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NRCS SSURGO-Certified Soils
- November 2010
The Soils datalayer has been automated from published soils surveys as provided on various media by the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS). All soils data released by MassGIS have been "SSURGO-certified," which means they have been reviewed and approved by the NRCS and meet all standards and requirements for inclusion in the national release of county-level digital soils data. Soil survey areas are roughly based on county boundaries.
The SSURGO-certified soils dataset is generally the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was prepared by digitizing maps, by compiling information onto a planimetric correct base and digitizing, or by revising digitized maps using remotely sensed and other information. The data include a detailed, field verified inventory of soils and miscellaneous areas that normally occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. Data for survey areas were developed using various scale base maps: some areas at a 1:25,000 or 1:12,000 scale, or at larger scales where source materials (e.g. 1:5,000 MassGIS ortho imagery) were available. Details for a specific survey area are provided in the NRCS-produced metadata that are distributed with the spatial data.
The soil map units are linked to attributes in the National Soil Information System (NASIS) relational database, which gives the proportionate extent of the component soils and their properties.
At MassGIS the soils datalayer is stored in ArcSDE for Oracle as the statewide feature class SOILS_POLY. Two companion layers, SOILSPOT_PT and SOILSPOT_ARC, represent "special" or "ad hoc" features such as gravel pits, wet areas, bedrock escarpments and others. These layers display the location of features too small to delineate at the mapping scale, but they are large enough and contrasting enough to significantly influence use and management.
The status for each survey area is stored in the statewide layer named SOILSTAT_POLY. View the
Status Map
Updated November 5, 2010, for new data for Plymouth. Also, the adjacent survey areas (Barnstable, Bristol North, Bristol South, and Norfolk-Suffolk) were replaced, as these were edited to edge-match with Plymouth.
With the November 2010 update, soils data are available for all survey areas in the state except for Franklin, which is under development.
Maps that use NRCS SSURGO data must
show the source (NRCS) and date and, space permitting, contain the following
notation: "This Soil Survey Geographic (SSURGO)
data base was produced by the U.S. Department of Agriculture, Natural Resources
Conservation Service and cooperating agencies for the Soil Survey of _______
County, (state). The soils were mapped at a scale of ______ with
a _______ acre minimum size delineation. Enlargement of these maps to scales
greater than that at which they were originally mapped can cause misunderstanding
of the detail of mapping. If enlarged, maps do not show the small areas
of contrasting soil that could have been shown at a larger scale. The depicted
soil boundaries and interpretations derived from them do not eliminate
the need of onsite sampling, testing, and detailed study of specific sites
for intensive uses. Thus, this map and its interpretations are intended
for planning purposes only. Digital data files are periodically updated.
Files are dated, and users are responsible for obtaining the latest version
of the data."
Scale and minimum mapping unit, along with all other details of production and editing of both the spatial and attribute data,
may be found in the FGDC-style metadata produced for each survey area
by NRCS. These metadata files (in plain text format) are distributed with the data by MassGIS and also may be viewed at http://soildatamart.nrcs.usda.gov/Survey.aspx?State=MA (select a survey area and click the "View Metadata" button).
This data set is not designed for use as a primary regulatory tool in permitting or siting decisions, but may be used as a reference source. This is public information and may be interpreted by organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application. Federal, State, or local regulatory bodies are not to reassign to the Natural Resources Conservation Service any authority for the decisions that they make. The Natural Resources Conservation Service will not perform any evaluations of these maps for purposes related solely to State or local regulatory programs.
Photographic or digital enlargement of these maps to scales greater than at which they were originally mapped can cause misinterpretation of the data. If enlarged, maps do not show the small areas of contrasting soils that could have been shown at a larger scale. The depicted soil boundaries, interpretations, and analysis derived from them do not eliminate the need for onsite sampling, testing, and detailed study of specific sites for intensive uses. Thus, these data and their interpretations are intended for planning purposes only. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.
