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NSSH Part 614

Applying Soil Taxonomy
 

614.00  Definition and Purpose

The national system of soil classification identifies sets of soil properties and groups them in taxonomic classes. The system is dynamic and amended as needed. The purpose of soil classification is to order, name, organize, understand, remember, transfer, and use information about soils.
 

614.01  Policy and Responsibilities

The National Cooperative Soil Survey (NCSS) is directed, administered, managed, conducted, and supported at various organizational levels within NRCS. Additional information about responsibilities at various levels of the organization can be found in Part 608.07(b) of this handbook and in the General Manual, Title 430, Part 402.

The partnership of the NCSS is represented by a broad diversity of educational, research and scientific, land management, and operational organizations who have a stake in the content, detail, quality, and utility of soil survey products.

It is the responsibility of all NCSS partners to participate in the review, update, and management of soil survey standards, as well as adherence to these standards relative to the Soil Survey Program. Specific responsibilities of principle partners and staff are outlined below.

The Natural Resources Conservation Service (NRCS) maintains and provides leadership for amending Soil Taxonomy and for maintaining the soil series classification data. All soil surveys within NCSS must use Soil Taxonomy.

  1. National Headquarters Office (NHQ)

    1. The Director of the Soil Science Division:
      1. Provides final concurrence to additions or amendments to Soil Taxonomy and NCSS standards documents.
      2. Supports the function of ICOMTAX:
        • Recommends membership, and
        • Supports international participation.
      3. Facilitates logistical support and communication.
      4. Supports regional and SSO staff participation in regional technical committees.
         
  2. National Soil Survey Center (NSSC)

    1. The Director of the NSSC:
      1. Provides facilities and staff necessary to review and publish approved amendments and additions to NCSS standards and other documents.
      2. Concurs on recommendations forwarded by the National Leader for Soil Survey Standards.
         
    2. The National Leader for Soil Survey Standards:
      1. Coordinates the review of proposals and amendments.
      2. Facilitates review by NCSS regional committees and ICOMTAX:
        • Notifies regional committee chairs and the Chair of ICOMTAX of needs,
        • Develops charges to the committee(s), and
        • Establishes a review schedule/timetable.
      3. Collates recommendations from all interested entities.
      4. Serves as the primary contact for the person initiating the proposal and reports interim status and final decisions.
      5. Posts original proposal, review reports and recommendations, and final decisions to publically accessible online sites.
      6. Develops comprehensive recommendations to the Director of the National Soil Survey Center and the Director of the Soil Science Division for concurrence.
      7. Codifies and publishes changes to Soil Taxonomy and other impacted standards documents, including the current version of the Keys to Soil Taxonomy and the Soil Survey Manual.
         
    3. The Technical Branches at the NSSC, within their area of responsibility or technical expertise:
      1. Assess, as assigned, the scientific validity of a proposal.
      2. Assess impacts of proposed amendments to other technical documents and standards of NCSS.
      3. Evaluate changes to soil survey information and products, including soil survey descriptions and information, interpretations and ratings, maps and geospatial products, data collection and management, survey methodologies, training, and publication.
         
  3. NCSS Regions and Cooperators

    1. Regional staff and cooperators participate as members of the various technical and business committees on standards.
       
    2. Regional staff and cooperators provide reviews of and support for Soil Taxonomy and other technical documents of NCSS.
       
    3. The Chair of the Regional Committee on Standards:
      1. Conducts reviews and develops report recommendations in timely manner.
      2. Coordinates input and comments from cooperators and stake holders.
      3. Provides written responses to the National Leader for Soil Survey Standards.
         
  4. The International Committee on Soil Taxonomy (ICOMTAX)

    1. The committee reviews proposals forwarded by the National Leader for Soil Survey Standards.
       
    2. The committee analyzes the international applications or impacts of a proposal.
       
    3. The committee sponsors proposals originating from the international community.
       
    4. The Chair of ICOMTAX:
      1. Coordinates reviews by members of ICOMTAX.
      2. Collates responses from members.
      3. Reports on findings to the National Leader for Soil Survey Standards.
         
    5. The U.S. Soil Taxonomy specialist at the NSSC serves as secretary to ICOMTAX.
       
  5. Soil Survey Regional Offices (SSROs)

    1. The Regional Director:
      1. Provides data and technical support to the review committee(s).
      2. Coordinates proposals originating from soil survey offices.
         
  6. Soil Survey Offices (SSOs)

    1. The MLRA SSO Leader:
      1. Collects data to support the review and analysis of proposals.
      2. Develops and forwards proposals to regional standards committees in order to improve soil survey standards documents (e.g., Soil Taxonomy and the Soil Survey Manual).
         
  7. State Offices

    1. State soil scientists (SSS):
      1. Assist and coordinate with NCSS State partners regarding proposals and amendments to Soil Taxonomy and NCSS standards.
      2. In general, assist all users of soil survey and ecological site information.
         

614.02  National Soil Classification System

The national soil classification system has two parts:

The first part is Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys, second edition, Agriculture Handbook No. 436, herein referred to as Soil Taxonomy. This part provides definitions and nomenclature for classifying soils. NCSS adopted this system in January 1965. Amendments to the system are periodically placed into a revised edition of the Keys to Soil Taxonomy.

The second part consists of the official soil series descriptions. The Soil Science Division maintains the official soil series descriptions in a file-share storage system  and the soil series classifications in a database. The file share and database list the classification of established, tentative, and inactive soil series of the United States, Puerto Rico, the Pacific Basin, and the U.S. Virgin Islands. The file share of the official soil series description is the official reference to soil series descriptions. The soil series classification (SC) database is the official source for the taxonomic classification of the soil series. The database contains other information about the soil series, such as which soil survey regional office (SSRO) has responsibility for the series, the series status, dates of origin and establishment, related geographic areas, and benchmark soil designation. Both the official soil series description file and the soil series classification database are available on the Internet.
 

614.03  Use of the National Soil Classification System in Soil Surveys

Soil surveys use Soil Taxonomy to provide:

  • A connotative naming system that enables those users familiar with the nomenclature to remember selected properties of soils;
  • A means for understanding the relationships among soils within a given area and in different areas;
  • A means of communicating concepts of soils and soil properties;
  • A means of projecting experience with soils from one area to another; and
  • Names that can be used as reference terms to identify soil map unit components.

Chapter 5 of Soil Taxonomy provides general information on the application of soil classification to soil maps of various scales.

The names of soil taxa are reference terms for naming the soil components of a map unit in most soil surveys. Soil taxa are classes at any categorical level in the multi-categorical system of Soil Taxonomy. The name used is generally from a taxon of the lowest category that identifies the dominant kind(s) of soil. Because soil taxa names can have several meanings, the names must be clearly understood. Chapter 7 of Soil Taxonomy provides more information. Even though names of one or more taxonomic classes identify map units, map units are not the same as soil taxa. If the fixed limits of soil taxa are superimposed on the pattern of soils in nature, the limits of taxonomic classes rarely, if ever, coincide precisely with mappable areas. In addition to the named component or components, a map unit contains components of minor extent that may be similar or dissimilar to the named soil. Part 627 of this handbook discusses major and minor map unit components and dissimilar and similar soils.

A map unit name is distinguished from a soil taxon name by adding one or more phase terms to the soil taxon reference name. For example, Gamma is a soil taxon; Gamma silt loam, saline, 0 to 2 percent slopes, is a map unit name. Part 627 of this handbook provides direction in naming map units. Chapter 5 of Soil Taxonomy and chapter 2 of the Soil Survey Manual provide additional information on the relationship between soil taxa and map units and the naming of map units.
 

614.04  Soil Taxonomy Committees, Work Groups, and Referees

  1. Regional Soil Taxonomy Committees. Each group of States within the experiment station region has a soil taxonomy committee (or other standards-related committee) as part of the Regional Cooperative Soil Survey Conference. The membership and operational procedures of the committee are described in the regional conference by-laws. These committees work on standards-related issues that are identified as being important within the region and also review proposed amendments referred to them by the National Leader for Soil Survey Standards. Members serve on a continuous basis, as needed.
     
  2. National Soil Taxonomy Committee. The National NCSS Conference has a Standing Committee on Standards that includes some members from the regional committees as well as members appointed by the Conference Steering Committee. The membership and operational procedures of the committee are described in the national NCSS conference by-laws. This committee works on standards-related issues that are identified by the Conference Steering Committee as being important, considers business items referred to it by the regional committees, and reviews proposed amendments that are referred to it by the National Leader for Soil Survey Standards.
     
  3. International Committee for Soil Taxonomy (ICOMTAX). In order to continue the improvement of Soil Taxonomy and broaden interests and global application, the International Committee for Soil Taxonomy (ICOMTAX) was established to actively promote input from the international community. ICOMTAX evaluates the technical soundness and appropriateness of international proposed amendments for inclusion in Soil Taxonomy and the Keys to Soil Taxonomy. It may also provide review of any amendments having potential international application.

    ICOMTAX operates in an advisory capacity under the Director of the Soil Science Division. Membership is by invitation of the director. It promotes the international use of Soil Taxonomy and supports the submission and review of proposals to amend Soil Taxonomy for greater use and applicability worldwide.

    ICOMTAX reviews, analyzes, and develops recommendations on amendments to Soil Taxonomy, including issues of nomenclature, diagnostic properties, features and horizons, and classes.
     
    1. ICOMTAX addresses international soil classification issues relative to Soil Taxonomy as referred from the National Leader for Soil Survey Standards. The business of ICOMTAX is conducted remotely via mail or email, teleconferences, and public comment forums. When feasible, face-to-face meetings concurrent with meetings of professional societies, such as the Soil Science Society of America (SSSA), the International Union of Soil Science (IUSS), and the World Congress of Soil Science (WCSS), are conducted.
       
    2. Members of ICOMTAX are selected from active members of NCSS, IUSS, and similar national professional soil science organizations.
       
    3. A chair and co-chair, which are appointed by the Director of the Soil Science Division, lead ICOMTAX business. The chair conducts meetings, develops reports of analyses, and provides recommendations to the National Leader for Soil Survey Standards. The co-chair assists the chair and takes over the position when the term of the current chair expires. The NRCS national technical lead for soil classification at the National Soil Survey Center serves as secretary and permanent member of the committee. This person facilitates communication, distributes proposals and recommendations, and maintains records of meetings and reports.
       
    4. Membership consists of 9 to 17 rotating members recommended by IUSS and NCSS and appointed by the Director of the Soil Science Division. Terms are 3 years. Consecutive terms are permitted and terms are staggered to provide continuity. Ad hoc participation by invited technical experts is recommended to address little known or complex issues
       
    5. The committee develops operational procedures (by-laws) and guidance documents, as needed. These documents clearly address:
      1. Receipt of proposed amendments;
      2. Discussion, analysis, and development of recommendations; and
      3. The recommendations to present to the National Leader for Soil Survey Standards.
         
    6. The National Leader for Soil Survey Standards reviews and processes the recommendations of ICOMTAX for final determination.
       
  4. National Ad Hoc Work Groups. The Director of the Soil Science Division appoints work groups as needed. The work groups review reports from regional soil taxonomy committees and recommend additional study or implementation of proposed amendments. Members include representatives of State and Federal agencies and may include international representatives. The chairperson of a group, usually a member of the National Soil Survey Center staff, and other members are chosen according to the nature of the recommended changes and the expertise needed.
     
  5. International Committees. The Director of the Soil Science Division may establish international committees under the structure of ICOMTAX to address technical or scientific issues that affect international users of Soil Taxonomy and require major additions or changes in the soil classification system. Membership is open to any user of Soil Taxonomy and usually includes representatives of State and Federal agencies as well as international cooperators. Charges are focused and specific, and committees operate for a specified duration.
     
