gSSURGO SurveyAreas FY 2013


Tags
vector, United States of America, Geospatial Data Gateway, Arkansas, Soil Survey, environment, AR001,AR003,AR007,AR009,AR011,AR015,AR017,AR021, AR025,AR027,AR029,AR031,AR033,AR035,AR037,AR041, AR043,AR045,AR047,AR051,AR053,AR055,AR057,AR061, AR063,AR067,AR071,AR075,AR077,AR083,AR087,AR093, AR095,AR097,AR099,AR101,AR103,AR105,AR107,AR109, AR111,AR113,AR115,AR119,AR121,AR123,AR125,AR127, AR129,AR131,AR133,AR135,AR137,AR139,AR143,AR145, AR147,AR149,AR610,AR620,AR630,AR640,AR650,AR660, AR670,AR680, soils, USA, GDG, gSSURGO, farming, SSURGO


Summary

This is a customized SSURGO "Survey Area" vector-format dataset for Arkansas' GeoStor system. It was derived from the new gSSURGO datasets distributed by USDA-NRCS and are scheduled to be updated, annually, on a statewide basis. The Gridded SSURGO (gSSURGO) is similar to the standard USDA-NRCS Soil Survey Geographic (SSURGO) Database product but in the format of an Environmental Systems Research Institute, Inc. (ESRI®) file geodatabase. A file geodatabase has the capacity to store much more data and thus greater spatial extents than the traditional SSURGO product. This makes it possible to offer these data in statewide or even Conterminous United States (CONUS) tiles. gSSURGO contains all of the original soil attribute tables in SSURGO. All spatial data are stored within the geodatabase instead of externally as separate shapefiles. Both SSURGO and gSSURGO are considered products of the National Cooperative Soil Survey (NCSS) partnership. The gridded SSURGO (gSSURGO) dataset was created for use in national, regional, and statewide resource planning and analysis of soils data. Full SSURGO metadata may be accessed online: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/publication/?cid=nrcs142p2_053631

Description

This dataset of SSURGO Survey Areas (SA_POLYGON feature class) originated within the Gridded SSURGO (gSSURGO) Database and is derived from the Soil Survey Geographic (SSURGO) Database. SSURGO is generally the most detailed level of soil geographic data developed by the National Cooperative Soil Survey (NCSS) in accordance with NCSS mapping standards. The tabular data represent the soil attributes, and are derived from properties and characteristics stored in the National Soil Information System (NASIS). The gSSURGO data were prepared by merging traditional SSURGO digital vector map and tabular data into State-wide extents, and adding a State-wide gridded map layer derived from the vector, plus a new value added look up (valu) table containing "ready to map" attributes. The gridded map layer is offered in an ArcGIS file geodatabase raster format. The raster and vector map data have a State-wide extent. The raster map data have a 10 meter cell size that approximates the vector polygons in an Albers Equal Area projection. Each cell (and polygon) is linked to a map unit identifier called the map unit key. A unique map unit key is used to link to raster cells and polygons to attribute tables, including the new value added look up (valu) table that contains additional derived data. The value added look up (valu) table contains attribute data summarized to the map unit level using best practice generalization methods intended to meet the needs of most users. The generalization methods include map unit component weighted averages and percent of the map unit meeting a given criteria.

Credits

The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data.

Use limitations

The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data. This dataset 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. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.

Extent

West  -94.618290    East  -89.616749
North  36.531902    South  32.969213

Scale Range

ArcGIS Metadata 

Topics and Keywords 

Themes or categories of the resource  farming, environment


*Content type  Downloadable Data


Place keywords  United States of America, Arkansas, AR001,AR003,AR007,AR009,AR011,AR015,AR017,AR021, AR025,AR027,AR029,AR031,AR033,AR035,AR037,AR041, AR043,AR045,AR047,AR051,AR053,AR055,AR057,AR061, AR063,AR067,AR071,AR075,AR077,AR083,AR087,AR093, AR095,AR097,AR099,AR101,AR103,AR105,AR107,AR109, AR111,AR113,AR115,AR119,AR121,AR123,AR125,AR127, AR129,AR131,AR133,AR135,AR137,AR139,AR143,AR145, AR147,AR149,AR610,AR620,AR630,AR640,AR650,AR660, AR670,AR680, USA

Thesaurus
Title Counties and County Equivalents of the States of the United States and the District of Columbia (FIPS Pub 6-3)




Theme keywords  vector, Geospatial Data Gateway, Soil Survey, soils, GDG, gSSURGO, SSURGO

Theme keywords  environment, farming

Thesaurus
Title ISO 19115 Topic Categories




Citation 

Title gSSURGO SurveyAreas FY 2013
Publication date 2012-11-20


Presentation formats* digital map
FGDC geospatial presentation format  vector and raster digital map data and tabular digital data


Citation Contacts 

Responsible party
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service
Contact's role  originator


Responsible party
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service
Contact's role  publisher


Contact information
Address
Delivery point Fort Worth, Texas



Resource Details 

Dataset languages  English (UNITED STATES)


Status  under development
Spatial representation type  vector


Processing environment Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.3.0.4322


Credits
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data.

