NSSH Part 609

Quality Control, Quality Assurance, and Soil Correlation

Definition and Purpose of Quality Control and Quality Assurance (609.00)

Soil survey quality control, defined

Soil survey quality control is the collective set of activities described in NCSS standards and procedures whose purpose is to achieve a high level of quality. Controlling quality involves providing direct review and inspection, direction, and coordination of soil survey production activities to ensure that soil survey products meet the defined standards for content, accuracy, and precision. The quality of soil survey products is controlled at the level where each of the soil survey process steps (from field work through publication) takes place. Quality control at the field level is the responsibility of the MLRA soil survey office leader.
Soil survey quality assurance, defined

Soil survey quality assurance is the process of providing technical standards and guidelines, oversight and review, and training to ensure that soil survey products meet National Cooperative Soil Survey standards. Responsibility for assuring the quality of soil survey products such as maps, descriptions, data, texts, photographs, etc., rests with the MLRA regional office.
Purpose

Quality control and quality assurance are important at all levels of the preparation, publication, and update of a soil survey. Their purpose is to ensure that soil survey products are accurate, consistent, meet the objectives outlined in the memorandum of understanding or project plan, and satisfy the needs of the majority of soil survey users. Quality control and/or quality assurance activities are also carried out at other locations where soil survey products are developed such as the National Soil Survey Laboratory, National Cartography and Geospatial Center, etc.

Policy and Responsibilities for Quality Control and Quality Assurance (609.01)

The Natural Resources Conservation Service (NRCS) ensures the quality and integrity of soil surveys through a system of quality control and quality assurance at all levels of activity. The NRCS has the leadership responsibility for nationwide soil correlation within the National Cooperative Soil Survey (NCSS). For soil surveys on federal lands, the NRCS works closely with partner agencies in carrying out these responsibilities.

MLRA Soil Survey Office (SSO), or Soil Survey Project Office for initial (or extensive update) soil surveys.

The MLRA Soil Survey Office Leader is a key decision maker in the NCSS for mapping, data collection, and soil survey product development. Decisions have a broad affect and errors are not easily detected or corrected. The MLRA Soil Survey Office Leader is responsible for:
1. controlling the quality of all soil survey products developed by that office;
2. periodically conducting quality control reviews to ensure all products meet NCSS standards;
3. ensuring that all soil survey products submitted for quality assurance review and certification have passed prior quality control inspections;
4. making initial correlation decisions for the survey area using NCSS standards and MLRA specific information provided by the MO;
5. conducting progressive soil correlation during the course of all soil survey activities;
6. ensuring that all changes to map unit names and legends, and the reasons for the changes, are recorded in NASIS;
7. ensuring seamless soil survey products across political and physiographic boundaries in the survey area as defined in part 609.03;
8. assessing training needs of the SSO staff and requesting training from the MO and the State Soil Scientist;
9. timely preparation of agendas, soil descriptions, lab data, maps, and other information needed for quality assurance reviews conducted by the MO;
10. ensuring findings and recommendations identified in the MO quality assurance reviews are addressed and implemented in a timely manner;
11. developing soil survey publications that meet the NCSS standards as outlined in part 644;
12. developing digital spatial information that meet the NCSS standards as outlined in part 647; and
13. ensuring that draft or revised Official Soil Series Descriptions (OSDs) meet NCSS standards as outlined in part 614, and have passed the OSD Check Program prior to being submitted for processing.
MLRA Regional Office (MO).

The MO is responsible for:
1. coordination and quality assurance for all production soil survey and update activities and products, including all data collection, NASIS data population, interpretation, correlation, publications, and digital map development; to ensure that all soil survey products developed in the MLRA Region meet NCSS standards;
2. making broad regional decisions to determine where to separate soils based on performance, classification, and other factors in order to ensure a seamless and scientifically credible soil survey for the nation;
3. conducting quality assurance reviews to:
  1. ensure that products developed by the SSO have passed quality control inspections and meet NCSS standards,
  2. ensure that progressive correlation is being implemented and followed by the SSO staff,
  3. identify training needs, management and performance issues, and communicate those needs and concerns to the supervisor;
4. providing states with findings, recommendations and commendations from quality assurance reviews;
5. providing timely quality assurance review reports and follow-up from other assistance activities to soil survey offices and state offices;
6. providing (or helping to arrange) training for soil survey office staff in data collection and analysis, mapping techniques, map unit design and naming, soil classification, legend management, NASIS data population, interpretations, soil technologies, quality control procedures, progressive soil correlations concepts and techniques, and overall management of the soil survey;
7. quality assurance of all attribute data residing in NASIS, and the OSD and Soil Classification (SC) databases;
8. quality assurance of all OSDs developed or revised in the MLRA Region;
9. maintenance of the OSD and SC databases;
10. quality assurance of all spatial data developed in the MLRA Region;
11. assuring the development of seamless soil survey products across political and physiographic boundaries in the MLRA Region as defined in part 609.03;
12. developing a blanket memorandum of understanding for the entire MLRA region, that outlines the responsibilities and specifications for conducting soil surveys in the region;
13. providing MLRA-specific correlation guidelines on soil temperature and moisture regimes and their associated ecological zones and vegetation and any other MLRA-specific information;
14. providing leadership for the coordinated collection of soil survey related soil characterization data and investigations in the region; and
15. approving final correlation documents for initial soil surveys.
State Soil Scientist.

The state soil scientist is responsible for:
1. providing administrative and management support and guidance to the soil survey offices that they supervise;
2. participating in quality assurance review activities sufficiently to support and concur with findings and recommendations;
3. providing leadership and working with NCSS partners in identifying the need for new soil survey information and interpretations within the state;
4. providing digital files for general soil maps, index maps, soil legend and special features legend, geology maps, and block diagrams for use in publications;
5. submitting complete manuscripts that have passed a State quality control review to the MO; and
6. ensuring findings and recommendations identified in the MO quality assurance reviews are addressed and implemented in a timely manner.
State Conservationist.

The State Conservationist is responsible for:
1. providing leadership in the conduct of soil surveys in their state;
2. providing funding support for soil survey offices;
3. certifying the quality of soil survey products; and
4. ensuring the findings and recommendations identified in the MO quality assurance reviews are addressed and implemented in a timely manner.
National Soil Survey Center.

The National Soil Survey Center is responsible for:
1. formulation and coordination of national guidelines, procedures, and criteria for producing soil survey information;
2. quality control of the criteria for classifying soils and of training in soil taxonomy;
3. quality control of the standards for making soil interpretations;
4. quality control of standards and criteria and of training for the soils portion of geographic and information systems; and
5. quality control of analytical procedures used in both laboratory and field investigation of soils.
National Cartography and Geospatial Center.

The National Cartography and Geospatial Center is responsible for:
1. ensuring the cartographic quality of soil survey maps for archiving and distribution;
2. providing technical guidance specific to cartography and map production;
3. providing subsets of the Digital General Soil Map of the U.S. and Index to Map Sheets;
4. coordinating requests for cartographic products;
5. developing standards, specifications, and providing quality assurance for spatial soil data capture;
6. providing training in SSURGO quality assurance activities;
7. assisting MO offices in the quality assurance of SSURGO, digital map finishing, and other cartographic soil survey products; and
8. providing geospatial web map services (WMS), image map services (IMS), feature map services (FMS), and the Geospatial Gateway for soil survey data distribution and application.

