Comparing “Warm Season” and “Snowmelt”
Pedogenesis in Soils
Randall J. Schaetzl and Scott A. Isard
This study compares the ionic concentrations of soil solutions of sandy Spodosols (Podzols) in Alberta, Michigan, USA, during both the warm season and snowmelt. Also, a computer hydrologic model was used to estimate the daily amount of water moving into the mineral soil (out of the litter) for 1957-1987. Soil solutions were extracted in situ from soils, and ionic composition (Fe, Al, H) determined, to examine processes of podzolization.
Results suggest that March and April (snowmelt) are the main periods of soil leaching, each with larger cumulative infiltration events and greater total infiltration than any warm season month. Warm season pedogenesis may primarily involve upper solum weathering of primary minerals, as suggested by low soil solution pH and relatively high ionic concentrations in O, A and E horizons. Thus, weathering intensity in the warm season (within eluvial horizons) may exceed eluviation rates.
During snowmelt, soils may respond to the release and flush of organic acids, as indicated by higher concentrations of Fe and Al in the soil solutions of illuvial horizons. Findings suggest that in some environments, snowmelt may provide the main pedogenic “pulse” or “pulses” for Fe and Al translocation, and hence, pedogensis.