LOCATION REND ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, mesic Fragic Oxyaquic Hapludalfs
TYPICAL PEDON: Rend silt loam - on a 6 percent linear back slope in a grass field. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 5 inches; dark brown (10YR 4/3) silt loam, pale brown (10YR 6/3) dry; weak fine angular blocky structure parting to weak fine granular; friable; many fine roots throughout; few fine rounded iron-manganese concretions; slightly acid; abrupt smooth boundary. (4 to 8 inches thick)
Bt1--5 to 15 inches; yellowish brown (10YR 5/4) silty clay loam; moderate fine prismatic structure parting to strong fine subangular blocky; firm; common fine roots between peds; common distinct dark yellowish brown (10YR 4/6) clay films on faces of peds and in pores; few fine rounded iron-manganese concretions; about 5% sand; very strongly acid; abrupt smooth boundary.
Bt2--15 to 24 inches; yellowish brown (10YR 5/4) silty clay loam; common medium prominent strong brown (7.5YR 5/6) redox accumulations; strong medium prismatic structure parting to moderate medium subangular blocky; firm; common very fine and fine roots between peds; many distinct brown (10YR 4/3) clay films on faces of peds and in pores; few fine rounded iron-manganese concretions; about 5% sand; very strongly acid; abrupt smooth boundary.
2Btx1--24 to 40 inches; yellowish brown (10YR 5/6) silt loam; common medium faint yellowish brown (10YR 5/4) and common fine and medium distinct light brownish gray (10YR 6/2) redox depletions; weak coarse prismatic structure; firm; brittle; few very fine roots between prisms; few prominent light gray (10YR 6/1) silt coatings on faces of peds; few distinct dark yellowish brown (10YR 4/4) clay films on faces of peds and in pores; few fine rounded iron-manganese concretions; about 20 percent sand; very strongly acid; clear smooth boundary.
2Btx2--40 to 50 inches; yellowish brown (10YR 5/4) silt loam; common fine and medium distinct light brownish gray (10YR 6/2) redox depletions; weak coarse prismatic structure; firm; brittle; few very fine roots between prisms; few prominent light gray (10YR 6/1) silt coatings on faces of prisms; few distinct dark yellowish brown (10YR 4/4) clay films on faces of peds and in pores; common fine rounded iron-manganese accumulations; about 20 percent sand; strongly acid; clear smooth boundary.
2Btx3--50 to 61 inches; yellowish brown (10YR 5/4) silt loam; many fine and medium yellowish brown (10YR 5/6) redox accumulations; moderate coarse prismatic structure; firm; brittle; few distinct dark yellowish brown (10YR 4/4) clay films on faces of peds and in pores; few prominent black (2.5Y 2/0) iron-manganese stains on prisms; common fine and medium rounded iron-manganese accumulations; about 20 percent sand; slightly acid.
TYPE LOCATION: Franklin County, Illinois; about one-quarter mile northwest of maintenance office of Wayne Fitzgarrell State Park; 710 feet south and 320 feet west of the northeast corner of section 14, T. 5 S., R. 2 E.
RANGE IN CHARACTERISTICS: The depth to the top of the brittle layer ranges from 16 to 40 inches. The particle size control section averages between 27 and 35 percent clay.
The upper one-third to one-half of the control section has average sand content of 2 to 10 percent, and an average coarse fragment content of 0 to 1 percent. Reaction ranges from moderately acid to extremely acid. Liming has raised the pH in the surface layer in some pedons. Individual horizons have properties as follows:
The Ap horizon has value of 4 or 5, and chroma of 2 or 3. It typically is silt loam, but includes silty clay loam in some eroded pedons.
Some pedons have an E horizon that is 2 to 6 inches in thickness. It is silt loam.
The Bt horizon has value of 4 to 6, and chroma of 3 to 6. It is silty clay loam or silt loam. It is strongly acid or very strongly acid.
The lower one-half to two-thirds of the control section is brittle in at least the upper subhorizons. Average sand content ranges from 15 to 45 percent, and an average coarse fragment content of 1 to 15 percent. Individual horizons have properties as follows:
The 2Btx (or Bx, 2Bx, or 2Btx) horizon has hue of 10YR or 7.5YR, value of 4 to 6, and chroma of 2 to 8. The primary structure is coarse prismatic. It is brittle. The prisms or groups of prisms are separated or surrounded by cracks filled with silt or silt loam that has grayer color than the interiors of the prisms. It is silt loam or silty clay loam. The average clay content ranges form 20 to 30 percent.
Some pedons have 3Bt horizons with hue of 10YR, 7.5YR, or 2.5Y, value of 4 to 6, and chroma of 1 to 6. It is loam, silt loam, clay loam, or silty clay loam. Clay content ranges form 18 to 35 percent and sand content ranges from 15 to 45 percent. Coarse fragment content ranges from 1 to 15 percent.
COMPETING SERIES: This is the Wrengart series. Wrengart soils have more than 15 percent rock fragments in the lower part of the series control section.
GEOGRAPHIC SETTING: Rend soils are on gently sloping, convex summits and shoulder slopes and on convex to linear back slopes of valley benches, mainly adjacent to tributaries of the Mississippi River. Slopes range from 5 to 10 percent. Rend soils formed in 16 to 40 inches of Peorian loess and in 30 to 60 inches of other silty to loamy materials which overly valley fill materials. The second increment of silty material is thought to be erosional sediments (pedisediment) or locally reworked A horizon of paleosols and early Wisconsinan loess (mixed zone). It often contains a few igneous pebbles or coarse fragments from local bedrock deposited as glacial drift. The mean annual air temperature ranges from 54 to 57 degrees F, mean annual precipitation ranges from 40 to 45 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the bench phases of Bluford, Cisne, and Wynoose soils. The somewhat poorly drained Bluford soils and poorly drained Cisne and Wynoose soils are on broader summits or in lower positions than the Rend soils.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is medium. Permeability is moderate in the upper part and slow in the lower part. The perched seasonal high water is at a depth of 2 to 3.5 feet during late winter through spring in most years.
USE AND VEGETATION: Most areas of Rend soils are used to grow corn, grain sorghum, soybeans, wheat and pasture. Native vegetation is deciduous forest consisting mainly of oaks and hickory.
DISTRIBUTION AND EXTENT: Southern Illinois. Rend soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Franklin County, Illinois, 1993.
REMARKS: Classification was adjusted to agree with ST Issue #17 on 23 Aug 94 by CLG. The geomorphology of these soils is the subject of a study being conducted by the NSSL and NSSC.
Diagnostic horizons and features recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 5 inches (Ap horizons); argillic horizon - the zone from 5 to 61 inches (Bt and 2Bt horizons); fragic properties - coarse structure and brittleness - the zone from 24 to 61 inches