LOCATION SAWMILL IL+IA MN
Established Series
Rev. SES-AAC-RLL
09/2016
SAWMILL SERIES
The Sawmill series consists of very deep, poorly drained and very poorly drained soils formed in alluvium on flood plains. Slope ranges from 0 to 3 percent. Mean annual precipitation is about 1016 mm (40 inches), and mean annual temperature is about 11.1 degrees C (52 degrees F).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Endoaquolls
TYPICAL PEDON: Sawmill silty clay loam - on a nearly level flood plain subject to frequently flooding in a cultivated field at an elevation of about 163 meters (535 feet) above mean sea level. (Colors are for moist soil unless otherwise stated. When described the soil was wet below 117 cm (46 inches).
Ap--0 to 25 cm (0 to 10 inches); very dark gray (10YR 3/1) and very dark grayish brown (10YR 3/2) silty clay loam, gray (10YR 5/1) dry; weak fine subangular blocky structure; firm; few fine roots; few subrounded pebbles 1 to 3 mm in diameter; slightly acid; clear smooth boundary.
A1--25 to 43 cm (10 to 17 inches); black (10YR 2/1) and very dark grayish brown (10YR 3/2) silty clay loam, dark gray (10YR 4/1) dry; moderate fine subangular blocky structure; firm; few fine roots; few subrounded pebbles 1 to 3 mm in diameter; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries lining root channels and pores; few fine prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral; clear smooth boundary.
A2--43 to 64 cm (17 to 25 inches); black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry; moderate fine and medium angular blocky structure; firm; few fine roots; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries on surfaces along root channels and pores; few fine prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral; clear smooth boundary.
AB--64 to 81 cm (25 to 32 inches); very dark gray (10YR 3/1) silty clay loam, gray (10YR 5/1) dry; weak medium prismatic structure parting to moderate fine subangular blocky; firm; few fine roots; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries on surfaces along root channels and pores; few fine prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; neutral; clear smooth boundary. [Combined thickness of the A horizon is 46 to 91 cm (18 to 36 inches).]
Bg--81 to 102 cm (32 to 40 inches); dark gray (10YR 4/1) silty clay loam; weak medium prismatic structure parting to moderate fine and medium angular blocky; firm; common faint very dark gray (10YR 3/1) organic coatings on faces of peds; few fine roots; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries on surfaces along root channels and pores; few fine prominent strong brown (7.5YR 5/6) masses of oxidized iron in the matrix; slightly alkaline; clear smooth boundary.
Btg1--102 to 124 cm (40 to 49 inches); grayish brown (10YR 5/2) silty clay loam; moderate medium prismatic structure parting to weak medium angular blocky; firm; common distinct dark gray (10YR 4/1) clay films on faces of peds; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries on surfaces along root channels and pores; few fine prominent strong brown (7.5YR 5/6) and common fine distinct yellowish brown (10YR 5/4) masses of oxidized iron in the matrix; slightly alkaline; clear smooth boundary.
Btg2--124 to 147 cm (49 to 58 inches); grayish brown (2.5Y 5/2) silty clay loam; moderate medium prismatic structure; firm; common distinct gray (10YR 5/1) clay films on faces of peds; few fine spherical black (7.5YR 2.5/1) weakly cemented iron-manganese concretions with diffuse boundaries on surfaces along pores; few fine prominent yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; slightly alkaline; clear smooth boundary. [Combined thickness of the Bg and/or Btg horizons is 20 to 91 cm (8 to 36 inches).]
Cg--147 to 165 cm (58 to 65 inches); grayish brown (2.5Y 5/2) silty clay loam; massive; firm; very dark gray (10YR 3/1) channel linings and fillings; many medium prominent yellowish brown (10YR 5/6) masses of oxidized iron on surfaces along pores; slightly alkaline.
TYPE LOCATION: Sangamon County, Illinois; about 2 miles southwest of Rochester on the flood plain of the South Fork of the Sangamon River; 750 feet east and 300 feet south of the northwest corner of sec. 20, T. 15 N., R. 4 W.; USGS New City topographic quadrangle; lat. 39 degrees 44 minutes 33.27 seconds N. and long. 89 degrees 34 minutes 16.07 seconds W., WGS84; UTM Zone 16, 279693 easting and 4402347 northing, WGS84.
RANGE IN CHARACTERISTICS:
Depth to the base of the cambic horizon: 91 to 152 cm (36 to 60 inches)
Thickness of the mollic epipedon: 61 to 91 cm (24 to 36 inches), and includes the upper part of the B horizon in some pedons.
Redoximorphic features: present throughout
Particle-size control section: averages between 27 and 35 percent clay
Moisture control section, in most years, is not dry for 30 cumulative days out of the 120 days following the summer solstice.