Soil Correlation (609.02)

The NRCS has the leadership for soil correlation within the NCSS. Each MO assures quality of soil surveys through a formal process of soil correlation within each major land resource area (MLRA). For soil surveys on federal lands, the NRCS works closely with partner agencies in carrying out these responsibilities. Soil correlation ensures consistent and accurate mapping, naming, classification, joining, database population, and interpretation within the MLRA. Soil correlation requires that data entered into the soil survey database meets national standards. Soil correlation ensures that all adjacent soil survey maps sharing the same purpose, scale, and order of survey exactly join. Soil correlation requires that soil properties are populated using standard criteria in part 618 that each map unit is distinguished from all others, and that proper interpretations are assigned to each map unit component. Correlation facilitates the effective transfer of technology.

Progressive soil correlation.

Progressive soil correlation is a process that identifies and records all the issues and decisions surrounding soil map unit level information throughout the course of a soil survey. Progressive soil correlation is used in initial soil surveys and update soil surveys requiring extensive revision as well as in MLRA soil surveys. It is practiced throughout the course of a soil survey, keeping pace with progress. Field reviews and field assistance visits are vehicles through which the SSO and the MO promote progressive correlation, maintain quality control and quality assurance, and ensure that technical standards are met. Progressive correlation requires that, during each review or field assistance visit, any changes, deletions, or additions to taxonomic units and map units recognized since the last review or assist are evaluated and, if appropriate, certified. For soils that extend beyond the boundary defining the project area, data and descriptions representing the soil on similar landforms and parent materials are considered in defining ranges for soil properties and determining map unit composition and contribute to the documentation of the survey in progress. All soil survey activities, including interpretation, legend development, joining, soil investigation, and report development, are concurrent with mapping.
Recording progressive soil correlation decisions.

All progressive soil correlation decisions and their reasoning are recorded in NASIS. Any changes or additions to legends, taxonomic units, or map units must be recorded. Significant changes to soil property data and interpretive data, such as ecological site designation, farmland classification, land capability classification, or crop yields, should also be recorded. The reasons for the decision should be recorded if it is relevant and important to future users of the information.
Final correlation.
1. Final correlation is a process that is used when an initial soil survey is near completion. If, during the course of an initial soil survey, effective progressive soil correlation has taken place, the final correlation is primarily a review of the progressive soil correlation decisions that have been previously made. The final correlation serves as a data check and also identifies any incomplete work that needs to be completed prior to the soil survey being certified.
2. After the final field review the SSO and the MO schedule a time for a final correlation conference, the outcome of which is the draft correlation document. Although the final correlation is a joint effort between the SSO and the MO, it is the responsibility of the SSO to ensure that all data to be reviewed has passed prior quality control inspections. The SSO is also responsible for gathering and preparing all materials needed for the final correlation.
3. Items to be reviewed and completed at the final correlation include:
  1. Review and confirm the classification of each pedon that has been analyzed in a soil survey laboratory or engineering laboratory and revise the classification, as needed. If needed, update NRCS-SOI-8 input form for the index of soil laboratory data for all pedons sampled in the survey area.
  2. Review taxadjuncts and taxons needing a correlation note, and record the reason for the taxadjunct or correlation note in NASIS. Record unique or unusual information about a taxon that may prove useful to future users of the information.
  3. Review and confirm taxonomic units and their classification. Summarize and process final edits and changes to taxonomic unit descriptions.
  4. Review and confirm series validity and their classification. Summarize and process final edits and changes to official soil series descriptions.
  5. Review and confirm map unit names and ensure their conformity with current naming convention and consistency in the survey area. Summarize and process final edits and changes to map unit descriptions.
  6. Review NASIS database entries for accuracy, completeness, and consistency.
  7. Review interpretations for accuracy and consistency.
  8. Review draft report and identify any needed edits or changes.
  9. Review and examine maps for joins, proper labeling, and line conformity with the landform imagery.
  10. Prepare a join statement that documents where and why map units do not join across survey boundaries. Identify how, where, and when field maps will be compiled, digitized, and map finished.
  11. Prepare and review other supporting documents or information to be included in the correlation document. This may include items such as soil-vegetation-climate schema or models, special investigative studies, and lists of references used throughout the course of the survey.
  12. Record where all field documentation, field maps, and other supporting materials and information will be archived.
  13. Prepare a draft correlation document. The MLRA Regional Office Leader is responsible for approving the final correlation.
Correlation document.

A correlation document, also sometimes referred to as a correlation memorandum, is a hard copy product that is developed and distributed after the completion of an initial soil survey.

Exhibit 609-1 describes the format of a correlation document. It includes items such as:
1. Heading
2. Introductory Paragraph
3. Headnote for Detailed Soil Survey Legend
4. Series Established, Dropped, or Made Inactive with the Correlation
5. Conversion Legend Showing Field and Publication Names and Symbols
6. Map Unit Legend Sorted Alphabetically
7. General Soil Map Unit Legend
8. Feature and Symbol Legend
9. Cooperator’s Names and Credits
10. Prior Soil Survey Publications
11. Instructions for Map Compilation, Digitizing, and Finishing
12. Join Statement
13. Classification of Pedons Sampled for Laboratory Analysis
14. Sampled Pedons in Published Soil Survey Report
15. Notes to Accompany the Classification and Correlation of the Soils in the Survey Area
16. Classification of the Soils
17. Miscellaneous Items
18. Certifications
19. Signatures
Development, distribution, and amendment policy for the correlation document.

All changes to legends, map units, or taxons for a soil survey area, either initial or update, must be documented and recorded in NASIS. Recording changes to legends, map units, or taxons in NASIS will ensure portions of the correlation document can be generated directly from NASIS.
1. For initial soil surveys, a correlation document will be produced by the MLRA Regional Office and distributed per the following guidelines:
  1. The state conservationist and the MO Team Leader sign the final correlation document. Their signatures certify that the soil survey is complete and accurate.
  2. The state conservationist distributes copies of the signed classification and correlation document and of any subsequent amendments to the document as follows:
    - One copy to the MO of responsibility for the survey area.
    - One copy to each MO that has responsibility for soil series used in the survey area.
    - One copy to each state that adjoins the survey area.
    - One copy to Director, National Cartography and Geospatial Center.
    - One copy to the Director, National Soil Survey Center.
    - One copy to NCSS cooperating agencies as appropriate.
    - Distribution to NRCS staff within the issuing state is made at the discretion of the state conservationist.
  3. The final correlation document is archived in the Legend Correlation table in NASIS.
  4. Prior to SSURGO certification, the archived final correlation document can be amended and hard copies redistributed for an initial soil survey area. Amendments to the final correlation document receive the same signatures and distribution as the original document.
  5. Once a survey is SSURGO certified, and is deemed to be in update status, the correlation document and amendments are archived in NASIS. Subsequent correlation decisions are recorded in NASIS, but the original correlation document is no longer amended.
2. For update surveys:
  1. All changes to legends, map units, or taxons must be documented and recorded in NASIS. However, the archived correlation document will not be amended and redistributed each time a change occurs as part of update activities.
  2. In lieu of amending and redistributing a hard copy of the correlation document, a report will be generated from NASIS that lists and identifies all changes to legends, map units, and taxons. This report can be printed and distributed as the MO or state deems necessary.
  3. A formal correlation document may be prepared and distributed for an MLRA soil survey, or for a special project, or to satisfy an agreement item with a cooperator.

