction, unsaturated layered soil, B horizon, thickness, tonguing