LOCATION HARRISON IL

Established Series
Rev. JWS-RT-AAC
01/2011

HARRISON SERIES

The Harrison series consists of very deep, moderately well drained, moderately permeable soils on uplands. They formed in 40 to 60 inches of Wisconsinan loess and the underlying silty or loamy materials. Slope ranges from 0 to 10 percent. Mean annual precipitation is about 914 mm (36 inches) and mean annual temperature is about 12.2 degrees C (54 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Oxyaquic Argiudolls

TYPICAL PEDON: Harrison silt loam - on a convex slope of 3 percent in a cultivated field at an elevation of 203 meters (665 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 25 cm (0 to 10 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine granular structure; friable; common very fine and few fine roots; slightly acid; abrupt smooth boundary. [18 to 31 cm (7 to 12 inches) thick]

BA--25 to 36 cm (10 to 14 inches); brown (10YR 4/3) silt loam; weak very fine and fine subangular blocky structure; friable; few very fine roots; many distinct very dark grayish brown (10YR 3/2) organic coatings on faces of peds; moderately acid; clear smooth boundary. [0 to 15 cm (0 to 6 inches) thick]

Bt1--36 to 51 cm (14 to 20 inches); brown (10YR 4/3) silt loam; moderate fine subangular blocky structure; friable; few very fine roots; common distinct very dark grayish brown (10YR 3/2) and few distinct very dark gray (10YR 3/1) organo-clay films on faces of peds; few fine faint dark yellowish brown (10YR 4/4) masses of oxidized iron along micropores; few fine masses of manganese oxides in the matrix; moderately acid; clear smooth boundary.

Bt2--51 to 69 cm (20 to 27 inches); brown (10YR 4/3) silty clay loam; weak fine prismatic structure parting to moderate medium subangular blocky; firm; few very fine roots; common distinct very dark grayish brown (10YR 3/2) organo-clay films on faces of peds; few fine faint brown (7.5YR 4/4), brown (10YR 5/3) and dark yellowish brown (10YR 4/4) masses of oxidized iron along micropores; few fine masses of manganese oxides in the matrix; moderately acid; clear smooth boundary.

Bt3--69 to 89 cm (27 to 35 inches); brown (10YR 5/3) silty clay loam; moderate medium subangular blocky structure; firm, few very fine roots; few distinct dark grayish brown (10YR 4/2) clay films on faces of peds; many fine faint dark yellowish brown (10YR 4/4) and few fine faint brown (7.5YR 4/4) masses of oxidized iron along micropores; few fine masses of manganese oxides in the matrix; moderately acid; clear smooth boundary.

Bt4--89 to 114 cm (35 to 45 inches); yellowish brown (10YR 5/4) silt loam; weak medium and coarse subangular blocky structure; firm; few very fine roots; few distinct dark grayish brown (10YR 4/2) clay films on faces of peds; many fine distinct grayish brown (10YR 5/2) iron depletions along micropores; common fine faint dark yellowish brown (10YR 4/4) and few fine faint brown (7.5YR 4/4) masses of oxidized iron in the matrix; few fine masses of manganese oxides in the matrix; moderately acid; clear smooth boundary. [Combined thickness of the Bt horizons is 56 to 117 cm (22 to 46 inches).]

2Btg--114 to 165 cm (45 to 65 inches); grayish brown (10YR 5/2) silty clay loam; weak medium and coarse subangular blocky structure; firm; few distinct gray (10YR 5/1) clay films on faces of peds; few fine faint brown (10YR 5/3), common fine and medium distinct dark yellowish brown (10YR 4/4), and few fine distinct brown (7.5YR 4/4) masses of oxidized iron in the matrix; few fine masses of manganese oxides in the matrix; about 15 percent sand; about 1 percent gravel; slightly acid; abrupt smooth boundary. [18 to 61 cm (7 to 24 inches) thick]

3Btgb--165 to 203 cm (65 to 80 inches); grayish brown (2.5Y 5/2) clay loam; moderate coarse subangular blocky structure; firm; common distinct olive gray (5Y 4/2) clay films on faces of peds; common medium distinct yellowish brown (10YR 5/4) masses of oxidized iron in the matrix; few fine masses of manganese oxides in the matrix; about 5 percent gravel; neutral.

TYPE LOCATION: Christian County, Illinois; about 6 miles south and 2 1/4 miles east of Taylorville; 228 feet north and 1350 feet west of the southeast corner of sec. 24, T. 12 N., R. 2 W.; USGS Clarksdale, IL. Topographic quadrangle; lat. 39 degrees 27 minutes 59 seconds N. and long. 089 degrees 15 minutes 17 seconds W.; NAD 27.

RANGE IN CHARACTERISTICS:
Depth to the base of the argillic horizon: 114 to 178 cm (45 to 70 inches)
Thickness of the loess: 102 to 152 cm (40 to 60 inches)
Particle-size control section: averages between 27 and 35 percent clay and less than 5 percent sand.
Depth to carbonates: greater than 152 cm (60 inches)
Redox depletions with chroma of 2 or less: not present in the 15 cm (6 inches) immediately below the mollic epipedon.

Ap and A horizons:
Hue: 10YR
Value: 2 or 3 (4 or 5 dry)
Chroma: typically 1 or 2, but some pedons have chroma of 3.
Reaction: neutral or slightly acid
Other features:
In some pedons, an A horizon beneath the Ap horizon is as much as 8 inches in thickness.

