LOCATION HERBERT ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Udollic Epiaqualfs
TYPICAL PEDON: Herbert silt loam - on a south-facing slope with less than 1 percent gradient in a cultivated field at an elevation of 257 meters (842 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 20 cm (0 to 8 inches); very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; moderate very fine granular structure; friable; many very fine and fine roots; slightly acid; abrupt smooth boundary. [15 to 23 cm (6 to 9 inches) thick]
E--20 to 30 cm (8 to 12 inches); dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; weak medium and thick platy structure parting to moderate fine granular; friable; many very fine roots; few fine faint brown (10YR 5/3) masses of iron accumulation in the matrix; slightly acid; clear smooth boundary. [0 to 18 cm (0 to 7 inches) thick]
Bt1--30 to 41 cm (12 to 16 inches); brown (10YR 4/3) silty clay loam; moderate very fine subangular blocky structure; firm; many very fine roots; common distinct dark grayish brown (10YR 4/2) clay films on the faces of peds; few fine faint brown (10YR 5/3) masses of iron accumulation in the matrix; few fine faint grayish brown (2.5Y 5/2) iron depletions in the matrix; slightly acid; clear smooth boundary.
Bt2--41 to 51 cm (16 to 20 inches); brown (10YR 4/3) silt clay loam; moderate fine subangular blocky structure; firm; many very fine roots; many distinct dark grayish brown (10YR 4/2) clay films on the faces of peds; few fine dark brown (10YR 3/3) iron-manganese oxide concretions throughout; few fine distinct yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; common fine faint grayish brown (2.5Y 5/2) iron depletions in the matrix; moderately acid; clear smooth boundary.
Bt3--51 to 66 cm (20 to 26 inches); grayish brown (10YR 5/2) silty clay loam: moderate medium subangular blocky structure; firm; common very fine roots; common distinct dark grayish brown (2.5Y 4/2) clay films on the faces of peds; common distinct very dark brown (10YR 2/2) organic coatings in root channels; few fine dark brown (10YR 3/3) iron-manganese oxide concretions throughout; common medium prominent strong brown (7.5YR 5/6) and yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; moderately acid; clear smooth boundary. [The combined thickness of the Bt horizon is 20 to 71 cm (8 to 28 inches).]
2Bt4--66 to 84 cm (26 to 33 inches); brown (7.5YR 5/4) clay loam; moderate medium angular and subangular blocky structure; firm; common very fine roots; common distinct dark grayish brown (2.5Y 4/2) clay films on the faces of peds; common distinct very dark brown (10YR 2/2) organic coating in root channels; few fine dark brown (10YR 3/3) iron-manganese oxide concretions throughout; common medium distinct strong brown (7.5YR 5/6) and yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; 2 percent pebbles; moderately acid; clear smooth boundary.
2Bt5--84 to 91 cm (33 to 36 inches); brown (7.5YR 5/3) clay loam; weak coarse angular blocky structure; firm; common very fine roots; common distinct dark grayish brown (2.5Y 4/2) clay films on the faces of peds; common distinct very dark brown (10YR 2/2) organic coatings in root channels; few fine dark brown (10YR 3/3) iron-manganese oxide concretions throughout; common medium distinct strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; common medium faint light brownish gray (10YR 6/2) iron depletions in the matrix; 2 percent pebbles; neutral; clear smooth boundary. [The combined thickness of the 2Bt horizon is 5 to 30 cm (2 to 12 inches).]
2C--91 to 152 cm (36 to 60 inches); brown (7.5YR 5/4) loam; massive; firm; few very fine roots; few fine light gray (10YR 7/1) very weakly cemented calcium carbonate concretions throughout; few fine distinct very pale brown (10YR 7/3) and few fine prominent gray (5Y 6/1) iron depletions in the matrix; 3 percent pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: DeKalb County, Illinois; about 4.8 km (3 miles) northwest of Genoa, Illinois; 123 m (405 feet) south and 93 m (306 feet) east of northwest corner, sec. 14, T. 42 N., R. 4 E; USGS Genoa topographic quadrangle; lat. 42 degrees 07 minutes 24 seconds N., and long. 88 degrees 44 minutes 38 seconds W., NAD 27; UTM Zone 16T, 355845 easting, and 4664945 northing, NAD 83.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon ranges from 56 to 102 cm (22 to 40 inches). The depth to horizons with more than 15 percent sand ranges from 51 to 102 cm (20 to 40 inches). The series control section ranges from moderately acid to neutral in the upper one-half and from slightly acid to moderately alkaline in the lower one-half.
The Ap or A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 to 3. It is silt loam. The E horizon, where present, has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 or 2. It is silt loam.
The Bt or Btg horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 1 to 6. It is silty clay loam or silt loam. Clay content averages 25 to 35 percent.
The 2Bt or 2Btg horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 2 to 6. It is loam or clay loam. Clay content averages 22 to 35 percent, and sand content averages 20 to 45 percent. Gravel content ranges from 0 to 10 percent
The 2C or 2Cg horizon has hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 2 to 6. It is loam or sandy loam. Average clay content ranges from 15 to 25 percent, and sand content averages 25 to 55 percent. Gravel content ranges from 2 to 15 percent. Carbonates are present, and the calcium carbonate equivalent ranges from 10 to 40 percent.
COMPETING SERIES: This is the Toronto series. Toronto soils are 102 cm (40 inches) or more to the base of soil development.
GEOGRAPHIC SETTING: Herbert soils are on nearly level to gently sloping glacial till plains and moraines. Slope gradients range from 0 to 3 percent. Herbert soils formed in 51 to 102 cm (20 to 40 inches) of loess or other silty material and in the underlying loamy till of Wisconsin Age. Mean annual air temperature ranges from 7 to 11 degrees C (45 to 52 degrees F), mean annual precipitation from 760 to 1020 mm (30 to 40 inches), frost free days range from 140 to 180 days; and the elevation ranges from 207 to 351 meters (679 to 1152 feet) above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Danabrook, Drummer, Kidami, Lisbon, Mayville, and Octagon soils. The moderately drained Danabrook, Kidami, Mayville, and Octagon soils are on higher positions on the landform. The poorly drained Drummer soils are in slight depressions and drainageways. Lisbon soils have a mollic epipedon and are on similar landform positions nearby.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. An intermittent perched high water table is at a depth of 15 to 61 cm (0.5 to 2.0 feet) below the surface between January and May in most years. The potential for surface runoff is low. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers per second) in the solum and moderately high (1.41 to 4.23 micrometers per second) in the underlying material. Permeability is moderate in the solum and moderately slow in the underlying material.
USE AND VEGETATION: These soils are cropped mostly to corn, soybeans, small grain, and meadow. Native vegetation is prairie grasses and scattered hardwood trees.
DISTRIBUTION AND EXTENT: Eastern and northern Illinois. Extent is small in MLRAs 95B, 108A, and 110.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Illinois, 1935.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 30 cm (12 inches) (Ap and E horizons); albic horizon - 20 to 30 cm (8 to 12 inches) (E horizon); argillic horizon - 30 to 91 cm (12 to 36 inches) (Bt1, Bt2, Bt3, 2Bt4, and 2Bt5 horizons); discontinuity at 66 cm (26 inches) - the contact between the Bt3 and 2Bt4 horizons.