LOCATION TAMA               IA+IL IN MN WI

TAMA SERIES

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Argiudolls

TYPICAL PEDON: Tama silty clay loam, on a west-facing, convex slope of 3 percent, in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 centimeters; very dark brown (10YR 2/2) silty clay loam, very dark grayish brown (10YR 3/2) dry; weak fine granular structure; friable; strongly acid; abrupt smooth boundary.

A1--15 to 25 centimeters; very dark brown (10YR 2/2) silty clay loam, very dark grayish brown (10YR 3/2) dry; moderate medium granular structure; friable; strongly acid; gradual smooth boundary.

A2--25 to 36 centimeters; very dark brown (10YR 2/2) silty clay loam, dark grayish brown (10YR 4/2) dry; moderate medium granular structure; friable; strongly acid; gradual smooth boundary. (Combined thickness of the A horizon is 25 to 50 centimeters.)

BA--36 to 46 centimeters; very dark grayish brown (10YR 3/2) and brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure; friable; when dry, few faint gray (10YR 6/1) silt coats on faces of peds; many roots; common worm casts and holes; strongly acid; gradual smooth boundary. (0 to 15 centimeters thick)

Bt1--46 to 81 centimeters; brown (10YR 4/3) silty clay loam, dark yellowish brown (10YR 4/4) when kneaded; moderate fine subangular blocky structure; friable; many fine roots; common fine pores; common distinct clay films; when dry, few faint gray (10YR 6/1) silt coats on faces of peds; common worm casts and holes; strongly acid; gradual smooth boundary.

Bt2--81 to 114 centimeters; dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4) silty clay loam; weak medium prismatic structure parting to weak medium subangular blocky; friable; many fine roots; many fine pores; few distinct clay films; when dry, few faint gray (10YR 6/1) silt coats on faces of peds; few fine faint brown (10YR 5/3) and few fine prominent yellowish brown (10YR 5/8) redoximorphic concentrations; strongly acid; gradual smooth boundary. (Combined thickness of the Bt horizon is 30 to 107 centimeters.)

BC--114 to 152 centimeters; yellowish brown (10YR 5/4) silty clay loam; weak very coarse prismatic structure; very friable; when dry, few faint gray (10YR 6/1) silt coats on faces of peds; many fine distinct yellowish brown (10YR 5/6) redoximorphic concentrations; few fine distinct grayish brown (10YR 5/2) redoximorphic depletions; moderately acid.

TYPE LOCATION: Major Land Resource Area (MLRA) 104-Eastern Iowa and Minnesota Till Prairies, Tama County, Iowa subset; about 3 miles north and 1 mile west of Gladbrook; located about 760 feet east and 186 feet north of the southwest corner of section 28, T. 86 N., R. 16 W.; USGS Gladbrook topographic quadrangle; lat. 42 degrees 13 minutes 31 seconds N. and long. 92 degrees 43 minutes 32 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon--25 to 50 centimeters
Depth to carbonates--112 to more than 203 centimeters
Clay content of the particle-size control section (weighted average)--24 to 32 percent
Sand content of the particle-size control section (weighted average)--less than 5 percent
Rock fragment content--0 percent

A or Ap horizon:
Hue--10YR
Value--2 or 3
Chroma--1 or 2
Texture--silty clay loam or silt loam
Clay content--22 to 30 percent
Sand content--less than 10 percent
Reaction--strongly acid to neutral

BA horizon (when present):
Hue--10YR
Value--3 or 4
Chroma--2 or 3
Texture--silty clay loam or silt loam
Clay content--24 to 32 percent
Sand content--less than 10 percent
Reaction--strongly acid to slightly acid

Bt horizon:
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silty clay loam or silt loam
Clay content--24 to 32 percent
Sand content--less than 5 percent
Reaction--strongly acid to slightly acid

Some pedons have subhorizons with a clay content of up to 35 percent

Some pedons have silt or very fine sand coats on ped faces which are more noticeable when the soil is dry

BC horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--3 or 4
Texture--silt loam or silty clay loam
Clay content--20 to 30 percent
Sand content--less than 5 percent
Reaction--strongly acid to neutral

C horizon (when present):
Hue--10YR
Value--4 or 5
Chroma--3 to 6
Texture--silt loam or silty clay loam
Clay content--18 to 30 percent
Sand content--less than 5 percent
Reaction--strongly acid to neutral

