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The following instructions, definitions, concepts, and codes are a field guide for making or reading soil descriptions and sampling soils as presently practiced in the USA. (Note: References cited in the Foreword are listed at the end of Chapter 1 [p. 1–31].)


Soil description methodology was developed by soil scientists throughout the entire course of the soil survey. The USDA published small instruction booklets for field parties, including soil descriptions, in 1902–1904, 1906, and 1914. The first USDA guide for soil horizon identification and description was released in 1937 (Bureau of Chemistry and Soils, 1937). Dr. Roy Simonson and others later summarized and revised this information (Soil Survey Staff, 1951; Soil Survey Staff, 1962). Brief “color-book” inserts with shorthand notation were released by the Soil Conservation Service (Spartanburg, SC, 1961; Western Technical Center, Portland, OR, 1974). Previous Field Books were released in 1998 (Schoeneberger et al.) and 2002 (Schoeneberger et al.). This is an updated Field Book version that summarizes current knowledge, includes updates since 2002, and reflects changes in source documents.


This Field Book summarizes and updates current National Cooperative Soil Survey conventions for describing soils (Soil Survey Manual [Soil Survey Division Staff, 1993]; National Soil Survey Handbook [Soil Survey Staff, 2012d]; National Soil Information System (NASIS), release 6.2 [Soil Survey Staff, 2012c]; and NASIS Data Dictionary [Soil Survey Staff, 2012a]). Some content is an abbreviation of primary sources.

Regarding Pedon PC and NASIS

The Field Book is a current, practical soil description guide for the soil science community. It is not a guide on “How To Use Pedon PC or NASIS.” Differences and linkages between soil science conventions, Pedon PC, NASIS, and older systems are shown, where reasonable to do so, as an aid for interpreting and converting archived data.

Standard procedures and terms for describing soils have changed and increased in recent years (e.g., redoximorphic features). Coincident with these changes has been the development and use of computer databases to store soil descriptions and associated information. The nature of databases, for better or worse, requires consistent and “correct” use of terms.


This Field Book draws from several primary sources: The Soil Survey Manual (Soil Survey Division Staff, 1993) and the National Soil Survey Handbook (NSSH), Parts 618 and 629 (Soil Survey Staff, 2012d). Other important sources are footnoted throughout to give appropriate credit and encourage in-depth information review. Other material is unique to this book.


In a field book, brevity is efficiency. Despite this book’s apparent length, the criteria, definitions, and concepts are condensed. We urge users to review the comprehensive information in original sources to avoid errors resulting from our brevity.

Measurement Units

For soil description, metric units are the scientific standard. Both NASIS and Pedon PC use metric units.


The “Site Description” and “Profile Description” sections generally follow conventional profile description format and sequence (e.g., SCS-Form 232, December 1984). Some descriptors are arranged in a sequence more compatible with field description rather than data entry (e.g., Horizon Boundary is next to Horizon Depth, rather than at the end). The sequence followed differs somewhat from and does not supersede convention for writing formal soil descriptions in soil survey reports or Official Soil Series Descriptions (e.g., National Soil Survey Handbook, Part 614; Soil Survey Staff, 2012d).


Shorthand notation is listed in the Code column for some descriptors. Long-standing conventional codes are retained because of widespread recognition. Some recent codes have been changed to make them more logical. Some data elements have different codes in various systems (e.g., conventional [Conv.] vs. NASIS vs. Pedon PC), and several columns may be shown to facilitate conversions. If only one code column is shown, it can be assumed that the conventional, NASIS, and Pedon PC codes are all the same.

Standard Terms vs. Creativity

Describe and record what you observe. Choice lists in this document are a minimal set of descriptors. Use additional descriptors, notes, and sketches to record pertinent information and/or features if no data element or choice list entry exists. Record such information as free-hand notes under Miscellaneous Field Notes.


Soil science is an evolving field. Changes to this Field Book should and will occur. Please send comments or suggestions to the Director, National Soil Survey Center, USDA-NRCS; 100 Centennial Mall North, Rm. 152; Lincoln, NE 68508-3866.