Ferro-Humic Podzols of Coastal British Columbia: I. Morphology, Selected Properties, and Classification
1989
Sanborn, P. | Lavkulich, L. M.
Ferro-Humic Podzols (Cryorthods and Cryochrepts) of loamy texture on western Vancouver Island, British Columbia, have distinctively high organic matter and sesquioxide concentrations and limited albic horizon development. Their properties and taxonomic status were evaluated in relation to Spodosols of other maritime regions. Oxalate-extractable Al concentrations (10–70 g kg⁻¹) are comparable to those in podzolized soils containing tephra. Free Fe concentrations exceed 35 g kg⁻¹ in most Bhs horizons, with approximately half in crystalline forms. Oxalate-extractable Si concentrations suggest a substantial allophane content in some Bhs horizons. Maximum C concentrations (110–180 g kg⁻¹) occur at 0.5- to 2.0-m depth above root restricting layers or in channel-like features initiated by tree roots. The maximum organic C content (170 g kg⁻¹) allowed by the Canadian classification for mineral soil horizons may be too restrictive. Clay concentrations are high enough to exclude some pedons of podzolic morphology from the Spodosols of the U.S. system of soil taxonomy. Adoption of a required (Alₚ + Feₚ)/clay ratio lower than the current minimum of 0.2 for spodic horizons in the U.S. system would provide a more realistic classification of these soils.
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