EVALUATION OF CRITERIA FOR THE CLASSIFICATION OF GLEYSOLIC SOILS IN SASKATCHEWAN

Abstract

Six soils within and adjacent to two willow-ring depressions in hummocky moraine of the Dark Brown soil zone were monitored for seasonal changes in water table levels, redox status, and soil temperature to evaluate color citeria for identifying saturated and reduced soils of the Gleysolic order. Soils in the center of the willow-ring depressions had water table levels close to the soil surface, Ept values of < 100 mV, and were covered by hydrophytic vegetation. Soils near the perimeter of the willow-ring depression had water table levels generally below 1 m, Ept values > 400 mV, and were covered by hydrophytic vegetation. Three of the depressional soils had matrix chromas of 1 in the Ae and/or Bt (Btj) horizons, with prominent rusty mottles, and met the color criteria of Humic Luvic Gleysols. The fourth depressional soil had matrix chromas of 1 in the Btj horizon, but no mottles were present within 50 cm of the soil surface, and met the color criteria of an Orthic Humic Gleysol. Two nondepressional soils, on lower slope positions just outside the willow-ring depressions, exhibited water table levels generally below 1.5 m, had an Ept of > 400 mV, and lacked hydrophytic vegetation. Of these, one soil had matrix chromas of 2 and prominent rusty mottles within 50 cm of the soil surface and met the color criteria of a Rego Humic Gleysol. The other had mottles of low chroma within 1 m of the surface and met the color criteria of a Gleyed Rego Dark Brown. Based on this study, the color criteria are adequate for depressional soils but are inadequate for the classification of soils beyond the willow-ring. Key words: Water table level, redox potential, soil temperature, morphological criteria, gleying