ArcGIS item properties
*Name asdi.farming.GSSURGO_SURVEYAREAS
*Size 1.822
*Location Server=170.94.248.50; Service=sde:postgresql:170.94.248.50; Database=asdi; User=sde; Version=sde.DEFAULT
*Access protocol ArcSDE Connection

Extents 

Extent
Geographic extent
Bounding rectangle
West longitude -94.61829
East longitude -89.616749
South latitude 32.969213
North latitude 36.531902

Extent
Description
publication date

Temporal extent
Date and time 2012-10-15

Extent
Geographic extent
Bounding rectangle
Extent type  Extent used for searching
*West longitude -94.618290
*East longitude -89.616749
*North latitude 36.531902
*South latitude 32.969213
*Extent contains the resource Yes

Extent in the item's coordinate system
*West longitude 355106.972900
*East longitude 803102.645500
*South latitude 3652544.741400
*North latitude 4042946.758200
*Extent contains the resource Yes

Resource Points of Contact 

Point of contact
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center
Contact's role  point of contact


Contact information
Phone
Voice 402 437 5499

Address
Type postal
Delivery point 100 Centennial Mall North
Delivery point Federal Building, Room 152
City Lincoln
Administrative area NE
Postal code 68508-3866
e-mail addressSoilsHotline@lin.usda.gov



Resource Maintenance 

Resource maintenance
Update frequency  annually


Resource Constraints 

Legal constraints
Limitations of use
Although these data have been processed successfully on a computer system at the U.S. Department of Agriculture, no warranty expressed or implied is made by the Agency regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. The U.S. Department of Agriculture will warrant the delivery of this product in computer readable format, and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer input peripherals, or when the physical medium is delivered in damaged condition. Request for adjustment of credit must be made within 90 days from the date of this shipment from the ordering site. The U.S. Department of Agriculture, nor any of its agencies are liable for misuse of the data, for damage, for transmission of viruses, or for computer contamination through the distribution of these datasets. The U.S. Department of Agriculture (USDA) prohibits discrimination in all of its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, (including gender identity and expression), marital status, familial status, parental status, religion, sexual orientation, political beliefs, genetic information, reprisal, or because all or part of an individual's income is derived from any public assistance program. (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 to USDA, Assistant Secretary for Civil Rights, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, S.W., Stop 9410, Washington, DC 20250-9410, or call toll-free at (866) 632-9992 (English) or (800) 877-8339 (TDD) or (866) 377-8642 (English Federal-relay) or (800) 845-6136 (Spanish Federal-relay). USDA is an equal opportunity provider and employer.

Constraints
Limitations of use
The U.S. Department of Agriculture, Natural Resources Conservation Service, should be acknowledged as the data source in products derived from these data. This dataset 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. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data.

Spatial Reference 

ArcGIS coordinate system
*Type Projected
*Geographic coordinate reference GCS_North_American_1983
*Projection NAD_1983_UTM_Zone_15N
*Coordinate reference details
Projected coordinate system
Well-known identifier 26915
X origin -5120900
Y origin -9998100
XY scale 10000
Z origin -100000
Z scale 10000
M origin -100000
M scale 10000
XY tolerance 0.001
Z tolerance 0.001
M tolerance 0.001
High precision true
Latest well-known identifier 26915
Well-known text PROJCS["NAD_1983_UTM_Zone_15N",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-93.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",26915]]

Reference system identifier
*Value 26915
*Codespace EPSG
*Version 8.2.6


Spatial Data Properties 

Georectified Grid
Number of dimensions 2




Cell geometry  area




Vector
*Level of topology for this dataset  geometry only


Geometric objects
Feature class name asdi.farming.GSSURGO_SURVEYAREAS
*Object type  composite
*Object count 67



Vector
*Level of topology for this dataset  geometry only


Geometric objects
Feature class name asdi.farming.GSSURGO_SURVEYAREAS
*Object type  composite
*Object count 67



ArcGIS Feature Class Properties
Feature class name asdi.farming.GSSURGO_SURVEYAREAS
*Feature type Simple
*Geometry type Polygon
*Has topology FALSE
*Feature count 67
*Spatial index TRUE
*Linear referencing FALSE



Data Quality 

Scope of quality information
Resource level  dataset




Data quality report - Topological consistency
Evaluation method
The raster dataset uses the topologically correct vector SSURGO dataset for its source. The feature to raster conversion uses the cell center to decide the value of a raster pixel. The raster layer was snapped to the 2006 National Land Cover Database (NLCD) during processing. The tests of logical consistency are performed using vendor software.





