Submitted to: Seasonally Frozen Soils Symposium
Publication Type: Proceedings
Publication Acceptance Date: 6/12/1997
Publication Date: N/A
Technical Abstract: Overwinter freezing and thawing of soils causes movement of soil water and solutes in the soil profile. Experiments were conducted to measure the effects of freeze/thaw on soil water and solute movement in a Webster silt clay loam (fine-loamy, mixed mesic Typic Haplaqualls). PVC cylinders (0.13 m inside diameter and 1.2 m long) were packed with topsoil. A potassium bromide tracer was placed in the top 0.05 to 0.15 m of the soil layer in some of the columns. The soil columns were buried vertically in the field and exposed to the winter freeze/thaw conditions. Field columns were extracted throughout the winter and sectioned into 0.05 m layers. Each layer was analyzed for water content, bulk density, and electrical conductivity. Water moved upwards to the freezing zone carrying along some solutes. Electrical conductivity values verified the movement of solutes during the freeze/thaw periods. Bulk density changed abruptly due to expansion and compression of the soil matrix during freeze/thaw periods. Physical properties of thawed soil retained some of the changes caused by freezing and remained more variable compared to the properties of unfrozen soil.