Seamless Soil Survey (609.03)

The goal of soil survey is a seamless product across political and physiographic boundaries. A seamless product entails an exact join of attribute and spatial data between soil survey areas. In some situations, an exact join may not be possible and an acceptable join is achieved.

Exact Joins.

An exact join between soil survey areas occurs when soil polygon lines and features are continuous across and along the common boundary and joined soil polygons share the same basic soil properties and selected soil qualities (Exhibit 609-2). Sharing basic properties and selected qualities includes major and minor component composition, basic property ranges (low, high, rv), as well as layer depths. An exact join should be achieved between two surveys of the same, or nearly the same, vintage, stated purpose, scale, and order of survey.
Acceptable Joins.

It is the responsibility of the MLRA Regional Office when employing the acceptable join to affect the best join possible and to document the need for future improvement to the join as appropriate. Acceptable joins are employed primarily when joining previously correlated surveys that would require field investigations to resolve the join discrepancies.
1. An acceptable join between soil survey areas occurs when soil polygon lines and features are continuous across and along the common boundary and soil properties and selected soil qualities share the same basic soil properties and selected soil qualities (Exhibit 609-2) for most polygons.
2. Where map unit components do not match, they fit the concept of similar soils.
3. Rationale for the non-joined polygons (map units) is to be documented.
Joining Requirements.
1. When completing a soil survey, map unit delineations along the boundary with each of the adjacent survey areas are to be joined. To achieve this goal, soil landscape features must be identified, mapped, and described consistently across political and physiographic boundaries. Data collection, analysis, and summary must represent these natural landscapes.
2. In most cases, an exact join should be achieved. An acceptable join may be the best join that can reasonably be achieved at the current time. It is a joint responsibility of the MO and state soil scientist to determine the appropriate join between soil survey areas.
3. If two soil surveys of different orders of mapping are adjacent, an exact join is in effect since the boundary between soil survey areas also serves as soil map unit boundaries. On hard copy maps, a note is printed parallel to the boundaries that separate the areas of each survey order, such as “Limit of Order 3 Survey”. Chapter 2 of the Soil Survey Manual provides more information. Each soil line in the survey of lower intensity must have a corresponding soil line in the adjacent survey of higher intensity, but the converse is not required.
4. If an ongoing soil survey borders a survey area that requires extensive revision and is out-of-date and therefore acknowledged as being obsolete, the MO should effect the best join possible using available knowledge and tools, but it is not required to revise any part of the out-of-date survey until such time as an update project is initiated. The joining statement in the correlation document should state the situation.
5. The MLRA SSO prepares a “Join Statement” document that records all discrepancies from an exact join, and any changes made to enact an exact or acceptable join between map unit polygons. Reasons for these changes should also be included in the join statement. This join statement documentation is included in the final correlation document and in NASIS.
6. Changes in map unit names, or additions and deletions of map units or delineations to an existing soil survey as part of the SSURGO certification process must be documented with an amendment to the final correlation document. Part 609.02 (e) provides information on amending the final correlation document.
7. When two previously correlated surveys are prepared for SSURGO, there is usually no project office staff available to investigate join discrepancies in the field. To expedite SSURGO preparation, compilers may have to adjust lines and associated data as is practical from the office to affect the best possible join. This generally involves moving lines slightly to conform with new imagery and to come together at the same point along the survey boundary, and coordinating the boundary between the two surveys. Changes in map unit names, or additions and deletions of map units or delineations must be documented with a correlation amendment. Digital soil surveys and discrepancy documentation and statements recorded in NASIS are tools for future update activities to implement MLRA legends and exact joins.

Quality Control Reviews (609.04)

Each individual involved in soil survey operations; whether it is mapping and describing soils in the field, on-screen digitizing of soil boundaries, sampling and classifying pedons, analyzing and summarizing data, populating databases, developing report materials, or any other soil survey activity; has the greatest influence on the quality of the work they perform. All are expected to perform their duties in a way that results in soil survey products that meet NCSS standards and are of a high quality.

The MLRA Soil Survey Project Leader is the first level manager who is responsible to see that all work performed within their assigned area is of high quality and meets NCSS standards. Much of this quality control responsibility is carried out on a day-to-day basis through direct interaction with subordinate staff members to schedule activities and make work assignments, review completed work, provide on the job training, and other related activities. In addition to these routine management activities, systematic reviews are periodically conducted to document the success of the quality control procedures used. The specific details of the items to be reviewed will vary with the kind of activities being carried out as described in the project plan of operations.

Exhibit 609-10 is an example of a Quality Control Review template for an initial soil survey. MLRA Regional Offices are encouraged to adapt this or develop a new one to reflect the activities to be reviewed in a particular MLRA Soil Survey Office. The kinds of activities reviewed may include items such as:

administrative and scheduling
progress reporting
review of mapping
legend development and progressive correlation
adequacy of field documentation
field investigations and sampling
database development
digital map development
publication development

The template (Exhibit 609-10) provides separate sections for various soil survey process steps and a set of specific items to be reviewed and certified for each. MLRA Regional Offices should work with the soil survey offices in their region to implement a quality control review process appropriate to their needs.

Quality Assurance Reviews (609.05)

Quality assurance reviews are scheduled on a regular frequency to ensure that technical standards of the National Cooperative Soil Survey are met. In addition, quality assurance reviews can also evaluate and certify that progress is consistent with timelines agreed upon in the work plan. To a lesser degree they can serve to help the soil survey office staff solve problems or provide on-the-job training for the project staff, but these goals are best achieved through separate field assistance visits scheduled for those purposes.

The NRCS General Manual Title 340, Subpart E, Internal Management Reviews, contains the NRCS policy for and content of other reviews. Access is through the NRCS Electronic Directives System at http://policy.nrcs.usda.gov. The NRCS conducts five types of reviews: Oversight and Evaluation Studies, Leadership Reviews, Operations Management Reviews, Program Operations Reviews, and Functional Reviews. Each type may include soil survey issues. Exhibit 609-7 lists potential items for these reviews.

Leadership and Participation.

The MLRA Regional Office, or the lead agency for quality assurance, conducts the review. The MLRA Soil Survey Office Leader must be present. Other suggested participants are:
1. Soil scientists from other nearby areas;
2. Members of the survey project;
3. The local district conservationists;
4. The representatives of cooperating agencies;
5. The state soil scientist or their designee;
6. Resource Soil Scientists familiar with the area; and
7. Discipline specialists such as engineers, geomorphologists, plant scientists, geologists, and others are encouraged to attend as applicable to the agenda for the review.
Kinds of Reviews for Initial Soil Surveys or Update Soil Surveys Requiring Extensive Revision.

Each initial survey or update survey with extensive revision (remapping) requires initial, progress, and final field reviews. Each of these surveys requires one initial field review and one final field review. Most require a yearly progress review. MLRA soil survey projects are reviewed for the status of progress toward meeting the goals and objectives set out in the long range and annual plans of operation. The field review report is a record of items such as the current status of the fieldwork, of observations and decisions, digital map and database development, and of recommended actions. This working document guides future operations and certifies that completed work meets NCSS standards.
1. Initial field reviews.
  