  6. Referees. The director may request that referees prepare position papers on proposed amendments. The referee requests, as needed, a review by peers and assumes the responsibility for decisions regarding the proposal.
     

614.05  Procedures for Amending Soil Taxonomy

Soil Taxonomy is a dynamic system for classification of soils. It is designed to be open-ended, permitting the addition of diagnostic features and classes which help explain the pedogenic history and broad interpretative qualities of soils. Inferred taxonomic classes are not added until they are actually described and documented.

Recommendations for amending Soil Taxonomy must be fully developed and documented prior to submission to the National Leader for Soil Survey Standards. Established guidelines are followed in proposals and the submission of proposals as well as in the evaluation and testing. Proposals that meet requirements and are approved are drafted into amendment form and posted for open review and comment. Based upon review comments, the proposal is adopted and integrated, rejected, or sent back for further development and documentation. Exhibit 614-1 illustrates the processing of proposals to amend Soil Taxonomy.

  1. Considerations in Proposing Amendments to Soil Taxonomy

    1. An amendment should address questions of soil classification, including diagnostic features, diagnostic criteria, and taxonomic classes through family level.
       
    2. An amendment should add value and clarity to Soil Taxonomy, or accommodate needed classes as discovered.
       
    3. An amendment should be based upon soil properties that can be observed or measured and serve as the basis for diagnostic criteria.
       
    4. An amendment should be placed logically within the Soil Taxonomy hierarchy, ie., within the order, suborder, great group, subgroup, family, or series.
       
    5. Definitive diagnostic criteria should be developed and defined.
       
    6. The impacts or consequences to the overall system of Soil Taxonomy should be considered. For example:
      1. Does the amendment provide clarity to the classification system or improve interpretative value?
      2. Will the amendment require excessive modifications throughout the Soil Taxonomy system, affecting a large number of taxa or series?
      3. Will the amendment impact existing State or Federal regulations or statutes?
      4. Can the amendment be implemented readily?
         
  2. Submitting Proposed Amendments

    1. Proposals may be made by anyone using Soil Taxonomy from within or outside the United States. Proposals that originate in the United States should be submitted to the National Leader for Soil Survey Standards. This individual determines routing to the appropriate regional soil taxonomy committee chairs and ICOMTAX.
       
    2. Proposals that originate outside the United States should be submitted to the National Leader for Soil Survey Standards at the National Soil Survey Center, Federal Building, Room 152, 100 Centennial Mall North, Lincoln, Nebraska, 68508-3866. Proposals may be surface mailed or sent as attachments in email messages. (See the National Soil Survey Center Directory for the current email address of the National Leader for Soil Survey Standards.)
       
  3. Documenting Proposed Amendments

    1. Criteria for new taxa above the family category. The minimum supporting evidence for all proposed classes must include pedon descriptions, the impact on interpretations, an estimate of geographical extent, and certain laboratory data. Laboratory data is required for at least the critical parts of diagnostic horizons in the proposed new class if the limits between the proposed class and the other recognized classes cannot be adequately identified using field criteria alone.
       
    2. Criteria for a new class in the family category. The minimum supporting evidence includes about 10 pedon descriptions or a description of a proposed soil series and the expected impact on interpretations for the intended use. Laboratory data is required for at least the critical parts of the proposed new class if the limits between the proposed class and the other recognized classes cannot be adequately identified using field criteria alone.
       
    3. Support of the review process. Proposals should include the following materials:
      1. Soil/site descriptions, as appropriate to support the proposal
      2. Definitions of new terminology
      3. Analytical results using procedures in SSIR #42 (the Laboratory Methods Manual)
      4. Graphics, illustrations, maps, and photos
      5. Citations and technical references
      6. Justification of metrics and limits for the classes or differentiae being proposed
      7. Brief analysis of improvement to soil survey maps, data, and descriptions relative to use and management of soil or improvements to soil science procedures and processes in general
      8. Brief analysis of geographic extent or application of the proposal
      9. If appropriate, brief analysis of impacts to NCSS soil survey standards and procedures, such as the Keys to Soil Taxonomy and the Soil Survey Manual
         
  4. Evaluating Proposed Amendments

    1. The National Leader for Soil Survey Standards, located at the National Soil Survey Center, circulates the proposed amendment to NCSS cooperators and ICOMTAX for review. Proposed amendments are also posted online on the Soil Taxonomy webpage under the heading “Proposals to Amend Soil Taxonomy.” Review and comment are welcome from any interested cooperators. Those who are current members of the regional taxonomy committees have a special obligation to review and comment on proposals. Review teams recommend approval without change, approval with change, or rejection.
       
    2. The National Leader for Soil Survey Standards evaluates all proposals from the international committees and other proposals that originate outside the
      United States, arranges a review of these proposals by cooperators or work groups and by ICOMTAX, and determines disposition for proposals.

       
    3. If a significant proposal is rejected, the originator is typically sent recommendations for improving the amendment for a future resubmission. Rejected
      amendments can be appealed to the Director of the Soil Science Division for reconsideration.

       
    4. Recommendations to change or reject the proposal are documented. The National Leader for Soil Survey Standards reviews the recommendations and either makes a decision to return the proposal to the originator with reasons for the rejection or includes the proposal in a transmittal (by email or surface mail) to the chairs of the regional soil taxonomy committees and ICOMTAX.
       
    5. If the proposal is accepted and concurred by the Director of the Soil Science Division, it is incorporated into Soil Taxonomy and related standards documents.
       
    6. The Deputy Chief for Soil Science and Resource Assessment in NRCS issues a national bulletin to announce changes to the Keys to Soil Taxonomy or Agriculture Handbook 436 (Soil Taxonomy). Issuance of this bulletin gives the final official approval for the changes.
       
  5. Distributing Amendments. The publication of proposed amendments constitutes final approval. New editions of the Keys to Soil Taxonomy and/or Soil Taxonomy include these amendments. All soil scientists of NCSS and other soil scientists, both national and international, receive new editions of these documents.
     

614.06  The Soil Series

The soil series is the lowest category of the national soil classification system. The name of a soil series or the phase of a soil series is the most common reference term used in soil map unit names. The name of a soil series is also the most common reference term used as a soil map unit component. The purpose of the soil series category is closely allied to the interpretive uses of the system. Map unit components provide the interpretive applications within soil survey for the most detailed purposes. Soil series are the most homogeneous classes in the classification system.

Chapter 21 of Soil Taxonomy and chapter 17 of the current edition of the Keys to Soil Taxonomy provide guidance for series differentiae within a family.

  1. Establishing Norms and Class Limits for Soil Series

    1. In developing or revising soil series concepts, systematic procedures are essential. They reduce the possibility of recognizing more soil series than are necessary to organize and present existing knowledge about soil behavior. The distinctions between one soil series and its competitors must be large enough to be consistently recognized and to be recorded clearly. Clearly differentiate each soil series from all other soil series. Simplify this differentiation by using the systematic procedure described in this section.
       
    2. Assemble and study all available information on morphology, composition, position on the landscape, and geographic distribution of the soils being considered. Compare the available information with the concepts of existing soil series and evaluate possible concepts for new soil series. Refine soil characteristics that define higher categories of Soil Taxonomy to differentiate one soil series from another. These characteristics reflect the kind and sequence of horizons that can be observed, or they are observable and can be consistently measured. Only use those characteristics that are observed or measured within the soil series control section to differentiate soil series. Chapter 21 of Soil Taxonomy provides more information on the series control section. A significant soil characteristic is one that has genetic implication, such as the nature or arrangement of horizons or the absence of horizons, or one that has an influence on use and management, such as percent of gravel or reaction. Exercise judgment in the selection and weighing of soil characteristics used to separate soil series. Chapter 21 of Soil Taxonomy and chapter 17 of the current edition of the Keys to Soil Taxonomy further discuss soil series and their differentiae.
       
    3. Competing soil series are those that are in the same family as the soil series under study. Changing the concept of one soil series likely necessitates modification to the concepts of other soil series in the family.
       
    4. When proposing a new series, conceptualize a model of it. Develop a model with a specific norm and range in characteristics for the proposed soil series description. Some of the characteristics of the new series may overlap the characteristics of an existing series; however, the range for differentiating characteristics cannot overlap that of an existing soil series in the same family. Limits of the range in soil characteristics for the proposed soil series may be as wide as those permitted in the family to which it belongs. Generally keep the range in differentiating soil characteristics of the soil series narrower than that for the span of the family. The permissible ranges must not be too narrow for precise and consistent identification. They must be practical.
       
    5. Select a pedon that is typical for the soil series concept. The typical pedon is a reference specimen that illustrates the central concept for the soil series. This pedon, along with other very similar pedons, forms the model for the soil series class. Thus, the selection of a typical pedon is a very important process and must be done with great care. Base it on the arrayed data on morphology, composition, and geographic distribution. A pedon is not likely to be central for all ranges, but the representative pedon should lie reasonably near the center of the ranges for most physical and chemical properties and for the geographic distribution. If the pedon selected to typify a soil series has one or more properties unusual for the soil series class, record the properties as part of the range of characteristics and note them in the “Remarks” section of the description.
       
    6. After selecting the typical pedon, define the permissible ranges for soil properties and qualities. Use the arrayed information on morphology and composition of the soils, especially the profile descriptions, field notes, and laboratory analyses. If laboratory data are used to define ranges in soil properties, use the conventional rules for rounding (see Exhibit 614-4) to round numerical values to digits used for taxonomic classification (see Exhibit 614-5).
       
    7. Although only part of the set of observed properties defines the classification of any soil, all properties should be considered when defining the soil series. Not all observable soil properties are necessarily definitive for a soil series class. The definitive properties that separate a soil series from similar but competing soil series are essential. Emphasize these properties in the statement of the range of characteristics. Also describe the ranges in significant properties that do not differentiate between the soil series being described and its competing soil series.
       
    8. Test the soil series concept. Check the norm and ranges in characteristics against the class limits for the family to which the soil series belongs. Do not cross the limits of the family with the ranges specified for the soil series. The distinctions in definitive characteristics between the norms for the proposed soil series and the norms for competing soil series must be clearly greater than what may be normal errors of observation or be based on laboratory data and geomorphic or geographic information. Do not overlap ranges in differentiating characteristics.
       
    9. Differences in a single characteristic are seldom used to separate soil series. Use the distinctions in several characteristics to separate soil series. Some may have greater importance than others. A new soil series is justified if the differences in morphology and composition are clearly greater than what could be normal errors of observation and these differences affect use and management. Deciding whether or not to propose a new soil series is difficult when two or more properties of the soils to be classified are outside but near the limits of an existing soil series. Propose new soil series if the soils differ in characteristics that have practical significance to use and management.
       
  2. Allowing Normal Errors of Observation. As a general rule, a new soil series differs appreciably in either morphology or composition, or both, from already defined soil series. Differences in relevant characteristics must be larger than what may be normal errors of observation or estimates. The following paragraphs give examples of allowed normal errors of observation and tolerance. Soils within these tolerances do not need a new series, nor do they need to be named as taxadjuncts.

    1. Identification of soil color in the field is subject to errors because of (i) changes in the quality of light and in soil moisture, (ii) differences in the visual acuity and skill of individuals, and (iii) limitations in the standards used to determine color. Chapter 3 of the Soil Survey Manual provides a discussion of soil color. Field observations of soil color are taken at different times of the day and at differing soil moisture contents. These variables could result in differences as large as a full interval between chips in the Munsell color system. The differences in identification of soil color resulting from one person looking at the same specimen at different times and under different conditions or from a group of individuals looking at the same specimen together are an example of normal errors of observation. Optimum field conditions allow soil color to be matched to within one-half interval between chips on the color chart. The normal range of difference between careful observations is plus or minus a half interval between chips of the same hue or between chips of the same value and chroma on adjacent hues. Color distinctions, if definitive, between the soils of two soil series must be greater than this normal range.
       
