LOCATION NAHMA              MI+WI

NAHMA SERIES

The Nahma series consists of moderately deep, poorly drained soils formed in loamy deposits overlying limestone, dolomitic sandstone, or dolomite bedrock. These soils are in depressional ground moraines and bedrock benches. Permeability is moderate. Slopes range from 0 to 2 percent. Mean annual precipitation is about 30 inches, and mean annual temperature in about 43 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, active, nonacid, frigid Histic Humaquepts

TYPICAL PEDON: Nahma mucky loam - on a 1 percent slope in a forested area. (colors are for moist soil unless
otherwise stated.)

Oa--0 to 4 inches; black (5YR 2/1) muck; weak medium granular structure; very friable; neutral; clear smooth boundary. (4 to 16 inches thick)

A--4 to 9 inches; black (10YR 2/1) mucky loam; moderate medium granular structure; friable; neutral; clear smooth
boundary. (0 to 6 inches thick)

Bg--9 to 13 inches; gray (10YR 5/1) loam; common medium faint mottles of dark gray (10YR 4/1), and few fine distinct mottles of olive brown (2.5YR 4/4); weak medium subangular blocky stucture; friable; neutral; clear smooth boundary. (3 to 6 inches thick)

Bw--13 to 19 inches; brown (7.5YR 5/4) fine sandy loam; few medium faint mottles of brown (10YR 5/3); weak
medium platy structure; friable; neutral; abrupt smooth boundary. (4 to 14 inches thick)

C--19 to 29 inches; pale brown (10YR 6/3) loam; common medium distinct mottles of yellowish brown (10YR 5/6 and 5/8) and white (10YR 8/2); massive; friable; strong effervescence; moderately alkaline; clear wavy boundary. (6 to 20 inches thick)

Cg--29 to 33 inches; light greenish gray (5G 7/1) loam mixed with weathered bedrock fragments; common fine prominent mottles of light olive brown (2.5Y 5/6); massive; friable; strong effervescence; moderately alkaline; abrupt smooth boundary. (0 to 6 inches thick)

R--33 inches; limestone bedrock.

TYPE LOCATION: Delta County, Michigan; about 4 miles south of Ensign, 100 feet south of the northwest corner of sec. 26, T. 40 N., R. 21 W.

RANGE IN CHARACTERISTICS: The depth to limestone bedrock ranges from 20 to 40 inches. The texture of the
solum and C horizons is commonly loam but the range includes sandy loam, fine sandy loam, or their gravelly analogues. Loamy sand lenses are in some pedons. Soil contains from 2 to 20 percent by volume of limestone flags and stones and from 0 to 15 percent gravel. The solum ranges from slightly acid to mildly alkaline with the depth to free carbonates ranging from about 11 to 20 inches.

The Oa horizon is highly decomposed and in some pedons contains as much as 50 percent mineral material. It is black, with a hue of 10YR, 7.2YR, 5YR, or is neutral.

The A horizon has a hue of 10YR, 7.5YR, or 5YR; value of 2; and chroma of 0 to 2. It is loam, sandy loam, fine sandy loam, or their mucky analogues.

The Bg horizon has a hue of 10YR, 2.5Y, or 5Y; value of 4 to 6; and chroma of 1 or 2.

The Bw horizon has a hue of 5YR, 7.5YR, or 10YR; value of 4 to 6; and chroma of 3 or 4. Some pedons have BC
horizons.

The C horizon has a hue of 5YR, 7.5YR, 10YR, 2.5Y, 5Y, or 5G; value of 5 to 7; and chroma of 1 to 6. Faint, distinct or prominent mottling of olive brown, brown, or yellowish brown is in the B and C horizons.

COMPETING SERIES: This is the Peacham, Sago, Waucedah, and Witbeck series in the same family and Angelica,
Burt, Ensley, Ruse, Sundell, and Thomas series. Peacham, Sago, Angelica, Ensley, Thomas, Waucedah, and Witbeck soils lack bedrock at depths within 40 inches. Burt soils are underlain by sandstone bedrock at depths of less than 20 inches and have more acid sola. Ruse soils are underlain by limestone bedrock at depths between 10 and 20 inches. Sundell soils do not have a histic epipedon, have albic horizons and a mottled spodic horizon.

GEOGRAPHIC SETTING: Nahma soils occupy level to nearly level depressional areas on ground moraines and
bedrock benches. Slopes range from 0 to 2 percent. Mean annual precipitation ranges from 26 to 33 inches, and the
mean annual air temperature ranges from 41 to 44 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: The competing Angelica and Ruse soils are poorly drained mineral
associates. The Cathro and Chippeny soils are the commonly associated organic soils. The well drained Cunard and
Longrie soils and the somewhat poorly drained Sundell soils form a drainage sequence with Nahma soils. The deep well drained Onaway and shallow Summerville soils are better drained.

DRAINAGE AND PERMEABILITY: Nahma soils are poorly drained. The potential surface runoff is very low or negligible. Permeability above the bedrock is moderate.

USE AND VEGETATION: Used mainly for forest with black ash, balsam fir, white birch, and northern white-cedar
being the common tree species. A few areas are used for pasture.

DISTRIBUTION AND EXTENT: Southern and eastern upper peninsula, northern lower peninsula of Michigan, and
probably northern Wisconsin. The series is of moderate extent with about 18,000 acres correlated.

MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Delta County, Michigan, 1969.

REMARKS: Diagnostic horizons and features recognized in this pedon are: histic epipedon - the zone from the surface to 9 inches (Oa and A horizons); cambic horizon - the zone from 9 to 13 inches (Bg and Bw horizons); aquic moisture regime; lithic contact of limestone bedrock at 33 inches.