Isothermal and non-isothermal infiltration experiments with tracer breakthrough were carried out in the laboratory
on one intact column (18.9 cm in diameter, 25 cm in height) of sandy loam soil. For the isothermal experiment, the
temperature of the infiltrating water was 20°C to the initial temperature of the sample. For the two non-isothermal experiments
water temperature was set at 8°C and 6°C, while the initial temperature of the sample was 22°C. The experiments
were conducted under the same initial and boundary conditions. Pressure heads and temperatures were monitored in two
depths (8.8 and 15.3 cm) inside the soil sample. Two additional temperature sensors monitored the entering and leaving
temperatures of the water. Water drained freely through the perforated plate at the bottom of the sample by gravity and
outflow was measured using a tipping bucket flowmeter. The permeability of the sample calculated for steady state stages
of the experiment showed that the significant difference between water flow rates recorded during the two experiments
could not only be justified by temperature induced changes of the water viscosity and density. The observed data
points of the breakthrough curve were successfully fitted using the two-region physical non-equilibrium model. The results
of the breakthrough curves showed similar asymmetric shapes under isothermal and non-isothermal conditions.