NSSH Part 638

Soil Data Systems

Definition and Purpose (638.00)

(a) Soil data systems aid the collection, storage, manipulation, and dissemination of soil information. Soil data systems consist of multiple automated soil applications or modules that stand alone or interact with each other to provide information.

(b) The National Cooperative Soil Survey (NCSS) collects, manages, interprets, and disseminates soil survey information using a dynamic soil information system from which many different products can be made.

Policy and Responsibilities (638.01)

(a) Policy

Soil survey information is maintained in the National Soil Information System. Users of automated soil applications who are members of NCSS are provided support and training on the use and management of all automated soil applications.

(b) Responsibilities

(1) State soil scientist responsibilities

The state soil scientist is responsible for:

distributing soil information to users;
assisting users of the information system;
supplementing the system by developing soil interpretive group assignments and forwarding to the MLRA office for inclusion;
maintaining current soil information in the field office computer systems (FOCS); and
coordinating instate training on the use of automated soil applications.

(2) MLRA office responsibilities

The MLRA office is responsible for:

for the technical quality and completeness of the information in the National Soil Information System;
providing user training for automated soil applications;
providing continuing user support for all automated soil applications;
managing the system and maintaining the soil information in the system;
providing a liaison to the National Soil Survey Center and Technical Information System Division staffs;
evaluating proposals for new applications and for enhancements to existing applications; and
recommending development priorities to the National Soil Survey Center.

(3) National Soil Survey responsibilities

The National Soil Survey Center is responsible for:

developing and implementing policy and guidelines for data administration and management, including quality control procedures;
providing application analysis to support system development;
managing the NCSS soil data dictionary as a subset of the NRCS corporate data dictionary;
providing training to MLRA offices and assisting MLRA office staffs in providing training to project offices;
assisting in system building tasks, such as developing documentation, testing, and data conversion; and
coordinating with the Information Technology Center to develop software for soil data systems.

(4) NRCS responsibilities

The NRCS develops and maintains the National Soil Information System, the official series description (OSD), the soil classification (SC), the national soil survey database, and the national soil characterization database.

National Soil Information System (NASIS) (638.02)

Components of NASIS are released in increments. NASIS will eventually encompass four major data categories--map unit records including legends, map units, and the physical, chemical, and morphological properties and interpretations for map unit components; geographic area records including symbols, names, and acreages; point characteristics including soil profile descriptions, laboratory characterization data, field measurements, transect observations, and other site specific information; and standards, criteria, and guidelines including taxonomic class limits, series ranges in characteristics, interpretation criteria, and other data and documents used to establish concepts, assist aggregation, and communicate policy. These databases are intended to be available on a national basis, as well as in state or local subsets. Part 639 provides more specific information on NASIS.

Map Unit Record File (638.03)

(a) The map unit record database of NASIS was initially populated by converting soil survey area specific information and interpretations in the State Soil Survey Database map unit interpretation records into a new format. Procedures are developed to generate interpretations within the NASIS software in future releases. This information will then be used to develop manuscript tables and for downloading to other application systems such as geographic information systems and Field Office Computing System (FOCS).

(b) Data of the map unit records for correlated soil surveys are certified by the MLRA office to be correct, current, and complete. Data within the map unit record are updated as needed after correlation and after the soil survey is published so that the data remain current and correct.

(c) When revising data refer to part 610 concerning the official copy of the soil survey and types of revisions and required procedures.

Official Series Descriptions File (OSD) and the Soil Classification File (638.04)

(a) Official series descriptions are accessed in the soil survey database in every MLRA office. Official series descriptions are updated and processed with utilities that are part of the soil survey database. As MLRA offices add, delete, or revise series for which they have responsibility, they transmit these series to the Iowa State University Statistical Laboratory at Ames, Iowa, where the series from all states are stored in the official series description file. The soil classification file is also maintained at Ames; and, as series are added to the official series description file, the soil classification file needs to be updated accordingly. The classification of a soil series listed on the official series description and that listed in the soil classification file are kept in agreement by the MLRA office.

(b) The State Soil Survey Database User's Manual provides specific information and instructions on management of the official series description files until these files are incorporated into the National Soil Information System.

Soil Survey Schedule Database (638.05)

The Soil Survey Schedule is a database that is stored in the State Soil Survey Database. It provides a method of tracking the progress of soil surveys at the State level. The database has the ability to provide this information to the National Soil Survey Center, where surveys are tracked at the National level. The State Soil Survey Database User's Manual and part 608 of this handbook provide additional information on the Soil Survey Schedule.

The Pedon Description Program (PDP) (638.06)

(a) Description

The Pedon Description Program is a database of information gathered by describing pedons in the field. The database can be used to sort, select, aggregate, and compare data; it is also programmed to produce a written copy of the pedon description. The Pedon Description Program User's Manual provides detailed information on the Pedon Description Program.

