LOCATION PRAIRIEVILLE ILEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Oxyaquic Argiudolls
TYPICAL PEDON: Prairieville silt loam - on a southwest-facing slope of 1 percent in a cultivated field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 9 inches; very dark gray (10YR 3/1) silt loam; dark grayish brown (10YR 4/2) dry; moderate medium granular structure; friable; common fine roots; neutral; abrupt smooth boundary.
A--9 to 12 inches; very dark grayish brown (10YR 3/2) silt loam; dark grayish brown (10YR 4/2) dry; moderate medium granular structure; friable; common fine roots; medium acid; clear smooth boundary. (Combined thickness of the A horizon is 10 to 20 inches.)
BA--12 to 18 inches; dark brown (10YR 4/3) silt loam; moderate medium subangular blocky structure; friable; common fine roots; many thin very dark grayish brown (10YR 3/2) organic coats on faces of peds; strongly acid; clear smooth boundary.
Bw--18 to 26 inches; brown (10YR 4/3) loam; moderate medium subangular blocky structure; friable; few fine roots; common thin very dark grayish brown (10YR 3/2) organic coats on faces of peds; few pebbles 2-5 mm in diameter; strongly acid; clear smooth boundary. (Combined thickness of the BA and Bw horizons is 3 to 19 inches.)
2Bt1--26 to 31 inches; yellowish brown (10YR 5/6) clay loam; moderate medium subangular blocky structure; firm; few fine roots; common thin dark grayish brown (10YR 4/2) clay films on faces of peds; few pebbles 2-20 mm in diameter; strongly acid; clear smooth boundary.
2Bt2--31 to 41 inches; yellowish brown (10YR 5/6) clay loam; few fine distinct strong brown (7.5YR 5/8) mottles; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; few fine roots; common thin dark yellowish brown (10YR 4/4) clay films on faces of peds; few dark concretions (Fe & Mn) oxides; strongly acid; clear smooth boundary.
2Bt3--41 to 57 inches; yellowish brown (10YR 5/6) clay loam; few fine distinct strong brown (7.5YR 5/8) and few fine faint brownish yellow (10YR 6/8) mottles; moderate medium prismatic structure parting to moderate medium subangular blocky; firm; few fine roots; many moderately thick dark brown (10YR 4/3) clay films on faces of peds; few dark concretions (Fe & Mn) oxides; slightly acid; clear smooth boundary.
2Bt4--57 to 60 inches; yellowish brown (10YR 5/4) clay loam; few fine distinct strong brown (7.5YR 5/8) mottles; weak coarse prismatic structure; firm; few fine roots; few dark grayish brown (10YR 4/2) root channel fillings; neutral. (Combined thickness of the 2Bt horizon is 30 to 52 inches.)
TYPE LOCATION: Lee County, Illinois; about 1 1/2 miles northwest of Amboy, Illinois; 1,855 feet north and 346 feet west of the southeast corner of sec. 5, T. 20 W., R. 10 E.
RANGE IN CHARACTERISTICS: The solum typically is more than 5 feet thick and ranges from 48 inches to more than 75 inches. The depth to free carbonates is greater than 60 inches. The mollic epipedon ranges from 10 to 15 inches in thickness. The depth to the 2B horizon ranges from 13 to 34 inches. The control section averages from 30 to 35 percent clay and from 25 to 45 percent sand.
The A horizon has hue of 10YR, value of 2 or 3 moist and 3 through 5 dry, and chroma of 1 through 3. It typically is silt loam but some pedons are loam. It ranges from medium acid to neutral.
The BA or Bw horizon formed in loamy aeolian material. It has hue of 10YR, value of 4 or 5, and chroma of 3 or 4. It commonly is silt loam or loam but ranges to clay loam or silty clay loam. It typically is medium acid or slightly acid but ranges from very strongly acid to neutral in some subhorizons. Some pedons contain only a BA horizon in this material and some pedons contain both BA and Bw horizons. The Bw horizon contains clay films on faces of peds on some pedons.
Many of the properties of the 2Bt horizon are believed to be inherited from a paleosol of probable Sangamon age truncated by Wisconsinan glacial meltwaters. Matrix colors typically have hue of 10YR or 7.5YR, value of 4 through 6, and chroma of 3 through 8; but some pedons have one or more subhorizons with hue of 2.5Y or 5Y, value of 4 through 7, and chroma of 1 through 8. It commonly is clay loam but some pedons have subhorizons that are loam or clay depending on the degree of truncation. Vertical wedges of sandy loam or loamy sand are in the till in some pedons. The upper part is strongly acid to slightly acid. The lower part ranges from medium acid to neutral.
