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Detailed Soil Map Units <br /> The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas <br /> in the survey area. The map unit descriptions in this report, along with the maps, can be used to determine <br /> the composition and properties of a unit. <br /> A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or <br /> miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the <br /> dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On <br /> the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all <br /> natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a <br /> taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including <br /> areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous <br /> areas for which it is named, soils that are similar to the named components, and some minor components <br /> that differ in use and management from the major soils. <br /> Most of the soils similar to the major components have properties similar to those of the dominant soil or soils <br /> in the map unit, and thus they do not affect use and management. These are called noncontrasting, or <br /> similar, components. They may or may not be mentioned in a particular map unit description. Some minor <br /> components, however, have properties and behavior characteristics divergent enough to affect use or to <br /> require different management. These are called contrasting, or dissimilar, components. They generally are in <br /> small areas and could not be mapped separately because of the scale used. Some small areas of strongly <br /> contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the <br /> database for a given area, the contrasting minor components are identified in the map unit descriptions along <br /> with some characteristics of each. A few areas of minor components may not have been observed, and <br /> consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it <br /> was impractical to make enough observations to identify all the soils and miscellaneous areas on the <br /> landscape. <br /> The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. <br /> The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into <br /> landforms or landform segments that have similar use and management requirements. The delineation of <br /> such segments on the map provides sufficient information for the development of resource plans. If intensive <br /> use of small areas is planned, however, onsite investigation is needed to define and locate the soils and <br /> miscellaneous areas. <br /> An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes <br /> general facts about the unit and gives important soil properties and qualities. <br /> Soils that have profiles that are almost alike make up a soil series. All the soils of a series have major <br /> horizons that are similar in composition, thickness, and arrangement. Soils of a given series can differ in <br /> texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect <br /> their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown <br /> on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature <br /> that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha <br /> series. <br /> Some map units are made up of two or more major soils or miscellaneous areas. These map units are <br /> complexes, associations, or undifferentiated groups. <br /> A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small <br /> areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or <br /> miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an <br /> example. <br /> An association is made up of two or more geographically associated soils or miscellaneous areas that are <br /> shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it <br /> was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and <br /> relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha-Beta association, 0 to 2 <br /> percent slopes, is an example. <br /> An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped <br /> individually but are mapped as one unit because similar interpretations can be made for use and <br /> management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not <br />