LOCATION LYCURGUS IAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Argiudolls
TYPICAL PEDON: Lycurgus silt loam on a 17 percent east-facing sloping in a pasture. (Colors are for moist soil unless otherwise stated.)
A1--0 to 3 inches; very dark brown (10YR 2/2) silt loam (19% sand), dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure parting to weak fine granular; friable; many medium discontinuous tubular and many fine discontinuous tubular roots; few fine tubular pores; neutral; clear smooth boundary.
A2--3 to 7 inches; very dark brown (10YR 2/2) silt loam (20% sand), dark grayish brown (10YR 4/2) dry; weak fine subangular blocky structure parting to weak fine granular; friable; many medium discontinuous tubular roots; few fine tubular pores; neutral; clear smooth boundary.
A3--7 to 13 inches; dark brown (10YR 3/3) silt loam (19% sand); very dark grayish brown (10YR 3/2) and very dark brown (10YR 2/2) streaks and pockets; brown (10YR 5/3) dry; weak fine subangular blocky structure; friable; common very fine discontinuous tubular roots; few fine tubular pores; neutral; clear smooth boundary. (combined thickness of the A horizons is 10 to 20 inches)
BA--13 to 20 inches; brown (10YR 4/3) silt loam (18% sand); dark brown (10YR 3/3) and very dark grayish brown (10YR 3/2) streaks and pockets; weak fine and medium subangular blocky structure; friable; few very fine discontinuous tubular and few fine discontinuous tubular roots; few fine tubular pores; a few pebbles; neutral; gradual smooth boundary. (5 to 9 inches thick)
Bt1--20 to 30 inches; dark yellowish brown (10YR 4/4) silt loam (16% sand); weak medium subangular blocky structure; friable; few fine discontinuous tubular roots; few fine tubular pores; discontinuous faint very dark grayish brown (10YR 3/2) clay films on vertical and horizontal faces of peds; a few chert pebbles; a few sandstone fragments; neutral; gradual smooth boundary.
2Bt2--30 to 38 inches; yellowish brown (10YR 5/6) silty clay loam (6% sand); few fine faint grayish brown (10YR 5/2) mottles; weak medium prismatic structure parting to weak medium subangular blocky; friable; few fine discontinuous tubular roots; few fine tubular pores; patchy faint dark yellowish brown (10YR 4/4) clay films on faces of peds; neutral; gradual smooth boundary.
2Bt3--38 to 47 inches; yellowish brown (10YR 5/4) silty clay loam (6% sand); few fine faint grayish brown (10YR 5/2) mottles; weak coarse prismatic structure parting to weak medium subangular blocky; friable; few fine discontinuous tubular roots; few fine tubular pores; faint dark yellowish brown (10YR 4/4) clay films on faces of peds; slightly acid; gradual smooth boundary.
2Bt4--47 to 60 inches; yellowish brown (10YR 5/4) silt loam (7% sand); few fine faint grayish brown (10YR 5/2) mottles; weak coarse prismatic structure parting to weak medium subangular blocky; few fine discontinuous tubular roots; few fine tubular pores; discontinuous distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; slightly acid.
TYPE LOCATION: Allamakee County, Iowa; about 4 miles northeast of Waukon; 1,950 feet east and 2,050 feet north of the southwest corner of section 4, T. 98 N., R. 5 W.
RANGE IN CHARACTERISTICS: The thickness of the solum is typically more than 60 inches but ranges from 48 to more than 60 inches. The loamy sediment ranges from 20 to 48 inches and contains 10 to 40 percent sand, with the higher sand content in the upper part. The lower part contains less than 10 percent sand.
The A or Ap horizon has hue of 10YR, value of 2 or 3 moist and 4 or 5 dry, and chroma of 1 to 3. It typically is silt loam, but loam is within the range.
