Natural Resources Conservation Service (NRCS) GIS Data
A wide range of GIS data resources are available from the USDA Natural Resources Conservation Service. Highlights include SSURGO and gSSURGO soils data, US General Soils Map (STATSGO2), and the National Resources Inventory (NRI) all of which are documented on this page.
The Soil Survey Geographic (SSURGO) Data Base consists of 1:12,000 to 1:63,360 scale detailed local soils data. "SSURGO digitizing duplicates the original soil survey maps. This level of mapping is designed for use by landowners, townships, and county natural resource planning and management. The user should be knowledgeable of soils data and their characteristics."--(NRCS site).
gSSURGO - file geodatabase that contains vector (MUPOLYGON), raster (MapunitRaster_10m), and relational attribute tables. The "valu1" table is a compilation of 57 pre-summarized or "ready to map" attributes. For much more helpful information, be sure to read the gSSURGO User Guide.
It is recommended that you use SSURGO and gSSURGO data only from one of these sources because they have been certified by NRCS for accuracy and are regularly updated.
- Web Soil Survey
- If you are interested in a small area of up to 100,000 acres (single farm, neighborhood, small watershed) then create an "Area of Interest (AOI)" and you can generate reports and maps within the online app.
- If you are interested in an entire county or a large portion of a county, you can download the county's SSURGO shapefile and do your analysis with desktop GIS software. To access the county files, click the "Download Soils Data" tab and then "Soil Survey Area (SSURGO)" link. (Note: using shapefiles are more challenging if you're working with soil attributes. Instead use gSSURGO data.)
- Geospatial Data Gateway - USDA data portal. Download state gSSURGO data, as well as a wide range of other map layers.
- Soils folder on Box - Used by NRCS for very large files.
- gSSURGO - download by state and entire conterminous U.S.
- gNATSGO - A composite database that provides complete coverage of the best available gridded soils information for all areas of the United States and Island Territories. It was created by combining data from the Soil Survey Geographic Database (SSURGO), State Soil Geographic Database (STATSGO2), and Raster Soil Survey (RSS) databases into a single seamless ESRI file geodatabase.
- Soil Color Maps - statewide tif images showing soil colors by depth. Color values "are translated from Munsell color notation to sRGB using the aqp library" within R statistical package.
- SSURGO Downloader - ArcGIS Online app for downloading soil data map packages (geo data combined with a lot of attributes) by river basin usable in ArcGIS Pro. Once open in ArcGIS Pro, it can be clipped to other extents and exported for use in other software.
NC Soils data by County
Derived from the statewide gSSURGO FY2020 geodatabase for North Carolina, this data was created by joining the Valu1 attribute table containing 57 pre-summarized common soil attributes to the MUPOLY feature class. Data for each county were selected and exported to a shapefile. Zip files are named based on FIPS number and include metadata. The Great Smokey Mtns. Natl. Park is named TN640 and encompasses parts of Haywood and Swain Counties -- thus Haywood's file name is NC606 and Swain's file name is NC605.
The North Carolina Dept. of Agriculture and Consumer Services provides NC statewide soils, forest, and farmland productivity data through an ArcGIS REST Map Service. Zoom in to a relatively large scale to see the data.
See also the Web-based data viewers, below.
NRCS maintains a Github site with tools for R and ArcGIS. (NRCS link page). From here, the Soil Data Development Toolbox is highly recommended for working with SSURGO and gSSURGO data in ArcMap 10.x (not compatible with ArcGIS Pro). Once installed, this toolbox will make it much easier to work with soils data. Contact Data Services for assistance getting started.
Web-based data viewers
Esri Living Atlas maps. These can also be added to a GIS project and used as a data source for analysis.
- USA Soil Map Units - Clickable soil units feature layer, with nice colors and attribute pop-ups.
- Image layers for various themes - Such as farmland, crop production, hydric, derived from attribute table fields.
Working with soil data attributes
Many attribute tables are used for a wide range of variables to represent soil conditions across the landscape and into the depths of the soil profile. There are good pre-compiled data options for working with attributes that are described above and include: the Web Soil Survey for small study areas, the SSURGO downloader app, gSSURGO polygon or raster data joined to the Valu1 table, Living Atlas layers, and the Soil Data Development Toolbox. If the attributes you need are not available with one of these methods, you will need to read the SSURGO and gSSURGO user guides and metadata in more depth to learn how to work with the attribute and relational database tables.
Soil Surveys from the past
To better understand the soil maps and data, it may be useful to refer to the printed soil survey for your county of interest.
- PDFs of current and past print US soil surveys
- NC State University Libraries has soil surveys in print for all North Carolina counties, and many other counties in the US. Search the Catalog for library locations. The maps in these documents are considered to be superceded by current online SSURGO data.
Data that were digitized by NC CGIA (status graphic) in the 1990's from soil survey hardcopy maps are available in ArcInfo Coverage format and shapefiles on the Geodata server (see the Detailed Data Listing). This data is kept for archival purposes and only recommended for historical comparisons.
US General Soils (STATSGO2)
The US General Soil Map (STATSGO2) consists of "state general soil maps made by generalizing the detailed soil survey data. The level of mapping is designed to be used for broad planning and management uses covering state, regional, and multi-state area. The original STATSGO (stands for State Soil Geographic Database) data were revised and updated in 2006, and hence renamed to version 2.
- Download STATSGO2 by state or for the entire US from the Web Soil Survey under the "Download Soils Data" tab.
- Full details, download options, and metadata about STATSGO2 data are on this NRCS website.
Watershed Boundary Dataset (WBD)
Natural Resources Inventory
The National Resources Inventory "...is a statistically based sample of land use and natural resource conditions and trends on U.S. nonfederal lands. It is the most comprehensive database of its kind ever attempted anywhere in the world" (NRCS). Since 1982, the NRI was conducted every 5 years; but, beginning with 2001, it is conducted annually.
Two CD-ROM products have been released of the NRI and are available from D. H. Hill, Jr. Library:
According to the NRI website, annual inventory data is only available via the website (limited summary) or the NRI Online Analysis System used by NRI Coordinators.