Ap, A, and AB horizons:
Hue: 10YR, 2.5Y, 5Y, or N (neutral)
Value: 2, 2.5, or 3
Chroma: 0 to 2
Texture: silty clay loam
Reaction: moderately acid to slightly alkaline
An overwash phase with a lighter colored silt loam surface layer less than 51 cm (20 inches) thick is recognized.
Bg and/or Btg horizons:
Hue: typically 10YR, 2.5Y, or 5Y, but in some pedons individual horizons have hue of 7.5YR
Value: 3 to 6
Chroma: 1 or 2
Texture: dominantly silty clay loam but the lower part in some pedons grades to clay loam or loam, and some pedons contain strata of silt loam or sandy loam.
Reaction: moderately acid to slightly alkaline
Cg horizon:
Hue: typically 10YR, 2.5Y, or 5Y
Value: 3 to 6
Chroma: 1 or 2
Texture: silty clay loam, clay loam, loam, silt loam, sandy loam, silty clay, or stratified with these textures
Rock fragment content: 0 to 5 percent fine gravel
Reaction: slightly acid to moderately alkaline
Some pedons contain carbonates within a depth of 122 cm (48 inches).
COMPETING SERIES: These are the
Afton,
Catherine,
Clementine,
Colo,
Humansville,
Otter,
Pastolla, and
Whitewood series. Afton soils are in upland drainageways at elevations higher than 305 meters (1000 feet), and are generally in cooler and wetter climates (see Remarks). Catherine, Clementine, and Whitewood soils are dry in the moisture control section for more than 30 cumulative days out of the 120 days following the summer solstice. Colo soils have mollic epipedons more than 36 inches (91 cm) in thickness. Humansville soils have mean annual soil temperature greater than 13 degrees C (55 degrees F). Otter soils average less than 27 percent clay in the particle-size control section. Pastolla soils are less acid in the A horizon and do not have a cambic horizon.
GEOGRAPHIC SETTING: The Sawmill soils are on flood plains and valley floors, and in some drainageways that extend into the uplands. Slope ranges from 0 to 3 percent. Sawmill soils formed in alluvial sediments from drift thought to be of Wisconsin Age. Mean annual air temperature ranges from 7.2 to 13.9 degrees C (45 to 57 degrees F). Mean annual precipitation ranges from 760 to 1140 mm (30 to 45 inches). Frost-free period is 140 to 190 days. Elevation is 104 to 305 meters (340 to 1,000 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Otter series and the
Beaucoup,
Lawson,
Tice,
Wabash, and
Zook series. All of these soils are in similar positions on the flood plain, but the somewhat poorly drained Lawson and Tice soils are on slightly higher positions or are closer to the stream channel. Beaucoup and Tice soils have mollic epipedons less than 61 cm (24 inches) thick. Wabash and Zook soils average more than 35 percent clay in the particle-size control section.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained and very poorly drained. Where drained, these soils have an apparent seasonal high water table 15 cm (0.5 foot) above the surface to 30 cm (1.0 foot) below the surface at some time between January and May in most years. In undrained conditions, the apparent seasonal high water table is 15 cm (0.5 foot) above the surface to 15 cm (0.5 foot) below the surface at some time between November and June in most years. The potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per second). Permeability is moderate. Flooding is rare to frequent for brief to long periods between November and June.
USE AND VEGETATION: Many areas of Sawmill soils are cultivated. Corn, soybeans, and meadow are the principal crops. Undrained areas are mostly used for pasture or woodland. Native vegetation is grasses and trees. See Additional Data section for native vegetative cover in Iowa and Minnesota.
DISTRIBUTION AND EXTENT: MLRAs 95B, 97, 98, 104, 105, 108A,108B, 108C, 110, 113, 114B, 115A, and 115C in Illinois, Iowa, and Minnesota. The type location is in MLRA 108B. The extent is large with more than 314,000 acres (127,074 hectares) correlated.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: DeWitt County, Illinois, 1937.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: from the surface to a depth of 81 cm (32 inches) (Ap, A1, A2, and AB horizons).
Cambic horizon: from 81 to 147 cm (32 to 58 inches) (Bg, Btg1, and Btg2 horizons).
Aquic conditions: chroma of 2 or less and redox concentrations in all layers below the Ap horizon; endosaturation.
Differentia from Afton series need further study and refinement.
ADDITIONAL DATA: In Iowa and Minnesota, the native vegetative cover is a herbaceous wetland community commonly inhabited with Bluejoint Grasses, Fowl Bluegrasses, Green Muhlies, Fox Sedges, Field Sedges, Dudleys Rushes, Torreys Rushes, Swamp Milkweeds, False Sneezeweeds, False Asters, New England Asters, White Panicled Asters, and Wild Mints. Source: Iowa State Office, Natural Resources Conservation Service, Des Moines, IA.
Pedon number for the typical pedon is 1995IL167001.
Data from the Kellogg Soil Survey Laboratory is available for additional pedons.
National Cooperative Soil Survey
U.S.A.