Keys to Soil Taxonomy, 13th Edition

This publication, Keys to Soil Taxonomy, 13th edition, 2022, incorporates the amendments approved by the regional and national conferences of the National Cooperative Soil Survey since publication of the last edition of the Keys in 2014. The authors of the Keys to Soil Taxonomy are identified as the “Soil Survey Staff.” This term is meant to include all of the soil classifiers in the National Cooperative Soil Survey program and in the international community who have made significant contributions to the improvement of the taxonomic system.

Many changes in this edition are intended to make Soil Taxonomy more intelligible to cooperators who use soil surveys for conservation planning and land use purposes. For example, taxonomic names, such as Vertic Torrifluvents, can be daunting to the non-specialist. In chapter 1, the method for understanding taxonomic names, by dividing them into syllables (formative elements) from right to left, is explained. Tables of the Greek and Latin root words used as formative elements are provided. Understanding the combination of formative elements allows much insight about a particular soil and the landscape where it occurs.

More headings and endnotes have been added, especially in chapter 3, to aid the understanding of concepts. The headings are intended to break up long definitions containing multiple criteria by showing the reader the general concept for each criterion. Endnotes provide rationale for the criteria and refer the reader to citations for more explanation. Several photos of diagnostic features and a few charts were also added as aids for understanding concepts.

Several of the proposed changes resulted from a refinement of the definitions of existing taxa as more experience with those taxa was gained. In addition, new taxa have been added as a result of mapping formerly unmapped terrain, especially in Alaska. Still other amendments account for the changing needs of the soil survey database, particularly with regard to carbon buried at depths below 1 meter.