Soils Polygons
Each SOILS_POLY polygon contains the following
items:
|
| MUSYM | |
Map Unit symbol. This field is included in data distributed by NRCS from
the SSURGO Data Mart Web site and uniquely identifies each closed delineation mapunit. |
|
| MUKEY |
|
Map Unit Key for linking information in the National Soil Information System (NASIS) tables. This field is included in data distributed by NRCS
from the SSURGO Data Mart Web site. |
|
| SS_AREA |
|
Abbreviation for soil survey area (MassGIS added this field):
| BARN | | BARNSTABLE |
| BERK |
| BERKSHIRE |
| BRIS |
| BRISTOL SOUTH |
| BRISNO |
| BRISTOL NORTH |
| DUKES |
| DUKES |
| ESNOR |
| ESSEX NORTH |
| ESSOU |
| ESSEX SOUTH |
| FRAN |
| FRANKLIN |
| HAMDCE |
| HAMPDEN CENTRAL |
| HAMPCE |
| HAMPSHIRE CENTRAL |
|
|
| HHEA | | HAMPDEN-HAMPSHIRE EAST |
| HHWE |
| HAMPDEN-HAMPSHIRE WEST |
| MIDDSX |
| MIDDLESEX |
| NANTCK |
| NANTUCKET |
| NORSUF |
| NORFOLK-SUFFOLK |
| PLYMTH |
| PLYMOUTH |
| WONE |
| WORCESTER NORTHEAST |
| WONW |
| WORCESTER NORTHWEST |
| WORS |
| WORCESTER SOUTH |
|
|
|
| MUSYM_AREA |
|
Concatenation of MUSYM and SS_AREA, to correlate the map unit symbol to its soil survey area. In
some cases, a mapunit may have different properties in different survey areas. Useful for some table joins. MassGIS added this field. |
|
| SLOPE |
|
Slope of the landscape, derived from the last character of the MUSYM item, if present. MassGIS added this field. Possible SLOPE codes are:
| A: 0-3% |
| B: 3-8% | | C: 8-15% |
| D: 15-25% |
| E: 25-35% |
|
0: Water or urban land (no assigned slope) |
|
Special ("spot") Features
Each special/ad hoc feature (SOILSPOT_ARC and SOILSPOT_PT) contains the following items:
| AREASYMBOL | |
The identifying symbol given to the specified geographic area to which the legend applies. |
|
| SPATIALVER | |
A sequential integer number used to denote the serial version of the spatial data for a soil survey area. |
|
| FEATSYM | |
A symbol that, within the context of a particular soil survey area, uniquely identifies a point or line spot feature. Current codes include:
| BLD | | Boulder spot |
| BLO | | Blowout |
| BOU | | Bouldery spot |
| CLA | | Clay spot |
| DIS | | Disturbed area |
| DRY | | Dry spot |
| ESB | | Escarpment, bedrock |
| ESO | | Escarpment, other |
| GPI | | Gravel pit |
| GRA | | Gravelly spot |
| GUL | | Gully |
| LDF | | Landfill |
| LVS | | Levee |
| MAR | | Marsh or swamp |
| MPI | | Mine or quarry |
|
|
| ROC | | Rock outcrop |
| SAN | | Sandy spot |
| SIL | | Silt spot |
| SKP | | Stockpile |
| SLP | | Short, steep slope |
| SLW | | Spoil area or landfill |
| SNK | | Sinkhole |
| SPO | | Spoil Area |
| STN | | Stony spot |
| STR | | Stripped land |
| STV | | Very stony spot |
| TLL | | Till spot |
| WAT | | Perennial water |
| WET | | Wet spot |
| WOI | | Intermittent water body |
|
|
 |
| FEATKEY | |
A non-connotative string of characters used to uniquely identify a record in the Feature Description table. |
|
| SS_AREA | |
Abbreviation of the survey area (field added by MassGIS) | |
| LABEL | |
Equal to the FEATSYM field, kept in the data distributed by MassGIS for legacy application purposes. |
|
Soils Project Status
The SOILSTAT_POLY attribute
table contains the following items storing status information for each
survey area:
| SS_AREA |
|
Abbreviation of the survey area |
| SURVEY_ARE |
|
Full survey area name |
| COUNTY |
|
County name (the survey area may comprise part of a county) |
| STATUS |
|
Status code |
| STATUS_DESC |
|
Status description |
Current STATUS and STATUS_DESC values include:
SC - SSURGO CERTIFIED (Available for disribution)
DC - DATABASE COMPILATION UNDERWAY |
Prime Farmland Soils
In
ArcSDE, MassGIS has created the spatial view SOILS_POLY_PRIMEFARMLAND,
based on the FARMLNDCL field in the SOILS_POLY_MAPUNIT table.
Categories of prime farmland include:
All Areas Are Prime Farmland
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Land
that has the best combination of physical and chemical characteristics
for producing food, feed, forage, fiber, and oilseed crops, and is also
available for these uses (the land could be cropland, pastureland,
rangeland, forest land, or other land, but not urban built-up land or
water). For a full definition, see http://soils.usda.gov/technical/handbook/contents/part622.html#04.
