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Hydric Soils - Overview

The Hydric Soils section presents the most current information about hydric soils. It updates information that was previously published in "Hydric Soils of the United States" and coordinates it with information that has been published in the "Federal Register". It also includes the most recent set of field indicators of hydric soils.

Four types of technical information about hydric soils are presented.

  1. The current definition of a hydric soil -- This definition has evolved over the last 10 years or so, but has been consistent in the overall concept that hydric soils are those soils that are sufficiently wet in the upper part to develop anaerobic conditions during the growing season.
     
  2. The criteria for hydric soils and the lists which are generated from them -- The criteria are selected soil properties that are documented in Soil Taxonomy and were designed primarily to generate a list of hydric soils from soil survey databases. The purpose of the criteria is to generate a list of soil series that are likely to meet the hydric soil definition. Caution must be used when comparing the list of hydric soil series to soil survey maps. Many of the soils on the list have ranges in water table depths that allow the soil to range from hydric to nonhydric depending on the location. Lists of hydric soils along with soil survey maps are good off-site ancillary tools to assist in wetland determinations, but they are not a substitute for on-site investigations.
     
  3. The list of field indicators of hydric soils -- The field indicators are morphological properties known to be associated with soils that meet the definition of a hydric soil. Presence of one or more field indicators suggests that the processes associated with hydric soil formation have taken place on the site being observed. The field indicators are particularly useful for hydric soil identification because once formed, they persist in the soil during both wet and dry seasonal periods.
     
  4. The Hydric Soil Technical Notes -- Contain National Technical Committee for Hydric Soils (NTCHS) updates, insights, standards, and clarifications.

Next item  -- Introduction

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