LOCATION ISABELLA                MI

Established Series
Rev. NWS-WEF-MLK
08/2012

ISABELLA SERIES

The Isabella series consists of very deep, well drained soils or moderately well drained soils formed in till on till plains and moraines. Slope ranges from 0 to 55 percent. Mean annual precipitation is about 762 mm (30 inches), and mean annual temperature is about 6.7 degrees C (44 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, active, frigid Alfic Haplorthods

TYPICAL PEDON: Isabella loam, on a 4 percent slope in a wooded area on a moraine. (Colors are for moist soil unless otherwise stated).

Oe--0 to 5 cm (2 inches); black (7.5YR 2.5/1) partially decomposed forest litter; weak fine granular structure; very friable; abrupt smooth boundary. [0 to 8 cm (3 inches) thick]

AE--5 to 8 cm (2 to 3 inches); brown (7.5YR 4/2) loamy sand; weak fine granular structure; very friable; many fine and medium roots; 3 percent gravel; very strongly acid; abrupt smooth boundary. [0 to 10 cm (4 inches) thick]

E--8 to 13 cm (3 to 5 inches); pinkish gray (7.5YR 6/2) loamy sand; weak fine subangular blocky structure; very friable; many fine and medium roots; 7 percent gravel; very strongly acid; wavy broken boundary. [0 to 15 cm (6 inches) thick]

Bs--13 to 36 cm (5 to 14 inches); dark yellowish brown (10YR 4/4) sandy loam; weak fine subangular blocky structure; very friable; many fine to coarse roots; 6 percent gravel; strongly acid; clear wavy boundary. [0 to 23 cm (9 inches) thick]

E'--36 to 46 cm (14 to 18 inches); brown (10YR 5/3) sandy loam, light gray (10YR 7/2) dry; weak medium subangular blocky structure parting to weak thin platy; firm; many medium and coarse roots; 9 percent gravel; brittle when dry; moderately acid; gradual irregular boundary. [8 to 18 cm (3 to 7 inches) thick]

E/B--46 to 66 cm (18 to 26 inches); brown (10YR 5/3) sandy loam (E) which surround peds of brown (7.5YR 4/4) sandy clay loam (Bt); weak medium subangular blocky structure; firm with some pockets of friable E material; few fine roots; 3 percent gravel; moderately acid; gradual irregular boundary. [5 to 25 cm (2 to 10 inches) thick]

Bt--66 to 89 cm (26 to 35 inches); brown (7.5YR 4/4) sandy clay loam; moderate medium angular blocky structure parting to moderate fine subangular blocky; firm; few fine roots between ped cleavage planes; many faint strong brown (7.5YR 5/6) clay films on faces of peds; 8 percent gravel; moderately acid; clear wavy boundary. [15 to 64 cm (6 to 25 inches) thick]

C--89 to 152 cm (35 to 60 inches); brown (10YR 4/3) fine sandy loam; weak fine subangular blocky fragments; friable; few fine roots between ped cleavage planes; 12 percent gravel; slightly effervescent; moderately alkaline.

TYPE LOCATION: Ogemaw County, Michigan; about 4 miles north-northeast of West Branch; 530 feet east and 1320 feet north of the southwest corner of sec. 33, T. 23 N., R. 2 E.

RANGE IN CHARACTERISTICS:
Thickness of the solum: typically 91 to 122 cm (36 to 48 inches), but ranges from 76 to 152 cm (30 to 60 inches)
Reaction: strongly acid to slightly acid in the upper part of the solum and moderately acid to neutral in the lower part
Rock fragment content: 0 to 6 percent gravel and cobbles throughout

A, AE, or Ap horizon:
Hue: 7.5YR or 10YR
Value: 2 to 4
Chroma: 1 or 2
Texture: loam, fine sandy loam, sandy loam, or loamy sand; where severely eroded, it is loam or sandy clay loam

E horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6
Chroma: 2 or 3
Texture: loam, fine sandy loam, sandy loam, or loamy sand

Bs horizon:
Hue: 5YR to 10YR
Value: 4 or 5
Chroma: 3 to 6
Texture: loam, fine sandy loam, or sandy loam

Some severely eroded pedons do not have Bs horizons.

E' horizon and E part of the E/B horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7
Chroma: 2 to 4
Texture: sandy loam, fine sandy loam, or loam
Consistence: firm and brittle when dry; brittle material comprises less than 40 percent of the horizon

Bt part of the E/B horizon and the Bt horizon:
Hue: 5YR to 10YR
Value: 3 or 4
Chroma: 3 or 4
Texture: sandy clay loam, loam, or clay loam

C horizon:
Hue: 5YR to 10YR
Value: 4 to 7
Chroma: 2 to 4
Texture: sandy clay loam, clay loam, loam, or fine sandy loam

COMPETING SERIES: This is the Bohemian series. Bohemian soils are stratified in the lower part of the series control section.

GEOGRAPHIC SETTING: Isabella soils are on till plains and moraines. Slope ranges from 0 to 55 percent. These soils formed in till. Mean annual precipitation ranges from 660 to 813 mm (26 to 32 inches). Mean annual temperature ranges from 5.6 to 8.3 degrees C (42 to 47 degrees F). Mean summer temperature ranges from 18.3 to 20.0 degrees C (65 to 68 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the McBride, Montcalm, and Twining soils. McBride and Montcalm soils are coarse-loamy. Twining soils are somewhat poorly drained soils in depressions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained or moderately well drained. Potential for surface runoff is negligible to high depending upon slope. Saturated hydraulic conductivity is moderately high. Permeability is moderate.

USE AND VEGETATION: A large part of the gently sloping areas are cropped to corn, small grains, beans, and legume-grass hay. Steeper areas are in permanent pasture or forest. Native vegetation is northern hardwood forests of sugar maple, American beech, and American basswood.

DISTRIBUTION AND EXTENT: MLRAs 94A and 98 in the northern part of Lower Michigan. The series is of moderate extent.

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

SERIES ESTABLISHED: Isabella County, Michigan, 1923.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from the surface to a depth of 8 cm (3 inches) Oe, AE horizons).
Albic horizon: zone from a depth of 8 to 13 cm (3 to 5 inches) and from 36 to 46 cm (14 to 18 inches) (E and E' horizons).
Spodic horizon: from a depth of 5 to 14 cm (5 to 14 inches) (Bs horizon).
Argillic horizon: from a depth of 66 to 89 cm (26 to 35 inches) (Bt horizon).
Alfic feature: depth to the argillic horizon is 66 cm (26 inches).

Although pedon fails the chemical criteria for a spodic horizon, the pedon is being classified as Alfic Haplorthods based on morphology.

ADDITIONAL DATA: For laboratory data supporting classification refer to S85MI-129-5 (S85 CFFC 129-5), Michigan Technological University, Ford Forestry Center, L'Anse, Michigan.

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National Cooperative Soil Survey
U.S.A.