LOCATION RUMA ILEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Hapludalfs
TYPICAL PEDON: Ruma silty clay loam - in an area of Ruma-Atlas complex, severely eroded; in a hay field on a south-facing shoulder slope with a gradient of 12 percent at an elevation of about 485 feet above sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 5 inches; mixed dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/4) silty clay loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky structure; friable; many very fine and common fine and medium roots; few very fine and fine constricted tubular pores; about 29 percent clay; slightly acid; abrupt smooth boundary. (3 to 10 inches thick)
Bt1--5 to 13 inches; yellowish brown (10YR 5/4) silty clay loam; moderate medium subangular blocky structure; firm; common very fine and few fine and medium roots; many distinct dark brown (10YR 3/3) clay films on faces of peds; about 33 percent clay; strongly acid; clear smooth boundary.
Bt2--13 to 28 inches; dark yellowish brown (10YR 4/6) silty clay loam; moderate fine prismatic structure parting to moderate medium angular blocky; firm; common very fine and few fine roots; many distinct dark yellowish brown (10YR 3/4) clay films on faces of peds; about 32 percent clay; strongly acid; gradual smooth boundary.
Bt3--28 to 40 inches; dark yellowish brown (10YR 4/6) silty clay loam; moderate medium prismatic structure parting to moderate medium and coarse angular blocky; firm; few very fine roots; few very fine constricted tubular pores; common distinct dark yellowish brown (10YR 4/4) clay films on faces of peds; few prominent black (10YR 2/1) iron-manganese coatings on vertical faces of peds and lining root channels; about 28 percent clay; moderately acid; gradual smooth boundary.
Bt4--40 to 48 inches; yellowish brown (10YR 5/6) silt loam; weak medium prismatic structure; friable; few very fine roots; few very fine and fine constricted tubular pores; few distinct dark yellowish brown (10YR 4/4) clay films on vertical faces of peds; few fine rounded very dark brown (7.5YR 2.5/2) masses of iron-manganese accumulation with clear strong brown (7.5YR 5/6) boundaries; about 23 percent clay; slightly acid; clear smooth boundary. (Combined thickness of the Bt horizon is 37 to 60 inches.)
2BCt1--48 to 62 inches; brown (7.5YR 4/4) silt loam; massive; friable; few very fine roots; common very fine and fine tubular pores; very few distinct dark yellowish brown (10YR 4/4) clay films lining root channels; few fine rounded very dark brown (7.5YR 2.5/2) masses of iron-manganese accumulation with clear strong brown (7.5YR 5/6) boundaries; about 25 percent clay and 8 percent sand; slightly acid; gradual smooth boundary.
2BCt2--62 to 95 inches; brown (7.5YR 4/4) silt loam; massive; friable; few very fine roots; few fine and medium tubular pores; very few distinct dark yellowish brown (10YR 4/4) clay films lining root channels; few fine distinct pinkish gray (7.5YR 6/2) iron depletions along root channels; few fine rounded black (7.5YR 2.5/1) masses of iron-manganese accumulation with clear strong brown (7.5YR 5/6) boundaries; about 24 percent clay and 12 percent sand; neutral. (Combined thickness of the 2BCt horizon is 30 to 50 inches.)
TYPE LOCATION: St. Clair County, Illinois; about 2 miles east of Floraville; approximately 1,515 feet south and 1,030 feet west of the northeast corner of sec. 7, T. 2 S., R. 8 W.; USGS MILLSTADT, ILL. topographic quadrangle; lat. 38 degrees 22 minutes, 06 seconds N. and long. 90 degrees 01 minutes 18 seconds W.
RANGE IN CHARACTERISTICS: Depth to the base of the argillic horizon is 40 to 70 inches, and the depth to the base of soil development is greater than 80 inches. The particle-size control section averages 27 to 35 percent clay and averages less than 7 percent sand.
The upper part of the series control section is as follows: The Ap horizon has value of 4 or 5 (6 or 7 dry) and chroma of 2 to 4. In undisturbed areas the A horizon has value of 3 (5or 6 dry) and chroma of 1 or 2. Texture is silt loam or silty clay loam. Clay content is 18 to 35 percent. Sand content is less than 7 percent. Reaction is moderately acid to neutral, depending on the liming history.
The E, EB, BE horizons, where present, have value of 4 or 5 and chroma of 2 to 4. Clay content is 15 to 27 percent. Reaction is very strongly acid to neutral.