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Farmland of Unique Importance
|
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Land
other than prime farmland that is used for the production of specific
high value food and fiber crops. Examples of such crops are citrus,
tree nuts, olives, cranberries, fruit, and vegetables. |
Farmland of Statewide Importance
|
|
This
is land, in addition to prime and unique farmlands, that is of
statewide importance for the production of food, feed, fiber, forage,
and oil seed crops, as determined by the appropriate state agency or
agencies. Generally, these include lands that are nearly prime farmland
and that economically produce high yields of crops when treated and
managed according to acceptable farming methods. |
For full defnitions of these categories see Section 657.5 -- Identification of Important Farmlands on http://soils.usda.gov/technical/handbook/contents/part622.html.
To create this theme using shapefiles or personal geodatabase feature
classes, join SOILS_POLY to SOILS_POLY_MAPUNIT on the MUKEY field
and display on FARMLNDCL.
These tables are contained in Microsoft Access 2000 databases
(one for each available survey area) created by NRCS and which conform to the SSURGO II National Soil Information System (NASIS)
attribute structure. This attribute database gives the
proportionate
extent of the component soils and the properties for each soil. The
database contains both estimated and measured data on the physical and
chemical
soil properties and soil interpretations for engineering, water
management,
recreation, agronomic, woodland, range, and wildlife uses of the soil.
The Access databases are available by clicking on the "Soils Polygons
and Special (Spot/Ad Hoc) Features" download link at the top of this
page (this will take you to the download page, and the Access databases
are listed in the "Metadata" column). The databases are also
distributed on
MassGIS
Data Viewer CDs. When the Access databases are first opened, a Soil
Reports form appears that allows the user to quickly query the database
and create a report for that survey area. For descriptiions of the
Access tables, see the "SSURGO Metadata" reports inside each Access
database.
For documentation of all the tables in the Access databases see http://soildatamart.nrcs.usda.gov/SSURGOMetadata.aspx.
In the ArcSDE database internal to MassGIS, combined tables exist for the following relational tables:
Table Name
|
|
Description |
|
What it Contains |
| SOILS_POLY_COMPONENT |
|
Map Unit Component |
|
Lists the map unit components identified in the referenced map unit, and selected properties of each component. |
| SOILS_POLY_COCROPYLD |
|
Component Crop Yield
|
|
Lists commonly grown crops and
their expected range in yields when grown on the referenced map unit
component. Yields for the map unit as a whole are given in the Mapunit
Crop Yield table (SOILS_POLY_MUCROPYLD).
|
| SOILS_POLY_COFORPROD |
|
Component Forest Productivity |
|
Lists the site
index and the annual productivity in cubic feet per acre per year
(CAMI) of forest overstory tree species that typically occur on the
referenced map unit component. |
| SOILS_POLY_COHYDRICCRITERIA |
|
Component Hydric Criteria |
|
Lists the hydric soil criteria met for those referenced map unit components that are classified as a "hydric soil." |
| SOILS_POLY_COINTERP |
|
Component Interpretation |
|
Lists the predictions of behavior and limiting features for specified uses made for the referenced map unit component. |
SOILS_POLY_COMONTH
|
|
Component Month
|
|
Lists
the monthly flooding and ponding characteristics for the referenced map
unit component. This table has one row for each month of the year for
each component key.
|
| SOILS_POLY_COPWINDBREAK |
|
Component Potential Windbreak |
|
Lists
the windbreak plant species commonly recommended for the referenced map
unit component. A windbreak plant listed in this table may be used
alone or in combination with other plants.
|
| SOILS_POLY_CORESTRICTIONS |
|
Component Restrictions
|
|
Lists the root restrictive feature(s) or layer(s) for the referenced map unit component. |
| SOILS_POLY_COSOILMOIST |
|
Component Soil Moisture
|
|
Describes the typical soil
moisture profile for the referenced map unit component during the month
referenced in the Component Month table. The soil moisture profiles for
each month, taken as a group of twelve months, describe the
representativesituation for the component throughout the year. |
SOILS_POLY_COTREESTOMNG
|
|
Component Trees To Manage |
|
Lists the trees commonly recommended for managing on the referenced map unit component. |
| SOILS_POLY_MAPUNIT |
|
Mapunit |
|
Identifies the
map units included in the referenced legend. Data related to the map
unit as a whole are also given. Includes map unit (MUSYSM) and map unit
description (MUNAME) for all unique map units across the state.
|
| SOILS_POLY_MUAGGATT |
|
Mapunit Aggregated Attribute
|
|
Records
a variety of soil attributes and interpretations that have been
aggregated from the component level to a single value at the map unit
level. They have been aggregated by one or more appropriate means in
order to express a consolidatedvalue or interpretation for the map unit as a whole.
