LOCATION AVA IL+IN OH

Established Series
Rev. JBF-JCD-SEW
01/2013

AVA SERIES

The Ava series consists of moderately well drained soils on convex ridges and side slopes of drainageways on till plains. They formed in loess and the underlying silty or loamy deposits that overlie a strongly developed paleosol. They are moderately deep to a fragipan and greater than 80 inches to bedrock. Slope ranges from 0 to 18 percent. Mean annual precipitation is about 1067 millimeters (42 inches) and mean annual air temperature is about 13 degrees C. (55 degrees F.).

TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Oxyaquic Fragiudalfs

TYPICAL PEDON: Ava silt loam - on a 3 percent convex slope in a pasture of grass-legume mixture at an elevation of about 134 meters (440 feet) above MSL. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 centimeters (0 to 6 inches); dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; friable; many fine roots; slightly acid; abrupt smooth boundary. (12 to 25 cm or 5 to 10 inches thick)

E--15 to 25 centimeters (6 to 10 inches); brown (10YR 4/3) silt loam; weak medium platy structure; friable; few fine roots; strongly acid; clear smooth boundary. (0 to 20 cm or 0 to 8 inches thick)

BE--25 to 36 centimeters (10 to 14 inches); yellowish brown (10YR 5/6) silt loam; moderate fine and medium subangular blocky structure; friable; common fine roots; strongly acid; clear smooth boundary. (0 to 15 cm or 0 to 6 inches thick)

Bt--36 to 61 centimeters (14 to 24 inches); yellowish brown (10YR 5/4) silty clay loam; strong fine and medium subangular blocky structure; firm; few fine roots; very few distinct brown (7.5YR 5/4) clay films and light yellowish brown (10YR 6/4) silt coatings on faces of peds; very strongly acid; clear smooth boundary. (20 to 36 cm or 8 to 14 inches thick)

Bt/E--61 to 69 centimeters (24 to 27 inches); yellowish brown (10YR 5/4) silty clay loam (Bt) and light yellowish brown (10YR 6/4) silt (E), light gray (10YR 7/2) dry; the E material occurs as common distinct silt coatings on faces of peds and as fillings in spaces between peds; moderate fine and medium subangular blocky structure; firm; few fine roots; common medium distinct brown (7.5YR 4/4) masses of oxidized iron; few fine distinct black (10YR 2/1) iron-manganese concretions; very strongly acid; clear smooth boundary. (0 to 15 cm or 0 to 6 inches thick)

Bt--69 to 86 centimeters (27 to 34 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; few fine roots; common distinct brown (10YR 4/3) clay films and few distinct light gray (10YR 7/2) silt coatings on faces of peds; common fine distinct grayish brown (10YR 5/2) iron depletions and few fine distinct yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; very strongly acid; gradual smooth boundary. (0 to 51 cm or 0 to 20 inches thick)

2Btx1--86 to 112 centimeters (34 to 44 inches); grayish brown (10YR 5/2) silty clay loam; moderate very coarse prismatic structure parting to weak coarse subangular blocky; very firm; cracks between polygons filled with light gray (10YR 7/1) silt loam; common coarse prominent yellowish brown (10YR 5/8) masses of oxidized iron in the matrix; common coarse prominent dark red (2.5YR 3/6) and distinct brown (7.5YR 4/4) weakly cemented iron-manganese nodules and few fine distinct black (10YR 2/1) iron-manganese concretions; about 12 percent sand; brittle; very strongly acid; gradual smooth boundary.

2Btx2--112 to 127 centimeters (44 to 50 inches); brown (10YR 5/3) loam; weak very coarse prismatic structure parting to weak coarse subangular blocky; very firm; few vertical streaks and cracks between polygons filled with light gray (10YR 7/1) silt; common coarse faint dark yellowish brown (10YR 4/4) masses of oxidized iron and common fine faint grayish brown (10YR 5/2) iron depletions in the matrix; few black (10YR 2/1) iron-manganese concretions; about 30 percent sand; brittle; very strongly acid; gradual smooth boundary. (Combined thickness of the Btx horizons is 25 to 91 cm or 10 to 36 inches.)

