LOCATION AVISTON ILEstablished Series
The Aviston series consists of very deep, moderately well drained, moderately permeable soils formed in loess or in loess and silty pedisediment on till plains. Slope ranges from 2 to 10 percent. Mean annual precipitation is about 38 inches, and mean annual temperature is about 55 degrees F.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Oxyaquic Argiudolls
TYPICAL PEDON: Aviston silt loam - with an east-facing slope with a 3 percent gradient on a convex summit in a cultivated field at an elevation of about 500 feet above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 10 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; moderate very fine granular structure; friable; common very fine and fine roots throughout; about 18 percent clay; neutral; abrupt smooth boundary.
A--10 to 16 inches; very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak fine and medium subangular blocky structure parting to moderate fine granular; friable; common very fine and fine roots throughout; common distinct very dark gray (10YR 3/1) organic coatings on faces of peds; about 22 percent clay; neutral; clear smooth boundary. (Combined thickness of the Ap and A horizons is 10 to 20 inches.)
Bt1--16 to 23 inches; brown (10YR 4/3) silty clay loam; moderate fine prismatic structure parting to moderate medium subangular blocky; friable; common very fine roots between peds; many distinct very dark grayish brown (10YR 3/2) organo-clay films on faces of peds; about 33 percent clay; slightly acid; clear smooth boundary.
Bt2--23 to 32 inches; brown (10YR 5/3) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; friable; common very fine roots between peds; many distinct very dark grayish brown (10YR 3/2) organo-clay films on faces of peds and few prominent very dark gray (10YR 3/1) organic coatings lining root channels; common fine faint light brownish gray (10YR 6/2) iron depletions and common fine distinct yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; common fine and medium irregular black (10YR2/1) masses of iron-manganese accumulation; about 30 percent clay; slightly acid; clear smooth boundary.
Bt3--32 to 39 inches; brown (10YR 5/3) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; friable; few very fine roots between peds; common distinct dark grayish brown (10YR 4/2) clay films on faces of peds and few prominent very dark gray (10YR 3/1) organic coatings lining root channels; common fine faint light brownish gray (10YR 6/2) iron depletions and common fine distinct yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; common fine and medium irregular black (10YR 2/1) masses of iron-manganese accumulation; about 28 percent clay; slightly acid; gradual smooth
boundary.
Bt4--39 to 48 inches; brown (10YR 5/3) silty clay loam; moderate medium prismatic structure; friable; few very fine roots between peds; common distinct dark grayish brown (10YR 4/2) clay films on vertical faces of peds and few prominent very dark gray (10YR 3/1) organic coatings lining root channels; common fine faint light brownish gray (10YR 6/2) iron depletions and common fine prominent strong brown (7.5YR 4/6) masses of iron accumulation in the matrix; common fine and medium irregular black (10YR 2/1) masses of iron-manganese accumulation; about 28 percent clay; slightly acid; gradual smooth boundary.
Bt5--48 to 67 inches; brown (10YR 5/3) silt loam; weak medium prismatic structure; friable; few very fine roots between peds; few faint grayish brown (10YR 5/2) clay films on vertical faces of peds and very few prominent very dark gray (10YR 3/1) organic coatings lining root channels; many fine faint light brownish gray (10YR 6/2) iron depletions and common fine prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; common fine and medium irregular black (10YR 2/1) masses of iron-manganese accumulation; about 24 percent clay; slightly acid; clear smooth boundary. (Combined thickness of the Bt horizon is 42 to 60 inches.)
2BC--67 to 84 inches; brown (7.5YR 5/3) silt loam; weak coarse prismatic structure; friable; few distinct brown (10YR 4/3) clay films on vertical faces of peds; many medium faint light brown (7.5YR 6/2) iron depletions and many fine and medium distinct strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; few fine irregular black (10YR 2/1) masses of iron-manganese accumulation; about 17 percent clay; slightly acid.
TYPE LOCATION: Washington County, Illinois; about 1 mile southwest of Addieville,
approximately 2,540 feet north and 1,820 feet east of the southwest corner of sec. 2, T. 2 S., R. 4 W.; USGS OKAWVILLE, ILL. topographic quadrangle; lat. 38 degrees 22 minutes 53 seconds N. and long. 89 degrees 30 minutes 20 seconds W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon is 52 to more than 80 inches. Loess is 60 to about 80 inches in thickness. Depth to carbonates, if present, is more than 60 inches. The particle-size control section averages 27 to 35 percent clay and contains less than 7 percent sand. The mean annual soil temperature is 56 to slightly less than 59 degrees F.
