LOCATION IUKA AL+AR FL GA KY LA MS NC OK TN TX VAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, siliceous, active, acid, thermic Aquic Udifluvents
TYPICAL PEDON: Iuka fine sandy loam, on a smooth concave 0.5
percent slope, in field.
(Colors are for moist soil.)
Ap--0 to 7 inches; brown (10YR 4/3) fine sandy loam; weak
medium granular structure; friable; fine pebbles of chert and quartzite, medium acid; abrupt smooth boundary. (0 to 8 inches thick)
A1--7 to 13 inches; brown (10YR 5/3) fine sandy loam; single grained; friable; very strongly acid; gradual wavy boundary. (5
to 8 inches thick)
C--13 to 22 inches; light yellowish brown (10YR 6/4) fine
sandy loam and few thin strata of loamy sand; common medium
distinct strong brown (7.5YR 5/6) and grayish brown (10YR 5/2) mottles; massive; friable; very strongly acid; gradual wavy
boundary. (8 to 20 inches thick)
Cg--22 to 60 inches; coarsely mottled gray (10YR 6/1) and yellowish brown (10YR 5/4) sandy loam and lenses of loamy fine
sand and loam; massive; friable, few soft dark colored bodies in lower part; very strongly acid.
TYPE LOCATION: Franklin County, Alabama; 2.1 miles northwest of
New Union Church and 300 feet south and 100 feet west of stream crossing at Brush Creek. NW1/4NW1/4 sec. 15, T. 7 S., R. 15 W.
RANGE IN CHARACTERISTICS: The soil is strongly acid or very
strongly acid except for surface layers that are limed. Thin
bedding planes of contrasting textures are common in most pedons.
The A horizon has hue of 10YR or 7.5YR, value of 4 through 7, and chroma 2 to 4. Texture is fine sandy loam, sandy loam, loamy
sand, silt loam, or loam.
The C horizon has hue of 10YR, 7.5YR, or 2.5Y, value of 4 through
6, and chroma of 3 through 6 or it may have hue of 10YR or 7.5YR, value of 4, and chroma of 2. Mottles with chroma of 2 or less
are within 20 inches of the surface. It is sandy loam, fine
sandy loam, loam, or silt loam.
The Cg horizon may lack a matrix color and be mottled with shades
of gray, brown, red, or it may be dominantly gray with many
brown, red, and yellow mottles. It is sandy loam, fine sandy
loam, loam, silt loam, or loamy sand.
Clay content of the 10- to 40-inch control section is 10 to 18 percent. Some pedons have thin gravelly or sandy strata and some pedons have textures of sandy clay loam or clay loam at depths
below 40 inches. A few flakes of mica and soft dark colored
bodies or fine black and brown concretions are allowed in the C horizons. Some pedons have buried A horizons at depths below 20 inches.
COMPETING SERIES: These are
Adler,
Bibb,
Buncombe,
Cartecay,
Chewacla,
Collins,
Congaree,
Kirkville,
Mantachie,
Neubert,
Ochlockonee, and
Toccoa series. Adler and Collins soils are silty and have mixed mineralogy. Adler soils, in addition, are nonacid. Bibb soils are dominantly gray, and the upper 12 inches are seasonally saturated with water. Buncombe soils are sandy and are high in mica. Cartecay soils have mixed mineralogy and contain common to many flakes of mica. Chewacla soils have mixed
mineralogy, the 10- to 40-inch control section contains more than
18 percent clay, and below the A horizon there is evident soil structure. Congaree soils have mixed mineralogy, and lack mottles
of 2 or lower chroma within 20 inches of the surface. Kirkville soils lack the thin stratification in the upper 20 inches of the soil. Mantachie soils are dominantly gray within 20 inches of the surface. Neubert soils have more than 18 percent clay in the 10-
to 40-inch control section. Ochlockonee soils lack mottles of 2
or lower chroma within 20 inches of the surface. Toccoa soils
lack mottles of chroma 2 or less within 20 inches of the surface, have mixed mineralogy, are nonacid, and contain common flakes of mica.
GEOGRAPHIC SETTING: Iuka soils are on nearly level flood plains draining sandy areas. Slopes range from 0 to 2 percent. Soil
formed in sandy or loamy alluvium commonly 6 or more feet thick.
The climate is warm and humid. Near the type location the average daily temperature for January is 42 degrees F., the average daily temperature for July is 79 degrees F., the mean annual temperature
is about 61 degrees F., and the mean annual precipitation is about
54 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Bibb,
Kirkville,
Mantachie, and
Ochlockonee series and the
Cahaba and
Kalmia series. Cahaba and Kalmia soils have argillic horizons
that contain 18 to 35 percent clay in the upper 20 inches and lack mottles of low chroma within 20 inches of the surface.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability. Iuka soils are rarely to commonly
flooded. A water table is at depths of 12 or more inches, and
the soil is commonly saturated with water between 12 and 40
inches during some season of most years.
USE AND VEGETATION: Much of the soil has been cleared and cultivated. It is cropped to corn, soybeans, small grains, truck crops, and hay or is in pasture. Native vegetation is forest of water oak, willow, beech, sweetgum, hickory, maple, ironwood,
eastern cottonwood, alder, white oak, and in some places, pine.
DISTRIBUTION AND EXTENT: Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, and possibly Kentucky and Virginia. The series
is of large extent.
MLRA OFFICE RESPONSIBLE: Auburn, Alabama
SERIES ESTABLISHED: Tishomingo County, Mississippi; 1938.