LOCATION BOLD IL+MNEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Typic Udorthents
TYPICAL PEDON: Bold silt loam (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; yellowish brown (10YR 5/6) silt loam, brownish yellow (10YR 6/6) dry; weak very fine and fine granular structure; very friable; slightly effervescent; slightly alkaline; abrupt smooth boundary. (3 to 12 inches)
C1--7 to 30 inches; mottled yellowish brown (10YR 5/6 and 5/8) and light gray (10YR 7/2) silt loam; massive; very friable; strongly effervesent; moderately alkaline; gradual wavy boundary. (6 inches to several feet thick)
C2--3 to 60 inches; light gray (10YR 7/2) silt loam; massive; very friable; common medium distinct brownish yellow (10YR 6/8) masses of iron accumulation in the matrix; strongly effervescent; moderately alkaline.
TYPE LOCATION: Menard County, Illinois; about 1 mile southwest of Athens; 1,250 feet north and 650 feet east of southwest corner of sec. 2, T. 17 N., R. 6 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 3 to 12 inches. The thickness of the loess ranges from 6 feet to more than 30 feet. It commonly is calcareous throughout. Pedons which lack carbonates in the upper 10 inches are not excluded. They are slightly alkaline or moderately alkaline throughout. Secondary lime concretions are present in many pedons. Calcium carbonate equivalent commonly ranges from 12 to 30 percent in the C horizon. The particle size control section is silt loam; it contains between 12 and 18 percent clay and less than 10 percent total sand.
The Ap horizon has 10YR hue, value of 4 through 6, and chroma of 2 through 6. Pedons with A horizons have value of 3 or 4, and chroma of 1 through 4.
An AC horizon is present in some pedons.
The C horizon commonly has hue of 10YR, value of 4 through 7, and chroma of 2 through 8. Some pedons have hue of 5YR in thin bands.
COMPETING SERIES: These are the Hamburg, Mula and Netawaka (T) series. Hamburg soils average less than 12 percent clay and more than 10 percent sand in the control section. Mula and Netawaka (T) soils have less than 12 percent calcium carbonate equivalent.
GEOGRAPHIC SETTING: Bold soils are on the side slopes of dissected uplands. Slopes dominately are between 10 and 40 percent but range from 4 to 75 percent. The soils formed in thick calcareous loess. The mean annual temperature ranges from about 45 to 56 degrees F, and the mean annual precipitation ranges from about 28 to 40 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alford, Fayette, Sylvan, Tallula, and Timula soils. Alford, Fayette, and Sylvan soils have argillic horizons. They are generally on less sloping areas both upslope and downslope from the Bold soils. Tallula soils have a mollic epipedon and are generally on the less sloping part of the landscape. The Timula soils have cambic horizons and are generally on the less sloping part of the landscape.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to rapid. Permeability is moderate.
USE AND VEGETATION: Most areas of this soil are used for hay and pasture. Some areas are cropped to corn, soybeans, and small grain. Native vegetation is hardwood trees or prairie grasses.
DISTRIBUTION AND EXTENT: Illinois and Minnesota. The extent is moderate.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Henderson County, Illinois, 1947