Preface (Second Edition 1987)

This revised publication replaces The Canadian System of Soil Classification published in 1978. The changes incorporated in the present publication are based on the work of the Soil Classification Working Group of the Expert Committee on Soil Survey.

Major revisions have been carried out on both the Gleysolic and Organic orders to incorporate the new information obtained on these soils and to overcome difficulties in their classification under the earlier system. Soil scientists from all over Canada requested that the classification of Gleysols be reviewed. This review resulted in the revision of the basic rationale commonly used in the past by which all poorly drained soils were identified as Gleysols. The revised classification of the Gleysolic soils presented here is based on soil properties that indicate reduction during the genesis of the soil and not on the current soil water regime. Although many Gleysolic soils are poorly or very poorly drained, some are imperfectly drained and others, in which drainage has been modified, are now well drained. Because of these changes, the section on the Gleysolic order now has a slightly longer introduction.

The main initiative for reviewing the Organic order, especially the Folisol great group, came from British Columbia, where most of these soils are found. The importance of organic soil layers in forest ecosystems has been emphasized by foresters and forest soil specialists working in that province. This view is reflected in the revised Folisol great group. With this change the Folisol great group and the other great groups of the Organic order now have a common basis for classification.

The revision of the Podzolic order was minor and was carried out to make the definitions more specific. The new definition for contrasting horizons and layers was made more detailed in an attempt to avoid the misinterpretations that occurred in the past.

In addition to the revisions described, a number of errors in the 1978 edition of The Canadian System of Soil Classification have been corrected.

Most of the work relating to these changes was carried out by members of the Soil Classification Working Group: T.M. Lord and R. Trowbridge, British Columbia; L. Turchenek, Alberta; R.J. St. Arnaud, Saskatchewan; W. Michalyna and G.F. Mills, Manitoba; L.J. Evans, Ontario; J-M. Cossette, Quebec; K.T. Webb, Nova Scotia; C.A.S. Smith, Yukon Territory; and J.A. McKeague, C.A. Fox, J.A. Shields, and C. Tarnocai, Ottawa, Ont.

The members of the Working Group wish to express their appreciation to all those who cooperated in this work, with special thanks to H.A. Luttmerding for his work on Gleysols and Folisols and to C. Wang for his work on the Gleysolic and Podzolic soil classification.

Questions and suggestions on soil classification are welcomed and should be sent to the chairperson of the Soil Classification Working Group, Expert Committee on Soil Survey, Land Resource Research Centre, Agriculture Canada, Ottawa, Ont., KlA 0C6.

C. Tarnocai
Soil Classification Working Group

Source: The Canadian System of Soil Classification (Third Edition)