Minnesota has seven of the 12 soil orders and with those 7 orders there are
14 suborders. Suborders are divisions of the orders where climate or water
table is different based on the the soil moisture regime or other special
feature. Learning about the suborders of Minnesota will help you understand the
soil forming factors for our state or any state you might visit.
Orders in Minnesota: The Epipedon and Diagnostic Subsurface Requirements
Suborders are identified by placing a short prefix in front of the order root. The following are the suborder prefixes for Minnesota soils.
Ud - Udic moisture=moist climate similar to that found in southern Minnesota.
Aqu - Aquic moisture=saturated soil. These soils have a high water table and gleyed conditions in the subsoil, or gray colors and red or gray mottles.
Orth- true or simple - This is used for the regular Entisols & Spodosols and implies that they are the non special examples of these orders.
Psamm - sand - used for soils that are dominated by loamy sand or sand textures.
Fluv - floodplain soils - These are for soils found on river bottoms or areas that frequently flood. The soils frequently have layers of different color due to frequent depositions.
Bor- Boreas=northern Minnesota with cold soil temperatures (Frigid temperature regime). Note: this suborder designation was dropped from use in 1998. Therefore any soil with a Bor designation is now a Ud (Boroll=Udoll and Boralf=Udalf)
Fib, Hem, Sap - state of decomposition for organic soils. Histosol suborders are determined by the amount of decomposition of the organic material. Undecomposed is Fibrist, moderate decomposition is Hemist and highly decomposed peat is Saprist.
Entisol Suborders=Aquents, Orthents, Psamments, & Fluvents. Entisols occupy about 18% of Minnesota or 10.7 million acres.
Aquents are the Entisols that have poor drainage, they are in low lying areas that have not developed a mollic or histic epipedon. They are predominantly sandy soils supporting forest vegetation. They occur in north-central and northwestern Minnesota. Aquent Profile
Orthents are the Entisols that are typical of soils that have minimal horizon development. They are shallow to bedrock or developed in areas that did not allow for the development of a cambic horizon. They occur mainly in northeastern Minnesota. Orthent Profile
Psamments are Entisols that are loamy sand or sand texture. They develop in outwash, sand dunes, sandstone bedrock, or floodplains. They occur central Minnesota on outwash and in southeastern Minnesota from St. Peter Sandstone. They may have a Bw horizon but it is not a cambic horizon. Psamment Profile from Rock & Psamment from Outwash
Fluvents are Entisols that develope in floodplains of the Minnesota, Mississippi, and other major rivers. They do not have developed horizons but layers representing the frequent times they have been flooded and sediments deposited. On the soil suborders map for Minnesota the Fluvents are the along the Minnesota and Mississippi River south of St. Paul. Fluvent Profile
Vertisol Suborders =Aquert. Vertisols occupy about 1.2% of Minnesota or 0.8 million acres.
Aquerts are Vertisols that have a high water table and gray subsoils. They occur in the low lying areas of the Red River Valley of northwestern Minnesota. Aquerts are very productive for agriculture but difficult to use for roads and buildings. Internal water movement is very slow. The high clay content of the lacustrine parent material resulted the the formation Aquerts. Aquert Profile
Mollisol Suborders=Aquoll, Udoll, Ustoll. Mollisols occupy about 32% of Minnesota or 18.8 million acres
Aquolls are wet prairie soils. These Mollisols have a water table that is near the surface. Subsoils are gray in color and have redoximorphic features. Extensive areas of these soils occur in the Red River Valley and in south-central Minnesota. These soils are very productive when the excess water is removed by drainage. These soils are considered wetlands if the water is not removed. Aquoll Profile
Udolls are moist prairie soils. These soils cover much of southern Minnesota and are the most extensive soil in the state (19%). These are very productive agricultural soils. The dominant crops today are corn and soybeans. Udoll Profile
Ustolls are dry prairie soils. They are only found in the southwest corner of the state and are more extensive to the south and west of Minnesota. In dry years water will limit productivity for corn and soybeans the major crops. Ustoll Profile
Alfisol Suborders =Aqualf, Udalf. Alfisols occupy about 27 % of Minnesota or 16 million acres.
Aqualfs are wet forested soils. Because of their position in the landscape they are wet much of the year. In northern Minnesota they support aspen forests with a mixture of black ash and alder. They are most common in the basins of glacial lakes that formed in the latter part of the ice age. Aqualf Profile
Udalfs are forested soils that had aspen and pine in the north and the big woods sugar maple and basswood forest in the southeast. The Udalfs occur on ridges with Udolls in the valley floors and ridge summits. Generally the southern Udalfs are more productive due to warmer climate than the northern Udalfs. Northern Udalf & Southern Udalf & Central Udalf
Inceptisol Suborders =Aquepts, Udepts. Inceptisols occupy about 9.4 % of Minnesota or 5.5 million acres.
Aquepts are wet soils of the mixed conifer-deciduous forest. They are scattered over the northern two-thirds of the state. They often occur in association with peatlands. Aquept Profile
Udepts are forested soils developed primarily from glacial till in northern Minnesota. They are low in lime and contain many large boulders. They were once covered by red and white pine and today are mostly aspen forests. Udept Profile -Till--- Udept Profile -Loess
Spodosol Suborders =Orthod. Spodosols occupy 0.2% of Minnesota or 0.1 million acres.
Orthods are forested soils with a sandy texture. They are frequently found in small areas that are downslope form a summit and before the wetland. Orthods are covered by forests of aspen or pine and rarely for agriculture because of their acid, droughty nature. Minnesota is on the western edge of the Spodosol regions and the spodic horizon is minimally developed.Orthod Profile 1 & Orthod Profile 1
Histisol Suborders =Fibrist, Hemist, Saprist. Histosols occupy 5.3 % of Minnesota or 3 million acres. The dominant suborder is the Hemist and is the only one identified on the map, though some areas may be Fibrist or Saprist.
Fibrist soils are found in open peatlands where sphagnum moss is the dominant plant along with scattered spruce or tamarack forests. Fibrist Profile
Hemists soils are found in areas where the peat has undergone more decomposition. Vegetation includes reeds, sedges and other wetland plants. Today these areas are used for peat mining, sod production or willow production for biomass fuel. Hemist Profile
Saprists soils are found in small areas of southern Minnesota and are frequently used for vegetable or sod production. Saprist Profile
Map of Soil Suborders. as found in the publication "Soils and Landscapes of Minnesota"
The soils of Wisconsin will be similar the the soils of Minnesota. For a state soil map of Wisconsin go to Soils of Wisconsin - and for a look at the state soil Antigo go to Wisconsin State Soil http://www.wi.nrcs.usda.gov/technical/soil/antigo.html
© Regents of the University of Minnesota, 2007. The University of Minnesota is an equal opportunity educator and employer.
Prepared by tcooper@umn.edu