The upper part of the series control section (Ap and A) has hue of 10YR, value of 3 (5 dry), andchroma of 1 to 3. In undisturbed areas the A horizon has value of 2 or 3 (4 or 5 dry) and chroma of 1 or 2. Clay content is 15 to 27 percent and sand content is less than 7 percent. Reaction is moderately acid to neutral, depending on the liming history.
Some pedons have an AB or a BA horizon.
The middle part of the series control section (Bt) has hue of 7.5YR, 10YR, 2.5Y; value of 4 to 6; and chroma of 3 to 6 (2 to 6 in the lower part). Redoximorphic iron depletions are in the lower part, above 40 inches. It typically is silty clay loam, but the lower part is silt loam in some pedons. Clay content is 27 to 35 percent in the upper part and is 24 to 32 percent in the lower part. Reaction is strongly acid to neutral.
The lower part of the series control section (2Bt, 2BC, and 2C, where present) has hue of 7.5YR, 10YR, or 2.5Y; value of 5 or 6; and chroma of 1 to 4. It is silt loam, but is silty clay loam in the upper part in some pedons. Clay content is 18 to 30 percent in the upper part and is 15 to 27 percent in the lower part. Sand content is less than 15 percent. Reaction is moderately acid to slightly alkaline.
COMPETING SERIES: These are the Assumption, Barrington, Blackberry, Catlin, Clare, Dana, Danabrook, Geryune, Graymont, Harrison, Keltner, Saybrook, and Totanang (T) series. Assumption, Barrington, Blackberry, Clare, Dana, Danabrook, Geryune, Keltner, Saybrook, and Totanang (T) soils have a mean annual soil temperature less than 56 degrees F. and contain more than 15 percent sand in the lower part of the series control section. In addition, Keltner soils have a paralithic contact at depths of 40 to 60 inches. Catlin soils contain more than 15 percent sand in the lower part of the series control section and have carbonates at depths of 40 to 60 inches. Graymont soils have a mean annual soil temperature less than 56 degrees F. and have carbonates at depths of less than 40 inches. Harrison soils contain more than 15 percent sand in the lower part of the series control section.
GEOGRAPHIC SETTING: The Aviston soils are on gently sloping to moderately sloping convex summits, shoulders, and backslopes on till plains. Slope ranges from 2 to 10 percent. These soils formed in loess or in loess and the underlying silty pedisediment. The pedisediment is below a depth of 60 inches, where present. The sequence of materials is: Peoria Silt, Roxana Silt, silty pedisediment, and Illinoian drift (typically with a strongly developed paleosol). Mean annual temperature is 54 to 57 degrees F., mean annual precipitation is 36 to 40 inches, frost-free period is 170 to 200 days, and elevation is 400 to 800 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Herrick,
Homen,
Negley,
Oconee,
Ruma, and
Virden soils. The somewhat poorly drained Herrick soils and the poorly drained Virden soils are on nearly level interfluves nearby and they form a hydrosequence with the Aviston soils. The moderately well drained Homen soils are in similar landscape positions closer to the drainageways and they form a biosequence with the Aviston soils. The well drained Negley soils developed in strongly weathered Illinois outwash and are on steep slopes below the Aviston soils. The somewhat poorly drained, fine-textured Oconee soils are on less sloping summits closer to the drainageways. The well drained Ruma soils are on convex slopes closer to the drainageways.
DRAINAGE AND PERMEABILITY: Moderately well drained and moderate permeability. The potential for surface water runoff is medium. Depth to an intermittent apparent high water table is 2.0 to 3.5 feet from January to April in most years.
USE AND VEGETATION: Most areas are cropped to corn, soybeans, and wheat. Native vegetation is tall prairie grasses.
DISTRIBUTION AND EXTENT: Southwestern Illinois. Extent is moderate and mainly in MLRA(s) 108B and 114.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Washington County, Illinois, 1995. The Aviston series was named for a town in Clinton County.
REMARKS: Aviston soils were formerly included with the Harrison series (Oxyaquic
Argiudolls).
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 16 inches (Ap and A horizons). Argillic horizon - the zone from approximately 16 to 67 inches (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons). Redoximorphic iron depletions - the zone from 23 to 84 inches (Bt2, Bt3, Bt4, Bt5, and 2BC horizons). Udic moisture regime.
ADDITIONAL DATA: See pedon S89IL-027-148 sampled as the Harrison series in Clinton County, Illinois and analyzed by the NSSL in Lincoln, Nebraska; samples
89P-487-2725-2736.