    2. Field estimates of texture are commonly within plus or minus one-half class of the actual texture, though errors by highly skilled individuals are smaller. To separate soil series that are based in part on differences in texture, use distinctions that are greater than the probable error of field estimates or use laboratory data and geomorphic or geographic information. This rule applies to the entire soil series control section and any of its parts. Not all differences among soil series are obvious. The limit between the fine-loamy and fine particle-size classes is a clay content of 35 percent. The experienced mapper has little difficulty in distinguishing between 30 percent and 40 percent clay. However, only the laboratory can consistently distinguish between 34 percent and 36 percent clay content. If this is the only difference, the distinction is not important for most uses of the soil map. Name the map unit for either of the two soil series that have a common conceptual boundary at 35 percent clay. Differences that are no greater than the normal errors of observation cause many needless decisions, even for an experienced mapper. If the estimate of the properties varies by these normal errors, the similar soils do not seriously affect the use of the map as long as the map units are defined to allow for the variation.
       
  3. Proposing and Naming a Soil Series

    1. Soil scientists in NCSS write and complete descriptions of new soil series and their ranges for soil properties. Ranges for soil properties are estimated, measured, or both. Part 627.08(e)(1) of this handbook contains documentation requirements.
       
    2. The soil series classification (SC) database contains a complete list of active and inactive soil series. It provides the official classification for all soil series in the official soil series description (OSD) file share. When naming a proposed series, give preference to the names of geographic places as a source of possible names.

      In choosing a name, avoid using:
      1. Names consisting of very long words;
      2. Names with any characters other than letters, spaces, periods, apostrophes, or grave accents;
      3. Bizarre, discriminatory, comical, or vulgar words;
      4. Geological terms, such as the names of rocks, minerals, landforms, and the formations of a locality;
      5. Names of plants and animals;
      6. Given names of persons, unless the name is a known geographic location or feature;
      7. Copyrighted names and registered trademarks;
      8. Names essentially identical in pronunciation to a name already in use (e.g., Whit vs. Witt); and
      9. Names similar in spelling to a name already in use (e.g., Tonnor vs. Tonor).
        Series names with a similar spelling should differ by at least two characters. Names consisting of two words must differ by more than just the space between the two words from similarly spelled single-word series names. Names of local geographic feaures of places are preferred. If these are unavailable, the coined names may be used. Geographic place names must also avoid all restrictions listed above. Coined names must be consistent with American usage and free from the restrictions listed above. The series name can contain only letters, spaces, periods, or apostrophes (single quotes), and the grave accent (`) as characters. The words “AUX,” “CON,” “NUL,” and “PRN” are considered reserved and cannot be used as soil series names due to constraints imposed by the SC database. Refer to the SC/OSD maintenance tool user’s guide for more information on series names.

         
    3. After the proposed soil series description is revised within the MLRA soil survey region, the soil survey regional office (SSRO) that has responsibility for the new series approves the name and reserves the series by entering required data into the SC database. The minimum data required to enter a new series into the SC database consists of the series name, responsible SSRO, State having the type location, complete taxonomic classification, and at least one MLRA in which that series occurs. By default, the new soil series is identified as having tentative status and the current year of proposal is assigned. The SSRO enters the soil series description into the OSD file share, where it is available for the adjoining SSROs and cooperators to review and provide comment. The entry of new OSDs should occur as soon as possible in order to minimize the inconvenience to other users of having series in the SC database without a corresponding OSD for viewing. A notification and request for comments is sent to adjoining SSROs, state soil scientists within the MLRA, and to all other SSROs that have soil series in the same family as the proposed series.
       
    4. The responsible SSRO evaluates any comments and prepares a revision of the soil series description. The revised description is transmitted to the official soil series description file. If the decision is made not to use the series, the SSRO removes the tentative soil series from the SC database. This causes the tentative soil series description in the OSD file share to move to an inaccessible file.
       
    5. The responsible SSRO resolves disagreements on concepts of soil series. It assembles and evaluates available evidence on the points in question and, if necessary, requests additional information about the soils under consideration from one or more MLRA soil survey regions. If the soil series is in dispute or if the questions about the soil series concept are of considerable importance, a joint field study may be necessary. After the differences have been resolved, the SSRO updates the soil series description in the OSD file share.
       
  4. Revising Official Soil Series Descriptions

    1. Soil scientists must revise soil series descriptions if one or more of the following conditions exist:
      1. A change in the concept of the soil series, including the range in characteristics;
      2. A change in the classification of the soil series; or
      3. A change in the type location of the soil series.
         
    2. Any soil scientist in NCSS can write revisions of soil series descriptions. These descriptions are submitted to the SSRO assigned responsibility for the series. The responsibility for maintenance of a series is populated in the SC database and is shown in the OSD. The revision is based on pedon descriptions, laboratory data, and other available sources of information about the soils that represent the series.
       
    3. If the soil series classification, range in characteristics, or type location is changed, the SSRO reviews these changes within the MLRA soil survey region and with other MLRA soil survey regions and state soil scientists in which the soil series or competing series is known or expected to occur. After critical review, scientists return comments to the originating SSRO. The staff soil scientist at the SSRO evaluates the comments and makes the necessary changes in the revised description of the soil series. The SSRO soil scientist updates the classification of the soil series in the soil series classification file, if necessary, and then revises the official soil series description.
       
  5. Inactivating an Established Soil Series. When it is appropriate, SSROs may change the status of a soil series from “established” to “inactive.” They support the decision to inactivate a soil series with documentation as to why the soil series should be made inactive and a recommendation for the disposition of the soils that have been classified in the inactive series. Before changing the status of a soil series to inactive, the SSRO with responsibility for the series sends a memorandum of intentions and supporting reasons to affected state soil scientists and SSROs. The responsible SSRO notifies members of other disciplines and cooperators who may use the series name in databases and publications. About 45 days are allowed for filing objections to the recommendation. If the SSRO determines that the soil series should be made inactive, it notifies the affected regions. The memorandum includes the reclassification to the appropriate soil series or to a taxon of a higher category of all pedons in the inactive series that have been sampled and analyzed by NRCS, cooperating universities, highway departments, or other laboratories. Inactive soil series are retained in the soil series classification database. The OSD of the inactivated series is updated with information from the memorandum of intentions that provides the reason for the status change and the recorrelation of existing components to other named series.
     
  6. Reactivating an Inactive Soil Series Name. Do not reuse the name of a soil series that is placed on the inactive list unless the series concept is the same as in the previous description. If a SSRO wants to reactivate a soil series name, they follow the procedure that is used to propose a soil. Make a notation under “Remarks” that the soil series name is being reactivated.
     
  7. Dropping a Tentative Soil Series. Drop a tentative soil series from the soil series classification database if it duplicates an already recognized series.

    1. If multiple SSROs use the soil series, the SSRO with responsibility for the series requests concurrence from affected SSROs to drop the series. Note that responsibility for maintenance is generally determined by the type location of a series. Upon concurrence, the SSRO notifies the users that the series is dropped. The notification includes a statement of reasons for dropping the series. Note the name of the dropped series in the correlation document of the soil survey area that has the type location.
       
    2. If only the SSRO with responsibility is using a soil series listed as tentative, it drops the series by listing it as dropped in the correlation document of the survey area that has the type location.
       
    3. Remove the name and record from the soil series classification database. This causes the description in the official soil series description file to move to an inaccessible file. Do not list a tentative soil series as inactive.
       
  8. Transferring Responsibility for a Soil Series and Changing the Type Location. Approval for transfer of the responsibility for a soil series and change of type location is as follows:

    1. The responsible SSRO approves changes within the MLRA soil survey region.
       
    2. Mutual consent of the SSROs allows transfers of responsibility between MLRA soil survey regions. All transfers of soil series responsibility and changes of type location require a series description using the new type location. The SSRO receiving responsibility enters the new description into the database.
       
  9. Establishing a Soil Series. A soil series is established when it is used in the correlation of a survey area and the correlation document is approved and signed by the SSRO. The correlation document contains a list of the soil series that are established by that correlation. If a soil series is established by a correlation, the responsible SSRO changes the status of the series in the official soil series description file and the soil series classification database from “tentative” to “established” and concurrently changes the heading from “SERIES PROPOSED” to “SERIES ESTABLISHED” in the official description. The SSRO also enters the year that the soil series is established in both the soil series classification database and the official series description file and then enters the name of the survey area (which may be a MLRA) in which it is established. The SSRO uses the SC/OSD maintenance tool (a web application protected by USDA eAuthentication) to perform these tasks. If a tentative soil series is not used and established in the correlation document for the survey area in which it was proposed and no other potential use is pending, the soil series is removed from the soil series classification database.
     
  10. Making and Managing Official Soil Series Descriptions

    1. The term “official soil series description” indicates the description approved by the SSROs which defines a specific series in the United States. The description follows a prescribed format, which is defined in Exhibit 614-3. An official soil series description needs to be revised if more information about the soils in the series is available or if the classification of the series changes because of revisions to the national system of soil classification. All soil scientists working in NCSS must be familiar with the requirements for adequate soil series descriptions. The Soil Survey Manual and chapter 21 of Soil Taxonomy discuss the concept of the soil series and requirements for descriptions. Field descriptions and official soil series descriptions should use metric units of measurement.
       
    2. The official soil series descriptions are descriptions of the taxa in the series category of the national system of soil classification. They mainly serve as specifications for identifying and classifying soils. Field soil scientists must have access to all the existing official soil series descriptions that are applicable to their soil survey areas and other official soil series descriptions that include soils in adjacent or similar survey areas. Scientists in other disciplines, such as agronomists, horticulturists, engineers, planners, and extension specialists, also use the descriptions to learn about the properties of soils in a particular area.
       
    3. The major items in descriptions and the order in which they appear are as follows:
      1. Location line with first instance of series name and the States using it (FIPS code)
      2. Status of soil series (tentative, established, or inactive)
      3. Initials of authors
      4. Date of latest revision (auto-generated in mm/yyyy format)
      5. Name of soil series
      6. Introductory paragraph
      7. Taxonomic class
      8. Typical pedon
      9. Type location
      10. Range in characteristics
      11. Competing series
      12. Geographic setting
      13. Geographically associated soils
      14. Drainage and saturated hydraulic conductivity (permeability in older series)
      15. Use and vegetation
      16. Distribution and extent
      17. Soil survey regional office (SSRO) responsible
      18. Series proposed or series established
      19. Remarks on diagnostic horizons and features recognized in the pedon
      20. Additional data as needed

        Every official soil series description includes all but the “additional data” item, which is used only as needed. Exhibit 614-2 is an example of an official soil series description as it would appear on the Internet. Exhibit 614-3 explains the content of a soil series description.

         
    4. Each description must be complete and as brief as possible without omitting any essential information. It must clearly differentiate between the series being described and all other series. It must state the present concept of a soil series rather than past concepts or its evolution. The description must record the soil properties that:
      1. Define the soil series,
      2. Distinguish it from other soil series,
      3. Serve as the basis for the placement of that soil series in the soil family, and
      4. Are needed to generate soil interpretations in the National Soil Information System (NASIS).
         
    5. In the competing series paragraph, give differentiae used to separate other soils in the same family in terms of soil properties, diagnostic horizons, or features.
       
    6. Use the standard terminology that is defined in the Soil Survey Manual as appropriate. If applicable, use terms defined in Soil Taxonomy. The rule for the use of standard terms applies to all parts of soil series descriptions but is especially important for descriptions of individual horizons. Some soil descriptions need to use some terms that are not defined in the Soil Survey Manual or Soil Taxonomy. Use such terms in their ordinary, standard, dictionary sense.
       

