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Soil Surveys

soil-survey-bannerSelect Soil Survey Area:

Below is a direct "Area of Interest" to select a Soil Survey Area for Web Soil Survey.

Official Soil Survey Data is housed in Web Soil Survey. Once it leaves web soil survey it is no longer official.


Official Web Soil Survey - Soil Science Annual Data Refreshed in October

The National Cooperative Soil Survey Program is an endeavor of the United States Department of Agriculture Natural Resources Conservation Service (NRCS) and other federal agencies; state and local governments; and other cooperators. It provides a systematic study of the soils in a given area, including the classification, mapping, and interpretation of the soils. Soil types are classified from physical properties, drawing heavily on the principles of pedology, geology, and geomorphology.

The entire national official soils data will be refreshed in October during each calendar year to ensure updated official data is available to all farmers, landowners, and partners. Refreshed soil survey information published to the Official Web Soil Survey (WSS) will include the 2012‐2016 Soil Data Join and Recorrelation (SDJR) national initiative, charged by congress to inventory the soils of the U.S., interpret the soils for various uses, publish info to the public, and maintain inventory to meet user needs, will be completed in October. The SDJR national initiative has fully populated components for almost 700 million acres. Almost 2,900 of the 3,300 soil survey areas have been touched during SDJR. Interpretation criteria will be updated for many national interpretations.

Individuals interested in knowing when surveys in a particular state are updated should visit the WSS and click on the “Download Soils Data” tab, then choose the State they are interested in. WSS will display a list of all soil survey areas. Individuals interested in soil related issues may subscribe to topics of interest using a free subscription service through GovDelivery offsite link image    . Individuals can e-mail inquiries to soilshotline@lin.usda.gov for assistance with GovDelivery and WSS.

Customers may click on the “Contact Us” link in WSS to receive assistance though the Soils Hotline, a State Soil Scientist, or a local NRCS Service Center. Questions about soil data in a specific state should be directed to the State Soil Scientist. Contact information for all State Soil Scientists is available. For more information on the Web Soil Survey, see our recent report Soil Survey: Uses & Limitations or visit the Wisconsin NRCS Soils Webpage.

Official Soil Survey Data

Official soil survey information is in the public domain and is available on the Web Soil Survey.The Web Soil Survey is the sole source for official soil survey data. When data is updat­ed on the Web Soil Survey, the older data is no longer considered official.

Example:

The soils data files for RUSLE2 (R2) are currently gen­erated by the State Agronomist from official soils data. Because of soils data being refreshed once a year, there may be minor differences between the soils data in R2 and the soils data in the WSS until the State Agronomist updates the R2 soils information.

Other soils data:

Outside groups are free to use whatever soils data they want to use for models or decision support systems like SnapPlus. If they chose to not update their soils information on an annual basis when NRCS updates our official soils information, there will, inevitably, be differ­ences between their soils data and the official soils data and these will increase over time.

Uses of the Soil Survey

Soil survey information can be used to predict or esti­mate the potentials and limitations of soils for many spe­cific uses. A soil survey includes an important part of the information that is used to make workable plans for land management. The information must be interpreted to be useable by professional planners and others.

Predictions based on soil surveys serve as a basis for judgment about land use and management for areas ranging from small tracts to regions of several million acres. These predictions, however, must be evaluated along with economic, social, and environmental consider­ations before they can be used to make valid recommen­dations for land use and management.

Examples

Soil survey information is important for planning the spe­cific land uses and practices needed to obtain specific results. For example, a soil survey can indicate the limita­tions and potentials of the soil for development of recre­ational areas. A landscape architect can use a soil survey when designing for the area. A contractor can use the survey in planning, grading, and implementing an erosion control program during construction. A horticulturist can use it in selecting suitable vegetation.

Soil surveys provide the basic information needed to make decisions about land management, including those operations that must be combined for satisfactory soil performance. For example, soil survey information is useful in planning, designing, and implementing an irrigation system for a farm. A knowledge of the charac­teristics of the soil helps in determining the run length, water application rate, soil amendment needs, leaching requirements, general drainage requirements, and field practices needed to maintain optimal soil conditions for plant growth.

Soil surveys are also helpful for locating possible sources of sand, gravel, or topsoil.

Technology Transfer

Soil surveys are an important component of technolo­gy transfer. They are needed to move knowledge from agricultural research fields and plots to other areas. Soil surveys allow us to identify areas that have soils that are similar to those in the research fields. Knowledge about the use and management of soils is spread by applying experience from studied areas to areas that have similar soils and related conditions.

The relationships between soils and deficiencies of phos­phorus, potassium, nitrogen, magnesium, and sulfur are widely known. In recent years, important relationships have been worked out between many soils and their deficiencies of trace elements, such as copper, boron, manganese, molybdenum, iron, cobalt, chromium, sele­nium, and zinc. Relationships between soils and some toxic chemical elements have also been established. By no means have all of the important soils been character­ized, especially for the trace elements. More research is needed.

Land Valuations

Soil is one of many attributes that contribute to land val­ue. The relative importance of soil varies widely among land uses. The soil is a major factor in areas used for farming, ranching, and forestry. In these areas, the soil’s capacity to produce and its requirements for production are critical elements of land value. Soil interpretations are used in assessing farmland for taxation and equalization, in appraising land for loans, and in guiding land buyers.

The soil is one of several elements in the appraisal of land value within a specific local, economic, and institutional environment. Many of the other elements that determine value of real estate change with time. The soil types recorded in an official soil survey, however, remain valid over time and can be easily reinterpreted as eco­nomic or institutional conditions change.

Limitations of the Soil Survey

Soil survey data seldom contain detailed, site-specific information. They are not intended for use as primary regulatory tools in site-specific permitting decisions. They are, however, useful for broad regulatory planning and application.

Soil survey information cannot replace site-specific details, which require onsite investigation. It is a valuable tool where acquiring onsite data is not feasible or is cost prohibitive. It is most useful as a tool for planning onsite investigation. Understanding the capability and limitations of the different types of soil data is essential for making the best conservation-planning decisions.

Soil Interpretations

Any use of soils data to make predictions falls under the broad category that soil scientists call “soil interpre­tations.” NRCS maintains a set of interpretations in the Web Soil Survey. These include calculated values, such as K and T, and features, such as Hydrologic Soil Groups and Unified Soil Classification. The interpretations also include various ratings of suitability and limitation for land uses.

Official soils data may be interpreted by organizations, agencies, units of government, or others based on their own needs; however, users are responsible for this use. NRCS does not accept reassignment of authority for decisions made by other Federal, State, or local regula­tory bodies. NRCS will not make changes to Official Soil Survey Information, or provide supplemental soil map­ping, for purposes related solely to State or local regula­tory programs. Official Soil Survey Information is science based. NRCS should be consulted regarding the poten­tials and consequences of soil interpretations beyond those in the Web Soil Survey.

NRCS understands that other entities will develop soil interpretations without technical assistance from NRCS. It is important, however, to reiterate that NRCS does not accept responsibility for soil interpretations other than those delivered by the Web Soil Survey. Collaboration with NRCS on soil interpretations is critical to the suc­cessful use of soils data.