Field Book Forward

Purpose

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.

Background

The methodology of soil descriptions was developed by soil scientists during the entire course of the soil survey program.  The USDA published small booklets of Instructions to Field Parties, including soil descriptions in 1902-1904, 1906, and 1914.  The first USDA guide for identification and description for soil survey horizons was released in 1937 (Bureau of Chemistry and Soils, 1937).  Roy Simonson and others later summarized and revised this information (soil survey staff, 1951; soil survey staff, 1961).  Very brief, color-book inserts with short-hand notation released by the Soil Conservation Service (e.g., Spartanburg, SC, 1961; Western Technical Center, Portland, OR, 1974). This document is an expanded and updated version of earlier guides that summarizes the present knowledge base. This version (2.0) includes minor corrections and recent updates to the original 1998 release (version 1.1); Schoeneberger, et al., 1998) and updates in source documents.

Standards

This book summarizes and updates the earlier National Cooperative Soil Survey conventions for describing soils (SSM, 1993; NSSH, 1996; PDP 3.6, 1996; etc.). Much of the content is an abbreviation of the primary sources.

Regarding PEDON (PDP 3.5 / 3.6)

This document is intended to be both current and useable by the entire soil science community; it is not a guide on "How to use PDP". At this time, PDP is the most dated and therefore the least compatible NRCS document relative to the Soil Survey Manual, National Soil Survey Handbook, Soil Taxonomy, and NASIS. Differences and linkages between PDP 3.6 and NASIS are shown, where reasonable to do so, as an aid to interpreting and converting historical 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 information. The nature of databases, for better or worse, requires consistent and "correct" use of terms.

Sources

This Field Book draws from several primary sources: the Soil Survey Manual (Soil Survey Staff, 1993); the PEDON Description Program (PDP) Version 4 Design Documents (Soil Survey Staff, 1996); and the National Soil Survey Handbook (NSSH) -- Parts 618 and 629 (Soil Survey Staff, 2001). Other less pervasive sources are footnoted throughout the Field Book to encourage access to original information.

Brevity

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

Units

It is critical to specify and consistently use units for describing a soil. Metric units are preferred. NASIS requires metric units. (In PDP, you can choose Metric or English units.)

Format

The "Site Description Section" and "Profile Description Section" in this book generally follow conventional profile description format and sequence (e.g., SCS Form-232, December 1984). Some data elements (descriptors) are rearranged in this document into a sequence that is more compatible with the description process in the field (e.g., Horizon Boundary is next to Horizon Depth, rather than at the very end). This sequence is somewhat different from and does not supersede the conventions followed in writing formal soil descriptions for Soil Survey Reports or Official Soil Series Descriptions (i.e., National Soil Survey Handbook, Part 614; Soil Survey Staff, 2002).

Codes

Short-hand notation is listed in the Code column for each descriptor. Long-standing, conventional codes are retained because of their widespread recognition. Some codes of recent origin 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 Description Program codes (PDP)] and several columns may be shown to facilitate conversions. The preferred, standard code column is shown bold. If only 1 untitled code column is shown, it can be assumed that the conventional, NASIS, and PDP 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 for which no data element exists. Record such information as free-hand notes under Miscellaneous Field Notes (or User Defined Entries in PDP).

Changes

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.