Exhibit 614-1—Flow Chart of Amendment Process

Exhibit 614-1 - Flow Chart of Amendment Process.
















High Resolution Image (3000 x 2126, 806 KB, JPG format)
 

Exhibit 614-2—Example of an Official Soil Series Description in HTML

LOCATION GAMMA                  AA

Established Series
Rev. AAA-BBB-CCC
11/2013

GAMMA SERIES

The Gamma series consists of very deep, well drained soils that formed in marine sediments. Gamma soils are on broad summits, shoulders, and backslopes of deeply dissected, high marine terraces. Slopes are 0 to 30 percent. The mean annual precipitation is about 2030 mm and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-loamy, siliceous, semiactive, isomesic Typic Palehumults

TYPICAL PEDON: Gamma loam, on a north-facing, convex, 4 percent slope under conifers at an elevation of 200 meters. (Colors are for moist soil unless otherwise noted. When described on March 13, 1991, the soil was moist throughout.)

Oi--0 to 5 cm; slightly decomposed plant material consisting of needles, leaves, twigs, and other woody debris. (2 to 8 cm thick)

A1--5 to 13 cm; very dark grayish brown (10YR 3/2) loam, dark grayish brown (10YR 4/2) dry; weak very fine subangular blocky structure parting to weak fine granular; slightly hard, friable, nonsticky and nonplastic; weakly smeary; many fine and very fine and few medium and coarse roots; many fine and very fine interstitial pores; very strongly acid (pH 4.9); clear smooth boundary.

A2--13 to 43 cm; very dark grayish brown (10YR 3/2) loam, brown (10YR 4/3) dry; weak very fine subangular blocky structure parting to weak fine granular; slightly hard, friable, nonsticky and nonplastic; weakly smeary; many very fine and fine and few medium and coarse roots; many fine and very fine interstitial pores; very strongly acid (pH 4.5); abrupt smooth boundary. (Combined thickness of the A horizons ranges from 25 to 50 cm.)

2Bt1--43 to 80 cm; dark brown (7.5YR 3/4) loam, strong brown (7.5YR 5/6) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine and few medium and coarse roots; many very fine tubular pores; few faint clay films on all faces of peds; common faint clay films on surfaces along pores; 10 percent gravel; very strongly acid (pH 4.9); gradual smooth boundary.

2Bt2--80 to 100 cm; reddish brown (5YR 4/4) loam, yellowish red (5YR 5/8) dry; moderate medium and coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine and few medium and coarse roots; common very fine tubular pores; common distinct clay films on all faces of peds and on surfaces along pores; 10 percent gravel; very strongly acid (pH 5.0); clear smooth boundary.

2Bt3--100 to 135 cm; brown (7.5YR 4/4) clay loam, strong brown (7.5YR 5/6) dry; moderate medium and coarse subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common fine and few medium and coarse roots; many very fine tubular pores; common distinct clay films on all faces of peds and on surfaces along pores; 10 percent gravel; very strongly acid (pH 5.0); gradual smooth boundary. (Combined thickness of the 2Bt horizons is 75 to 120 cm.)

2BC--135 to 160 cm; strong brown (7.5YR 4/6) gravelly clay loam, strong brown (7.5YR 5/8) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common fine tubular pores; 20 percent gravel; very strongly acid (pH 5.0); gradual smooth boundary. (15 to 40 cm thick)

2C--160 to 200 cm; yellowish red (5YR 4/6) gravelly clay loam, reddish yellow (5YR 6/6) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common fine tubular pores; 20 percent gravel; very strongly acid (pH 5.0).

TYPE LOCATION: Any County, Anystate; located about 750 feet south and 2,220 feet east of the northwest corner of section 31, T. 40 S., R. 13 W; USGS named topographic quadrangle; latitude 42 degrees 4 minutes 31.6 seconds N. and longitude 95 degrees 17 minutes 30.3 seconds W., WGS84.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 10 to 12 degrees C, the mean summer soil temperature is 12 to 14 degrees C, and the mean winter soil temperature is about 8 to 10 degrees C. The difference between the mean summer and winter temperatures ranges from 3 to 4 degrees C. The soils are usually moist; they are dry for less than 45 consecutive days in all parts between depths of 10 to 30 cm in the 4 months following the summer solstice. The particle-size control section averages 25 to 35 percent clay. All horizons are very strongly acid or extremely acid. The umbric epipedon is 25 to 50 cm thick.

The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist or 3 or 4 dry, and chroma of 2 or 3 moist or dry. It is 10 to 20 percent clay and 30 percent sand and has 0 to 10 percent gravel.

The 2Bt horizon has hue of 7.5YR or 5YR, value of 3 or 4 moist or 4 or 5 dry, and chroma of 4 to 6 moist or 6 to 8 dry. It is gravelly loam, gravelly clay loam, loam, or clay loam. It averages 25 to 35 percent clay, 30 to 45 percent sand, and 5 to 20 percent gravel.

The 2BC horizon has hue of 7.5YR or 5YR, value of 4 to 6 moist or 5 to 8 dry, and chroma of 6 to 8 moist or dry. It is gravelly loam, gravelly clay loam, loam, or clay loam. It averages 25 to 35 percent clay, 30 to 45 percent sand, and 10 to 30 percent gravel.

The 2C horizon has hue of 7.5YR or 5YR, value of 4 to 6 moist or 6 to 8 dry, and chroma of 6 to 8 moist or dry. It is gravelly loam, gravelly clay loam, loam, or clay loam. It averages 25 to 35 percent clay, 25 to 45 percent sand, and 10 to 30 percent gravel.

COMPETING SERIES: This is the Beta series. Beta soils have less than 30 percent sand in the argillic horizon and hue of 10YR or yellower throughout the argillic horizon.

GEOGRAPHIC SETTING: Gamma soils are on broad summits, shoulders, and backslopes of deeply dissected, high marine terraces. Slope ranges from 0 to 30 percent. The soils formed in marine sediments. Elevations are 180 to 250 meters. The climate is humid and characterized by cool, wet winters and cool, moist summers with fog. Because of a strong marine influence, the diurnal and annual ranges of temperature are limited. The mean annual precipitation is 1800 to 2300 mm. The mean annual temperature is 10 to 12 degrees C. The frost-free period is 210 to 300 days. Gamma soils are on the Griggs geomorphic surface.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delta and Sigma soils. Delta soils have 35 to 45 percent clay in the argillic horizon and are on an adjacent higher marine terrace. Sigma soils have a cambic horizon, an umbric epipedon that is 50 to 75 cm thick, and are on adjacent, lower-level marine terraces.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity

USE AND VEGETATION: Gamma soils are used for homesites, timber production, recreation, water supply, pasture, and wildlife habitat. Native vegetation is Sitka spruce, Douglas-fir, red alder, red elderberry, salmonberry, evergreen huckleberry, sala, western swordfern, evergreen violet, and sweetscented bedstraw.

DISTRIBUTION AND EXTENT: Pleistocene marine terraces in the northwestern United States; MLRA 1. These soils are moderately extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: City, State

SERIES ESTABLISHED: Any County, Anystate, 2009

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Umbric epipedon – the zone from a depth of 5 to 43 cm (A1 and A2 horizons)
Argillic horizon – the zone from a depth of 43 to 135 cm (2Bt1, 2Bt2, and 2Bt3 horizons)

ADDITIONAL DATA: Partial laboratory data from pedon 89P0197, samples 89P1199-1202 from Any County, Anystate, is available from the NRCS-NSSC-Kellogg Soil Survey Laboratory, Lincoln, NE, 12/1989.

National Cooperative Soil Survey
U.S.A.
 

Exhibit 614-3—Explanation and Content of a Soil Series Description

Explanation of a Soil Series Description

After the introductory paragraph, the format for soil series descriptions arranges the subject matter in two main parts. The first part includes the taxonomic classification, the description of the typical pedon, the type location, the section on range in characteristics, and the section on competing series. This part and the description of the diagnostic horizons and features in the “Remarks” section defines the soil series as a class in the soil classification system insofar as the available information permits. The second part includes all the remaining sections of the soil series description which provide additional descriptive information.

The guidelines for keying soil series descriptions are as follows:

  • Left margin is in column 1. Right margin is in column 66.
     
  • Tabs, stop codes, required hyphen codes, required backspace codes, automatic centering, and underlines are not used. The spacebar is used instead of tabs.
     
  • Everything is left justified. The horizon designations do not need to be indented.
     
  • Section headings are in capital letters, for example, TAXONOMIC CLASS and TYPICAL PEDON, and followed by a colon (:). Do not begin any line, other than the section headings, with words or abbreviations in capital letters plus a colon. The validation of descriptions with the SC/OSD Maintenance Tool will return error messages for unexpected headings unless attention is given to proper format.
     
  • Depths and thickness (cm), temperature (whole degrees C), precipitation (mm), and elevation (meters) are in metric units of measure; acreage and legal descriptions (longitude and latitude in degrees, minutes, and seconds with WGS84 as horizontal datum are preferred) are in English units. General locations can be given in feet and miles.
     
  • Special symbols, subscripts, and superscripts must be expressed as words. (For example: 10° is changed to 10 degrees, CaCO3 is changed to calcium carbonate, and 10% is changed to 10 percent.)
     
  • The first 8 lines and the last line of the soil series description must be standardized in order for the validations of the SC/OSD maintenance tool to work. All entries are left justified and start in column 1.

The line-by-line instructions are as follows:

Line 1--LOCATION GAMMA                  NE (This line is entered in capital letters. The first letter of the State where the soil series is located must be in the 33rd character location starting from the leftmost side at the first character location. If other States are using the series, the first letter of the other State must be in the 36th character location. Any other States using the series follow in alphabetical order.)

Line 2--Blank line

Line 3--Tentative Series or Established Series (Note: Even series with inactive status are shown as such on this line.)

Line 4--Rev. MLD-JRC [These are the initials of the individuals who last revised the soil series. The initials are separated by a hyphen (-), a slash (/), or a comma (,).]

Line 5--08/2012 (This is the two-digit month and four-digit year in which the official soil series description was last revised in the soil series classification database or in the official series description file share. The system enters this date automatically.)

Line 6--Blank line

Line 7--GAMMA SERIES (All letters are capped.)

Line 8--Blank line

Line 8 is followed by the introductory paragraph and the rest of the soil series description.

Next to last line--National Cooperative Soil Survey

Last line--U.S.A. (All letters are capped and do not have spaces inbetween.)

The completed description must be run through a spell checker in word-processing software.
 

Content of a Soil Series Description

  1. Introductory paragraph. This paragraph carries no side heading. It briefly describes the depth, drainage class, soil parent materials, landform(s), and any other significant features that characterize the soil series and the geomorphic setting. This information benefits people who refer to the official soil series descriptions but are not well acquainted with the taxonomic classification system. If used in the introductory paragraph, depth refers to depth to bedrock unless some other restrictive feature that is important to plants or engineering interpretations is specified. If a restrictive feature is at some depth within the soil profile, describe by such statements as “very shallow to sandstone or shale,” “very deep soils that have gravel layers at a depth of 15 to 100 cm,” “moderately deep to rhyolite,” or “shallow to a duripan.” The temperature and precipitation are mean annual values for the soil series. Do not use the terminology in Soil Taxonomy in the introductory paragraph. Do not use hyphens in drainage classes (e.g., “well drained,” not “well-drained”).

    Examples of the introductory paragraph are:

    “The Sigma series consists of very deep, well drained soils that formed in a thin deposit of loess overlying loamy till. Sigma soils are on moraines, drumlins, and till plains. Slopes are 0 to 25 percent. The mean annual precipitation is about 600 mm, and the mean annual temperature is about 8 degrees C.”