The 2C horizon, where present, has hue of 10YR or 7.5YR in the matrix, value of 4 through 6, and chroma of 4 through 8. It commonly is mottled with low and high chroma mottles. It is clay loam, loam, or silt loam. It ranges from slightly acid to mildly alkaline and lacks free cabronates above a depth of 60 inches.
COMPETING SERIES: These are the Atkinson, Burchard, Calmar, Corwin, Cresco, Durand, Foresman, Friesland, Griswold, Hitt, Hochheim, Jasper, Joslin, La Rose, Linkville, Markesan, Moingona, Mona, Morrill, Pana, Parr, Plattville, Ringwood, Rockton, Rotamer, Schoolcraft, Shelby, Sibleyville, Symerton, Tippecanoe, Velma, Wea, and Winnebago series in the same family and the Assumption, Douglas, and Harrison series. Atkinson, Hitt, and Plattville soils have sola terminated by bedrock between depths of 40 and 60 inches. Burchard, Corwin, Foresman, Griswold, Hochheim, La Rose, Markesan, Mona, Parr, Ringwood, Rotamer, Symerton, and Velma have free carbonates within a depth of 60 inches. Calmar, Rockton, and Sibleyville soils have sola terminated by bedrock of limestone or sandstone at depths of less than 40 inches. Cresco soils formed on the Iowan erosional surface in finer textured Kansas till and are characterized by very firm consistence in the argillic horizon, higher content of clay in the lower part of the solum and the C horizon, and a more distinct band of coarse fragments in the upper part of the 2B horizons. Durand and Winnebago soils have hue of 5YR or redder in the matrix or as mottles in some part of the argillic horizon and contain more sand in the lower part of the sola. Friesland soils contain less clay in the argillic horizon. Jasper soils lack 2B horizons and are generally more friable and contain more sand and less clay in and below the argillic horizon. Joslin soils contain less than 27 percent clay in the control section and more than 35 percent in the 2B horizon which formed in lacustrine materials. Linkville, Pana, Schoolcraft, Tippecanoe, and Wea soils contain more sand and gravel in the lower part of the sola and in the underlying material. Moingona soils formed in alluvium and colluvium, lack a 2B horizon, and have less clay in the argillic horizon. Morrill soils formed in loamy till or outwash deposits and contain more sand throughout and coarser sand and redder hues in the upper part of the solum. Shelby soils contain more clay in the upper part of the solum and lack 2B horizons. In addition, they commonly contain free carbonates between depths of 40 and 60 inches. Assumption, Douglas, and Harrison soils are fine-silty and, in addition, Douglas and Harrison soils have their 2B horizons beneath 40 to 60 inches of loess.
GEOGRAPHIC SETTING: Prairieville soils are on till plains. Slope gradients commonly are 1 to 5 percent but range from 0 to 5 percent. They formed in 13 to 34 inches of loamy aeolian sediments and in paleosols of Sangamon age formed in Illinoian till. Mean annual temperature ranges from 37 to 52 degrees F, and mean annual precipitation ranges from 32 to 36 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Parr soils and the Nachusa, Odell, and Wolcott soils. The well drained Parr soils and the somewhat poorly drained Odell soils have thinner sola and commonly occur downslope from Prairieville soils in calcareous loam till and commonly are adjacent to major drainageways. The somewhat poorly drained Nachusa soils and the poorly drained Wolcott soils form a drainage sequence with Prairieville soils.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is medium. Permeability is moderate in the loamy sediments and moderately slow in the paleosolic till.
USE AND VEGETATION: Mainly cropped. Corn, meadow, soybeans, and small grain are the principal crops. Native vegetation was prairie grass.
DISTRIBUTION AND EXTENT: Northern Illinois. The soils of this series are not extensive.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Lee County, Illinois, 1981.
REMARKS: Classification was adjusted to agree with ST Issue #17 on 23 Aug 94 by CLG. These soils are borderline between fine-loamy and fine.
ADDITIONAL DATA: Mechanical analysis data are on file in the Illinois state office for two pedons including the typical pedon.