LOCATION LISCOMB IAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Hapludolls
TYPICAL PEDON: Liscomb loam - on an 11 percent convex northeast-facing sideslope in permanent pasture. (Colors are for moist soil unless otherwise stated. When described, the soil was moist throughout.)
A1--0 to 5 inches; very dark brown (10YR 2/2) loam, dark grayish brown (10YR 4/2) dry; weak very fine subangular blocky structure parting to weak very fine granular; friable; few fibrous roots; few worm channels; neutral; gradual smooth boundary.
A2--5 to 12 inches; very dark grayish brown (10YR 3/2) loam, grayish brown (10YR 5/2) dry; weak very fine subangular blocky structure parting to weak very fine granular; friable; few fibrous roots; few worm channels; neutral; clear smooth boundary. (Combined thickness of A horizons is 10 to 16 inches.)
Bw1--12 to 16 inches; dark brown (l0YR 3/3) loam, brown (l0YR 5/3) dry, very dark grayish brown (l0YR 3/2) coatings on faces of peds; weak very fine and fine subangular blocky structure; friable; few fibrous roots; few worm channels; medium acid; clear smooth boundary.
Bw2--16 to 29 inches; dark yellowish brown (10YR 4/4) loam, brown (10YR 4/3) coatings on faces of peds; weak very fine and fine subangular blocky structure; friable; few fibrous roots; few worm channels; slightly acid; gradual smooth boundary.
Bw3--29 to 35 inches; dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4) loam; common medium faint yellowish brown (10YR 5/6) mottles; weak medium prismatic structure parting to weak medium subangular blocky; friable; few fibrous roots; few pebbles; slightly acid; clear smooth boundary. (Combined thickness of the Bw horizons is 20 to 26 inches.)
BC--35 to 42 inches; dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4) loam, common fine faint grayish brown (2.5Y 5/2) and few fine faint yellowish brown (10YR 5/6) mottles; weak medium prismatic structure parting to weak medium subangular blocky; friable; few pebbles; slightly acid; gradual wavy boundary. (0 to 8 inches thick)
C1--42 to 50 inches; dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4) loam; common fine faint grayish brown (2.5Y 5/2) and few fine faint yellowish brown (10YR 5/6) mottles; massive; some verticle cleavage; firm, few pebbles; few fine calcium carbonate accumulations; neutral; diffuse wavy boundary. (7 to 15 inches thick)
C2--50 to 60 inches; mottled dark yellowish brown (10YR 4/4) yellowish brown (10YR 5/6), and grayish brown (2.5Y 5/2) loam; massive; firm; few fine calcium carbonate accumulations; mildly alkaline.
TYPE LOCATION: Marshall County, Iowa; about 1/4 mile north of Liscomb; 920 feet west and 840 feet north of SE corner, sec. 1, T 85 N, R 19 W.
RANGE IN CHARACTERISTICS: Thickness of the solum typically is 30 to 50 inches and commonly corresponds to the depth to calcium carbonates. The most acid part of the solum, which typically is the upper part of the Bw horizon, is medium acid.
The A or Ap horizon ranges from black (10YR 2/1) to very dark grayish brown (10YR 3/2). The A horizons are typically loam with a sand content of 30 to 45 percent. In some pedons the A horizon is silt loam with 20 to 35 percent sand and 50 to 60 percent silt.
The Bw horizon is loam, sandy clay loam or clay loam, and typically averages less than 27 percent clay. Sand content is 40 to 55 percent. In some pedons the Bw horizon has thin sandy loam or loamy sand subhorizons. The upper part of the Bw horizon ranges from very dark grayish brown (10YR 3/2) to brown (10YR 4/3). The lower part has hue of 10YR, value of 4 or 5, and chroma of 3 through 6. Mottles in the lower part of the Bw horizon have hue of 2.5Y, 10YR, or 7.5YR; value of 5 or 6; and chroma of 2 through 8. The BC horizon is friable or firm.
The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 4 through 6; and chromas 1 through 8. The C horizon is loam or sandy clay loam and is slightly acid to mildly alkaline.
COMPETING SERIES: These are the Arbor, Aredale, Bode, Clarion, Everly, Farrar, Frontenac, Garmore, Kenyon, Moland, Ocheyedan, Ostrander, and Rossfield series in the same family. Arbor soils have thicker A horizons and a higher content of clay in the B horizon. Aredale soils lack coarse fragments above depths of 40 inches or more have thicker sola and are deeper to firm glacial till. Bode, Clarion and Everly soils typically are less acid in the Bw horizons. Also, Bode and Everly soils contain more clay in the upper part of the solum and Clarion soils lack prismatic structure or vertical cleavage in the BC and C horizons and are more friable in these horizons. Farrar soils have sandy loam textures in the A horizon and upper part of the B horizon. Frontenac soils are underlain by loamy-skeletal residuum or colluvium. Garmore soils have a thicker solum and are deeper to carbonates. Kenyon and Ostrander soils have a more acid B horizon and a well pronounced stone line that separates glacial till and overlying sediments. In addition, Ostrander soils are more stratified in the lower part of the B horizon and lack mottles with chroma of 2 or less within depths of 40 inches. Moland soils formed partly in loess and have friable C horizons. Ocheyedan soils contain more silt and are more stratified in the lower part of the B horizon and in the C horizon. Rossfield soils formed in loamy sediments overlying limestone.
GEOGRAPHIC SETTING: Liscomb soils are on upland convex side slopes. Slope gradients are commonly 9 to 14 percent and range from 5 to 18. These soils formed in friable glacial till or loamy surficial sediment overlying firm glacial till. The mean annual temperature ranges from 45 to 49 degrees F, and mean annual precipitation ranges from 26 to 34 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dinsdale and Tama soils. Dinsdale and Tama soils are upslope from Liscomb soils and on summits. In some areas, Dinsdale is in an intermingled pattern with Liscomb soils. Tama and Dinsdale soils formed entirely or partly in loess.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to rapid. Permeability is moderate.
USE AND VEGETATION: The moderately steep areas are used mainly for pasture. The less strongly sloping areas are largely cultivated. Corn and soybeans and small grains and meadow are the principal crops. Native vegetation was tall grass prairie.
DISTRIBUTION AND EXTENT: East-central Iowa. This series is of small extent.
MLRA OFFICE RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Marshall County, Iowa, 1978.
REMARKS: This soil occurs in the south border area of the Iowan erosion surface. The mottles in the lower part of the B horizon are considered to be relict and not indicative of present drainage.