LOCATION PIERRON ILEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Typic Albaqualfs
TYPICAL PEDON: Pierron silt loam - nearly level in a cultivated field at an elevation of about 540 feet. (Colors are for moist soil unless otherwise stated.When described April 26, 1994, the soil was moist throughout.)
Ap--0 to 8 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; moderate medium granular structure; very friable; many very fine and common fine roots; few fine tubular pores; many distinct light brownish gray (10YR 6/2) dry, clay depletions throughout; few fine rounded black (5YR 2.5/1) iron-manganese nodules with sharp boundaries throughout; slightly acid; abrupt smooth boundary. (6 to 9 inches thick)
Eg1--8 to 12 inches; grayish brown (10YR 5/2) silt loam, light gray (10YR 7/2) dry; weak thin platy structure; very friable; few very fine roots; common very fine and fine tubular pores; common distinct light gray (10YR 7/1) dry, clay depletions on faces of peds; few medium distinct yellowish brown (10YR 5/4) masses of iron accumulation in the matrix; many fine and medium rounded reddish brown (5YR 4/4) and dark reddish brown (5YR 2.5/2) iron-manganese nodules with clear boundaries throughout; moderately acid; clear smooth boundary.
Eg2--12 to 20 inches; light brownish gray (10YR 6/2) silt loam, light gray (10YR 7/1) dry; moderate thick platy structure parting to weak fine subangular blocky; very friable; few very fine roots; common very fine tubular pores; many distinct white (10YR 8/1) dry, clay depletions on faces of peds; few distinct very dark grayish brown (10YR 3/2) organic coatings lining root channels; common medium prominent light olive brown (2.5Y 5/4) and few fine distinct dark yellowish brown (10YR 4/4) masses of iron accumulation in the matrix; common medium rounded black (5YR 2.5/1) iron-manganese nodules with clear reddish brown (5YR 4/4) boundaries throughout; strongly acid; abrupt smooth boundary. (Combined thickness of the Eg horizon is 8 to 15 inches.)
Btg1--20 to 29 inches; light brownish gray (2.5Y 6/2) silty clay; moderate medium prismatic structure parting to strong fine and medium angular blocky; very firm; few very fine roots; few prominent very dark grayish brown (10YR 3/2) organic coatings lining root channels; many prominent grayish brown (2.5Y 5/2) clay films on faces of peds; common medium prominent yellowish brown (10YR 5/4) and few fine distinct light olive brown (2.5Y 5/4) masses of iron accumulation in the matrix; common medium rounded dark reddish brown (5YR 2.5/2) iron-manganese nodules with clear strong brown (7.5YR 4/6) boundaries throughout; very strongly acid; clear smooth boundary.
Btg2--29 to 36 inches; light brownish gray (2.5Y 6/2) silty clay; strong medium prismatic structure parting to moderate medium angular blocky; very firm; common prominent very dark grayish brown (10YR 3/2) organic coatings lining root channels and pores; many prominent grayish brown (2.5Y 5/2) clay films on faces of peds; common coarse prominent yellowish brown (10YR 5/6) masses of iron accumulation in the matrix; common medium rounded dark reddish brown (5YR 2.5/2) iron-manganese nodules with clear strong brown (7.5YR 4/6) boundaries throughout; very strongly acid; clear smooth boundary.
Btg3--36 to 44 inches; light brownish gray (2.5Y 6/2) silty clay loam; moderate coarse prismatic structure parting to moderate medium angular blocky; very firm; common prominent very dark grayish brown (10YR 3/2) organic coatings lining root channels; many distinct grayish brown (2.5Y 5/2) clay films on faces of peds; many coarse prominent strong brown (7.5YR 5/6) masses of iron accumulation in the matrix; common medium rounded black (5YR 2.5/1) iron-manganese nodules with clear strong brown (7.5YR 4/6) boundaries throughout; strongly acid; clear smooth boundary.
Btg4--44 to 55 inches; light olive gray (5Y 6/2) silty clay loam; moderate coarse prismatic structure parting to moderate medium subangular blocky; firm; common distinct dark gray (10YR 4/1) organic coatings lining root channels; common distinct grayish brown (2.5Y 5/2) clay films on faces of peds; common coarse prominent strong brown (7.5YR 5/6) and common medium prominent light olive brown (2.5Y 5/6) masses of iron accumulation in the matrix; common medium rounded black (5YR 2.5/1) iron-manganese nodules with clear strong brown (7.5YR 4/6) boundaries throughout; moderately acid; gradual smooth boundary.
Btg5--55 to 66 inches; light olive gray (5Y 6/2) silty clay loam; weak coarse prismatic structure; friable; common distinct grayish brown (2.5Y 5/2) clay films on faces of peds; common medium prominent brownish yellow (10YR 6/8) and yellowish brown (10YR 5/8) masses of iron accumulation in the matrix; few fine irregular black (5YR 2.5/1) iron-manganese nodules with clear boundaries and common fine and medium strong brown (7.5YR 5/6) masses of iron-manganese accumulation in the matrix; slightly acid; clear smooth boundary. (Combined thickness of the Btg horizon is 36 to 56 inches.)
2Cg--66 to 80 inches; grayish brown (2.5Y 5/2) silt loam; massive; friable; common fine and medium prominent brownish yellow (10YR 6/6) masses of iron accumulation in the matrix; few fine and medium irregular black (10YR 2/1) soft masses of iron-manganese with diffuse strong brown (7.5YR 4/6) boundaries throughout; about 10 percent sand; neutral.