  The purpose of the initial field review is to guide the soil survey project at the start of mapping, to review the collection and recording of soil data, and to complete preparation of the first formal draft of the descriptive legend, based on the mapping completed and data collected. Exhibit 609-3 lists important items to check before and during the initial field review.
  1. Preparation for an initial field review. An approved soil survey memorandum of understanding must be available for the initial review. (The MLRA Region-wide MOU satisfies this requirement, but an MOU specifically for this project can be developed.) The long range plan of operations must be available. The project office assembles, reviews, and summarizes existing information about the major land resource area and the subset survey area. The staff is in place and has worked in the area long enough to become familiar with the project area and the surrounding surveys. The project office staff prepares:
    - preliminary concepts of the major soil-landscape models within the context of the larger MLRA region;
    - test mapping of sample areas for the provisional legend;
    - notes that support tentative judgments about the range of important soil properties within the most important kinds of mappable soil areas;
    - information on the kind and amount of mapping components;
    - information on geomorphology, surface features, and kinds of vegetation that provide clues to the kinds of soil and soil boundaries;
    - a test of the initial interpretations;
    - a first draft of the descriptive legend;
    - preliminary data to support judgments about the kinds and number of map units needed for the project area; and
    - the equipment, supplies, and base maps.
  2. Conduct of the review.
    - Initial preparations. The review team appraises all initial preparations to ensure that they are adequate and takes necessary action if they are not.
    - Field study. The review team evaluates the draft descriptive legend against mappable bodies of soil in the field and reviews the collected soil data. It checks the accuracy of descriptions and the adequacy of map units for making soil interpretations. It evaluates and comments on the mapping done in sample areas in relation to the adjacent surveys. It checks the joining of soil maps and selected soil properties or qualities within the soil survey area and to adjoining survey areas to coincide with the joining specification in the memorandum of understanding. It makes decisions on soils for which the classification is doubtful.
    - Descriptive legend. As a minimum, the descriptive legend consists of the taxonomic and map unit descriptions, the classification of the soils, the general soil map (Digital General Soil Map of the U.S. – STATSGO) and legend, the identification legend, and the feature and symbols legend. After the field study, the team evaluates the draft descriptive legend and makes necessary revisions. The review team examines the naming of the kinds of map units, the classification of the kinds of soil identified in the map units, the general soil map (Digital General Soil Map of the U.S. – STATSGO2) and legend, the list of features and symbols for the soil survey, and the definitions of ad hoc features. The team emphasizes the design and description of map units to meet the objectives of the survey. The descriptive legend includes only the map units and features that are actually identified and described before or during the initial field review.
    - Scheduling. The review team discusses and schedules long- and short-range activities that are necessary for completing the survey. Exhibit 609-3 identifies many of the items to check before and during the initial field review. The team discusses activities and schedules:
      1. preparation of parts of the soil handbook for the survey area,
      2. plans for soil investigations and collection of samples for laboratory analysis,
      3. collection of data on yields and soil performance in all land uses,
      4. recording of field notes, and
      5. preparation of the soil survey publication.
    - The review report initiates and includes arrangements for completing laboratory work and schedules subsequent progress field reviews and special studies.
  3. Preparation of the report. The leader of the initial field review prepares a report of the review. The report includes a “Quality Assurance Worksheet.” The MLRA Regional Office leader approves the report. Exhibit 609-8 is an example of a Quality Assurance Worksheet. In addition to the worksheet, the report includes:
    - the identification legend;
    - a progress map;
    - draft descriptions of proposed new soil series;
    - a statement on the accuracy of map unit composition and attribute data;
    - notes recording important observations made during the field study;
    - instructions and items agreed upon for the field soil scientists and others, which concern conduct of the survey and the assignment of responsibilities, priorities, and dates of accomplishment;
    - a list of classification of the taxa for the survey area;
    - a subset of the Digital General Soil Map of the U.S. (STATSGO) database for the survey area as a general soil map; and
    - a letter transmitting the report to the state conservationist and others as appropriate, in which the MLRA Regional Office leader highlights significant issues and items that are agreed upon.
2. Progress field reviews.
  
  The purpose of this review is to assess progress and assure that NCSS standards are being met. Progress field reviews emphasize progressive correlation in a manner consistent with the larger MLRA soil survey area, and certification of the work completed to date. Help may also be provided to the soil survey project staff on problems of soil classification; field mapping; data collection, storage, and retrieval; and soil interpretation, but these are generally best addressed during a separate field assistance visit.
  
  The frequency of progress reviews depends on the rate of progress, the complexity of the soil survey area, and the experience of the project office. Exhibit 609-4 gives a list of some of the important items to check before and during progress field reviews.
  1. Conduct of the review. The review team spends at least some of the time in the field observing examples of mapping, field descriptions, and associated data and interpretations to assure that the local quality control procedures are effective. They examine maps for correct soil identification, proper placement of boundaries, legibility, and kinds and amounts of components in delineations. They check the maps and databases for the join with adjacent surveys. The team compares findings with statements in the descriptive legend. Where problems are noted, the group concentrates on solutions to assist the staff in avoiding similar future problems.
    - The progress field review team reviews the recommendations of the soil survey staff for progressively correlating completed mapping. They make a record of the reason(s) for any correlation decisions and any work needed to update field sheets.
    - The review includes a check of all interpretations. The team cross-checks field data, such as forestry productivity, for use. The review recommends changes and additions soil property records.
    - The review includes the quality and status of the descriptive legend and the soil handbook of the survey area. The review team recommends revisions for the descriptive legend as necessary to meet the objective of the survey.
    - The review team checks the adequacy of field notes and the rate and progress of mapping and other scheduled survey activities.
    - The review team determines if action has been taken to correct deficiencies and complete items agreed upon that were noted in previous field reviews.
  2. Preparation of the report. The leader of the progress field review prepares a report of the review. The report includes a “Quality Assurance Worksheet” that has been approved by the MLRA office. Exhibit 609-8 is an example. In addition to the Quality Assurance Worksheet, the report includes:
    - a list of commendable activities of the soil scientists assigned to the survey area;
    - a list of items agreed upon, who is responsible, and the date for its completion;
    - a statement of the accuracy of map unit component and attribute data;
    - a progress map;
    - an updated list of classification of the taxa in the survey area;
    - notes recording important observations made during the field studies;
    - a record of additions, deletions, or other changes to the descriptive legend;
    - a complete updated identification legend;
    - a letter transmitting the report to the state conservationist and others as appropriate, in which the MLRA regional office leader highlights significant issues and items that are agreed upon; and
    - an evaluation and comments on the status of scheduled actions from earlier progress reviews.
3. Final field reviews.
  
  The purpose of the final field review is to evaluate the entire survey to assure that the work is of acceptable quality and to complete necessary modifications before field operations end. The final field review can be held about 1 year before the completion of mapping in initial soil surveys. Exhibit 609-5 provides a list of some of the important items to check before or during the final field review. Most soil survey activities are complete and the collected data is available prior to the final field review. The activities include:
  1. Completing the mapping; checking consistency and quality of mapping throughout the survey area; collecting soil sample and interpretation data for correlation; finishing the complete draft of the soil survey report and database entries; revising the Digital General Soil Map of the U.S. (STATSGO) database and if one is to be prepared, the general soil map; completing laboratory analysis and soil investigations; providing correlated names and classifications for pedons in the laboratory database; taking photographs; and preparing illustrations.
  2. Conduct of the review. The major portion of the review occurs in the office. Field checks take place if questions occur that can only be answered in the field. Those activities that were noted as needing corrective action during the last progress review receive special attention. Items scrutinized by the review team include the descriptive legend and supporting information; map unit names, composition, and associated data; the joining of the Digital General Soil Map of the U.S. (STATSGO) database; the draft soil survey report; and interpretative tables.
  3. Preparation of report. The leader of the final field review prepares a report of the review. The report includes a “Quality Assurance Worksheet” that has been approved by the MLRA Office. Exhibit 609-8 is an example of a Quality Assurance Worksheet. In addition to this worksheet, the report includes:
    - an identification legend;
    - a feature and symbol legend;
    - a progress map;
    - a record of soil characterization samples that were collected for laboratory analysis in the survey area;
    - a record of soil samples that were collected for engineering tests;
    - a statement on the accuracy of map unit component and attribute data;
    - an updated list of classification of taxa in the survey area;
    - an evaluation of the soil survey report;
    - a list of commendable activities of the survey project staff;
    - a list of actions agreed upon;
    - a record of the decisions made during the review; and
    - a preliminary correlation memorandum, as prescribed in part 609.02 of this handbook;
    - a letter transmitting the report to the state conservationist, and others as appropriate, in which the MLRA regional office leader highlights significant issues and items that are agreed upon; and
    - an evaluation and comments on the status of scheduled actions from any earlier progress reviews.
  4. Final Soil Survey Field Activities for Initial Soil Survey Projects and for Update Projects Requiring Extensive Revision.
    