    “The Beta series consists of very poorly drained, organic soils in drainageways and depressions on moraines, lake plains, and outwash plains. These soils formed in highly decomposed organic material over loamy glacial and lacustrine deposits. The organic material was derived from herbaceous plants. Slope ranges from 0 to 2 percent. The mean annual precipitation is about 800 mm, and the mean annual temperature is about 2 degrees C.”
     
  2. Taxonomic Class. This statement gives the family classification. If the classification is questionable, explain it in the “Remarks” section.
     
  3. Typical Pedon. Use the side heading in the description, as indicated. The soil series name and texture phase term or the word “series” follows the side heading. Next are the aspect, shape, and percent of slope and a word or phrase, such as “forested,” “pasture,” “cultivated field,” or other term, for use or cover that shows whether or not the soil at the site has been disturbed. Place a parenthetical statement immediately below the heading and soil name to specify the moisture state of the soil when it was described. If the soil was nearly dry in the upper 60 cm and moist below, the statement, “When described, the soil was slightly moist above a depth of 60 cm and moderately moist below” is used.

    An example of this paragraph is:

    “Gamma silt loam on a southeast-facing, concave, 3 percent slope under mixed hardwoods at an elevation of 500 meters. (Colors are for moist soil unless otherwise stated. When described on July 1, 1985, the soil was slightly moist to a depth of 60 cm and moderately moist below that depth.)”

    1. Descriptions of horizons. These descriptions are in paragraph form. They ordinarily consist of three parts: the horizon designation, the horizon depths, and the detailed description of the observed horizon morphology.
       
    2. Pedon described. Describe an actual pedon. The pedon chosen as the typical pedon must reflect the norm for the soil series as closely as possible. The norm is the concept or mental image of the central nucleus of pedons for the soil series. The pedon may depart in minor ways from the norm without a need for explanation. If it departs from the norm in some obvious feature, however, indicate the departure in the range of characteristics and in the “Remarks” section of the description. Describe the typical pedon in its dominant land use. Describe the pedon to a depth that is at least equal to that for the series control section. Describe the relevant characteristics of Cr and R layers [see section (e)(1)(ii) below].
       
    3. Horizon designations. Identify horizons using the horizon designations defined in chapter 3 of the Soil Survey Manual and chapter 18 of the current edition of the Keys to Soil Taxonomy. Taxonomic terms that are used for the diagnostic horizons and characteristics of the soil classification system do not describe horizons and are not an acceptable substitute for a thorough, detailed description of the features observed.
       
    4. Depth of horizons. Give the depths to the upper and lower boundaries of horizons in centimeters after the corresponding horizon designations. Insert a semicolon after “cm.” Use of the corresponding horizon depths in English units of measurement (inches) is discouraged due to the potential confusion and errors in conversion. Use the soil surface, excluding live and fresh (i.e., undecomposed) leaves and twigs, as a reference plane for depth and thickness measurements for all mineral and organic soil horizons.
       
    5. Features described for most horizons. These features are as follows:
      • color (dry or moist, the most common condition);
      • texture class (including texture modifiers for fragments and composition);
      • color (dry or moist, opposite of the condition initially given);
      • mottles (dry or moist colors given; these are not related to wetness);
      • structure (Do not use commas to separate terms in the phrase that describes structure. Use the word “structure” only once in describing compound structure, such as “weak coarse prismatic structure parting to moderate medium subangular blocky.”);
      • consistence (dry, moist, stickiness, plasticity);
      • roots;
      • pores;
      • additional features (See item 8 below);
      • reaction;
      • lower boundary; and
      • range in thickness.
    6. Sequence for describing features. Describe the features of each horizon in the order listed to make comparisons easier among horizons and among soil series. All features may not occur in every horizon. As previously specified, describe features in standard terminology as much as possible.
       
    7. Soil color. Give descriptions of colors, including Munsell notations, for individual horizons. Describe color by using Munsell notations to the nearest color chip. All surface horizons require both moist and dry colors. Other horizons require colors for both moist and dry conditions if the information is necessary for the classification of the soil series. Record colors for both dry and moist conditions, if known, even if the information is not required for classification. Give moisture conditions for individual color identifications or for the whole pedon, as previously specified. Most horizons have a dominant color that changes in value and, less commonly, in hue and chroma as the moisture content changes. See chapter 3 of the Soil Survey Manual for more information on dominant color. The color listed first represents the moisture content that is most often observed. In arid regions this is the color of dry soil, and in humid regions it is the color of moist soil. In the description of the horizon, first record the color of the matrix or interiors of the peds; then list the color of films or coating on peds if they are different from the interiors. Identify the positions of individual colors unless they are obvious from the context. Do not use hyphens in soil color names (e.g., “yellowish brown,” not “yellowish-brown”).
       
    8. Additional features. List these features separately because they do not occur in all soils or horizons. Examples include the following (in random order):
      • artifacts;
      • bioturbation (krotovinas, insect casts, wormcasts, etc.);
      • cementation;
      • clay films and clay bridging;
      • concretions (from various cementing agents);
      • cracks;
      • detached fragments of cemented genetic horizons (duripan, ironstone, petrocalcic, etc.);
      • durinodes and opaline silica coats;
      • fibers;
      • gelic materials (involutions, ice lenses, ice wedges, etc.);
      • gypsum;
      • hydrophobicity;
      • identifiable secondary carbonates;
      • lamellae;
      • manner of failure (brittleness, fluidity, smeariness);
      • nodules (from various cementing agents);
      • odor;
      • pararock fragments;
      • pipes or tongues of other soil materials;
      • plinthite;
      • pressure faces (stress cutans);
      • reaction to indicator solutions (alpha,alpha-dipyridyl, HCl, H2O2, etc.);
      • redoximorphic features (concentrations, depletions, reduced matrix);
      • rock fragments;
      • silt coats or films;
      • skeletans;
      • slickensides;
      • stone lines;
      • thin strata, laminae, and/or lenses;
      • visible soluble salts; and
      • wood fragments.

        If such features are not mentioned in the description of a horizon, it is assumed they are absent. If these features are described, give the size, color (if appropriate), kinds, and numbers of concretions, stones, and gravel; the distinctness, extent, color, and position of clay films; and the amounts and distribution pattern of secondary carbonates and soluble salts. Use the nomenclature for diagnostic characteristics, such as slickensides, durinodes, and plinthite, in the horizon description but provide a complete description of each.
    9. Reaction. Record reaction using the descriptive class terms listed in chapter 3 of the Soil Survey Manual. Give the pH value in parentheses following the descriptive terms. An example is “very strongly alkaline (pH 9.8).”
       
    10. Range in thickness of individual horizons. Although this range is part of the range in characteristics for the soil series, include it in parentheses with each horizon description in the typical pedon for convenience. The combined thickness of subhorizons may be given instead.
       
    11. Examples of descriptions of individual horizons.

      1. A sequence of two horizons:

        Oe1--0 to 20 cm; dark reddish brown (5YR 3/2) mucky peat, broken face hemic material, very dark brown (10YR 2/2) rubbed; about 60 percent fiber, 25 percent rubbed; massive; herbaceous fiber; about 15 percent mineral material; slightly acid (pH 6.5 in 1:2 0.01 M calcium chloride); abrupt smooth boundary.

        Oe2--20 to 45 cm; very dark grayish brown (10YR 3/2) mucky peat, broken face and rubbed hemic material; about 40 percent fiber, 20 percent rubbed; massive; herbaceous fiber; about 35 percent mineral material; few small snail shells; strongly effervescent; slightly alkaline (pH 7.6 in 1:2 0.01 M calcium chloride); abrupt smooth boundary. (Combined thickness of the Oe horizons is 15 to 50 cm.)

         
      2. A sequence of three horizons:

        E--2 to 25 cm; very pale brown (10YR 7/3) loam, light yellowish brown (2.5Y 6/4) moist; weak thin platy structure; soft, very friable, slightly sticky, nonplastic; few fine roots; few very fine pores; few fine black and dark brown concretions; 2 percent cobbles; slightly acid (pH 6.4); clear smooth boundary. (15 to 30 cm thick)

        Bt1--25 to 50 cm; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong coarse columnar structure; extremely hard, firm, moderately sticky and moderately plastic; common fine roots; many very fine vesicular pores in clean silt caps about 2.5 cm thick on tops of soil columns and many very fine tubular pores immediately below caps; few medium pores in lower part of columns; many distinct very dark brown (10YR 2/2) clay films on vertical faces of peds; common dark stains and clean sand grains on vertical faces of peds; slightly alkaline (pH 7.8); clear wavy boundary. (18 to 56 cm thick)

        2Bt2--50 to 75 cm; olive (5Y 5/3) silty clay loam; moderate fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine tubular pores; common fine prominent brown (10YR 5/3) and many fine prominent yellowish brown (10YR 5/8) masses of oxidized iron accumulation; common fine prominent gray (10YR 5/1) iron depletions; common distinct very dark grayish brown (2.5Y 3/2) clay films on surfaces along pores and on all faces of peds; thin black (5Y 2/1) flecks inside peds; slightly acid (pH 6.5); gradual wavy boundary. (15 to 35 cm thick)

         
      3. A single horizon:

        Cg3--125 to 150 cm; gray (10YR 5/1) silty clay loam; massive; firm, friable, moderately sticky and slightly plastic; few fine roots; few fine tubular pores; few medium distinct pale brown (10YR 6/3) masses of oxidized iron accumulation; common medium distinct black (10YR 2/1) concretions and masses of manganese accumulation; common prominent reddish brown (5YR 4/4) masses of oxidized iron accumulation on surfaces along root channels; moderately acid; gradual smooth boundary.

         
    12. General guidance for preparing pedon descriptions.

      1. Use “few,” “common,” or “many” for classes of numbers of redoximorphic features, roots, pores, and concentrations. Refer to chapter 3 of the Soil Survey Manual for a definition of the terms that apply to each of the features. Express rock fragments, pararock fragments, wood fragments, and artifacts as a percentage of the volume on a whole soil base.
         
      2. Use “uncoated” or “clean silt and sand grains” rather than “bleached silt and sand” or “grainy coats.”
         
      3. “Ped” is the preferred terminology for a natural structural unit. Clods and fragments result from tillage or cultural practices. The term “aggregate” is confusing because it has many different meanings. Use the expression “faces of peds” and not “ped faces.”
         
      4. Avoid expressions such as “weak to moderate” for grade of structure (or other property). Use “weak and moderate” if two grades of structure are present. If peds separate to form smaller peds, use the verbs “part” or “separate” to describe the formation of secondary peds. In contrast to a complete ped, a fragment of a ped has fracture surfaces rather than natural faces. The zero grade of structure (structureless) is single grain or massive. Do not use the term “structureless” because it is redundant if used with “massive” or “single grain.” Do not give a type of structure with either massive or single grain. Soil material of single grains does not have structure. Very fine or fine grade granular peds cannot be described as
        single grain. In addition, single grain soil material has a loose rupture resistance class.

         
      5. Do not use hyphens in the class names for stickiness and plasticity. For example, “nonsticky” (not “non-sticky”) is the correct spelling of the class name.
         
      6. By definition, concretions are cemented. Thus, the phrase “soft lime concretions” is not correct. Use “masses of calcium carbonate “ or some other appropriate description. By definition, masses are noncemented. Thus the phrase “weakly cemented iron masses” is not correct. Preferred expressions are:
        • common fine dark concretions (Fe and Mn oxides); or
        • common fine dark concretions (oxides).
      7. Carbonates commonly are criteria used to separate soil series. Carbonates may be present in segregated forms or disseminated in parts of the mass or throughout the mass. Soil series descriptions must specify the kind and distribution of carbonates within horizons.

