Chemical Properties and Classification of Organic Horizons From Selected Soils in British Columbia

In order to assess the extent to which chemical properties of organic horizons support their differentiation on the basis of morphological characteristics, as used in the Canadian System of Soil Classification (CSSC), a total of 265 samples of organic horizons (including L, F, H, Of, Om and Oh) were analyzed for 26 chemical properties (organic and inorganic). One-way analysis of variance, correlation analysis and tests of normality were used to select variables for canonical variates analysis (CVA). The results of CVA indicated that the six types of horizon could be distinguished by a combination of chemical properties, and that the grouped upland (L-F-H) horizons could be distinguished from the grouped wetland (Of-Om-Oh) horizons. The results provided support for the present usage in the CSSC, based on field morphology. It was concluded that there remained a need to improve definitions, to review designations, and to develop quantitative diagnostic criteria for organic horizons. Some problems in the classification of organic horizons are discussed, particularly in relation to a hierarchical system.