    The project office schedules time between the final field review and the final correlation for several tasks. These tasks are to complete the mapping, perform final checks, review the fieldwork and soil survey database, complete the final draft of the soil survey publication, and update all supporting records and data, such as map unit acreage data, map compilation, and statistical analysis for map unit composition information. Preparation of the final correlation memorandum requires completion of these activities. The final correlation memorandum is finalized upon signature by the MLRA regional office leader and state conservationist(s). Part 609.02 discusses preparing and distributing a correlation memorandum, and Exhibit 609-1 discusses the format of the final correlation memorandum.
MLRA Soil Survey Project Quality Assurance Reviews.
1. MLRA soil survey project progress reviews.
  
  Progress field reviews emphasize evaluation of activities of the field staff to assure that they are carrying out soil survey update activities as described in the project plan of operations for the area, NCSS policy and procedures are followed, and certification that the completed work meets NCSS standards. They may also provide help to the staff on problems such as soil classification; updating of maps; data collection and analysis, storage, and retrieval; and soil interpretation.
  
  The frequency of progress reviews depends on the rate of progress the complexity of the project area, and the kinds of update activities being conducted. Exhibit 609-6 gives a list of some of the important items to check before and during project reviews.
  1. Conduct of the review. Activities are tailored to reflect the nature of the work being performed. Commonly the review team spends part of the time in the field reviewing the collected soil data. They also examine digital maps for correct soil identification, proper placement of boundaries with landforms and imagery, and validity of models used in revising the soil maps. As necessary, the group concentrates on solutions to problems brought to their attention by the field staff or discovered during the review process.
    - The review team checks the adequacy of documentation and the rate and progress of scheduled survey activities.
    - The review team determines if action has been taken to correct deficiencies and complete items agreed upon that were noted in any previous field reviews.
  2. Preparation of the report. The leader of the project review prepares a report of the review. The report includes a “Quality Assurance Worksheet” that has been approved by the MLRA Regional Office. Exhibit 609-9 is an example of a Quality Assurance Worksheet. In addition to the worksheet, the report includes:
    - a list of commendable activities of the soil scientists assigned to the survey area;
    - a list of items agreed upon, who is responsible, and the date for its completion;
    - a statement of the accuracy of map unit component and attribute data;
    - an updated list of classification of the taxa in the survey area;
    - notes recording important observations made during the field studies;
    - a complete updated identification legend for the project area;
    - a letter transmitting the report to the state conservationist(s), and others as appropriate, in which the MLRA Regional Office leader highlights significant issues and items that are agreed upon; and
    - an evaluation and comments on the status of scheduled actions from any earlier progress reviews.
2. MLRA soil survey project completion reviews.
  
  The purpose of the project completion review is to evaluate the activities to ensure that the work meets NCCS standards and to complete necessary modifications before individual project operations end. The project completion review is held when activities described in the current plan of operations are nearing completion. Exhibit 609-6 provides a list of some of the important items to check before or during the project review.
  1. Activities completed prior to project completion reviews. The activities include completing the digital revisions, checking consistency and quality of previous mapping evaluated throughout the project area; collecting soil sample and interpretation data for correlation; completing laboratory analysis and soil investigations; and providing correlated names and classification for all applicable pedons in the laboratory database.
  2. Conduct of the review. The major portion of the review occurs in the office. Field checks generally are covered under field assistance visits (part 609.06) and take place if questions occur that can only be answered in the field. Those activities that were noted as needing corrective action during the any project progress review receive special attention. Items scrutinized by the review team include supporting information, the validity of map units and their names and the tabular database. A check is made to ensure that correlation decisions are recorded in NASIS.
  3. Preparation of report. The leader of the project completion review prepares a report of the review. The report includes a “Quality Assurance Worksheet” that has been approved by the MLRA Regional Office. Exhibit 609-9 is an example of a Quality Assurance Worksheet. In addition to this worksheet, the report includes:
    - an identification legend of revised map units
    - a feature and symbol legend;
    - a record of soil characterization samples that were collected for laboratory analysis in the survey area;
    - a record of soil samples that were collected for engineering tests;
    - a statement on the accuracy of map unit component and attribute data;
    - an updated list of classification of taxa in the survey area;
    - a list of commendable activities of the survey project staff;
    - a record of the decisions made during the review;
    - a letter transmitting the report to the state conservationist(s), and others as appropriate, in which the MLRA Regional Office leader highlights significant issues and items that are agreed upon; and
    - an evaluation and comments on the status of scheduled actions from any earlier progress reviews.
Signature and Approval of Review Reports.
1. Review team leader. The MLRA Regional Office or a cooperating agency leads the review and is responsible for preparing and signing all review reports, and transmitting copies of the review report to the state conservationist(s) and others as appropriate. The MLRA Regional Office leader signs the transmittal letter.
2. Representatives of cooperating agencies. Representatives of cooperating agencies may also sign all review reports, such as the Quality Assurance Worksheet. When other partner agencies (for example, the USFS) lead the review, NRCS participates in a quality assurance role which does not replace the responsibilities assigned to the partner agency. Field review reports and other documentation regarding survey quality on federal land require the signature of either a representative of the agency who participates in the review activity, or a designated representative of the agency, to document agreement or disagreement by signing the report.
3. State Conservationist. The state conservationist, or appointed designee, reviews and signs the report as a means of documenting the transfer of significant issues and agreed to items pertaining to the review.
  1. Arrangements for managing all review reports by participating cooperators can be described in the memorandum of understanding or the work plan.
  2. The signed document is a part of the soil survey record file.
Distribution and Review of Review Reports.

The MLRA Regional Office leader distributes copies of all field reviews within 30 days after the final day of the review. The leader sends at least one copy of the field review report and attachments and a letter of transmittal to the:
1. project office in charge,
2. state conservationist(s),
3. state soil scientist,
4. agencies cooperating in the survey,
5. MLRA Regional Office, and
6. others as appropriate.

Field Assistance Visits (609.06)

The MLRA Soil Survey Office, State Office, or a cooperating agency office may request help from the MLRA Regional Office as needed. The MLRA Regional Office may schedule field assistance visits as necessary also.

A written trip report is to be prepared documenting the activities from the field assistance visit and distributed to the participants, as well as the State Soil Scientist and any appropriate cooperating agencies. Decisions that affect the legend, data collection or recording, classification of soils, or interpretations become part of the permanent and formal record of the survey upon inclusion in the final field review or MLRA project completion report.