        The degree of effervescence after the soil is treated with 1N hydrochloric acid is described as very slightly, slightly, strongly, and violently effervescent. The degree of effervescence is related to the surface area of the carbonate minerals and to the kinds of minerals rather than to the total carbonate content. Thus, effervescence is not a reliable basis for estimating the amount of carbonates. A small amount of finely divided carbonates can produce a violent effervescence for a short time. Field tests for estimating the amount of carbonates in a soil are available. Record the content in parentheses after the degree of effervescence, such as “strongly effervescent (8 percent calcium carbonate equivalent).” Estimate carbonates to the nearest 1 percent if the content is less than 20 percent and to the nearest 5 percent if it is more than 20 percent. An example is “slightly effervescent (2 percent calcium carbonate equivalent); slightly alkaline.”

         
      8. If E and Bt horizons are described, parts that refer to each horizon are indicated as follows:

        E and Bt--95 to 145 cm; yellowish brown (10YR 5/4) fine sand (E); single grain; loose; lamellae and bands of dark brown (7.5YR 4/4) fine sandy loam (Bt); coarse subangular blocky structure in thicker bands; friable; wavy and discontinuous 2- to 4-cm-thick lamellae in upper part and bands 5 cm thick in lower part; moderately acid; gradual wavy boundary. (40 to 75 cm thick)

         
      9. Neutral colors are written such as “gray (N 5/)”. The hue is neutral (N) if the chroma is zero and the character (0) is not used.
         
      10. Do not place a plus sign after the last stated depth in the profile description. The last stated depth is the depth to which the profile was examined.
         
      11. Chapter 3 of the Soil Survey Manual and chapter 18 of the current edition of the Keys to Soil Taxonomy provide guidance and conventions on the designations used for horizons and layers.
         
      12. Indicate the range in thickness of horizons as follows:
        • The thickness of horizons that have two or more subhorizons can be combined. Note the range in thickness after the last subhorizon. For example, “The combined thickness of the Bw horizons is 50 to 75 cm.”
        • The thickness of horizons that are not essential to the classification and are not in all profiles is expressed as zero to an appropriate number of centimeters. For example, “0 to 60 cm thick.”
  4. Type Location. The location is a specific site. The county and State names are given first. It is described accurately enough in relationship to map coordinates or other geographic reference points that it could be located by a person unfamiliar with the area. For example:

    “Lucky County, Nebraska; about 10 miles north and 7 miles east of Eden; 90 feet west and 30 feet south of the northeast corner of sec. 7, T. 12 N., R. 26 W.; USGS named topographic quadrangle; lat. 40 degrees 40 minutes 20 seconds N. and long. 40 degrees 30 minutes 20 seconds W., WGS84.”

    Give the latitude, longitude, and horizontal datum (WGS84 is preferred) in both sectionized and nonsectionized areas. In sectionized areas, the four section corners and the center of a section may also be reference points. Do not use the term “1/4 corners” in giving the location. In nonsectionized areas, give
    locations using available permanent landmarks.
     
  5. Range In Characteristics. This section spells out observed ranges in soil properties for the soil series class as it is currently conceived. Give emphasis to properties that are definitive for the soil series or that affect use and management whether or not these properties are known to differentiate locally. As much as practical, give quantitative limits for the ranges in properties. The ranges specified must fall within the ranges of the family in which the soil series is classified. If the allowable range of a given property coincides with the range of the family or a higher category, the range does not have to be repeated in the description because it is implied by the classification given. A range in a soil series property commonly is narrower than the range for the family class. If it is, give the narrower range. If class limits in the classification system are soil series limits, observe these limits before recording their values. The ranges given are those that are considered to be limiting for the soil series and do not extend to taxadjuncts. The inclusion of unusual ranges in properties magnifies problems of identifying soil series apart from one another. Limit the recorded ranges to those that have been observed in the field or determined in the laboratory. Record assumed properties in the “Remarks” paragraph. This section of the soil series description, like others, is not meant to cover the soils of other series present within map units. Record data on minor components in the NASIS database rather than in the official soil series descriptions.

    A standard arrangement of information in this section makes comparisons among soil series easier. Both tabular or text formats are acceptable. The arrangement first presents information on the soil as a whole and then presents in subsequent paragraphs information on the major individual horizons.

    Enter numerical values for ranges after using the conventional rules for rounding shown in Exhibit 614-4. Significant digits for soil properties used in taxonomic classification, such as percent clay content, are shown in Exhibit 614-5.
     
    1. First paragraph.

      Include general pedon features that apply to the soil as a whole rather than to individual horizons. Present such features as the thickness of the subsoil, depth to bedrock, depth to a fragipan, stoniness, mineralogy, range in soil temperature, and frequency and duration of periods when soil moisture is at or below the wilting point. Information that has been obtained through direct observations or that can be reliably inferred is recorded.

      1. Use terms for diagnostic horizons or features in this section. If you use these terms, specify their relationship to the horizons and subhorizons of the typical pedon.
         
      2. Paralithic and lithic contacts, as defined in Soil Taxonomy, form the boundary between soil and paralithic materials and coherent underlying material, respectively. The concept of these root-limiting layers does not allow both of them to be present beneath a soil. Thus, soil series must not be defined as or differentiated from competing series by having, for example, a “paralithic contact over a lithic contact.” If paralithic materials become harder and more coherent with depth, this fact can be stated in the range in characteristics. Paralithic materials, however, can be used to differentiate soil series if the materials are within the series control section. Refer to chapter 17 of the current edition of the Keys to Soil Taxonomy for the key to the control section for the differentiation of series. The presence of hard, coherent bedrock below the series control section cannot be used to differentiate soil series but can be considered as a basis for phase distinctions.
         
      3. Characteristics can be presented in the first and subsequent paragraphs in either a semi-tabular (preferred) or full text format.

        An example of a semi-tabular format is:
        “Soil moisture: Moist in some part of the soil moisture control section from December to March; intermittently moist from July to September; driest in May and June; ustic moisture regime that borders on aridic.
        Soil temperature: 9 to 13 degrees C.
        Rock fragments: 15 to 50 percent gravel and 10 to 25 percent cobbles; average of more than 35 percent in the particle-size control section.
        Calcium carbonate equivalent: 15 to 40 percent.
        Depth to bedrock: 18 to 50 cm to a lithic contact.
        Reaction: Slightly alkaline or moderately alkaline.
        Organic matter content: Average of 1 to 5 percent in the surface layer.
        Clay content: 18 to 25 percent; textures of loam or silt loam with less than 40 percent sand.”

         
    2. Subsequent paragraphs.

      Describe each major horizon of mineral soils in a separate paragraph. Separate each paragraph with a double space. Use tiers or combinations of similar layers for organic soils.

      1. The horizons covered in the subsequent paragraphs are the major ones described and are significant to the definition of the soil series. Discuss the ranges in soil properties in the same order as they are listed in the typical pedon description.

        An example of text format is:
        “The Bt horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist or 3 or 4 dry, and chroma of 1 or 2 moist or dry. It is loam or clay loam. It averages 18 to 28 percent clay and 40 to 60 percent fine sand or coarser material. It has weak or moderate medium subangular blocky structure and is friable or very friable. It ranges from pH 6.2 to 7.6.”

        An example of a semi-tabular format is:
        “Bt horizon
        Hue: 10YR or 7.5YR.
        Value: 2 or 3 moist, 3 or 4 dry.
        Chroma: 1 or 2 moist or dry.
        Texture: Loam or clay loam.
        Clay content: 18 to 28 percent.
        Content of fine sand or coarser material: 40 to 60 percent.
        Structure: Weak or moderate medium subangular blocky.
        Moist consistence: Friable or very friable.
        Reaction (pH): 6.2 to 7.6.”

         
      2. Subdivisions of major horizons may be helpful for some soil series. The sequence begins with the uppermost horizon in the pedon and continues downward. Make subdivisions of major horizons only if necessary because the resulting long and detailed section may obscure important information.
         
      3. List the most common range of a soil characteristic before giving the complete range. For example, “The A horizon commonly is loamy sand and less commonly is loamy fine sand, fine sand, or fine sandy loam” or “The A horizon is most commonly sand, but the range includes fine sand and loamy sand.”
         
      4. If there is no known range of a particular characteristic, do not repeat the information provided in the typical pedon.
         
      5. Preferred expressions are:
        • “typically” or “in some pedons” rather than “frequently “ or “occasionally;”
        • “some pedons” rather than “some places” (for example, “The lower part of the fragipan in some pedons has evidence of illuviation”);
        • “do not have” rather than “lack;”
        • “is” or “are” rather than “may be;”
        • “2C horizon” rather than “2C material;”
        • “bedrock” rather than “R layer”;
        • “BC horizon” rather than “BC;”
        • “some pedons do not have a BC horizon” rather than “the BC horizon may be missing;”
        • “the upper part of the B horizon” rather than “the upper B horizon;”
        • “interfingering of albic materials into the Bt horizon” rather than “interfingering of the albic horizon into the argillic horizon;” and
        • “a thin stone line is at the boundary between the two materials” rather than “a thin stone line separates the two materials.”
  6. Competing Series. This section discusses the distinctions between the soil series being described and its major taxonomic competitors. It lists all the soil series of the same family and gives the principal differentiating characteristics that set them apart from the series being described. Because the properties that govern the classification of the soil series being described have already been stated, this section emphasizes those features that distinguish it from the competing series. The comparisons are as specific and quantitative as available information warrants. Comparisons may include reference to diagnostic horizons and other features.

    1. List all soil series in the same family in alphabetical order. List tentative soil series if the series being described is tentative. If the soil series being described is established, list tentative series if they are identified as tentative. Individually state the differentiating characteristics for soil series in the order of listing unless some can be grouped together and differentiated. If no soil series are in the same family, list series that are in similar families and their differentiating characteristics.
       
    2. Features that are used to differentiate or group soils include but are not limited to:
      • the presence or absence of a diagnostic horizon or feature;
      • the texture in some part of the series control section (the range is given in percent of soil separates);
      • carbonates above or within a specified depth;
      • depth to a lithic or paralithic contact;
      • content or type of fragments in the soils;
      • colors that are redder or yellower than a specified hue;
      • redoximorphic features that have low chroma within a specified depth;
      • soil temperature differences;
      • the thickness of the subsoil;
      • the thickness of the epipedon;
      • soil moisture differences; and
      • reaction in the series control section.
    3. In selecting preferred expressions, change:
      • “thicker darker surface horizon” to “Gamma soils have a mollic epipedon” when indicating that a soil has a mollic epipedon;
      • change “light colored surface” to “Gamma soils have an ochric epipedon” when distinguishing a soil that does not have a mollic epipedon;
      • “lower subsoil” to “lower part of the subsoil;”
      • “are redder” to “have hue redder than 10YR;”
      • “soils lack argillic horizons” to “soils do not have an argillic horizon;”
      • “soils have higher organic matter” to “soils contain more than __ percent organic matter;”
      • “have siltier textures in the upper subsoil” to “contain more than __ percent silt in the upper part of the subsoil;”
      • “lower value” to “colors of lower value than;”
      • “moist value” to “moist color value;”
      • “small proportion” to “small part;”
      • “have up to and including 10 cm” to “have as much as 10 cm;”
      • “strongly developed horizons” to “strongly expressed horizons;” and
      • “Gamma soils have argillic horizons with fine-silty textures” to “Gamma soils have a fine-silty particle-size class in the argillic horizon.”
  7. Geographic Setting. The items in this section include landscapes, landforms, relief, nature of regolith, climate, and any other features that are especially helpful in identifying the soils of the soil series. Indicate the name or names of the landform(s) and the range in slope gradient, kind of slope, and aspect for the soils of the series. Record landscape features that mark areas of the soils, such as common outcrops of rock, an erosional surface, or a depositional surface.

    1. Briefly describe the nature of the regolith in which the soils formed. Also list underlying rock. The purpose of this statement is to characterize the regolith to aid in identifying the soils rather than to define the soil series in the terms of underlying rock and mode of accumulation of the regolith.
       