3Btb--127 to 293 centimeters (50 to 80 inches); brown (10YR 5/3) loam; weak coarse prismatic structure; firm; common faint brown (10YR 4/3) clay films on faces of peds; common medium faint grayish brown (10YR 5/2) iron depletions in the matrix; strongly acid.

TYPE LOCATION: Edwards County, Illinois; about 10 miles north and 3 miles west of Albion; 925 feet south and 1,575 feet west of northeast corner of sec. 17, T. 1 N., R. 10 E.; USGS West Salem, Illinois, topographic quadrangle; lat. 38 degrees 31 minutes 24 seconds N., and long. 88 degrees 07 minutes 05 seconds W.; UTM Zone 16, 402959 Easting 4263623 Northing; NAD 83.

RANGE IN CHARACTERISTICS:
Depth to the second sequum (Bt/E or Bt horizon): 20 to 30 inches
Depth to the fragipan: 25 to 40 inches
Thickness of the Peoria Loess: 30 to 55 inches
Depth to the base of the argillic horizon: greater than 122 cm (48 inches)
Particle-size control section: Averages 24 to 35 percent clay

Ap or A horizon:
Hue: 10YR
Value: 4 or 5 (6 or 7 dry)
Chroma: 2 or 3
Texture: silt loam; silty clay loam in some pedons in eroded areas
Reaction: very strongly acid or strongly acid, except in areas that have been limed

E or EB horizon (if it occurs):
Hue: 10YR
Value: 4 or 5
Chroma: 3 to 6
Reaction: very strongly acid or strongly acid, except in areas that have been limed
Other characteristics: The E horizon has been mixed with the surface layer in some pedons in eroded areas.

Bt and Bt horizons:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 3 to 6
Texture: silty clay loam or silt loam
Reaction: strongly acid or very strongly acid
Other characteristics: Redoximorphic iron depletions are in the lower part of these horizons

Bt/E horizon (Bt part):
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 3 to 6
Texture: silty clay loam or silt loam
Reaction: strongly acid or very strongly acid
Bt/E horizon (E part):
Hue:10YR
Value: 5 to 8
Chroma: 1 to 4
Texture: silt loam or silt
Reaction: strongly acid or very strongly acid

Btx or 2Btx horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 2 to 8
Texture: silt loam, silty clay loam, or loam; clay content ranges from 20 to 35 percent and sand content ranges from 10 to 30 percent sand
Content of rock fragments: 0 to 4 percent
Reaction: strongly acid or very strongly acid
Other features: The primary structure is very coarse prismatic and the polygons are separated or surrounded by cracks filled with silt or silt loam that has grayer color or higher color value, and typically less clay, than the interiors of the polygons.

2Btb or 3Btb horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 2 to 6
Texture: loam, silt loam, clay loam, or silty clay loam
Content of rock fragments: 0 to 10 percent
Reaction-strongly acid or very strongly acid

COMPETING SERIES: These are the Apalono, Bedford, Cincinnati, Fountainville, Grantsburg, Hildebrecht, Hosmer, Nicholson, Omulga, Otwell, Otwood, Solsberry, Weisburg, and Zanesville series in the same family and the Boston and Lawrenceville series in closely related family (cation exchange activity class not assigned). Apalono, Bedford and Nicholson soils average more than 35 percent clay in the lower part of the series control section. Cincinnati, Hildebrecht and Solsberry soils have a horizon that contains 4 percent or more rock fragments within a depth of 152 cm (60 inches). Fountainville and Zanesville soils have a lithic contact within 203 cm (80 inches). Grantsburg and Hosmer soils average less than 10 percent sand to a depth of 152 cm (60 inches). Omulga and Otwell soils have subhorizons in the lower part of the series control section that have as much as 50 percent sand. Otwood soils contain mica flakes throughout the series control section. Weisburg soils have more than 40 percent clay in the lower part of the series control section. Boston soils average more than 35 percent clay in the lower part of the series control section. Lawrenceville soils have rock fragments in the upper part of the series control section.