Some pedons have sandy materials below a depth of 150 centimeters

COMPETING SERIES: These are the Ashdale, Broadwell, Dinsdale, Douglas, Elkhart, Elmont, Healing, Lycurgus, Malcolm, Meadowbank, Mendota, Mickle, Ogle, Osco, Parkway, Plano, Proctor, Richwood, Ripon, Sibley, Sidell, Tecumseh, Toddville, Wakenda, and Waupecan series.
Ashdale--have limestone bedrock within a depth of 150 centimeters
Broadwell--have a sand content of 50 to 90 percent in the lower third of the series control section
Dinsdale--have a sand content of 35 to 50 percent in the lower third of the series control section
Douglas--have a sand content of 15 to 45 percent in the lower third of the series control section
Elkhart--have carbonates within a depth of 102 centimeters
Elmont--have a paralithic contact within a depth of 150 centimeters
Healing--have chert and sandstone fragments in the lower third of the series control section
Lycurgus--have a sand content of 10 to 40 percent in the upper two thirds of the series control section
Malcolm--have a clay content of 12 to 18 percent in the lower half of the series control section
Meadowbank--have a clay content of less than 15 percent in the lower third of the series control section
Mendota--have carbonates within a depth of 102 centimeters and have a rock fragment content of 12 to 60 percent in the lower third of the series control section
Mickle--have a clay content that averages 18 to 30 percent in the particle-size control section and have a frequently saturated zone within a depth of 1.1 meter in normal years
Ogle--have matrix hues of 2.5YR, 5YR, or 7.5YR in the lower third of the series control section
Osco--have a frequently saturated zone within a depth of 1.8 meters in normal years
Parkway--have a sand content of 20 to 40 percent in the lower third of the series control section
Plano--have a sand content of more than 20 percent in the lower third of the series control section
Proctor--have a clay content of 10 to 20 percent in the lower third of the series control section
Richwood--have a sand content of 50 to 90 percent in the lower third of the series control section
Ripon--have limestone bedrock within a depth of 102 centimeters
Sibley--have a mollic epipedon 61 to 91 centimeters thick
Sidell--have a rock fragment content of 2 to 10 percent in the lower third of the series control section
Tecumseh--have a sand content of 30 to 50 percent in the lower third of the series control section
Toddville--have a sand content of more than 70 percent in the lower third of the series control section
Wakenda--are in areas that have a mean annual air temperature range of 11 to 14 degrees C
Waupecan--have an average rock fragment content of more than 15 percent in the lower part of the series control section

GEOGRAPHIC SETTING:
Parent material--loess
Landform--interfluves and side slopes on uplands and on treads and risers on stream terraces
Slope--0 to 20 percent
Elevation--210 to 430 meters above sea level
Mean annual air temperature--6 to 12 degrees C
Mean annual precipitation--735 to 1,090 millimeters
Frost-free period--145 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dinsdale, Colo, Ely, Garwin, and Muscatine soils.
Dinsdale--are in landscape positions similar to those of the Tama soils and have a sand content of 35 to 50 percent in the lower third of the series control section
Colo--are at lower landscape positions in drainageways, have a mollic epipedon more than 91 centimeters thick, and are frequently saturated at the surface of the soil during the wettest periods of normal years
Ely--are at lower landscape positions on base slopes, have a mollic epipedon 61 to 91 centimeters (24 to 36 inches) thick, and have a frequently saturated zone at a depth of 0.3 meter during the wettest periods of normal years
Garwin--are at higher landscape positions on interfluves and at lower landscape positions on head slopes and are frequently saturated at the surface of the soil during the wettest period of normal years
Muscatine--are at higher landscape positions on interfluves and have a frequently saturated zone at a depth of 0.3 meter in normal years

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained--a frequently saturated zone does not occur within a depth of 1.8 meters during normal years
Saturated hydraulic conductivity--1.00 to 10.00 micrometers per second (moderately high)
Surface runoff potential--negligible to high

USE AND VEGETATION:
Nearly level to gently sloping areas are cultivated. The principal crops are corn, soybeans, small grains, and legume hays. Steeper slopes are pastured. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.

DISTRIBUTION AND EXTENT:
Physiographic Division--Interior Plains
Physiographic Province--Central Lowland
Physiographic sections--Eastern lake section, Wisconsin driftless section, Dissected till plains, Till plains
MLRAs--Southern Wisconsin and Northern Illinois Drift Plain (95B),
Eastern Iowa and Minnesota Till Prairies (104),
Northern Mississippi Valley Loess Hills (105), and
Illinois and Iowa Deep Loess and Drift (108)
LRR M; Iowa, Illinois, Minnesota and Wisconsin
Extent--large

MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota

SERIES ESTABLISHED: Black Hawk County, Iowa, 1917

REMARKS:
Particle size control section--the zone from a depth of 46 to 96 centimeters (Bt1 and Bt2 horizons);
series control section--the zone from the surface to a depth of 150 centimeters (Ap, A1, A2, BA, Bt1, Bt2, and BC horizons).

Diagnostic horizons and features recognized in this pedon include:
mollic epipedon--the zone from the surface to a depth of 46 centimeters (Ap, A1, A2, and BA horizons);
argillic horizon--the zone from a depth of 46 to 114 centimeters (Bt1 and Bt2 horizons);
udic moisture regime.

The thickness of the A horizon, depth to sub-horizon highest in clay, maximum percent clay, thickness of Bt horizon, depth to carbonates, and depth to redoximorphic features usually decrease as gradient increases on convex slopes.

Cation-exchange activity class is supported by lab data from National Soil Survey Laboratory, Lincoln, Nebraska.

Clay content in the particle-size control section and lower third of the series control section is based on analysis of laboratory data (NSSL).

Taxonomy version--Keys to Soil Taxonomy, tenth edition, 2006.

ADDITIONAL DATA:
Laboratory data--National Soil Survey Laboratory, Lincoln, Nebraska--many pedons (http://ssldata.sc.egov.usda.gov/).
Laboratory data--Iowa State University, Ames, IA--many pedons