Data quality report - Conceptual consistency
Measure description
The raster dataset uses the topologically correct vector SSURGO dataset for its source. The feature to raster conversion uses the cell center to decide the value of a raster pixel. The raster layer was snapped to the 2006 National Land Cover Database (NLCD) during processing. The tests of logical consistency are performed using vendor software.





Data quality report - Completeness omission
Measure description
The data are being generalized during the vector to raster conversion. The acreage total of the cells will differ from the acreage total of the polygons. The SSURGO raster was also snapped to the 2006 National Land Cover Database (NLCD). The NLCD is used as a snap raster to anchor the starting point of the SSURGO grid matrix in the snap raster environment.





Lineage 

Process step
When the process occurred 2012-11-20
Description
A 10 meter file geodatabase raster layer was created by converting the 'MUPOLYGON' feature class from feature to raster using 'FeatureToRaster' which is a cell-center-based method in ArcGIS 10.1. The raster layer was snapped to the 2006 NLCD raster for CONUS. Pyramids and a raster attribute table were created. Using the 'Lookup_Mukey' table, a single attribute 'MUKEY' was added to the raster attribute table to facilitate joins with the attribute data.



Source data
Relationship to the process step used


Source citation
Alternate titles  NLCD








Process step
When the process occurred 2012-11-20
Description
A new table 'Lookup_Mukey' was created in order to facilitate the conversion of the MUPOLYGON feature class from polygon to raster. This table was derived from the MAPUNIT table in the Soil Data Mart and contains 'MUKEY' values for all soil surveys in the October 2012 Soil Data Mart database, not just those present in this geodatabase feature class. The table also contains an integer value attribute named 'CellValue'. This is the value used to generate the raster layer. 'CellValue' corresponds directly to the OBJECTID or internal record number of the MAPUNIT table.





Process step
Description
This dataset is a digital soil survey and generally is 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. This dataset consists of georeferenced digital map data and computerized attribute data. The map data are in a soil survey area extent format and 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. 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.



Source data
Relationship to the process step used


Source citation
Alternate titles  NRCS








Process step
When the process occurred 2012-11-20
Description
State-wide file geodatabases (ESRI) were exported from the October 15, 2012 snapshot of the NRCS Soil Data Mart at the National Soil Survey Center in Lincoln, Nebraska. Software used for all processes was ArcGIS 10.1. All existing SSURGO features and attributes were selected using the NASIS 'Legend Area Overlap' table to identify non-MLRA (Major Land Resource Area) soil survey areas that intersect this particular 'State or Territory'. The data were not clipped to a state boundary, thus in some instances feature classes may extend beyond a state's boundary. All conterminous United States (CONUS) datasets were projected from the original Geographic NAD83 coordinate system to 'USA_Contiguous_Albers_Equal_Area_Conic_USGS_Version'. Relationship classes between tables and feature classes were created in the geodatabase.



Source data
Relationship to the process step used


Source citation
Alternate titles  NRCS








Source data
Description
Soil Survey Geographic (SSURGO) database vector data



Source medium name  online link
Resolution of the source data
Scale denominator 0

Source citation
Title Soil Survey Geographic (SSURGO) database for Soil Survey Areas
Alternate titles  NRCS


Presentation formats  digital map
FGDC geospatial presentation format  vector digital data


Responsible party
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service
Contact's role  originator


Responsible party
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service
Contact's role  publisher


Contact information
Address
Delivery point Kansas City, Missouri





Extent of the source data
Description
publication date

Temporal extent
Beginning date 1995-01-01
Ending date
Indeterminate date now



Source data
Description
cell alignment layer



Source medium name  online link
Source citation
Title National Land Cover Database 2006
Alternate titles  NLCD
Publication date 2006-01-01


Presentation formats  digital map
FGDC geospatial presentation format  raster digital data


Responsible party
Organization's name U.S. Department of the Interior, U.S. Geological Survey
Contact's role  originator




