LOCATION SHAKAMAK INEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Aquic Fragiudalfs
TYPICAL PEDON: Shakamak silt loam, on a 2 percent slope in a cultivated field at an elevation of 146 meters (480 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 25 cm (0 to 10 inches); brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak fine granular structure; friable; many fine roots; neutral; abrupt wavy boundary. [15 to 30 cm (6 to 12 inches) thick]
BE--25 to 36 cm (10 to 14 inches); light yellowish brown (10YR 6/4) silt loam; weak medium subangular blocky structure; friable; many fine roots; few fine tubular pores; worm holes and root channels filled with brown (10YR 4/3) silt loam; strongly acid; clear wavy boundary. [0 to 20 cm (0 to 8 inches) thick]
Bt1--36 to 46 cm (14 to 18 inches); yellowish brown (10YR 5/6) silty clay loam; moderate medium subangular blocky structure; friable; few roots; few fine tubular pores; many distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; strongly acid; clear wavy boundary.
Bt2--46 to 58 cm (18 to 23 inches); yellowish brown (10YR 5/6) silty clay loam; weak medium prismatic structure parting to moderate medium subangular blocky; firm; few fine roots; few fine tubular pores; many distinct grayish brown (10YR 5/2) clay films on faces of peds; common fine faint strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; common fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; many prominent light gray (10YR 7/2) clay depletions on faces of peds; very strongly acid; clear wavy boundary.
Bt3--58 to 71 cm (23 to 28 inches); yellowish brown (10YR 5/6) silty clay loam; weak coarse prismatic structure parting to moderate medium subangular blocky; firm; common fine tubular pores; many distinct grayish brown (10YR 5/2) clay films on faces of peds; common fine faint strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; few black (10YR 2/1) weakly cemented iron and manganese oxide concretions; common fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; many prominent light gray (10YR 7/2) clay depletions on vertical and horizontal faces of peds; very strongly acid; clear wavy boundary. [Combined thickness of Bt horizon is 30 to 61 cm (12 to 24 inches).]
Btx1--71 to 89 cm (28 to 35 inches); yellowish brown (10YR 5/6) silty clay loam; moderate coarse prismatic structure parting to moderate thick platy; very firm; few fine roots between peds; many distinct grayish brown (10YR 5/2) clay films on faces of peds; common fine distinct brown (7.5YR 4/4) masses of iron accumulation in the matrix; common fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; many distinct pale brown (10YR 6/3) clay depletions on vertical faces of peds; 50 percent brittle; very strongly acid; gradual wavy boundary.
Btx2--89 to 119 cm (35 to 47 inches); yellowish brown (10YR 5/6) silt loam; moderate very coarse prismatic structure parting to moderate very thick platy; very firm; common fine vesicular pores; many distinct grayish brown (10YR 5/2) clay films on vertical faces of peds; common fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; many distinct pale brown (10YR 6/3) clay depletions on vertical faces of peds; 65 percent brittle; very strongly acid; clear wavy boundary.
Btx3--119 to 145 cm (47 to 57 inches); yellowish brown (10YR 5/6) silt loam; moderate very coarse prismatic structure; very firm; few fine vesicular pores; common distinct brown (7.5YR 4/4) clay films on faces of peds; few fine black (10YR 2/1) weakly cemented iron and manganese oxide concretions; few fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; many prominent grayish brown (10YR 5/2) clay depletions on vertical faces of peds; 2 percent fine gravel; 70 percent brittle; very strongly acid; gradual wavy boundary. [Combined thickness of the Btx horizon is 61 to 86 cm (24 to 34 inches).]
2Bt1--145 to 175 cm (57 to 69 inches); yellowish brown (10YR 5/6) silt loam; moderate coarse subangular blocky structure; firm; few very fine tubular pores; many prominent grayish brown (10YR 5/2) clay films on faces of peds; few fine black (10YR 2/1) weakly cemented iron and manganese oxide concretions; common medium prominent light brownish gray (10YR 6/2) iron depletions in the matrix; few distinct brown (10YR 5/3) clay depletions on faces of peds; 2 percent fine gravel; very strongly acid; gradual wavy boundary.
2Bt2--175 to 203 cm (69 to 80 inches); yellowish brown (10YR 5/6) clay loam; moderate coarse subangular blocky structure; firm; many prominent grayish brown (10YR 5/2) clay films on faces of peds; common medium distinct strong brown (7.5YR 5/8) masses of iron accumulation in the matrix; common fine black (10YR 2/1) weakly cemented iron and manganese oxide concretions; common fine prominent light brownish gray (10YR 6/2) iron depletions in the matrix; 3 percent fine gravel; strongly acid. [Thickness of the 2Bt horizon above 203 cm (80 inches) is 25 to 76 cm (10 to 30 inches).]
