LOCATION KNOWLES WIEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Hapludalfs
TYPICAL PEDON: Knowles silt loam - on a 4 percent slope in a cultivated field at an elevation of about 893 feet above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 8 inches; very dark grayish brown (10YR 3/2) silt loam, light brownish gray (10YR 6/2) dry; weak very fine granular structure; very friable; common fine roots; neutral; abrupt smooth boundary. (6 to 9 inches thick)
BE--8 to 12 inches; yellowish brown (10YR 5/4) silt loam; moderate very fine subangular b1ocky structure; friable; common fine roots; neutral; clear wavy boundary. (0 to 4 inches thick)
Bt1--12 to 23 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate very fine subangular blocky structure; firm; common fine roots; common faint clay films on faces of peds; moderately acid; clear wavy boundary.
Bt2--23 to 29 inches; brown (10YR 4/3) silty clay loam; moderate very fine angular blocky structure; firm; few fine roots; many faint clay films on faces of peds; moderately acid; clear wavy boundary. (Combined thickness of the Bt horizons ranges from 12 to 17 inches.)
2Bt3--29 to 35 inches; brown (10YR 4/3) clay loam, weak fine subangular blocky structure; firm; few fine roots; many faint clay films on faces of peds; about 4 percent gravel; slightly acid; clear wavy boundary. (2 to 6 inches thick)
2Bt4--35 to 39 inches; brown (7.5YR 4/4) sandy clay loam; weak medium subangular blocky structure; friable; few fine roots; many faint clay bridges between mineral grains; about 14 percent gravel slightly alkaline; abrupt wavy boundary. (0 to 4 inches thick)
3R--39 inches; dolomite bedrock.
TYPE LOCATION: Columbia County, Wisconsin; about 2 miles west of Columbus; 600 feet north and 270 feet west of the southeast corner of sec. 16, T. 10 N., R. 12 E. USGS Columbus Wisconsin topographic quadrangle; lat. 49 degrees 19 minutes 43 seconds N., and long. 89 degrees 04 minutes 08 seconds W., NAD 27.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon and to a lithic contact with dolomite bedrock ranges from 20 to 40 inches. Thickness of the loess mantle ranges from 18 to 36 inches. The particle-size control section averages between 25 and 35 percent clay. Rock fragments typically are absent in the loess. Volume of gravel ranges from 2 to 10 percent in the till. Volume of cobbles ranges from 0 to 2 percent in the till. Reaction naturally ranges from strongly acid to slightly acid in the loess but ranges to neutral in the upper part, where the soil is limed. Reaction ranges from slightly acid to moderately acid in the till.
The Ap horizon has hue of 10YR, value of 3 or 4, and chroma of 2 or 3. Where the moist value is 3, dry value is 6 or more. Uncultivated pedons have an A horizon with hue of 10YR, value of 2 or 3, and chroma of 1 to 3. Texture of the Ap or A is silt loam.
Some pedons have an E horizon with hue of 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is silt loam.
The BE horizon has hue of 7.5YR or 10YR; value of 4 or 5, and chroma of 3 or 4. Texture is silt loam.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5, and chroma of 3 or 4. Texture is silt loam or silty clay loam.
The 2Bt horizon has hue of 7.5YR or 10YR, value of 3 to 5, and chroma of 3 or 4. Texture is clay loam, sandy clay loam, or loam. Faint patchy or continuous clay films commonly of dark brown (7.5YR 3/2 & 3/3), are on most faces of peds in the Bt and 2Bt horizons.
The 3R horizon is dolomite bedrock.
COMPETING SERIES: These are the Bertrand, Camden, Dodge, Dubuque, Fayette, Flagg, Greenridge, Hackers, Jackson, Jemerson, La Farge, Lambeau, Lomira, Martinsburg, Menfro, Middletown, Navlys, Palermo, Palsgrove, Pepin, Piscasaw, Ridgway, Rozetta, Ruma, Rush, Russell, Seaton, St. Charles, Stookey, Sylvan, Thebes, and Yellowriver series. None of these soils, except Dubuque, have a lithic contact at depths of 20 to 40 inches. Dubuque soils have 40 to 55 percent clay in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: The Knowles soils typically are on ground moraines underlain by dolomite bedrock. Slope ranges from 0 to 30 percent. The soils formed in loess and in the loamy till underlain by dolomite bedrock. Mean annual precipitation ranges from 28 to 33 inches. Mean annual air temperature ranges from 45 to 49 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the LeRoy, Lomira, Ripon, and St. Charles soils. These soils, except Ripon, occupy areas next to bodies of Knowles where the depth to dolomitic limestone bedrock exceeds 60 inches. Ripon soils have a mollic epipedon and, in many places, are in complex association with Knowles soils.
DRAINAGE AND PERMEABILITY: Well drained. The potential for surface runoff ranges from low to high. Permeability is moderate in the loess and till and ranges from slow to moderate in the dolomite bedrock.
USE AND VEGETATION: Most areas of this soil are used for cropland. Common crops are corn, small grains, or hay. Some areas are used for pastureland and some are in woodland. Native vegetation is deciduous forests mainly oak-hickory with lesser amounts of maple-basswood.
DISTRIBUTION AND EXTENT: Southeastern Wisconsin. The Knowles soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Columbia County, Wisconsin, 1972.
REMARKS: This soil was formerly included with the Whalan soils. Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon - 0 to 12 inches (Ap, BE); argillic horizon - 12 to 39 inches (Bt1, Bt2, 2Bt3, and 2Bt4); lithic contact 39 inches (3R).