    2. Characterize climate in terms of temperature, precipitation, and indices. For example, express PE index as a range for the soil series. Only use indices that have been defined in widely available publications. Give information on climate in the descriptions of soil series. Give the range of the number of mean annual temperature (in degrees C) and mean annual precipitation (in millimeters). Also give the range of numbers for the frost-free period (in days), if pertinent. The statements should apply to the geographic setting and not to the information on soil temperature and soil moisture that is given in the range in characteristics section. If pertinent, give the range of elevation (in meters).
       
    3. Preferred expressions include:
      • “Gamma soils are nearly level” rather than “Gamma soils occur on nearly level”
      • “The soil formed in calcareous” rather than “The soil developed in calcareous”
      • “Mean annual temperature” rather than “Mean annual air temperature”
  8. Geographically Associated Soils. Use the list of geographically associated soils to inform users of the names of soil series in the same locality. For example, describe the actual geographic locations of the various series and how they differ. List the geographically associated soil series and include a brief comment to distinguish each of them from the series being described. Relate the landscape positions of the associated soil series. The comments do not clearly differentiate soil series but rather highlight major distinctions. Do not repeat the differentiae that are used in the section on competing soil series. A preferred expression for “associated landscapes” is “nearby landscapes.”
     
  9. Drainage and Saturated Hydraulic Conductivity. Give soil drainage for each soil series. Drainage is usually assigned as a single drainage class, or occasionally, two drainage classes. For some soil series, include segments of two adjacent drainage classes. Give the sequence of soil water states in addition to drainage class if it is a more useful way to record moisture regimes. Also include the characterization of saturated hydraulic conductivity in this section. Consider saturated hydraulic conductivity to a depth of 180 cm or to bedrock and describe it according to major changes, for example, “high in the upper part and moderately low in the lower part.” Always cite very high saturated hydraulic conductivity in the lower part of the profile. Surface runoff may be given in this section but it is not required. If it is important, describe run-on moisture in this section. If needed, also give statements about type and depths of saturation, flooding, and ponding. Avoid expressions such as “well drained to moderately well drained”. Instead use “well drained or moderately well drained” or “well drained and moderately well drained.” Do not assign more than two drainage classes to a soil series.

    Examples of statements are:
    • Well drained; moderately high saturated hydraulic conductivity.
    • The soils are moderately well drained and have moderately low saturated hydraulic conductivity. They are flooded for short periods in early spring.
    • The soils are well drained. Runoff is medium on the gentle slopes and high on the steeper slopes. Saturated hydraulic conductivity is moderately high in the subsoil and low in the underlying material.
  10. Use and Vegetation. List the major uses of the soil series in this section. If soils are used for crops, pasture, or forests or for urban or other uses, indicate the uses along with the general extent of each, if known. Do not discuss productivity levels, yields, limitations, or hazards. Also describe the native vegetation in this section if it covers an important part of the soil. If known, give the various plant communities in various successional stages. Refer to an ecological site if known. For some soil series, the kind of native vegetation is uncertain and no longer important because of current use. Do not describe the vegetation for these series. The description is brief since it is meant simply to aid in identifying the soils.

    A preferred expression for “Soils are under cultivation with corn and wheat, the principal crops” is “Soils are cultivated. Corn and wheat are the principal crops.”
     
  11. Distribution and Extent. This section is used to provide more information on the distribution of the series by State(s) and/or MLRA(s). If State information is given, use the complete spelling of State names instead of FIPS codes. Indicate the extent of the soils in a soil series using one of three classes. The names and extent figures for these classes are given below. Use either the substantive or adjective forms of the name, depending on which is more appropriate for the text.

    The terms and the extent ranges are as follows:
    • small extent or not extensive----less than 10,000 acres;
    • moderate extent or moderately extensive----10,000 to 100,000 acres; and
    • large extent or extensive----more than 100,000 acres.

    Supplement the designation of classes for soil series with extent figures when the soil series is not extensive and when the soil series is of large extent. Some examples are:

    • “The soils of this series are not extensive; their total extent is about 6,000 acres.”
    • “These soils are extensive, with about 214, 000 acres of the series mapped.”
  12. Soil Survey Regional Office (SSRO) Responsible. Use this heading to indicate which SSRO currently has responsibility for maintenance of the OSD. Check the entry against a like entry in the Soil Classification (SC) database at the time of updating. It must match the entry in the SC database for update of the series description to proceed. The format of the entry should look like: Portland, Oregon. The entries must be spelled correctly and must exactly match one of the 12 SSROs. Note that it is not recommended to enter the names or numbers of soil survey offices (SSO) in this section since a corresponding entry for these offices is not possible in the SC database and the validation of the entry will fail. This entry will be automatically changed to match the corresponding entry in the SC database when responsibility for the series is transferred. Responsibility is transferred by revising the entry in the “Responsible SSRO” field in the SC part of the SC/OSD maintenance tool.
     
  13. Series Proposed or Series Established. Use one of these headings, depending on the current status of the series. For tentative series, the place where the soil series was proposed and the date when the series received tentative status follow the side heading “Series Proposed.” For established soil series, the place and date of establishment follow the side heading “Series Established.” Give the names of the county and State and the year in which a soil series received tentative status or was established. If the survey area is a geographical or political subdivision other than a county, include the name of that subdivision. Give the source of the name for a soil series in the first description of a newly proposed series. A revised description does not need to include the source of the name if it has been recorded in an earlier description.
     
  14. Remarks. List the horizons and features that are considered diagnostic for the pedon described. The objective is a list of the features needed to classify and characterize the series. Restrict other remarks to those that can help in identifying soils of the soil series as it is currently conceived. For example, a proposal of a new soil series for soils originally from an already established series can be included in the “Remarks” section of the description of the new series. List any unresolved problem with defining the soil series or with differentiating it from others. Do not list laboratory data in this section.
     
  15. Additional Data. This section is optional. It lists sources of data, including pedons in the National Cooperative Soil Survey soil characterization database, study thesis information, data from State laboratories, and advance copies of data from unpublished soil survey investigations reports that were used in defining properties of the soil series. This section is intended to provide a reference to sources of additional information and should not be used to reproduce data that is best accessed from the source.
     

Exhibit 614-4—Rounding Numbers from Laboratory Data

Analytical data on soils will often be reported by laboratories using levels of precision that do not match the precision level of the criteria used in Soil Taxonomy (ST). For example, ST requires using percentages for clay content in whole numbers (integers) when applying criteria such as the required characteristics of the argillic horizon and the key to particle-size classes. However, primary characterization data supplied from the NSSC Kellogg Soil Survey Laboratory reports clay content (by weight) in tenths of a percent (one decimal place).

When evaluating numerical data to determine if the critical values used in ST are met, you must round the numbers to the same number of digits as used in the criteria. So if critical limits for percent clay are presented as whole numbers in a particular criteria, then weighted average clay contents must be rounded to a whole number. However, when using a series of numbers in a calculation (for example, when calculating a weighted average clay percentage for the particle-size control section), only round the final result, not the individual values used in the calculation. The conventional rules for rounding numbers are as follows:

If the digit immediately to the right of the last significant figure is more than 5, round up to the next higher digit.

e.g., 34.8 rounds to 35 (Round up because the digit to be dropped is more than halfway between 34 and 35.)

If the digit immediately to the right of the last significant figure is less than 5, round down to the next lower digit.

e.g., 34.4 rounds to 34 (Round down because the digit to be dropped is less than halfway between 34 and 35.)

If the digit immediately to the right of the last significant figure is equal to 5, round to the adjacent even number, either up or down.

e.g., 17.5 rounds to 18 (Round up because the result is an even number.)

34.5 rounds to 34 (Round down because the result is an even number.)
 

Exhibit 614-5—Significant Digits for Soil Property or Quality Measurements Used as Criteria in Soil Taxonomy

(This exhibit references items in the 12th edition of the Keys to Soil Taxonomy, 2014. In the third column, information in brackets indicates the location of specific information under each item.)

Measurement of soil property or quality (units) Significant digit used in Soil Taxonomy Taxonomic criteria and taxa in Soil Taxonomy [item code]
Al plus ½ Fe content, by ammonium oxalate (%) Tenths (0.1) Required characteristics for andic soil properties [2.c and 3.c];
“Andic” (except Kandic), Aquandic, and “vitr” subgroups
Al plus ½ Fe content, by ammonium oxalate (%) Hundredths (0.01) Definition of spodic materials [2.b.3];
Spodic subgroups of Entisols, Gelisols, Inceptisols, and Ultisols
     
