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Keys to Soil Taxonomy

Keys to Soil Taxonomy, Twelfth Edition (2014) (PDF; 3.87 MB)

Errata - Issued May 15, 2014 (PDF; 192 KB)

Recommended citation: Soil Survey Staff. 2014. Keys to Soil Taxonomy, 12th ed. USDA-Natural Resources Conservation Service, Washington, DC.

Summary of changes to Keys to Soil Taxonomy (DOC; 134 KB)

Previous versions of Keys to Soil Taxonomy

Illustrated Guide to Soil Taxonomy, version 2.0

Illustrated Guide (PDF; 21.6 MB)

Recommended citation: Soil Survey Staff. 2015. Illustrated guide to soil taxonomy. U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center, Lincoln, Nebraska.

The Illustrated Guide to Soil Taxonomy was produced for use by multiple audiences and is not intended to replace the full version of the Keys to Soil Taxonomy for the professional soil classifier. Some of the more technical and complicated criteria have either been omitted or referenced in notes to make the user aware that there are exceptions. More complete criteria and definitions are available in the full version of the Keys to Soil Taxonomy.

When using the illustrated guide, be sure to open the bookmarks tab on the left side of the screen in Adobe Acrobat. This will greatly aid the navigation of the document. Users should also review the Foreword and Part 1 regarding the purpose of this document.

This edition of the illustrated guide (version 2.0) is based upon the 12th Keys to Soil Taxonomy.  It corrects errors and omissions discovered during the initial testing period.  Future editions will be issued to keep in step with the latest Keys to Soil Taxonomy along with other improvements and enhancements. To comment or ask questions about the Illustrated Guide to Soil Taxonomy, please contact one of the contributors listed in the Foreword section or submit your question on the Soil Taxonomy Forum.

Spanish version of Keys to Soil Taxonomy

Claves para la Taxonomía de Suelos, Undécima Edición, 2010 (PDF; Spanish translation; 3.02 MB)

Recommended citation: Soil Survey Staff. 2010. Claves para la Taxonomía de Suelos, 11th ed. USDA-Natural Resources Conservation Service, Washington, DC.

For decades, NRCS has worked with soil scientists from around the world to increase awareness and expand knowledge of the importance of soil and its impact on all aspects of life. Many soil scientists and other professionals from Latin America, the United States, and other countries will benefit from this translation effort for years to come. According to NRCS leadership, the translation will expand the horizons of U.S. Soil Taxonomy by allowing professionals in all parts of the world to apply and interpret the system in a more uniform and consistent way. While soils differ globally, the ability to apply a system that is universally understood and accepted is a goal shared by many soil scientists. As the world struggles with global warming and other environmental challenges, having a universally accepted method that can be applied when soil problems are addressed will contribute to successful outcomes.

The translation of the “Keys” into Spanish was the initiative of Luis Hernández, Arkansas State Soil Scientist. Hernández coordinated this important effort with Dr. Carlos A. Ortiz, Professor of Soil Science, Colegio de Postgraduados, Montecillo, Mexico, who undertook the large task of translating the publication into Spanish with the collaboration of Ma. del Carmen Gutiérrez-Castorena and Edgar V. Gutiérrez-Castorena. Following the translation work, the technical review was done by Spanish-speaking NRCS soil scientists and cartographers from various states and field offices: Astrid Martínez, Wyoming; Carmen L. Santiago, Puerto Rico; Nelson Rolong, Arkansas; Edwin Muñiz, New Jersey; Manuel Matos, Florida; Martín Figueroa, Florida; Milton Cortés, North Carolina; and Jorge L. Lugo, Puerto Rico. Dr. Owen Williams served as an additional consultant on the project. Editorial support was provided by Pattie West, Editor, National Soil Survey Center, Lincoln, Nebraska.

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