TYPE LOCATION: Madison County, Illinois; about 2 miles northeast of Marine; approximately 1,730 feet east and 80 feet south of the northwest corner of sec. 14, T. 4 N., R. 6 W.; USGS Grantfork, Illinois, topographic quadrangle; lat. 38 degrees 48 minutes 2 seconds N., and long. 89 degrees 44 minutes 19 seconds W.; UTM Zone 16S, 0262130 Easting and 4297983 Northing; NAD 27
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon and depth to the base of soil development is 50 to 80 inches. Loess thickness typically is 55 to 80 inches. The particle-size control section averages 35 to 45 percent clay,
and the maximum clay content in any subhorizon is 48 percent. Sand content of the Ap and Eg horizons is less than 15 percent and includes iron-manganese nodules and concretions. Sand content is less than 7 percent in the particle-size control section. Carbonates, where present, are below a depth of 5 feet.
Some pedons contain krotovina. The mean annual soil temperature ranges from 56 to slightly less than 59 degrees F.
The Ap horizon has hue of 10YR, value of 4 or 5, and chroma of 1 or 2. Some undisturbed pedons have a thin A horizon with a color value of 3. Clay content averages 12 to 25 percent. Reaction is very strongly acid to neutral, depending on the liming history.
The Eg horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 1 or 2. It is silt loam or silt. Clay content averages 10 to 22 percent. Reaction is very strongly acid to moderately acid when not limed. Pedons that have been limed range to neutral.
Some pedons have a B/E horizon less than 3 inches in thickness immediately below the Eg horizon.
The Btg horizon has hue of 10YR, 2.5Y, or 5Y; value of 4 to 6; and chroma of 1 or 2. Redoximorphic features have hue of 5YR, 7.5YR, 10YR, 2.5Y, 5Y, or are neutral; value of 2 to 7; and chroma of 0 to 8. It is silty clay loam or silty clay and the zone of maximum clay is in the upper part. Clay content is 35 to 45 percent in the upper part and is 27 to 42 percent in the lower part. Reaction is extremely acid to strongly acid in the upper part and very strongly acid to slightly acid in the lower part.
Some pedons have a BCg horizon. It is silty clay loam or silt loam. Reaction is very strongly acid to slightly acid.
The Cg or 2Cg horizon has hue of 7.5YR, 10YR, 2.5Y, 5Y, or is neutral; value of 4 to 7; and chroma of 0 to 2. It typically is silt loam, but some pedons have a 2Cg horizon or buried horizons of older soils below a depth of 55 inches. These horizons are silt loam, loam, silty clay loam, or clay loam. Sand content is 7 to 30 percent. Reaction is strongly acid to neutral.
COMPETING SERIES: These are the
Ames,
Leaksville,
Rushville,
Watchung,
Wynoose, and
Zwingle series. Ames and Wynoose soils average more than 15 percent sand in some horizon within a depth of 40 inches. Leaksville soils have a lithic contact within a depth of 40 inches. Rushville soils have a mean annual soil
temperature less than 56 degrees F. Watchung soils are less than 40 inches to the base of the argillic horizon. Zwingle soils average more than 50 percent clay in the particle size control section and have hue redder than 10YR in the subsoil.
GEOGRAPHIC SETTING: Pierron soils are on nearly level or slightly depressional parts of broad interfluves on till plains. Slope ranges from 0 to 1 percent. These soils formed in more than 55 inches of loess. In pedons with less than 80 inches of loess, the lower part of the soil formed in silty pedisediment that contains a component of sand. 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 Coulterville, Cowden, Darmstadt, Marine, Oconee, and Homen soils. The somewhat poorly drained Coulterville, Darmstadt, Marine, and Oconee soils and the moderately well drained Homen soils are on convex summits and side slopes above the Pierron soils or on side slopes of drainageways below them. In addition Darmstadt soils have a natric horizon, Coulterville soils contain a oncentration of sodium in the subsoil, and Oconee soils have a dark surface layer. The poorly drained Cowden soils have a dark surface layer and are on similar landscape positions as the Pierron soils.
DRAINAGE AND PERMEABILITY: Poorly drained. Permeability is very slow. Surface runoff is very slow or ponded. In drained areas, depth to an intermittent perched high water table is 0.5 foot above the surface to 1 foot below from December to May in most years.
USE AND VEGETATION: Most areas are cropped to corn, soybeans, and small grain. Native vegetation is mixed hardwood forest.
DISTRIBUTION AND EXTENT: Southwestern and southeastern Illinois. Extent is moderate and mainly in MLRA 114.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Madison County, Illinois, 1995. The Pierron series was named for a town in Madison County.
REMARKS: Pierron soils were formerly included with the cool mesic Rushville series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surfaces to a depth of 20 inches (Ap, Eg1, and Eg2 horizons);
Albic horizon - the zone from 8 to 20 inches (Eg1 and Eg2 horizons);
Albaqualf feature - abrupt textural change from the Eg2 horizon to the Btg1 horizon;
Argillic horizon - the zone from approximately 20 to 66 inches (Btg1, Btg2, Btg3, Btg4, and Btg5 horizons);
Aquic conditions - periodic saturation and reduction indicated by redoximorphic features throughout the soil.
ADDITIONAL DATA: See the Washington County Typical Pedon for the Rushville series (S90IL-189-1, NSSL pedon number: 90P0534).