LOCATION TONKEY                  MI+WI

Established Series
Rev. RWJ-WEF-CLL
08/2012

TONKEY SERIES

The Tonkey series consists of very deep, poorly drained and very poorly drained soils formed in stratified loamy and sandy glaciofluvial deposits on lake plains, outwash plains, or glacial drainageways. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 737 mm (29 inches), and mean annual temperature is about 7.2 degrees C (45 degrees F).

TAXONOMIC CLASS: Coarse-loamy, mixed, semiactive, nonacid, frigid Mollic Endoaquepts

TYPICAL PEDON: Tonkey sandy loam, on a south-facing, 1 percent slope in a cultivated field. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 cm (8 inches); black (10YR 2/1) sandy loam; weak fine granular structure; very friable; neutral; abrupt smooth boundary. [18 to 25 cm (7 to 10 inches) thick]

Bg1--20 to 36 cm (8 to 14 inches); dark grayish brown (10YR 4/2) sandy loam; weak fine granular structure; very friable; few medium prominent strong brown (7.5YR 5/6) masses of oxidized iron; neutral; clear wavy boundary.

Bg2--36 to 71 cm (14 to 28 inches); light brownish gray (10YR 6/2) loam; weak medium subangular blocky structure; friable; common medium prominent strong brown (7.5YR 5/6) and common medium prominent brownish yellow (10YR 6/8) masses of oxidized iron; slightly alkaline; clear wavy boundary. [Combined thickness of the Bg horizon is 25 to 76 cm (10 to 30 inches).]

2Cg--71 to 152 cm (28 to 60 inches); gray (10YR 5/1) stratified sand and thin layers and lenses of gravel, silt, sandy loam, and loam; single grain in sand and gravel layers, massive in silt, sandy loam, and loam layers; very friable; slightly effervescent; moderately alkaline.

TYPE LOCATION: Arenac County, Michigan; 1860 feet west and 400 feet south of the northeast corner of sec. 7, T. 20 N., R. 5 E.

RANGE IN CHARACTERISTICS:
Thickness of the solum: 46 to 91 cm (18 to 36 inches)
Depth to carbonates: 51 to 76 cm (20 to 30 inches)
Particle-size control section: averages 5 to 18 percent clay

A or Ap horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 1 or 2
Texture: sandy loam, fine sandy loam, loamy sand, loamy fine sand, loam, or silt loam, or the mucky analogues of these textures
Reaction: moderately acid to slightly alkaline

Bg horizon:
Hue: 7.5YR to 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: loam, sandy clay loam, sandy loam, very fine sandy loam, or silt loam and are commonly stratified; thin strata of sand or loamy sand are in some pedons
Rock fragment content: 0 to 7 percent
Reaction: moderately acid to slightly alkaline ranging to moderately alkaline in the lower part

C or 2C horizon:
Hue: 7.5YR to 5Y
Value: 4 to 6
Chroma: 1 to 4
Texture: stratified sand to silt loam; thickness and sequence of layers is quite variable in short horizontal distances
Rock fragment content: 0 to 7 percent

COMPETING SERIES: This is the Breckenridge series. Breckenridge soils do not have stratified textures in the lower part of the series control section.

GEOGRAPHIC SETTING: Tonkey soils are on lake plains, outwash plains, and glacial drainageways. Slope ranges from 0 to 2 percent. These soils formed in stratified loamy or sandy glaciofluvial deposits. Mean annual precipitation ranges from 711 to 762 mm (28 to 30 inches). Mean annual temperature ranges from 5.6 to 8.3 degrees C (42 to 47 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: The well drained Alcona soils and the somewhat poorly drained Richter soils are in a drainage sequence with Tonkey soils and are common associates. The coarser textured Deford and Wainola soils and the finer textured Brimley soils are close associates on lake plains. Epoufette and Gladwin soils are associated in glacial drainageways.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained or very poorly drained. Depth to the top of a seasonal high water table ranges from 30 cm (1 foot) above the surface to 30 cm (1 foot) below the surface between November and May in normal years. Potential for surface runoff is negligible. Saturated hydraulic conductivity is moderately high. Permeability is moderate.

USE AND VEGETATION: Only a small part is used for cropland. Corn, small grain and hay are principal crops. A considerable part is in permanent pasture and the remainder is in woods of American elm, black ash, quaking aspen, American basswood, red maple, northern white cedar, alder and willow.

DISTRIBUTION AND EXTENT: MLRAs 90A, 91B, 93B, 94A, 94B, 96, 98, and 99 in the northern part of the Lower Peninsula and the Upper Peninsula of Michigan and northern Wisconsin. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AMHERST, MASSACHUSETTS

SERIES ESTABLISHED: Sanilac County, Michigan, 1955.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from the surface to a depth of 20 cm (8 inches) (Ap horizon).
Cambic horizon: from a depth of 20 to 71 cm (8 to 28 inches) (Bg1 and Bg2 horizons).
Aquic conditions: reduced matrix colors and/or redox concentrations in all horizons below the ochric epipedon.

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National Cooperative Soil Survey
U.S.A.