Extent of the source data
Description
publication date

Temporal extent
Date and time 2006-01-01



Geoprocessing history 

Distribution 

Distributor
Contact information
Individual's name Arkansas GIS Office
Organization's name State of Arkansas
Contact's role  distributor


Contact information
Phone
Voice 501-682-2929

Address
Type physical
Delivery point 1 Capitol Mall, Suite 6D
City Little Rock
Administrative area AR
Postal code 72212
Country US
e-mail addresscommunication@arkansasgisoffice.org



Ordering process

Transfer options
Online source
Locationhttp://gis.arkansas.gov/product/gssurgo-surveyareas-fy-2013/

Online source
Location https://gis.arkansas.gov/arcgis/rest/services/FEATURESERVICES/Farming/FeatureServer/6



Distribution format
*Name SDE Feature Class


Transfer options
Online source
Location URL:http://datagateway.nrcs.usda.gov

Fields 

Details for object asdi.farming.GSSURGO_SURVEYAREAS 
*Type Feature Class
*Row count 67


Field AREASYMBOL
 
*Alias AREASYMBOL
*Data type String
*Width 20
*Precision 0
*Scale 0
Field description
Column Physical Name: areasymbol Column Label: Area Symbol A symbol that uniquely identifies a single occurrence of a particular type of area (e.g. Lancaster Co., Nebraska is NE109).



Field Shape
 
*Alias Shape
*Data type Geometry
*Width 4
*Precision 0
*Scale 0
Field description
Feature geometry.

Description source
ESRI

Description of values
Coordinates defining the features.





Field OBJECTID
 
*Alias OBJECTID
*Data type OID
*Width 4
*Precision 10
*Scale 0
Field description
Internal feature number.

Description source
ESRI

Description of values
Sequential unique whole numbers that are automatically generated.





Field st_length(shape)
 
*Alias st_length(shape)
*Data type Double
*Width 0
*Precision 0
*Scale 0




Field st_area(shape)
 
*Alias st_area(shape)
*Data type Double
*Width 0
*Precision 0
*Scale 0




Field globalid
 
*Alias globalid
*Data type GlobalID
*Width 38
*Precision 0
*Scale 0




Field SHAPE_Leng
 
*Alias SHAPE_Leng
*Data type Double
*Width 8
*Precision 38
*Scale 8




Field lkey
 
*Alias LKEY
*Data type String
*Width 30
*Precision 0
*Scale 0
Field description
Column Physical Name: lkey Column Label: Legend Key A non-connotative string of characters used to uniquely identify a record in the Legend table.



Field Geostor_re
 
*Alias Geostor_re
*Data type String
*Width 5
*Precision 0
*Scale 0
Field description
This field indicates whether the Soil Survey polygon contained within the original SA_POLYGON feature class from NRCS (gSSURGO FY2013) is within the four (quartered) zones of the GeoStor division for these data. This divide was determined by the Arkansas Geographic Information Office (AGIO) so that the resulting file sizes can be managed most effectively by the GeoStor data distribution system (www.geostor.arkansas.gov).

Description source
Shelby Johnson, Seth Lemaster and Maria Owen, AGIO Office



Field SPATIALVER
 
*Alias SPATIALVER
*Data type Integer
*Width 4
*Precision 10
*Scale 0






Overview Description
Entity and Attribute Overview
Raster cell locations are based on map unit delineations which are closed polygons that may be dominated by a single soil or nonsoil component plus allowable similar or dissimilar soils, or they can be geographic mixtures of groups of soils or soils and nonsoil areas. The map unit symbol uniquely identifies each closed delineation map unit. Each symbol corresponds to a map unit name. The map unit key is used to link to information in the National Soil Information System (NASIS) tables. A new table, 'Lookup_Mukey' was created and contains the mukey value for all soil surveys in the database. The mukey column and value was added to the raster attribute table to facilitate joins with the attribute data.



Entity and Attribute Detail Citation
U.S. Department of Agriculture. 1999. Soil Taxonomy: A basic system of soil classification for making and interpreting soil surveys. Natural Resources Conservation Service, U.S. Dep. Agric. Handb. 436. U.S. Department of Agriculture. (current issue). Keys to Soil Taxonomy. Soil Surv. Staff, Natural Resources Conservation Service. U.S. Department of Agriculture. (current issue). National Soil Survey Handbook, title 430-VI. Soil Surv. Staff, Natural Resources Conservation Service. U.S. Department of Agriculture. 1993. Soil Survey Manual. Soil Surv. Staff, U.S. Dep. Agric. Handb. 18.