Final Soil Survey Field Activities for Initial Soil Survey Projects and Update Projects Requiring Extensive Revision (609.07)

The project office schedules time between the final field review and the final correlation for several tasks. These tasks are to complete the mapping, perform final checks, review the fieldwork and soil survey database, complete the final draft of the soil survey report, and update all supporting records and data, such as map unit acreage data, map compilation, and statistical analysis for map unit composition information. Preparation of the final correlation memorandum requires completion of these activities.

Final Correlation Memorandum. The draft of the final correlation memorandum is prepared at the final correlation conference. The final correlation memorandum is finalized upon signature by the MLRA Regional Office leader and State Conservationist(s). Part 609.02 discusses preparing and distributing a correlation memorandum and Exhibit 609-1 discusses the format of the final correlation memorandum.
Final Draft of the General Soil Map (Digital General Soil Map of the U.S.). The project office prepares the general soil map for the final field review on its publication scale base map in final form. This map is from the Digital General Soil Map of the U.S. database. Inclusion of this map in the soil survey publication is optional. Revise the general soil map unit names as needed to agree with the general soil map legend in the correlation memorandum.

General Soil Maps, Index Maps, and Location Maps (609.08)

The MLRA office assures the technical quality of general soil maps, index maps, and location maps. The general soil maps are optional in soil survey publications (manuscripts posted to the web or as hard copies), but index maps and location maps are required.

If a general soil map (GSM) is not to be included, cooperators should agree with the decision. Also, an up-to-date Digital General Soil Map of the U.S. (STATSGO) database map of the survey area should be readily available to the public. The availability of the Digital General Soil Map of the U.S. should be noted in the publication. For example, it could be noted in the section “How To Use This Soil Survey.”

General soil maps and index maps.
1. Each soil survey publication includes an Index to Map Sheets. The National Cartography and Geospatial Center staff provides an Index to Map Sheets. By request, a soil survey area subset of the Digital General Soil Map is provided by NCGC as one of the map sources for the GSM. The other source for GSM is SSURGO. NCGC assists in determining format and the number of maps needed. A draft of the general soil map developed from the Digital General Soil Map or SSURGO and associated legend are completed to the extent possible after correlation decisions have been finalized. The Data Quality Specialist reviews the GSM and legend to verify that:
  1. soil map boundaries are accurate;
  2. GSM map unit names conform to the correlated names on the detailed maps;
  3. the map legend and manuscript are in agreement;
  4. the general soil map legend matches adjoining survey areas which ensures that all delineations are closed and symbolized, that the area of each map unit compares with the percentage given for the survey area, and that the organization and levels of generalization of the map and legend are appropriate;
  5. map delineations and legends join the Digital General Soil Map of the U.S. for adjacent surveys; and
  6. if the percentage of each component in the GSM is given, the total acreage of each is not more than is shown on the acreage table for the detailed map units.
  Once the draft general soil map is approved, the detailed soil legend and feature and symbol legend can be ordered.
2. The procedure for ordering is as follows:
  1. Place orders with NCGC on-line at http://www.ftw.nrcs.usda.gov/ncgcos/
  2. Order the color check print of the general soil map, the index to map sheets, the feature and symbol legend, and the detailed soil legend from the National Cartography and Geospatial Center. List the headnote to accompany the detailed soil legend if it is different from that shown in the final correlation memorandum. If the headnote is different, amend the final correlation memorandum to reflect the change.
  3. Indicate additional instructions for completing the order as. Include special instructions needed by the cartographic staff to prepare the symbols legend. Show suggestions for the selection of the colors that show soil groupings or levels of generalization on the supplement or on the edited legend. Attach a copy of the final correlation memorandum, including any amendments, the electronic file of the Digital General Soil Map of the U.S., and a copy of the edited general soil map legend to the order.
3. MLRA Regional Office checking. The National Cartography and Geospatial Center completes the order and sends the Digital General Soil Map generated general soil map color check print, the index to map sheets, and the legends to the MLRA Regional Office for final review and approval. The MO checks:
  1. the GSM legend against the edited copy,
  2. the detailed soil map legend against the final correlation memorandum and any amendments,
  3. the names of cooperating agencies on maps and legends against the final correlation memorandum and any amendments,
  4. the name of survey area on maps and legends against the final correlation memorandum and any amendments, and
  5. the conventional and special symbols legend for agreement with maps and the final correlation memorandum.
  The MLRA Regional Office makes needed changes and corrections on the Digital General Soil Map of the U.S. and returns them to the National Cartography and Geospatial Center. The National Cartography and Geospatial Center staff makes the corrections identified.
Location maps.

Each soil survey publication requires a location map. This map shows the location of the survey area in the state. The MLRA Regional Office orders the location map at the time the soil survey manuscript is received for technical review. The National Cartography and Geospatial Center staff prepares the location map.

Format for Correlation Document (Exhibit 609-1)

The following outline shows the order and character of items and data ordinarily contained in a correlation document. It does not preclude the inclusion of other information pertinent to the survey or the explanation of actions taken in the correlation. An example follows each item.

1. Heading.

UNITED STATES DEPARTMENT OF AGRICULTURE
Natural Resources Conservation Service

Classification and Correlation
of the Soil Survey of
Any Area, Any MLRA, Any State

The United States Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at 202-720-2600 (Voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer.

2. Introductory Paragraph.

In this paragraph cite persons participating in the correlation, the date, the location, data reviewed, the basis for the correlation, and other items if pertinent. For example: “John C. Smith, soil data quality specialist, and David G. White, MLRA soil survey office, of the Natural Resources Conservation Service and Joseph I. Black, associate professor, Anytown State University at Any Town, Any State, prepared this correlation the week of October 21-25, 2000. The soil survey database, soil survey publication, field notes, interpretations, laboratory data, correlation samples, field map sheets, and materials from the adjacent soil surveys provide the basis for this correlation.”

3. Headnote for Detailed Soil Survey Legend.

This headnote is an explanation of the symbols on the detailed soil maps in the published survey. It appears on the “SOIL LEGEND” in the published report and precedes the list of map unit symbols and map unit names. For example: “Map unit symbols consist of numbers or a combination of numbers and letters. The initial numbers represent the kind of soil. A capital letter following these numbers indicates the class of slope. Map unit symbols without a slope letter indicate nearly level soils or miscellaneous areas.”

4. Field and Publication Names and Symbols.

The correlation of soil map units is formatted into four columns. List map unit symbols for publication alphabetically or numerically in sequence. The heading and format are as follows:

Field Map Unit Symbol	Field Map Unit Name	Publication Map Unit Symbol	Approved Map Unit Name
DeB	Delta sandy loam, 2 to 6 percent slopes	AbB	Alpha sandy loam, 2 to 6 percent slopes
Bf	Beta mucky silt loam	Be	Beta silt loam
GaB, GhB	Gamma silt loam, 2 to 6 percent slopes	GaB	Gamma silt loam, 2 to 6 percent slopes

5. Series Established by This Correlation.

List the soil series established by this correlation. List in parentheses, after the series name, the county, the parish or survey area, and the state in which the type location occurs if the type location is in a soil survey area other than the one being correlated. For example: “The Alpha series is established by this correlation, the Alpha type location in the adjoining Beta County soil survey area, Any State.” Enter “None” if no new series were established.

