LOCATION MACOMB                  MI+NY

Established Series
Rev. NWS-WEF
11/2021

MACOMB SERIES

The Macomb series consists of very deep, somewhat poorly drained soils formed in outwash and the underlying till on lake plains and till plains. Slope ranges from 0 to 2 percent. Mean annual precipitation is about 813 mm (32 inches), and the mean annual temperature is about 9.4 degrees C (49 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, semiactive, mesic Aquollic Hapludalfs

TYPICAL PEDON: Macomb loam, cultivated. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 cm (8 inches); very dark grayish brown (10YR 3/2) loam, grayish brown (10YR 5/2) dry; moderate fine granular structure; friable; many fine roots; 3 percent gravel; slightly acid; abrupt smooth boundary. [15 to 20 cm (6 to 8 inches) thick]

E--20 to 28 cm (8 to 11 inches); pale brown (10YR 6/3) loam; weak medium subangular blocky structure; friable; common fine roots; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; 3 percent gravel; slightly acid; clear wavy boundary. [0 to 15 cm (6 inches) thick]

Bt1--28 to 48 cm (11 to 19 inches); brown (10YR 5/3) clay loam; moderate medium subangular blocky structure; firm; common fine roots; continuous brown (10YR 5/3) clay films on faces of peds and in pores; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron; less than 5 percent gravel; neutral; gradual wavy boundary. [10 to 23 cm (4 to 9 inches) thick]

Bt2--48 to 74 cm (19 to 29 inches); pale brown (10YR 6/3) clay loam; moderate coarse subangular blocky structure; firm; few fine roots; continuous grayish brown (10YR 5/2) clay films on faces of peds and in pores; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron and prominent gray (5Y 6/1) iron depletions; 5 percent gravel; neutral; abrupt irregular boundary. [20 to 51 cm (8 to 20 inches) thick]

2C1--74 to 84 cm (29 to 33 inches); pale brown (10YR 6/3) very gravelly sand; single grain; loose; common medium distinct yellowish brown (10YR 5/6) masses of oxidized iron and prominent gray (5Y 6/1) iron depletions; 40 percent gravel; slightly effervescent; slightly alkaline; abrupt wavy boundary.

3C2--84 to 152 cm (33 to 60 inches); brown (10YR 5/3) clay loam; massive; firm; common medium prominent gray (5Y 6/1) iron depletions; 5 percent gravel; slightly effervescent; slightly alkaline.

TYPE LOCATION: Washtenaw County, Michigan; about 1 1/2 miles north and 1/2 mile east of Delhi Mills; 660 feet south and 430 feet west of the northeast corner of the southeast 1/4 of sec. 35, T. 1 S., R. 5 E.

RANGE IN CHARACTERISTICS:
Thickness of the solum: 51 to 102 cm (20 to 40 inches)
Depth to carbonates: 51 to 102 cm (20 to 40 inches)

Ap horizon:
Hue: 10YR
Value: 2, 2.5, or 3
Chroma: 1 or 2
Texture: loam, fine sandy loam, or sandy loam
Rock fragment content: 0 to 20 percent
Reaction: moderately acid to neutral

E horizon, where present:
Hue: 10YR
Value: 5 or 6
Chroma: 2 or 3
Texture: loam, fine sandy loam, or sandy loam
Rock fragment content: 0 to 20 percent
Reaction: moderately acid to neutral

Bt1 horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5
Chroma: 3 to 6
Texture: clay loam, loam, or sandy clay loam
Rock fragment content: 0 to 20 percent
Reaction: moderately acid to neutral

Bt2 horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6
Chroma: 3 or 4
Texture: clay loam, gravelly clay loam, sandy clay loam, gravelly sandy clay loam, or loam
Rock fragment content: 0 to 20 percent
Reaction: moderately acid to neutral

2C horizon:
Hue: 10YR
Value: 6
Chroma: 3 or 4
Texture: gravelly sand, gravelly loamy sand, or gravelly sandy loam
Rock fragment content: 20 to 60 percent
Reaction: slightly alkaline

3C horizon:
Hue: 10YR
Value: 5
Chroma: 4 to 6
Texture: clay loam, loam, or silty clay loam
Rock fragment content: 1 to 10 percent
Reaction: slightly alkaline

COMPETING SERIES: This is the Locke series. Locke soils have less than 20 percent rock fragments in the lower part of the series control section.

GEOGRAPHIC SETTING: Macomb soils are on till plains and lake plains that have a thin covering of gravelly outwash. Slope ranges from 0 to 6 percent, but typically are 0 to 2 percent. The Macomb soils formed in outwash and the underlying till. Mean annual precipitation ranges from 737 to 940 mm (29 to 37 inches). Mean annual temperature ranges from 7.2 to 10.0 degrees C (45 to 50 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Berville, Blount, Cadmus, Conover, Ionia, Kendallville, and Matherton soils. The Macomb soils are in a drainage sequence with the well drained Kendallville soils, the moderately well drained Cadmus soils, and the very poorly drained Berville soils. The finer textured Blount soils and the Conover soils, which do not have gravelly 2C horizons, are associated on till plains. The moderately well drained Ionia soils and somewhat poorly drained Matherton soils, which are fine loamy over sandy or sandy-skeletal, are associated where till plains join outwash plains.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. Potential for surface runoff is very low to medium. Saturated hydraulic conductivity is moderately high. Permeability is moderately slow.

USE AND VEGETATION: Most areas are cultivated. Corn, soybeans, small grains, and legume-grass hay are the principal crops. Some areas are used for permanent pasture or forest. Native vegetation is hardwoods; principally American elm, white ash, American basswood, red maple, hickory, and swamp white oak.

DISTRIBUTION AND EXTENT: MLRAs 98 and 111B in southern Michigan. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AMHERST, MASSACHUSETTS

SERIES ESTABLISHED: Tuscola County, Michigan, 1926.

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).
Albic horizon: from a depth of 20 to 28 cm (8 to 11 inches) (E horizon).
Argillic horizon: from a depth of 28 to 74 cm (11 to 29 inches) (Bt1 and Bt2 horizons).

---

National Cooperative Soil Survey
U.S.A.