Metadata Details 

Metadata language English (UNITED STATES)
Metadata character set  utf8 - 8 bit UCS Transfer Format


Scope of the data described by the metadata  dataset
Scope name* dataset


Last update 2014-04-08


ArcGIS metadata properties
Metadata format ArcGIS 1.0
Metadata style FGDC CSDGM Metadata
Standard or profile used to edit metadata FGDC


Created in ArcGIS for the item 2014-05-22 22:13:39
Last modified in ArcGIS for the item 2017-01-19 12:00:49


Automatic updates
Have been performed Yes
Last update 2017-01-19 12:00:49

Item location history
Item copied or moved 2014-04-24 15:01:43
From C:\Temp\TEST_GeoStor_SSURGO_download_Oct2013\SurveyPoly2012
To \\DAKAR\C$\Temp\TEST_GeoStor_SSURGO_download_Oct2013\soils_GSSURGO_ar_2492802_01_Apr4\soils\gssurgo_g_ar\Arkansas\SurveyPoly2012


Metadata Contacts 

Metadata contact
Organization's name U.S. Department of Agriculture, Natural Resources Conservation Service, National Soil Survey Center
Contact's role  point of contact


Contact information
Phone
Voice 402 437 5499

Address
Type postal
Delivery point 100 Centennial Mall North
Delivery point Federal Building, Room 152
City Lincoln
Administrative area NE
Postal code 68508-3866
e-mail addressSoilsHotline@lin.usda.gov



Metadata Maintenance 

Maintenance
Date of next update 2014-11-04
Update frequency  unknown


Thumbnail and Enclosures 

FGDC Metadata (read-only) 

Entities and Attributes 

Detailed Description
Entity Type
Entity Type Labelasdi.farming.GSSURGO_SURVEYAREAS

Attribute
Attribute LabelAREASYMBOL
Attribute Definition
Column Physical Name: areasymbol Column Label: Area Symbol A symbol that uniquely identifies a single occurrence of a particular type of area (e.g. Lancaster Co., Nebraska is NE109).

Attribute
Attribute LabelShape
Attribute Definition
Feature geometry.
Attribute Definition SourceESRI
Attribute Domain Values
Unrepresentable Domain
Coordinates defining the features.

Attribute
Attribute LabelOBJECTID
Attribute Definition
Internal feature number.
Attribute Definition SourceESRI
Attribute Domain Values
Unrepresentable Domain
Sequential unique whole numbers that are automatically generated.

Attribute
Attribute Labelst_length(shape)

Attribute
Attribute Labelst_area(shape)

Attribute
Attribute Labelglobalid

Attribute
Attribute LabelSHAPE_Leng

Attribute
Attribute Labellkey
Attribute Definition
Column Physical Name: lkey Column Label: Legend Key A non-connotative string of characters used to uniquely identify a record in the Legend table.

Attribute
Attribute LabelGeostor_re
Attribute Definition
This field indicates whether the Soil Survey polygon contained within the original SA_POLYGON feature class from NRCS (gSSURGO FY2013) is within the four (quartered) zones of the GeoStor division for these data. This divide was determined by the Arkansas Geographic Information Office (AGIO) so that the resulting file sizes can be managed most effectively by the GeoStor data distribution system (www.geostor.arkansas.gov).
Attribute Definition SourceShelby Johnson, Seth Lemaster and Maria Owen, AGIO Office

Attribute
Attribute LabelSPATIALVER

Overview Description
Entity and Attribute Overview
                            Raster cell locations are based on map unit delineations which are closed polygons that may be dominated by a single soil or nonsoil component plus allowable similar or dissimilar soils, or they can be geographic mixtures of groups of soils or soils and nonsoil areas. The map unit symbol uniquely identifies each closed delineation map unit. Each symbol corresponds to a map unit name. The map unit key is used to link to information in the National Soil Information System (NASIS) tables. A new table, 'Lookup_Mukey' was created and contains the mukey value for all soil surveys in the database. The mukey column and value was added to the raster attribute table to facilitate joins with the attribute data.
                          
Entity and Attribute Detail Citation
                            U.S. Department of Agriculture. 1999. Soil Taxonomy: A basic system of soil classification for making and interpreting soil surveys. Natural Resources Conservation Service, U.S. Dep. Agric. Handb. 436. U.S. Department of Agriculture. (current issue). Keys to Soil Taxonomy. Soil Surv. Staff, Natural Resources Conservation Service. U.S. Department of Agriculture. (current issue). National Soil Survey Handbook, title 430-VI. Soil Surv. Staff, Natural Resources Conservation Service. U.S. Department of Agriculture. 1993. Soil Survey Manual. Soil Surv. Staff, U.S. Dep. Agric. Handb. 18.