Anhydrite content (% by weight) Whole number (0) Required characteristics for anhydritic horizon [2];
Anhydritic [C.1] mineralogy class
Base saturation, by NH4OAc at pH 7 (%) Whole number (0) Required characteristics for mollic [4] and umbric [4] epipedons;
Key to soil orders [I.2];
Xerollic, Ustollic, Mollic, and Eutric subgroups of Alfisols;
Dystric and Humaqueptic subgroups of Entisols;
Humic subgroups of Aquepts;
Eutric subgroups of Inceptisols;
Dystric (“dystr”) and Eutric (“eutr”) great groups of Inceptisols;
Eutric (“eutr”) great groups and subgroups of Oxisols
Base saturation, by sum of cations at pH 8.2 (%) Whole number (0) Key to soil orders [H.1. and H.2.b];
Ultic subgroups of Alfisols, Andisols, and Mollisols;
Some Alfic [KFFT] and Dystric subgroups [KDEU] of Inceptisols;
Alfic subgroups of Spodosols
Bulk density, moist (g/cm3) Tenths (0.1) Definitions of mineral and organic soils;
Required characteristics for folistic and histic epipedons [1.a];
Key to soil orders [B.2.d]
Bulk density, at 33 kPa (g/cm3) Hundredths (0.01) Required characteristics for andic soil properties [2.a]
Bulk density, at 33 kPa (g/cm3) Tenths (0.1) “Andic” (except Kandic), Aquandic, and Vitrandic (“vitr”) subgroups
Calcium carbonate equivalent (%) Whole number (0) Required characteristics for the mollic epipedon [3.b and 3.c], calcic horizon [2], and sulfidic materials [2];
Rendolls suborder [IC.3];
Rendollic Eutrudepts subgroup [KFES];
Carbonatic mineralogy class [C.3]
Cation-exchange capacity, by 1N NH4OAc pH 7 (cmol(+)/kg clay) Whole number (0) Required characteristics for kandic [5] and oxic [6] horizons;
Kandic and Kanhaplic subgroups of Alfisols and Ultisols;
Udoxic and Ustoxic subgroups of Quartzipsamments;
Oxic subgroups of Inceptisols and Mollisols
Cation-exchange capacity (cmol(+)/kg organic matter, measured by loss on ignition) Whole number (0) Definitions of coprogenous earth and diatomaceous earth
Clay content (% by weight) Whole number (0) Definition of mineral soil material;
Required characteristics for the folistic and histic epipedons;
Required characteristics for the argillic, calcic, kandic, natric, and oxic horizons;
Required characteristics for the abrupt textural change;
Required characteristics for lamellae;
Key to soil orders [E.2, F.2, and K.2.a];
“Kandi” and “pale” great groups;
Albaquic, Abruptic, and some Haplic subgroups of Alfisols;
Abruptic subgroups of Aridisols;
Hydric (“hydr”) great groups and Haplic, Hydric, and Grossic subgroups of Entisols;
“Hydr” subgroups of Inceptisols;
Abruptic, “pale,” and Haplic Palexerolls subgroups of Mollisols;
Glossaquic Fragiudults [HCBC.1.c] and Haplic Plinthustults [HDAA.2] subgroups;
Entic subgroups of Vertisols;
Key to particle-size classes of mineral soils and of Histosols and Histels;
Strongly contrasting particle-size classes no. 20, 21, 29, 32, and 47
Effective cation-exchange capacity, by 1N NH4OAc pH 7 plus 1N KCl-extractable Al (cmol(+)/kg clay) Whole number (0) Required characteristics for kandic [5] and oxic [6] horizons
Effective cation-exchange capacity (cmol(+)/kg clay) Hundredths (0.01) Acric (“acr”) great groups of Oxisols
Effective cation-exchange capacity, by 1N NH4OAc pH 7 plus 1N KCl-extractable Al (cmol(+)/kg clay) Tenths (0.1) Acric (“acr”) subgroups of Ultisols
Electrical conductivity, in the extract from a saturated paste (dS/m) Whole number (0) Required characteristics for salic horizon;
Halic subgroups of Vertisols
Electrical conductivity, in the extract from a saturated paste (dS/m) Tenths (0.1) Dystric (“dystr”) great groups of Vertisols
Electrical conductivity, in 1:1 mixture of soil and water (dS/m) Whole number (0) Halic subgroups of Haplosaprists
Electrical conductivity, in 1:5 mixture of soil and water (dS/m) Tenths (0.1) Frasiwassists [BBA.] and Frasiwassents [LAA.] great groups
Exchangeable magnesium plus sodium greater than calcium plus extractable acidity at pH 8.2 (cmol(+)/kg fine-earth fraction) Tenths (0.1) Required characteristics for natric horizon [5.b];
Albic subgroups of Natraqualfs
Exchangeable sodium percentage, or ESP (%) Whole number (0) Required characteristics for natric horizon [5];
Key to soil orders [K.2.b(3)];
Albic subgroups of Natraqualfs; Natric subgroups of Alfisols;
Sodic subgroups of Aridisols, Entisols, Inceptisols, and Vertisols;
Haplic (“hapl”) subgroups of Natrustalfs and Natrargids;
Key to suborders of Inceptisols [KA.2] and Mollisols [IB.2];
Halaquepts great group [KAC.2]
Extractable Al3+, by 1N KCl (cmol(+)/kg fine-earth fraction) Tenths (0.1) Alic and some Eutric subgroups of Andisols
Extractable Fe2O3, by dithionite-citrate (% by weight) Whole number (0) Aquic conditions [1.c.(2)(c)];
Ferritic [A.1 and C.4], ferruginous [A.4], and sesquic [A.3.a] mineralogy classes;
Ferrihumic soil material
Extractable Fe2O3, by dithionite-citrate (% by weight) Tenths (0.1) Parasesquic mineralogy class [D.1 and E.2]
Extractable iron, by ammonium acetate (%) Hundredths (0.01) Alaquods [CAB] and Alorthods [CED] great groups;
Amorphic [B.2] and ferrihydritic [B.3] mineralogy classes
Extractable silicon, by ammonium acetate (%) Hundredths (0.01) Amorphic [B.2] and ferrihydritic [B.3] mineralogy classes
Fiber content, after rubbing (% by volume) Whole number (0) Definitions of kinds (fibric, hemic, sapric) of organic soil materials
Gibbsite content (% by weight) Whole number (0) Gibbsitic [A.2 and C.5], sesquic [A.3.b], allitic [A.5], and parasesquic [D.1 and E.2] mineralogy classes
Gypsum content (% by weight) Whole number (0) Required characteristics for gypsic [3] and petrogypsic [4] horizons;
Gypseous substitute classes [B.4];
Strongly contrasting particle-size classes no. 17, 42, 43, and 49;
Gypsifactic human-altered and human-transported material class [A.4];
Hypergypsic [B.1], gypsic [C.2], and carbonatic [C.3] mineralogy classes
Linear extensibility (cm) Tenths (0.1) Vertic (“ertic”) subgroups
Melanic index (ratio) Hundredths (0.01) Required characteristics for melanic epipedon [2.c]
Mica content (% by grain count) Whole number (0) Micaceous mineralogy class [E.1]
Nitrate concentration, in 1:5 extract of soil and water (mmol(-)/L) Whole number (0) Nitric subgroups of Gelisols
n value Tenths (0.1) Required characteristics for anthropic, mollic, and umbric epipedons;
Definitions of n value and manner of failure classes;
Key to soil orders [K.2.a];
Key to great groups of Aquents [LBB] and Wassents [LAD];
Haplic Sulfaquents [LBAA.1], Hydric Frasiwassents [LAAA], Grossic Hydrowassents [LADB], and Haplic Sulfiwassents [LACB.1] subgroups of Entisols;
Hydraquentic Humaquepts [KAHA.1] and Hydraquentic Sulfaquepts [KAAB] subgroups of Inceptisols
Optical density of oxalate extract Hundredths (0.01) Definition of spodic materials [2.b.(4)];
Spodic subgroups of Entisols, Gelisols, Inceptisols, and Ultisols
Organic-carbon content (kg/m2) Whole number (0) Humic subgroups of Oxisols;
Humults suborder [HB.2];
Humicryerts great group [FBA]
Organic-carbon content (% by weight) Whole number (0) Mineral soil material;
Required characteristics for folistic, histic, and melanic epipedons;
Required characteristics for andic soil properties [1]
Organic-carbon content (% by weight) Tenths (0.1) Required characteristics for mollic, plaggen, and umbric epipedons; Definition of spodic materials [1];
Fluvents [LD.3.a], Humods [CD], and Humults [HB.1] suborders;
Mollic subgroups of Haploxeralfs and Palexeralfs;
Pachic and Thaptic subgroups of Andisols;
“Fluv” great groups of Entisols;
Humic great groups (“humi”) and Humic and Entic subgroups of Spodosols;
Some Cumulic subgroups and many “fluv” subgroups
Particles 0.02 to 2.0 mm in diameter (% by weight) Whole number (0) Required characteristics for andic soil properties [3.a];
Description of resistant minerals, volcanic glass content, and weatherable minerals;
Aquandic and Vitrandic (“vitr”) subgroups;
Key to particle-size classes [B.1.b];
Siliceous mineralogy class [E.4]
Percentage of clay (2.5[% water at 1500 kPa tension - % OC]) Whole number (0) Required characteristics for kandic horizon [5];
Key to particle-size classes [section C];
Cation-exchange activity classes
Percentage of clay (3[% water at 1500 kPa tension - % OC]) Whole number (0) Required characteristics for oxic horizon [6];
Torroxic [IGGK] and Oxic [IGGL] subgroups of Haplustolls
pH, in ratio of 1:2 soil and 0.01M CaCl2 solution (pH units) Tenths (0.1) Dystric (“dystr”) great groups of Vertisols;
Key to calcareous and reaction classes
pH, on undried samples, in a ratio of 1:2 soil and 0.01 M CaCl2 solution (pH units) Tenths (0.1) Key to reaction classes for Histosols and Histels
pH, by 1N KCl (pH units) Tenths (0.1) Acric (“acr”) great groups and Anionic subgroups of Oxisols
pH, in suspension of 1 g soil and 50 ml 1M NaF (pH units) Tenths (0.1) Isotic mineralogy class [D.2.f.(2) and E.3.b]
pH, in ratio of 1:1 soil and water (pH units) Tenths (0.1) Definition of spodic materials [1];
Required characteristics for sulfidic materials;
Sulfic subgroups of Entisols and Inceptisols;
Anionic subgroups of Oxisols;
Sulfaqueptic Dystraquerts subgroup [FAFA]
pH, in saturated paste (pH units) Tenths (0.1) Dystrusterts [FEA] and Dystruderts [FFA] great groups
Phosphate retention (%) Whole number (0) Required characteristics for andic soil properties [2.b and 3.b]
Positive water potential at the soil surface (hours of each day in all years) Whole number (0) Wassists [BB] and Wassents [LA] suborders
Ratio of cation-exchange capacity (cmol(+)/kg fine-earth fraction) to clay content (% by weight) Hundredths (0.01) Key to cation-exchange activity classes
Ratio of fine clay to total clay content Tenths (0.1) Required characteristics for argillic horizon [1.b.(5)]
Ratio of 1500 kPa water content to measured clay content Hundredths (0.01) and
tenths (0.1)
Key to particle-size classes;
Cation-exchange activity classes
Ratio of 1500 kPa water content to measured clay content Tenths (0.1) Oxic subgroups of Inceptisols;
Isotic mineralogy class [D.2.f.(3) and E.3.c]
Resistant minerals, in 0.02 to 2.0 mm fraction (% by weight or grain count) Whole number (0) Quartzipsamments great group [LCC];
Siliceous mineralogy class [E.4]
Sand fraction content (% by weight) Whole number (0) Key to particle-size classes of mineral soils [sections B.4.b and C];
Strongly contrasting particle-size classes no. 26, 45, 50, 70, and 71
Saturated hydraulic conductivity (cm/hr) Tenths (0.1) Albaqualfs [JAH] and Albaquults [HAC] great groups
Saturation with water (month) 1/ Whole number (0) Key to soil orders [G.2.a)];
Aquisalids [GBA] and Aquicambids [GGA] great groups;
Aquic (“aqu”) subgroups of Aridisols
Slope gradient (%) Whole number (0) Fluvents suborder [LD.2 and LD.4.b.(2)];
Fluvaquents great group [LBF.2];
Cumulic and “fluv” subgroups of Orthels and Cumulic subgroups of Turbels;
Cumulic and “fluv” subgroups of Inceptisols;
“Fluv”subgroups and most Cumulic subgroups of Mollisols
Sodium adsorption ratio Whole number (0) Required characteristics for natric horizon [5];
Key to soil orders [K.2.b.(3)];
Natric subgroups of Alfisols;
Sodic subgroups of Aridisols, Entisols, Inceptisols, and Vertisols;
Haplic (“hapl”) subgroups of Natrustalfs and Natrargids;
Key to suborders of Inceptisols [KA.2] and Mollisols [IB.2];
Halaquepts great group [KAC.2]
Soil temperature (°C) Whole number (0) Required characteristics for mollic [7], plaggen [5], and umbric [7] epipedons;
Required characteristics for anhydrous conditions;
Soil moisture and temperature regimes;
Key to soil temperature classes;
Aridic (“id”), Torric (“torr”), Udic (“ud”), Ustic (“ust”), and Xeric (“xer”) subgroups of Alfisols, Aridisols, Entisols, Inceptisols, Mollisols, and Ultisols;
Torrerts suborder [FD]
Sulfur, dry mass (%) Hundredths (0.01) Required characteristics for sulfidic materials
Sum of extractable bases by NH4OAc plus extractable Al3+, by 1N KCl (cmol(+)/kg fine-earth fraction) Tenths (0.1) Acric (“acr”) and Dystric subgroups of Andisols
Sum of extractable bases, by NH4OAc (cmol(+)/kg fine-earth fraction) Tenths (0.1) Most Eutric subgroups of Andisols
Volcanic glass content (% by grain count) Whole number (0) Required characteristics for andic soil properties [3];
Fluvents suborder [LD.4.b.(2)]
Aquandic and Vitrandic (“vitr”) subgroups;
Key to particle-size classes [B.1.b];
Glassy mineralogy class [B.4]
Water retention, at 1500 kPa tension, on either air-dried or undried samples or both (%) Whole number (0) Vitrands suborder [DF];
Vitric (“vitr”) and Hydric (“hydr”) great groups and subgroups of Andisols;
Key to particle-size classes [section B];
Strongly contrasting particle-size classes no. 5, 51, 52, and 56
Water-soluble sulfate (%) Hundredths (0.01) Required characteristics for sulfuric horizon [1.b]
Weatherable mineral content (% by grain count) Whole number (0) Required characteristics for oxic horizon [3]

1/ For the saturation criterion, “1 month or more” is equivalent to “more than 15 days.”