LOCATION HUNTSVILLE IL+IA IN MN MO WIEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Hapludolls
TYPICAL PEDON: Huntsville silt loam on a 2 percent slope in a cultivated field at an elevation of about 203 meters (667 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 25 cm (0 to 10 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine and medium subangular blocky structure; friable; slightly acid; clear smooth boundary.
A1--25 to 41 cm (10 to 16 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; few faint very dark gray (10YR 3/1) organic coatings on faces of peds; neutral; clear smooth boundary.
A2--41 to 69 cm (16 to 27 inches); dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; weak fine granular structure; friable; few faint very dark gray (10YR 3/1) organic coatings on faces of peds; neutral; clear smooth boundary. [Combined thickness of the A horizon is 61 to 137 cm (24 to 54 inches).]
AC--69 to 132 cm (27 to 52 inches); brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak medium subangular blocky structure; friable; few faint very dark grayish brown (10YR 3/2) organic coatings on faces of peds; neutral; clear smooth boundary. [0 to 64 cm (0 to 25 inches) thick]
C1--132 to 165 cm (52 to 65 inches); dark brown (10YR 3/3) silt loam; massive; friable; slightly acid, clear smooth boundary.
C2--165 to 203 cm (65 to 80 inches); grayish brown (10YR 5/2) silt loam; massive; friable; few fine distinct yellowish brown (10YR 5/4 and 10YR 5/6) and few coarse prominent yellowish red (5YR 5/6) masses of iron in the matrix; few fine prominent black (N2/) accumulations of iron and manganese oxides in the matrix; neutral.
TYPE LOCATION: Knox County, Illinois; about 5 miles east and 2 miles north of Victoria; 2,475 feet east and 495 feet south of northwest corner of section 1, T. 12 N., R. 4 E.; USGS
Lafayette quadrangle; lat. 41 degrees 3 minutes 38 seconds N. and long. 89 degrees 59 minutes 42 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon is 61 to 145 cm (24 to 57 inches). The depth to carbonates is greater than 152 cm (greater than 60 inches). The particle-size control section averages 18 to 27 percent clay and 0 to 15 percent sand. Rock fragment content ranges from 0 to 2 percent throughout the profile. Some pedons have thin strata of fine sand.
The Ap or A horizon has hue of 10YR, value of 2 or 3 moist or 4 or 5 dry, and chroma of 1 to 3 moist or dry. It is silt loam. It averages 18 to 27 percent clay and 0 to 15 percent sand.
Reaction ranges from moderately acid to slightly alkaline.
The AC horizon has hue of 10YR, value of 3 to 5, and chroma of 3 or 4. It is silt loam. It averages 18 to 27 percent clay and 0 to 15 percent sand. Reaction ranges from moderately
acid to slightly alkaline.
The C horizon has huse of 10YR, value of 3 to 5, and chroma of 3 or 4. It is silt loam, loam, sandy loam, or very fine sandy loam. It averages 10 to 25 percent clay and 15 to 60 percent
sand. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: These are the
Allison,
Anthon,
Ivan,
Judson,
Kahola,
Kennebec,
Kenridge,
Lindstrom,
Napier,
Rossville,
Sturkie, and
Worthen soils. Allison soil have a clay content of 27 to 35 percent in the particle-size control section and have
strata of silt loam, loam, clay loam, or sandy loam below a depth of 76 cm (30 inches). Anthon soils have a sand content of 55 to 85 percent in the lower third of the series control section. Ivan soils have carbonates within a depth of 25 cm (10 inches). Judson soils have a clay content of 30 to 35 percent in the particle-size control section. Kahola soils have carbonates within a depth of 38 to 102 cm (15 to 40 inches). Kennebec soils have a clay content of 18 to 30 percent in the particle-size control section and have a matrix chroma of 1 or 2 in the throughout the series control section. Kenridge soils have a matrix chroma of 2 immediately below the mollic epipedon and have a clay content of 30 to 35 percent in the particle-size
control section. Lindstrom soils have clay content of 18 to 24 percent in the particle-size control section, have a cambic horizon, and have a reaction class range of moderately acid to
neutral throughout the series control section. Napier soils have a cambic horizon and have a clay content of 20 to 27 percent throughout the series control section. Rossville soils have a cambic horizon, have a clay content of 18 to 35 percent in the particle-size control section, and are in areas that have a mean annual temperature range of 11 to 13 degrees C (52 to 55
degrees F). Sturkie soils have a cambic horizon and are in areas that have a mean annual precipitation range of 107 to 114 cm (42 to 45 inches) and have a mean annual temperature
range of 12 to 14 degrees C (53 degrees to 58 degrees F). Worthen soils have a cambic horizon and have a clay content of 18 to 24 percent in the particle-size control section.
GEOGRAPHIC SETTING: Huntsville soils are on floodplains. Slope ranges from 0 to 6 percent. These soils formed in alluvium. The mean annual temperature is 6 to 12 degrees C (42 to 54 degrees F), mean annual precipitation is 710 to 1020 mm (28 to 40 inches), elevation ranges from 122 to 415 meters (400 to 1,360 feet) above sea level, and frost-free period is
140 to 190 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Lawson,
Littleton,
Radford, and
Sawmill, soils. Lawson soils are at lower elevations on floodplains and have a frequently
saturated zone within depths of 0.3 to 1.1 meters (1 to 3.5 feet) in normal years. Littleton soils are at slightly higher elevations on alluvial fans in large floodplains and are at lower elevations on smaller floodplains, have a cambic horizon, and have a frequently saturated zone within depths of 0.3 to 1.1 meters (1 to 3.5 feet) in normal years. Radford soils are in landscape positions similar to those of the Huntsville soils, have mollic epipedons 25 to 51 cm (10 to 20 inches) thick, and have buried horizons within depths of 51 to 102 cm (20 to 40 inches). Sawmill soils are at lower elevations on floodplains, have a clay content of 27 to 35 percent in the particle-size control section and have a frequently saturated zone within a depth of 0.3 meter (1 foot) in normal years.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. A frequently saturated zone occurs within depths of 1.2 to 1.8 meters (4 to 6 feet) during April to June in normal years and is considered apparent. Saturated hydraulic conductivity is 1.41 to 14.11 micrometers per second (moderately slow or moderate permeability). The potential for surface runoff is negligible to medium, depending on slope. Flooding frequency is rare to frequent for very brief or brief periods during the months of February to November from precipitation events and snowmelt.
USE AND VEGETATION: Most areas of Huntsville soils on the wider flood plains are cultivated. The principal crops are corn and soybeans. Many areas on narrow flood plains are pastured or wooded. The native vegetation is big bluestem, little bluestem, switchgrass, and other grasses of the tall grass prairie.
DISTRIBUTION AND EXTENT: LRR K and M, MLRA?s 95B, 103, 104, 105, 108, 114, and 115. Illinois, central and
northeastern Iowa, southeastern Minnesota, southwestern Wisconsin, northeastern Missouri, and western Indiana. The series is of large extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Schuyler County, Illinois, 1930
REMARKS:
Diagnostic horizons and features recognized in this pedon:
mollic epipedon: from a depth of 0 to 69 cm (0 to 27 inches) (Ap, A1, and A2 horizons);
cumulic subgroup:mollic epipedon more than 60 cm (24 inches) thick and an irregular decrease of organic carbon;
Cation-exchange activity class is inferred from lab data from similar soils in the surrounding area. Taxonomy version--Keys to Soil Taxonomy, ninth edition, 2003.