The middle part of the control section (Bt, BC) has a hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 3 to 6. It is silty clay loam in the upper part and is silty clay loam or silt loam in the lower part. Clay content is 27 to 35 percent in the upper part and is 22 to 32 percent in the lower part. Reaction is very strongly acid to slightly acid.
The lower part of the control section (2Bt, 2BCt, 2CB) has hue of 7.5YR, 10YR, or 2.5Y; value of 5 or 6; and chroma of 2 to 6. Clay content is 15 to 27 percent and sand content is 7 to 15 percent. Reaction is strongly acid to neutral.
COMPETING SERIES: These are the Baraboo, Bertrand, Blackhammer, Cadiz, Camden, Dodge, Dubuque, Fayette, Flagg, Hackers, Inton, Jackson, Jemerson, Knowles, La Farge, Lomira, Marseilles, Martinsburg, Mayville, Menfro, Minnith, Palsgrove, Pepin (T), Ridgway, Rush, Russell, Sandview, Seaton, Uniontown, Weingarten, Westbend, Westmore, Yellowriver, and Zurich series.
Baraboo, Dubuque, Knowles, Palsgrove, Pepin soils have a lithic contact in the series control section. Bertrand, Blackhammer, Camden, Flagg, Jackson, Mentor, Minnith, Ridgway, and Russell soils contain more than 15 percent sand in the lower part of the series control section. Cadiz, Dodge, Lomira, Mayville, Rush, and Westmore soils have rock fragments in the lower part of the series control section. Fayette, Inton, Martinsburg soils have a mean annual soil temperature of less than 56 degrees F. in the soil temperature control section. Hackers soils have hue redder than 7.5YR in the subsoil (Bt horizon). Jemerson and Seaton soils have less than 27 percent clay in the particle-size control section. La Farge, Marseilles, and Westbend soils have a paralithic contact in the series control section. Menfro soils contain less than 7 percent sand in the lower part of the series control section. Sandview soils have more than 27 percent clay in the lower part of the series control section. Uniontown and Zurich soils have carbonates in the lower part of the series control section. Weingarten soils have a layer in the series control section that has fragic soil properties. Yellowriver soils have more than 7 percent sand in the upper part of the series control section.
GEOGRAPHIC SETTING: The Ruma soils are on gently sloping to steep convex summits, shoulders, and backslopes on till plains. Slope ranges from 2 to 35 percent. These soils formed in loess, or in loess and the underlying silty pedisediment. The upper loess is Peoria Silt and the lower loess is Roxana Silt. 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 350 to 800 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atlas, Aviston, Blair, Bunkum, Hickory, Homen, Marine, Negley, and Ursa soils.
The somewhat poorly drained Atlas soils and the well drained Hickory, Negley, and Ursa soils are on lower lying backslopes and footslopes below the Ruma soils. Hickory and Negley soils contain more sand in the series control section. The moderately well drained Aviston soils have a dark surface layer and are farther from drainageways. The somewhat poorly drained Blair and Bunkum soils are on shoulders and backslopes of dissected tillplains. The moderately well drained Homen soils are typically on less sloping summits, shoulders and backslopes. The somewhat poorly drained, fine-textured Marine soils are on broader, higher lying summits.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability, and medium or rapid surface runoff. Depth to an intermittent apparent high water table is 3.5 to 6.0 feet from December to April in most years.
USE AND VEGETATION: Most areas are cropped to corn, soybeans, and wheat. A few areas are pastured or wooded. Native vegetation is deciduous trees.
DISTRIBUTION AND EXTENT: Southwestern Illinois. Extent is large, and mainly in MLRA(s) 108B and 114.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: St. Clair County, Illinois, 1995. The Ruma series was named for a town in Randolph County.
REMARKS: Ruma soils were formerly included with the Alford series (Ultic Hapludalfs), the Fayette series (Typic Hapludalfs), and the Pike series (Ultic Hapludalfs).
Diagnostic horizons and features recognized in this pedon are: Ochric epipedon - the zone from the surface to a depth of 5 inches (Ap horizon). Argillic horizon - the zone from approximately 5 to 48 inches (Bt1, Bt2, Bt3, and Bt4 horizons). Redoximorphic iron depletions - the zone from 62 to 80 inches. Udic moisture regime.
ADDITIONAL DATA: See the lab data from St. Clair County for pedon from the Glacial Lake Kaskaskia Study, Part I (S92IL-163-008, NSSL pedon number: 92P-578-3372-3383).