|
| SOILS_POLY_MUCROPYLD |
|
Mapunit Crop Yield
|
|
Lists
commonly grown crops and their expected yields for the referenced map
unit as a whole. Yields for individual map unit components are given in
the Component Crop Yield table (SOILS_POLY_COCROPYLD).
|
SOILS_POLY_MUTEXT
|
|
Mapunit Text
|
|
Notes and narrative descriptions related to the referenced map unit.
|
These additional non-relational tables
provide further information:
| SOILS_POLY_CODES |
|
Database codes |
|
Stores information on all codes
used in the database |
| SOILS_POLY_LEGEND |
|
Summary information on all available survey areas |
|
Survey area names, codes, total acreage, scale of data development |
| SOILS_POLY_MDSTATTABS |
|
Table Static Metadata
|
|
Records
metadata (names, descriptions, etc.) about the tables that make up the
tabular data set in each Access database. Each record in this table
represents one table.
|
| SOILS_POLY_MDSTATTABCOLS |
|
Table Column Static Metadata
|
|
Table
records the metadata for all columns of all tables that make up the
tabular data set. Each record in this table represents one column of a
particular table.
|
The following table provides descriptions
of the codes used in the SOILSPOT layers:
| SOILS_POLY_FEATURE |
|
Special feature codes |
|
Stores information on all codes
used in the 'LABEL' item in the SOILSPOT arc and point layers. |
For lists and descriptions of all the tables and the
codes in the SSURGO 2 database, please refer to the SSURGO Metadata PDF documents "Tables", "Table Columns", "Table Column Descriptions", and "Domains".
On
MassGIS Data Viewer CDs,
soils polygons and special features are included in Shapefile format
for
available areas in the 'Physical_Resources' folder. In the 'soilmeta'
sub-folder are the NASIS-formatted related tables
for all available survey areas, in Microsoft Access
2000 databases inside self-extracting executables. These NASIS tables
may
be used to produce reports and generate thematic soils maps, and are
necessary for use with NRCS' Soil Data Viewer product (see the next
section, Displaying the Data). Additionally, users may download data and metadata
from the links at the top of this page.
MassGIS distributes soils data online by survey area, not by USGS Quad (see download links above). Specifics for each survey area (such as dates of compilation and other details) can be found in the FGDC-compliant metadata text files that MassGIS distributes with all SSURGO data.
The soils polygons have very few attributes. A solid understanding of the many related data tables (listed above) is required to properly map and analyze these data. To decipher the many ways in which the soils data may be interpreted and displayed, using the related tables, USDA/NRCS has developed the Soil Data Viewer, a free extension for ArcGIS 8.3, 9.0/9.1, and 9.2 and above. See http://soils.usda.gov/sdv/ and click on "Download and Install Soil Data Viewer" on the left side of the page. It works with the shapefiles and Access databases for one survey area at a time.
In addition, NRCS has an online soils viewer ("Web Soil Survey") that displays a number of user-specified characteristics of soils. See http://websoilsurvey.nrcs.usda.gov/app/.

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These datalayers are
maintained
by NRCS. MassGIS will download and make available updated and new survey areas they become available.
Please see the current status map.
Further information is available
in the form of documents produced and maintained by the NRCS. These documents
include:
- SSURGO Metadata - documents, diagrams and reports describing
the SSURGO standard, as well as the tools and procedures that are
necessary to effectively use this data, can be found at http://soildatamart.nrcs.usda.gov/SSURGOMetadata.aspx.
- The National Soil Survey Handbook,
a multi-chapter guide that provides the main operational and procedural
guidance for the soil survey program. All Handbook chapters are
viewable on the Web and available for download in Microsoft Word 6.0 format.
Please visit http://soils.usda.gov/technical/handbook/.
-
The Soil Survey Manual, a single
volume book which provides the major principles and practices needed for
making and using soil surveys and for assembling and using data related
to them. The Manual is intended primarily for use by soil scientists engaged
in the classification and mapping of soils and in the interpretation of
soil surveys. Although the Manual is oriented to the needs of those actively
engaged in preparing soil surveys for publication, workers and students
who have limited soils experience or are less familiar with the soil survey
process also will be able to use the information. The Manual may
be viewed in Microsoft Word and Adobe PDF formats on the web at http://soils.usda.gov/technical/manual/.
- The NASIS (National Soil Information System) Web site at http://soils.usda.gov/technical/nasis/.
NASIS consists of multiple interrelated soil applications and databases. This data system aids in the collection, storage, manipulation and dissemination of soil information.
- Massachusetts Soil Survey - The Web site http://nesoil.com/massachusetts_soil_survey.htm contains information on Massachusetts soils surveys, including detailed descriptions of soil map units.
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