6. Series Dropped or Made Inactive.

List the soil series that were dropped or made inactive by the correlation. For example: “The Beta series is made inactive by this correlation.” Enter “None” if no series were dropped or made inactive.

7. Cooperators’ Names and Credits.

List the following:

The cooperators’ names, and credits to be given in the published soil survey.

The cooperators are:
“United States Department of Agriculture
Natural Resources Conservation Service
In cooperation with
Anystate Agricultural Experiment Station
Anystate Conservation Commission
Anystate Cooperative Extension Service
Any Soil and Water Conservation District”

The credits to be given in the published soil survey are as follows:
“This survey was made for Any Survey Area, Anystate, by the Natural Resources Conservation Service and the Anystate Agricultural Experiment Station, Anystate Conservation Commission, and the Anystate Cooperative Extension Service. It is part of the technical assistance furnished to the Any Survey Area Soil and Water Conservation District. The Any Survey Area Board of Commissioners provided financial assistance for the survey.”

8. Prior Soil Survey Publications.

Indicate the reference to prior soil survey publications that will appear in the introduction of the published soil survey. A prior published soil survey is a literature citation in the soil survey publication. For example: “The first soil survey for Any Survey Area, Anystate, was published by the U.S. Department of Agriculture in 1903. Maps were printed in 1905. This soil survey is on an aerial photography base and contains more interpretative information.” Enter “None” if there is no prior soil survey publication.

9. Miscellaneous Items.

Use the appropriate headings and include items pertinent to the correlation or publication of the survey. For example, the soil-vegetation-climate schema, or model, used to guide correlation for the survey area should be included. Other examples might include a summary of soil temperature or moisture studies, or special investigative reports that provided guidance for the survey area.

10. Instructions for Map Development.

These brief instructions should include:

Identifying who is responsible for the development of digital spatial data.
What is the date and projection of the orthophoto imagery being used for the base map.
Identifying who is responsible for digitizing the maps and when it is scheduled.
Identifying who is responsible for finishing the digital maps and when it is scheduled.
Identify if a layer for point and linear map units will be compiled and digitized.
Any other instructions that may be relevant to the achieving a digital soils layers.

Detailed instructions for map compilation are found in NSSH part 647.

11. Feature and Symbol Legend.

Include a copy of form NRCS-SOI-37A and indicate the features and symbols that are used in the survey area by highlighting or underlining in red. For example: “Only those symbols indicated on the NRCS-SOI-37A will be shown on the legend.” Complete the descriptions for standard landform and miscellaneous surface features and descriptions for ad hoc features on the back of the NRCS-SOI-37A for those features indicated.

12. General Soil Map Unit Legend.

List the general soil map unit that will be shown on the legend of the general soil map of the survey area. For example:

“The following map units will be used on the general soil map legend:
Alpha-Beta to Alpha-Beta association
Beta-Gamma-Zeta to Beta-Gamma-Zeta association.”

13. Conversion Legend.

List all field symbols and their approved publication symbols. A conversion legend is not needed if field symbols and publication symbols are identical. For example:

CONVERSION LEGEND, ANY SURVEY AREA, ANYSTATE
Field Symbol	Publication Symbol	Field Symbol	Publication Symbol
7A	7A	20B	20B
7B	7B	21C	21D
7C	7C	21E	21E

14. Legend of Map Units in Alphabetical Sequence.

This legend is used only where numeric symbols will be published to assist publication crosschecking. For example:

LEGEND OF MAP UNITS IN ALPHABETICAL SEQUENCE, ANY SURVEY AREA, ANYSTATE
Publication Symbol	Approved Map Unit Name
43	Alpha clay
37	Beta clay loam, 5 to 9 percent slopes, eroded
39	Beta clay loam, 9 to 14 percent slopes, eroded

15. Classification of Pedons Sampled for Laboratory Analysis.

This table lists pedons that have laboratory data or engineering test data. Give the source of the data and other pertinent information. In the table “Publication Symbols,” refer to the map symbol that identifies the area from which the sample was taken. Additional columns can be added if needed.

CLASSIFICATION OF PEDONS SAMPLED FOR LABORATORY ANALYSIS
Sampled as	Soil Survey Sample No.	Publication Symbol	Approved Series Name or Class Identification
1. Laboratory Data from the NSSC Soil Survey Laboratory
Alpha	S79AS-047-003	AbB	Alpha
Beta	S79AS-047-004	GbB	Gamma
2. Laboratory Data from the Anystate Agricultural Experiment Station Laboratory
Beta	S79AS-047-005	BgB	Beta
Gamma	S79AS-047-006	AaA	Alpha
3. Laboratory Data from the Anystate Highway Department Laboratory
Alpha	S79AS-047-007	AaA	Alpha
Beta	S79AS-047-008	BbC	Beta

16. Sampled Pedons in Published Soil Survey Report.

This table lists the pedons and laboratory data that will be included in the published soil survey report. These pedons should represent the typical pedon for the series in the survey area. Where the pedon is not the typical pedon for the series in the survey area, also place a tabular or semi-tabular description in the soil survey report.

Series	Sample No.	Status
Alpha	S79AS-047-003	Typical pedon for the Alpha in the survey area.
Alpha	S79AS-047-011	Typical pedon from map unit Aa.

17. Notes to Accompany the Classification and Correlation of the Soils of Any Major Land Resource Area, Any County, Any State, by A. B. Smith, Soil Correlator.

Any notes of general explanation that contribute to the understanding of the correlation can be included as an introductory paragraph. For example: “This survey area is in a transitional zone of temperature regimes. Soils of mesic and thermic temperature regimes have been correlated.”

In the notes, include items such as:

Pertinent information about series being established. For example: “Alpha Series. The Alpha series is established by this correlation for soils that were formerly mapped as Beta but that have mixed mineralogy rather than siliceous mineralogy as defined for Beta.”
How taxadjuncts differ from the series concept. For example: “Gamma Taxadjunct. This soil is a taxadjunct to the Gamma series because it contains less than 15 percent sand that is coarser than very fine. The soil classifies as coarse-silty.”
A correlation note for soils that are slightly outside the official series range but are not taxadjuncts. For example: “Beta soils in this survey have a redder subsoil and are slightly more acid throughout than those defined in the official series description. These differences do not affect taxonomic placement or use and management. The official series description was not revised because the color and reaction differences are due to the inherent characteristics of the Theta geologic formation in which these soils formed and which is not the typical formation in which the Beta series formed.”

18. Classification of the Soils.

This table is the classification of the taxonomic units that are used in the survey area. Classify taxonomic units that are named at a level above the series as precisely as the data permits. Designate taxadjuncts with an asterisk only if the representative pedon is a taxadjunct. Address map units with major components that are taxadjuncts in the “Notes”. Do not list miscellaneous area names in the classification table. For example:

CLASSIFICATION OF THE SOILS OF ANY SURVEY AREA, ANYSTATE
Soil Name	Family or Higher Taxonomic Class
Alpha	Coarse-loamy, mixed, active, frigid Aridic Haploxerolls
Beta	Fine-silty, mixed, active, frigid Cumilic Epiaquolls
Gamma*	Coarse-loamy, mixed, active, frigid Dystric Eutrudepts
Udorthents	Udorthents

* Taxadjunct. See “Notes to Accompany Classification and Correlation of the Soils of Any Survey Area, Anystate” for details.

19. Join Statement

The join statement prepared at the final field review is included that explains where an exact join was not achieved. It should identify what map units need to be reviewed and their joins resolved.

