LOCATION SENACHWINE IL+INEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Hapludalfs
TYPICAL PEDON: Senachwine silt loam - on an 11 percent convex slope in a cultivated field at an elevation of 856 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 6 inches; mixed brown (10YR 4/3) and yellowish brown (10YR 5/4) silt loam, pale brown (10YR 6/3) dry; moderate fine granular structure; friable; common fine roots; neutral; abrupt smooth boundary. (5 to 10 inches thick)
Bt1--6 to 15 inches; yellowish brown (10YR 5/4) silty clay loam; moderate fine subangular blocky structure; friable; few fine roots; common faint dark yellowish brown (10YR 4/4) clay films on faces of peds; moderately acid; clear smooth boundary.
2Bt2--15 to 28 inches; brown (7.5YR 5/4) clay loam; moderate medium subangular blocky structure; firm; few fine roots; many faint brown (7.5YR 4/4) clay films on faces of peds; few fine rounded black (N 2.5/0) weakly cemented iron-manganese concretions throughout; neutral; clear smooth boundary.
2BCt--28 to 34 inches; brown (7.5YR 5/4) loam; weak coarse prismatic structure; firm; few fine roots; common faint brown (7.5YR 4/4) clay films on faces of peds; 5 percent gravel; slightly effervescent; slightly alkaline; clear smooth boundary. (The combined thickness of the Bt plus 2Bt horizons ranges from 19 to 35 inches)
2C--34 to 60 inches; brown (7.5YR 5/4) loam; massive; firm; 5 percent gravel; strongly effervescent; moderately alkaline.
TYPE LOCATION: Bureau County, Illinois, 2 1/4 miles west and 1 1/4 mile south of Tiskilwa; 1,040 feet west and 1,345 feet south of the northeast corner sec. 21, T. 15 N., R. 8 E.; USGS Wyanet topographic quadrangle; lat. 41 degrees 16 minutes 25.4 seconds N., and long. 89 degrees, 34 minutes, 18 seconds W.; UTM Zone 16T, 0284602 easting 4572121 northing; NAD 27.
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon ranges from 24 to 40 inches. The depth to carbonates is 20 to 40 inches. Thickness of the loess is less than 18 inches. The particle-size control section averages between 27 and 35 percent clay.
The Ap or A horizon has hue of 10YR, value of 3 to 5, and chroma of 1 to 4. It is loam, silt loam, fine sandy loam, sandy loam, silty clay loam, or clay loam. It has 0 to 3 percent gravel. Reaction is moderately acid to neutral.
Some pedons have an E horizon with colors similar to the A horizon. Texture is silt loam. Reaction is moderately acid to neutral.
The Bt, 2Bt, BC, or 2BC horizon have hue of 10YR, 7.5YR, or 2.5Y; value of 4 to 6; and chroma of 3 to 6. The Bt horizons are silty clay loam or clay loam in the upper part and clay loam or loam in the lower part. Sand content ranges from 15 to 40 percent sand. It has 1 to 10 percent gravel. The Bt and 2Bt horizons range from slightly acid to strongly acid in the upper part and ranges to neutral in the lower part. The BC or 2BC horizon is neutral or slightly alkaline. The moist bulk density in the Bt or 2Bt horizon ranges from 1.4 to 1.7 g/cm3 and the moist bulk density in the BC or 2BC horizon ranges from 1.6 to 1.8 g/cm3.
The C or 2C horizon has hue of 10YR, 7.5YR, or 2.5Y; value of 5 or 6; and chroma of 3 or 4. It is clay loam or loam. Clay content ranges from 15 to 30 percent and sand content ranges from 20 to 55 percent. Gravel content ranges from 1 to 10 percent. Reaction is slightly alkaline or moderately alkaline. Calcium carbonate equivalent ranges from 20 to 40 percent. The moist bulk density ranges from 1.60 to 1.85 g/cm3.
COMPETING SERIES: These are the Amanda, Belmont, Belmore, Chenault, Chili, CliftyCreek, Conestoga, Crouse, Gallman, Greybrook, Hebron, Hickory, High Gap, Hollinger, Kalamazoo, Kanawha, Kidder, Kosciusko, LeRoy, Letort, Lumberton, Mandeville, Martinsville, Mifflin, Military, Nodine, Nollville, Ockley, Owosso, Princeton, Relay, Richardville, Riddles, Sisson, Skelton, Strawn, Theresa, Wawaka, Wawasee, Woodbine, and Wykoff soils. Amanda, Conestoga, Hollinger, Letort, and Wykoff soils do not have carbonates within a depth of 40 inches. Belmont, Chenault, High Gap, Lumberton, Mandeville, Mifflin, Military, Nollville, and Woodbine soils have a lithic or paralithic contact within a depth of 60 inches. Belmore, Chili, Kosciusko, and Wawaka soils have more than 10 percent gravel in the lower half of the series control section. CliftyCreek soils have more than 30 percent clay in the lower part of the series control section. Crouse, Gallman, Greybrook, Hickory, Kanawha, Martinsville, Nodine, Ockley, Richardville, Riddles, and Skelton soils are deeper than 40 inches to the base of the argillic horizon and to carbonates. Hebron and Sisson soils do not have gravel in the lower part of the series control section. Kalamazoo and Kidder soils have more than 55 percent sand in the lower part of the series control section. LeRoy and Strawn soils are less than 24 inches deep to the base of the argillic horizon and to carbonates. Owosso, Princeton, and Wawasee soils have less than 27 percent clay and more than 40 percent sand in the middle part of the series control section. Relay soils have hue of 5Y and rock fragments of gabbro, metagabbro, and granodiorite throughout the series control section. Theresa soils have a calcium carbonate equivalent of more than 40 percent in the lower part of the series control section.
GEOGRAPHIC SETTING: Senachwine soils are on till plains. Slope ranges from 2 to 60 percent. Senachwine soils formed in as much as 18 inches of loess or other silty material and in the underlying calcareous loamy till. Illite is the dominant clay mineral in the till. Mean annual precipitation ranges from 35 to 42 inches, mean annual temperature ranges from 48 to 54 degrees F, frost free period ranges from 150 to 180 days, and elevation ranges from 600 to 1,200 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Birkbeck, Catlin, Hennepin, La Rose and Strawn soils. The moderately well drained Birkbeck and Catlin soils have thicker loess over the till and are on upslope positions. Hennepin soils have lower average clay content in the subsoil. La Rose soils have darker surface layers. Hennepin and La Rose soils are on similar positions.
DRAINAGE AND PERMEABILITY: Well drained. The potential for surface runoff is low to high. Permeability is moderately slow.
USE AND VEGETATION: A large part is under cultivation. The principal crops are corn, soybeans, small grain, and hay. Much of the more sloping part is in permanent pasture or forest.
DISTRIBUTION AND EXTENT: Central and northern Illinois and in west central Indiana. The soil is moderately extensive in MLRAs 95B, 108, 110 and 111.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Bureau County, Illinois, 1996.
REMARKS: This series replaces the Miami series (Oxyaquic Hapludalfs) in many areas of MLRA 108 and 110 in Illinois.
Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - the zone from the surface of the soil to a depth of approximately 6 inches (Ap horizon);
argillic horizon - the zone from approximately 6 to 34 inches (Bt1, 2Bt2, 2BCt horizons);
udic moisture regime.