LOCATION SUOMI                   MN+ND

Established Series
Rev. GRN-CWT-AGG
12/2010

SUOMI SERIES

The Suomi series consists of very deep, moderately well drained soils formed in calcareous till on moraines. These soils have moderately slow to slow saturated hydraulic conductivity. Slopes range from 2 to 40 percent. Mean annual precipitation is about 25 inches, and mean annual air temperature is about 38 degrees F.

TAXONOMIC CLASS: Fine, smectitic, frigid Oxyaquic Glossudalfs

TYPICAL PEDON: Suomi loam on a northeast-facing convex slope of 3 percent in a pastured mixed hardwood forest. (Colors are for moist soil unless otherwise stated.)

A--0 to 4 inches; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; moderate fine granular structure; friable; many medium and fine roots; about 2 percent gravel; slightly acid; clear smooth boundary. (1 to 4 inches thick)

E--4 to 7 inches; grayish brown (10YR 5/2) silt loam; light gray (10YR 7/2) dry; weak fine subangular blocky structure; friable; many medium and fine roots; about 2 percent gravel; moderately acid; clear smooth boundary. (0 to 8 inches thick)

B/E--7 to 11 inches; 70 percent brown (10YR 4/3) silty clay loam (Bt) and 30 percent dark grayish brown (10YR 4/2) silty clay loam (E), pale brown (10YR 6/3) dry; moderate medium subangular blocky structure; friable; common fine roots; about 2 percent gravel; moderately acid; clear smooth boundary. (2 to 10 inches thick)

Bt1--11 to 20 inches; brown (10YR 4/3) silty clay; strong medium subangular blocky structure; firm; common fine roots; common very dark grayish brown (10YR 3/2) clay films on faces of peds; about 2 percent gravel; slightly acid; gradual smooth boundary.

Bt2--20 to 39 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; common fine roots; common very dark grayish brown (10YR3/2) clay films on faces of peds; few fine faint dark grayish brown (10YR 4/2) Fe depletions and few fine distinct yellowish brown (10YR 5/6) Fe concentrations; about 2 percent gravel; neutral; clear smooth boundary. (Thickness of the Bt horizon ranges from 6 to 30 inches.)

Bk--39 to 54 inches; brown (10YR 5/3) clay loam; weak fine subangular blocky structure; friable; few fine roots; common distinct dark grayish brown (2.5Y 4/2) Fe depletions and common yellowish brown (10YR5/6) Fe concentrations; few to common fine white (10YR 8/1) masses and threads of carbonates; about 5 percent gravel; strongly effervescent; moderately alkaline; gradual wavy boundary. (0 to 25 inches thick)

BC--54 to 80 inches; grayish brown (10YR 5/2) loam; weak fine and medium subangular blocky structure; friable; many distinct light brownish gray (2.5Y 6/2) Fe depletions and common medium distinct yellowish brown (10YR5/8) Fe concentrations; many light gray (10YR 7/1) masses and threads of calcium carbonate; about 5 percent gravel; strongly effervescent; moderately alkaline.

TYPE LOCATION: Koochiching County, Minnesota; about 4 miles north and 2 miles west of Northhome; 2,525 feet south and 150 feet west of northeast corner of sec. 20, T. 151 N., R. 29 W.

RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 16 to 48 inches. The particle size control section averages 20 to 40 percent fine sand and coarser and 35 to 50 percent clay. Rock fragments of mixed lithology range from 1 to 8 percent by volume throughout the profile.

Some pedons have Oa or Oe horizon (duff), 1 to 3 inches thick, with hue of 10YR or 7.5YR, value 2 or 3 and chroma 0 to 2. It is comprised of partially or well decomposed leaves, twigs, and other forest flora.

The A horizon has hue of 10YR, value of 2 or 3, chroma of 0 to 2, or is neutral. It is silt loam, loam, silty clay loam, or very fine sandy loam. It is strongly acid to neutral.

The E horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 3. It is silt loam, loam, silty clay loam, fine sandy loam, or very fine sandy loam. It is strongly acid to neutral.

The B/E horizon has properties of the Bt and E horizons respectively.

The Bt horizon has a hue of 10YR or 2.5Y, value of 3 to 5, and chroma of 2 to 4. It is silty clay, clay, silty clay loam, or clay loam. It is strongly acid to neutral.

The Bk horizon has hue of 2.5Y or 10YR, value of 4 to 7, and chroma of 1 to 4. It is silty clay loam, clay loam, or loam. Soft threads or rounded masses of calcium carbonate are common to many. It is slightly alkaline or moderately alkaline. Calcium carbonate equivalent is 12 to 20 percent.

The BC or C horizon has hue of 2.5Y or 10YR, value of 4 to 7, and chroma of 1 to 4. It is silty clay loam, clay loam, or loam. Few masses or threads of calcium carbonate are present. It is slightly alkaline or moderately alkaline. Calcium carbonate equivalent ranges from 5 to 15 percent.

COMPETING SERIES: These are the Grasston and Lewis Lake series. The Grasston soils do not have rock fragments in the series control section and formed in lacustrine sediments. Lewis Lake soils have sandy sediments in the lower third of the series control section.

GEOGRAPHIC SETTING: Suomi soils are on linear to convex surfaces of ground moraines, end moraines and bedrock controlled moraines. They formed in calcareous glacial till. The materials are of Late Wisconsin Age and contain significant areas stratified with glacio-lacustrine sediments. Slopes are 2 to 25 percent. Mean annual precipitation ranges from 23 to 28 inches, and mean annual air temperature ranges from 36 to 41 degrees F. The frost free period ranges from 90 to 120 days. Elevation above sea level ranges from 1200 to 1450 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashlake, Effie and Dora series. Somewhat poorly drained Ashlake soils are on less sloping and lower lying positions. The somewhat poorly drained Bionditch soils have bedrock at depths of 40 to 60 inches. The Dora soils are in depressions. The poorly drained Effie soils are in swales and flats.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. Surface runoff is medium to very high. Saturated hydraulic conducitivy is slow in the upper part and moderately slow in the lower part. Seasonal high saturation occurs at depths of 2.5 to 3.5 feet during April through June and October through November in most years.

USE AND VEGETATION: Most of this soil is forested. Northern hardwoods and aspen are predominant. Some areas are cleared and used for production of hay, oats, and pasture.

DISTRIBUTION AND EXTENT: MLRA 55A, 57, 88, and 93A. North central Minnesota and North Dakota, This soil is moderately extensive

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Itasca County, Minnesota, 1982.

REMARKS: Diagnostic horizons and features recognized in this soil are: ochric epipedon - the zone from the surface to 7 inches (A and E horizons); albic horizon - the zone from 4 to 7 inches (E horizon); glossic horizon - the zone from 7 to 11 inches (B/E horizon); argillic horizon - the zone from 7 to 39 inches (B/E, Bt1, and Bt2 horizons); Oxyaquic subgroup based on saturation above depths of 40 inches.

This soil could be challenged for an Oxyaquic Vertic Glossudalf. The cole in the upper 40 inches is close to 6 cm. Based on RV textures and clay, the cole will be less than 6 cm.

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National Cooperative Soil Survey
U.S.A.