The Bt and 2Bt horizons have hue of 10YR, value of 4 or 5, and chroma of 3 to 6. It is silt loam or silty clay loam with the finest part of the Bt horizon averaging between 27 and 35 percent clay. A few fine faint mottles of either high or low chroma are present in the lower part.
The C horizon, when present, has hue of 10YR with value and chroma of 4 to 6.
COMPETING SERIES: These are the Ashdale, Assumption, Barrington, Broadwell, Catlin, Cotter, Dana, Dinsdale, Douglas, Elkhart, Elmont, Harrison, Healing, Keltner, Malcolm, Mendota, Ogle, Plano, Proctor, Reading, Richwood, Ripon, Saybrook, Sibley, Sidell, Tama, Toddville, Troxel, Waupecan, and Wiota series in the same family. Ashdale and Dodgeville soils have the lower part of the solum formed in residuum weathered from limestone and have limestone at depths of 3 to 5 feet. Assumption soils have a paleosol in glacial till within a depth of 40 inches. Barrington soils have carbonates at shallower depths. Broadwell soils have loamy sand or sand at depths of 40 to 60 inches. Catlin, Dana, Dinsdale, Mendota, Ogle, Saybrook, and Sidell soils have glacial till at a depth of less than 60 inches. Cotter, Reading, Sibley, and Troxel soils have a mollic epipedon thicker than 24 inches. Douglas soils have glacial till at depths of 3 1/2 to 7 feet. Elkhart soils have thinner sola and are shallower to carbonates. Elmont and Keltner soils have shale C horizons and thinner sola. Harrison soils have a thinner mollic epipedon, have a gray E horizon. Healing soils have lower clay content in the B horizon. Malcolm soils have a thinner solum and are in areas with less precipitation. Plano, Proctor, Richwood, and Toddville soils all have more sand in their lower sola. Ripon soils have limestone bedrock within 40 inches. Tama soils have less sand in the upper 2 to 4 feet of the soil. Waupecan soils have beta B horizons in sandy and gravelly outwash. Wiota soils have thicker mollic epipedons, less contrast between the A and B horizons in amount of clay and more variable coarse silt-fine silt ratios in the sola.
GEOGRAPHIC SETTING: The Lycurgus soils are on plane to concave footslopes on uplands below steep and very steep soils derived from colluvium or weathered sandstone. Slope gradient ranges from 9 to 25 percent. Lycurgus soils formed in 2 to 4 feet of loamy sediments over loess. The loamy sediment is derived from loess and sandy bedrock residuum. Mean annual temperature is about 45 to 50 degrees F, and mean annual precipitation ranges from 29 to 38 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arenzville, Boone, Chaseburg, Churchtown, Downs, Eitzen, Lacrescent, Tama, and Valton soils. The Arenzville, Chaseburg, and Eitzen soils are in narrow drainageways below the Lycurgus soils. The Downs, Tama, and Valton soils are on less-sloping ridgetops and side slopes below the Lycurgus soils. Boone and Lacrescent soils are on steeper side slopes above the Lycurgus soils. The Churchtown soils form a biosequence with the Lycurgus soils and are on similar landscape positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Surface runoff is medium to rapid.
USE AND VEGETATION: The less-sloping areas are commonly used to grow corn, small grain, and legume hay. The steeper slopes are used for pasture. Native vegetation was prairie grasses with scattered deciduous trees.
DISTRIBUTION AND EXTENT: Northeastern Iowa and possibly southeastern Minnesota, and southwestern Wisconsin. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES PROPOSED: Allamakee County, Iowa, 1989. The name is from a former town within the county.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - the zone from the surface of the soil to a depth of approximately 13 inches (A1, A2, and A3 horizons); Argillic horizon - the zone from approximately 13 to 64 inches (BA, Bt1, Bt2, Bt3, and Bt4 horizons). These soils have been mapped as Tama, valleys.
ADDITIONAL DATA: This soil was sampled by the National Soil Survey Laboratory in 1986, NSSL Pedon Number 87P0071.