Freeze Thaw Cycle Effects on Infiltration Rate and Bulk Density of Three Saskatchewan Soils.

Many soils at high latitudes freeze and thaw seasonally. Predictions of frequent freeze-thaw cycles (FTC) imply a tremendous impact on ecosystem diversity and productivity. Freeze-thaw cycles provoque changes in soil physical properties and affect the water cycle. This research studied the effect of FTCs (0, 1, 5, and 10) and antecedent soil moisture (wilting point: WP, field capacity: FC, and 80% saturation: 80%sat) on infiltration rate and bulk density of three Saskatchewan soils: a clay, a loam and a loamy sand. A tension infiltrometer was used at tensions of -5, -10 and -15 cm. Infiltration rates were highest for coarser textures, at 5 cm tension, and at WP compared to other textures, tensions and soil moisture contents. Increasing FTCs at high soil moisture contents is expected to have a significant effect on infiltration rate compared to FTCs at low soil moisture contents. Infiltration rates of frozen soils depend largely on the soil moisture content at freezing. Soils with a high moisture content at freezing can be more susceptible to runoff and erosion at thawing than soils with a low moisture content at freezing.