AB or BA horizons (where they occur):
Hue: 10YR
Value: 3 or 4 (4 through 6 dry)
Chroma: 2 to 4
texture: silt loam or silty clay loam

Bt horizon:
Hue: 10YR
Value: 4 to 6
Chroma: typically 3 or 4 but including 2 through 6 in individual subhorizons
Texture: dominantly silty clay loam, but has`subhorizons of silt loam
Redox features:
Hue: 10YR, 7.5YR or 5YR
Value: 4 to 6
Chroma: 2 to 8
Reaction: strongly acid to slightly acid

2Bt, 2Btg, and/or 2BC horizons:
Hue: 10YR or 7.5YR, and less commonly 2.5Y
Value: 4 to 6
Chroma: 2 to 6
Texture: silty clay loam, silt loam, loam or clay loam
Redox features:
Hue: 7.5YR, 10YR, 2.5Y or 5Y
Value: 4 to 6
Chroma: 2 to 8
Reaction: moderately acid to neutral
Other features:
They contain more sand than the overlying loess, and typically contains some pebbles. Some pedons have a 2C horizon within a depth of 152 cm (60 inches), but most pedons have a buried soil (paleosol) beneath the 2Bt, 2Btg, and/or 2BC horizon within a depth of 178 cm (70 inches).

3Btgb horizon:
Hue: 10YR, 2.5Y or 5Y or N (neutral)
Value: 4 to 6
Chroma: 0 to 3 and is mottled.
Texture: typically clay loam or clay, but is silty clay or silty clay loam in some pedons.
Reaction: slightly alkaline to strongly acid

COMPETING SERIES: These are the Assumption, Aviston, Barrington, Blackberry, Buckhart, Catlin, Clare, Dana, Danabrook, Geryune, Graymont, Keltner, Saybrook, and Totanang series. Assumption and Clare soils have more than 15 percent sand in some horizon above a depth of 102 cm (40 inches). Aviston soils formed in more than 152 cm (60 inches) of loess and have less than 15 percent sand in the lower part of the series control section. Barrington, Catlin, Dana, Danabrook, Geryune, Graymont, and Saybrook soils have carbonates at depths of less than 152 cm (60 inches). Blackberry soils average less than 30 percent clay in the lower part of the series control section. Buckhart soils have less than 7 percent sand within a depth of 152 cm (60 inches). Keltner soils have a paralithic contact at depths of 102 to 152 cm (40 to 60 inches). Totanang soils have more than 15 percent rock fragments in the lower part of the series control section.

GEOGRAPHIC SETTING: Harrison soils are on the crests and upper side slopes of convex ridges and broad interstream divides on the Illinoian till plain. Slope gradients range from 0 to 10 percent. These soils formed in 102 to 152 cm (40 to 60 inches) of Wisconsinan loess and the underlying coarser textured Roxana silt or loamy materials. These materials contain more sand than the overlying loess. They are underlain at depths generally between 152 to 178 cm (60 and 70 inches) by Illinoian till that contains a strongly developed paleosol. Mean annual temperature varies from 11.1 to 13.9 degrees C (52 to 57 degrees F), and mean annual precipitation varies from 889 to 1016 mm (35 to 40 inches).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cowden, Darmstadt, Douglas, Herrick, Piasa, Tamalco, Velma, and Virden soils. Cowden, Piasa, and Virden soils are poorly drained, have a fine textured control section, and are on nearly level parts of the loess covered till plains nearby at either higher or lower elevations. In addition, the Piasa soils have a natric horizon. The somewhat poorly drained Darmstadt and the moderately well drained Tamalco soils are on similar parts of the landscape nearby or on side slopes along drainageways and have a natric horizon. The well drained Douglas soils are on slightly higher positions in the landscape. The somewhat poorly drained Herrick soils are nearby on convex ridges or interstream divides with low relief and are either at higher or lower elevations. The well drained Velma soils contain more than 15 percent fine sand or coarser in the control section and are down slope from Harrison soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. The potential for surface water runoff is medium. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometers per second) in the solum and moderately low to moderately high (0.42 to 1.41 micrometers per second) in the underlying till that contains a strongly developed paleosol. Permeability is moderate in the solum and slow in the underlying till that contains a strongly developed paleosol. Because of the underlying paleosol, these soils have a perched water table seasonally at depths of 61 to 107 cm (2 to 3.5 feet).

USE AND VEGETATION: Most areas of Harrison soils are cultivated. Corn, soybeans, and small grain are the principal crops. Native vegetation is prairie grasses.

DISTRIBUTION AND EXTENT: MLRAs 108B, 113, 114B, and 115C in southwestern and west-central Illinois. Harrison soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Schuyler County, Illinois, 1930.

REMARKS: The sequence of materials for the Harrison series is Peoria loess over coarser textured Roxana silts over Illinoian till that contains a paleosol. The pedon has been described to a depth of 178 cm (70 inches) to show the materials that affect interpretations.

Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 25 cm (10 inches) (Ap horizon); argillic horizon - the zone from about 36 to 165 cm (14 to 65 inches) (Bt1, Bt2, Bt3, Bt4, and 2Btg horizons).

National Cooperative Soil Survey
U.S.A.