(b) Project Office Responsibilities

The project office is responsible for:

using the Pedon Description Program within the soil survey area,
adequately describing a representative pedon for each component of each map unit in the soil survey area,
obtaining pedon descriptions for each pedon that is submitted for complete and partial laboratory analysis, and
entering all pedon descriptions and related information into the Pedon Description Program.

(c) MLRA Office Responsibilities

The MLRA office is responsible for:

ensuring the integrity and consistency of the data in the Pedon Description Program within the MLRA, and
assuring the quality of the data entered in the Pedon Description Program.

Guidelines for Changing, Adding, or Deleting Soil Property Data Elements (638.07)

(a) Data Dictionary

The NRCS, Soil Survey Division, maintains a soil data dictionary, which contains the national list of approved soil attributes and the standards for naming, defining, and implementing attributes in soil databases.

(b) National Soil Survey Center Responsibilities

The National Soil Survey Center is responsible for maintaining the soil data dictionary and for integrating soil data within soil information systems as well as within other NRCS information systems.

(c) Proposals for Change

Changes, additions, or deletions to soil data dictionary are proposed by any participant in the National Cooperative Soil Survey (NCSS). Those suggestions are transmitted to the National Soil Survey Center.

(d) Changes, Additions, or Deletions

Changes, additions, or deletions to the soil data dictionary are defined as:

adding or removing attributes from the approved list of soil attributes;
changing the definition of an existing attribute, including adding to, removing from, or redefining abbreviations or codes used to describe soil properties; and
adding to, removing from, changing, or redefining the method(s) used to obtain data for an attribute or changing the method(s) used for the derivation of data values for the attribute.

(e) Steps for Proposing New or Revised Data Elements

The following steps are followed in proposing new or revised soil property data elements.

(1) Formulate the need for new or revised soil attributes.

(2) Record the necessary descriptive information for the data element using Exhibit 638-3.

(3) Forward data element proposals for changes, additions, or deletions to the National Soil Survey Center for coordination of review and update of the soil data dictionary.

Certification and Distribution of Soil Data (638.08)

Data from NASIS are distributed in two ways.

(a) Soil Database Information in the Field Office Computer System (FOCS)

The soil data within the field office computer system is provided from the National Soil Information System map unit record. The state soil scientist is responsible for providing the current soil database to the field office computer system.

The state soil scientist certifies data downloaded to the field office computer system. An example certification letter for the field office computer system is provided in Exhibit 638-1. Soil data is not to be downloaded to the field office computer system until it has been edited. Soil data elements downloaded to the field office computer system are edited and certified for each field office computer system application, such as the Revised Universal Soil Loss Equation (RUSLE).

(b) Soil Database Information Distributed to Cooperators and the Public

(1) The state soil scientist will state the date and source of the data when distributing data to the public. An example letter for data distributed to the public is provided in Exhibit 638-2.

(2) Data are distributed from the National Soil Information System.

(3) The state soil scientist maintains a file of users who have received digital map unit record data sets. Minimum documentation in the file includes requester, date, and brief description of data provided.

(4) User documentation or a user guide is provided with each data set that is distributed. As a minimum, the following information is included:

the definition of data elements (data dictionary),
a description of the data format,
a disclaimer on the use of the data, and
a request that NRCS be acknowledged as the source of the data.

Example of Certification Information Given by the State Soil Scientist to the District Conservationist (Exhibit 638-1)

Subject:  SOI - Edit Certification of Soil Data for the
          Field Office Computer System Application Modules.


          To:  Jack Smith
          District Conservationist
          Paradise Field Office


     The soil data elements for the data set provided in this FOCS/soil
database download have been edited and coordinated for use in the
following FOCS applications: ____________________________________.


     The soil data elements have not been edited for the following FOCS
applications: ____________________________________, and reports that
are generated from these applications must not be distributed to the
public.





          Jane Smith
          State Soil Scientist

Example of a Statement to Include in Letters to Public When Distributing Map Unit Record (MUR) Data (Exhibit 638-2)

Map unit record (MUR) data from the ________ state subset of the
national soil information system are the source of digital attribute
soil data for soil maps in the Soil Survey(s) of _______________
County(ies).  Data in these files are periodically updated.  Files
are dated.  Users are responsible for obtaining the latest version of
the data.  For more information contact _____________________________.

Proposed Amendment to Soil Data Dictionary (Exhibit 638-3)

Attribute Name (proposed or modified):

______________________________________________________________________________



Data Type:  (check one)

_____    text <256 characters:  length __________


_____    text >256 characters


_____    number   lowest value _____  highest value _____  unit of measure _____

                integer? _______  float? _______  decimal places _______


_____    choice list __________    choices (attach)   choice definition (attach)



Definition of attribute:

______________________________________________________________________________

______________________________________________________________________________


Purpose (Why it is necessary, how it is used)

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________


Relationship to other data, validation, calculations

______________________________________________________________________________

______________________________________________________________________________

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Technical References

National Soil Survey Handbook