TYPE LOCATION: Greene County, Indiana; 150 feet west and 2,600 feet north of the southeast corner of sec. 32, T. 8 N., R. 6 W.
RANGE IN CHARACTERISTICS:
Depth to the base of the argillic horizon: more than 203 cm (80 inches)
Depth to horizon with fragic soil properties: 51 to 91 cm (20 to 36 inches)
Depth to fragipan: 76 to 102 cm (30 to 40 inches)
Ap horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 2 or 3
Texture: silt loam
Reaction: very strongly acid to neutral, depending on liming practices
EB or BE horizon, where present:
Hue: 10YR
Value: 6
Chroma: 4 to 6
Texture: silt loam
Reaction: very strongly acid to neutral, depending on liming practices
Bt horizon:
Hue: 10YR
Value: 4 to 6
Chroma: 4 to 6
Texture: silt loam or silty clay loam
Clay content: 24 to 32 percent
Sand content: 2 to 10 percent
Reaction: very strongly acid or strongly acid, and ranges to neutral in the upper part in limed areas
Btx horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6
Chroma: 4 to 8
Texture: silt loam or silty clay loam
Clay content: 20 to 30 percent
Sand content: 2 to 20 percent
Reaction: very strongly acid or strongly acid
2Bt horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6
Chroma: 4 to 8
Texture: loam or clay loam; some pedons may be silt loam in the upper part
Clay content: 18 to 34 percent
Sand content: 20 to 40 percent
Rock fragment content: 1 to 7 percent gravel
Reaction: very strongly acid to slightly acid
COMPETING SERIES: These are the Chalfont, Gudgel, Haubstadt, Nabb, Pierpont, Plumfield, Robbs, and Sciotoville series. Chalfont soils have rock fragments of shale in the lower part of the series control section. Gudgel soils have a paralithic contact within a depth of 152 cm (60 inches). Haubstadt soils do not have a horizon with fragic soil properties above the fragipan. Nabb soils average more than 10 percent sand in the upper part of the argillic horizon. Pierpont and Sciotoville soils are less than 203 cm (80 inches) to the base of the argillic horizon. Plumfield soils are less than 76 cm (30 inches) to the top of a fragipan. Robbs soils average less than 1 percent rock fragments in the lower part of the series control section.
GEOGRAPHIC SETTING: Shakamak soils are on loess-covered till plains of Illinoian age. Slope ranges from 1 to 3 percent. The soils formed in 127 to 165 cm (50 to 65 inches) of loess and in the underlying paleosol in till. Mean annual precipitation ranges from 965 to 1092 mm (38 to 43 inches). Mean annual air temperature ranges from 11 to 13 degrees C (52 to 55 degrees F). Frost-free period ranges from 170 to 200 days. Elevation ranges from 107 to 305 meters (350 to 1000 feet) above mean sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arney, Ava, Hickory, Lieber, and Vigo soils on till plains. The more permeable Arney soils are on summits, shoulders, and backslopes. The Ava soils are on shoulders and backslopes and have a thinner mantle of loess. The well drained Hickory soils are on backslopes. The somewhat poorly drained Lieber soils are on summits and shoulders. The somewhat poorly drained Vigo soils are on broad summits.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. The depth to the top of an intermittent perched high water table ranges from 46 to 61 cm (1.5 to 2.0 feet) between December and April in normal years. The potential for runoff is medium or high. Saturated hydraulic conductivity is moderately high in the upper part of the solum and low or moderately low in the lower part. Permeability is moderate in the upper part of the solum and very slow or slow in the lower part.
USE AND VEGETATION: Most areas are used for growing corn and soybeans. A few areas are used for growing small grain, hay or pasture, or are in woodland. Native vegetation is mixed hardwood forest.
DISTRIBUTION AND EXTENT: Southern Indiana; MLRAs 114B and 115A. The type location is in MLRA 114B. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana.
SERIES ESTABLISHED: Greene County, Indiana, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: from the surface to a depth of 25 cm (Ap horizon).
Argillic horizon: from a depth of 25 to 203 cm (Bt, Btx, 2Bt horizons).
Fragic soil properties: from a depth of 71 to 89 cm (Btx1 horizon).
Fragipan: from a depth of 89 to 145 cm (Btx2, Btx3 horizons).
Aquic conditions: redox depletions in all horizons below a depth of 46 cm.
ADDITIONAL DATA: Lab data for the typical pedon S79IN55-28 and for an additional pedon S79IN55-5 is at the Agricultural Experiment station, Purdue University. Data for pedon S87IN119-2 is at the National Soil Survey Laboratory, Lincoln, Nebraska.