GEOGRAPHIC SETTING: Ava soils are on convex ridges, shoulders and backslopes on loess-covered dissected till plains. Slope gradients are 0 to 18 percent. Ava soils formed in 76 to 140 cm (30 to 55 inches) of loess (considered to be of Wisconsin age) and in the underlying silty or loamy deposits. The underlying deposits contain more sand than the overlying loess mantle and consist of erosional sediments or reworked material of the A horizon of the paleosol and an admixed amount of earliest Wisconsinan loess. Locally these soils often contain a band of pebbles of the Illinoian till concentrated by erosion. Ava soils are underlain, at a depth of about 122 to 2136 centimeters (4 to 7 feet), by a strongly developed paleosol considered to be from the Illinoian till stage. The mean annual air temperature ranges from 10 to 14 degrees C. (50 to 58 degrees F.), the mean annual precipitation ranges from 965 to 1143 mm (38 to 45 inches), frost free period ranges from 170 to 200 days, and elevation ranges from 106 to 267 meters (350 to 875 feet) above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bluford, Hickory, Parke, and Wynoose soils. The somewhat poorly drained Bluford soils are on higher lying broader summits or lower lying backslopes. The well drained Hickory soils do not have a fragipan and are on lower lying backslopes. The well drained Parke soils do not have a fragipan, have redder colors, and lower base saturation in the lower part of the solum, and are on similar convex ridges of eskers, kames, outwash plains. The poorly drained Wynoose soils are on flats of the till plains. The Bluford and Wynoose soils form a hydrosequence with Ava soils. In Indiana the Ava soils are also associated with the well drained Cincinnati, moderately well drained Shakamak, and the somewhat poorly drained Vigo soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. The potential for surface runoff is high. Saturated hydraulic conductivity is moderately high or high (4.23 to 14.11 micrometers/s) above the fragipan and low to moderately high (0.07 to 1.41 micrometers/s) in the fragipan and below. Permeability is moderate in the upper part of the solum and very slow in the fragipan. Depth to an intermittent perched high water table is at 46 to 106 cm (1.5 to 3.5 feet) from January through April in most years.

USE AND VEGETATION: Many areas of Ava soils are cultivated. Corn, soybeans, small grain, and pasture are the main crops. Some areas are in woodland. Native vegetation is deciduous trees.

DISTRIBUTION AND EXTENT: Southern Illinois, South-Western Indiana, and Ohio. Ava soils are extensive (more than 500,000 acres correlated), and are mainly in MLRA's 113 and 114B.

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

SERIES ESTABLISHED: Washington County, Illinois, 1927.

REMARKS: We now believe that the illuvial layer of the lower sequum (B't horizon) is the main part of the argillic horizon, and that the part of the solum that meets the current definition of a fragipan horizon is below the B't horizon. Horizon designations have been adjusted to reflect this thinking. Water is perched on the B't horizon or on the fragipan, and free water flows laterally through or above the B/E horizon.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to a depth of 36 cm (14 inches), (Ap, E, and BE horizons);
Argillic horizon - the zone from 36 to 130 cm (14 to 50 inches), (Bt, Bt/E, B't, 2Btx1 and 2Btx2 horizons);
Fragipan - the zone from 86 to 130 cm (34 to 50 inches), (2Btx1 and 2Btx2 horizons);
Udic moisture regime;

ADDITIONAL DATA: Data for several pedons are on file at the Illinois state office. Engineering test data for the typical pedon is published in
the Soil Survey of Edwards and Richland Counties, Illinois. Also lab data from Indiana is on file at the Major Land Resource Area Office (MO11) at Indianapolis.

National Cooperative Soil Survey
U.S.A.