20. Certifications.

The correlation document is to contain certification of the following:

Mapping is complete. For example: “Mapping completed in June 1999.”
General soil maps and detailed maps are to exactly join with those of adjacent survey areas, and detailed maps join within the survey area. Discrepancies in the join of maps with those of adjacent areas are documented, and a detailed statement of join differences is referenced and included in the correlation document. The reason the maps cannot be joined is given in the join statement.
Databases and interpretations are coordinated and complete. For example: “Databases and interpretations are coordinated, map unit lines of adjoining surveys are continuous across and along the shared borders and the joined map units share basic soil properties and selected soil qualities. All data elements are populated and no obsolete terms are used.”
Type locations are in soil areas that have the referenced names, and location descriptions are correct. For example: “The locations of all typical pedons used in this survey are within the major land resource area and are correct and are within delineations that have the referenced name.”
Forestland and rangeland site plots were taken in soil areas that have the referenced series names and the series names have been correlated in the forestland and rangeland databases and all data is certified.
All typical pedons are classified according to Soil Taxonomy, 2nd Edition and the latest amendment. For example: “All typical pedons are correctly classified according to Soil Taxonomy, 2nd Edition and the latest amendment.”
Only approved names for miscellaneous areas have been used as component names.
The soil maps have been reviewed for completeness, accuracy, and consistency. For example: “The soil maps are complete, accurate, and consistent.”

21. Approval Signature and Date.

__________________________________
State Conservationist

__________________________________
MLRA Regional Office Team Leader

______________________
Date

______________________
Date

List of Soil Property or Quality Attributes for Joining (Exhibit 609-2)

The following list provides basic soil properties and selected soil qualities that are to be joined between soil surveys to achieve an “exact” join. National Soil Information System (NASIS) data element names are used for convenience, but their usage is not intended to suggest a database solution.

National Attributes *

Soil Property or Quality Name
aashto_group_classification
aashto_group_index
albedo_dry
aluminum_oxalate
available_water_capacity
bulk_density_fifteen_bar
bulk_density_one_tenth_bar
bulk_density_one_third_bar
bulk_density_oven_dry
calcium_carbonate_equivalent
cation_exch_capcty_nh4oacph7
clay_sized_carbonate
clay_total_separate
component_kind
component_name
component_percent
corrosion_concrete
corrosion_uncoated_steel
diag_horz_feat_depth_to_botm
diag_horz_feat_depth_to_top
diag_horz_feat_kind
diag_horz_feat_thickness
earth_cover_kind_level_one
earth_cover_kind_level_two
effective_cation_exch_capcty
electrical_conductivity
elevation
erosion_accelerated_kind
erosion_class
excavation_difficulty_class
excavation_difficulty_moist_st
exists_on_feature
extractable_acidity
extractable_aluminum
flooding_duration_class
flooding_frequency_class
fragment_hardness
fragment_kind
fragment_roundness
fragment_shape
fragment_size
fragment_volume
free_iron_oxides
geomorph_feat_modifier
geomorph_micro_relief
geomorphic_feat_id
geomorphic_position_flats
geomorphic_position_hills
geomorphic_position_mountains
geomorphic_position_terraces
gypsum
hillslope_profile
horizon_depth_to_bottom
horizon_depth_to_top
horizon_designation
horizon_thickness
horz_desgn_discontinuity
horz_desgn_letter_suffix
horz_desgn_master
horz_desgn_master_prime
horz_desgn_vertical_subdvn
hydrologic_group
iron_oxalate
linear_extensibility_percent
liquid_limit
local_phase
major_component_flag
manner_of_failure
mean_distance_between_rocks
month
organic_matter_percent
parent_material_general_mod
parent_material_group_name
parent_material_kind
parent_material_modifier
parent_material_order
parent_material_origin
particle_density
ph_01m_cacl2
ph_1_1_water
phosphorous_bray1
phosphorous_oxalate
phosphorous_total
phosphorous_water_soluble
plasticity
plasticity_index
ponding_depth
ponding_duration_class
ponding_frequency_class
pore_continuity_vertical
pore_quantity
pore_shape
pore_size
potential_frost_action
restriction_depth_to_bottom
restriction_depth_to_top
restriction_hardness
restriction_kind
restriction_thickness
rock_frag_3_to_10_in
rock_frag_greater_than_10_in
rupture_resist_block_cem
rupture_resist_block_dry
rupture_resist_block_moist
rupture_resist_plate
rv_indicator
sand_coarse_separate
sand_fine_separate
sand_medium_separate
sand_total_separate
sand_very_coarse_separate
sand_very_fine_separate
sat_hydraulic_conductivity
shape_across
shape_down
sieve_number_10
sieve_number_200
sieve_number_4
sieve_number_40
silt_coarse_separate
silt_fine_separate
silt_total_separate
slope_aspect_clockwise
slope_aspect_counterclockwise
slope_aspect_representative
slope_gradient
slope_length_usle
sodium_adsorption_ratio
soil_erodibility_factor_rf
soil_erodibility_factor_whole
soil_moist_depth_to_bottom
soil_moist_depth_to_top
soil_moisture_status
soil_temp_depth_to_bottom
soil_temp_depth_to_top
soil_temperature_mean_monthly
stickiness
stratified_textures_flag
structure_grade
structure_group_name
structure_id
structure_parts_to
structure_size
structure_type
sum_of_bases_nh4oacph7
surface_frag_cover_percent
surface_frag_hardness
surface_frag_kind
surface_frag_roundness
surface_frag_shape
surface_frag_size
t_factor
terms_used_in_lieu_of_texture
texture_class
texture_modifier
texture_modifier_and_class
total_subsidence
unified_soil_classification
water_fifteen_bar
water_one_tenth_bar
water_one_third_bar
water_satiated
wind_erodibility_group
wind_erodibility_index

* Soil performance elements (range and forest production, etc.) and linkage to ecological site related data are not included as being required to be joined, but they should at least be coordinated between surveys.

Initial Field Review Checklist for Initial Soil Surveys and for Update Soil Surveys Requiring Extensive Revision (Exhibit 609-3)

(Completed by the review leader)

______ Review completed mapping (digital or field sheets) for completeness
______ Review acreage for completed mapping and map units
______ Inspection of mapping in the field
______ Review of taxonomic and map unit descriptions
______ Review progressive correlation of map units
______ Review Digital General Soil Map of the U.S. update and map unit descriptions
______ Review Digital General Soil Map of the U.S. join
______ Check join to adjacent surveys and among field sheets
______ Review photographs and other figures for soil survey publication
______ Review soil interpretations
______ Review lab data
______ Review classification of all pedons with lab data
______ Review classification of all described pedons
______ Compare typical pedon to the OSD
______ Review transect/random sampling data
______ Review statistical data
______ Check documentation distribution and content
______ Update databases
______ Update long-range plan as needed
______ Review memorandum of understanding
______ Discuss development of annual plan for coming year
______ Complete Quality Assurance Worksheet
______ Complete comments, correlation notes, things-to-do, agreed-to-items, and commendable items
______ Provide completed report to MLRA Regional Office
______ Review proposed new soil series OSD and submit to MLRA Regional Office
______ Circulate proposed new soil series for peer review
______ Update soil data in field office technical guide
______ Update OSD(s) as needed
______ Update Soil Survey Schedule

Progress Field Review Checklist for Initial Soil Surveys and for Update Soil Surveys Requiring Extensive Revision (Exhibit 609-4)