LOCATION STRAWN IL+IN MI OHEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Hapludalfs
TYPICAL PEDON: Strawn loam - in a pasture with an 18 percent slope at an elevation of 630 feet above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 18 cm (0 to 7 inches); brown (10YR 4/3) and brown (10YR 5/3) loam, pale brown (10YR 6/3) and very pale brown (10YR 7/3) dry; weak fine and medium granular structure; friable; common fine roots; few pebbles; neutral; abrupt smooth boundary.[10 to 20 cm (4 to 8 inches) thick]
Bt1--18 to 28 cm (7 to 11 inches); brown (10YR 4/3) clay loam; moderate fine subangular blocky structure; firm; few fine roots; many faint brown (10YR 4/3) clay films on faces of peds; few pebbles; neutral; clear smooth boundary.
Bt2--28 to 56 cm (11 to 22 inches); brown (10YR 4/3) clay loam; moderate medium subangular blocky structure; firm; few fine roots; many faint brown (10YR 4/3) clay films on faces of peds; few pebbles; neutral; clear smooth boundary. [Combined thickness of the Bt horizons is 18 to 46 cm (7 to 18 inches).]
C--56 to 152 cm (22 to 60 inches); brown (10YR 5/3) loam; few fine prominent strong brown (7.5YR 5/8) masses of oxidized iron in the matrix; massive; firm; few pebbles; strongly effervescent; moderately alkaline.
TYPE LOCATION: Tazewell County, Illinois; about 2 miless northwest of Armington; 194 feet north and 96 feet west of the southeast corner of sec. 17, T. 22 N., R. 2 W.; USGS Armington topographic quadrangle; lat. 40 degrees 21 minutes 28 seconds N., and long. 89 degrees 20 minutes 56 seconds W.; NAD27; UTM Zone 16T, 0300533E and 4470121N, NAD 83..
RANGE IN CHARACTERISTICS: The depth to the base of the argillic horizon is 16 to 24 inches. Depth to carbonates is 14 to 24 inches. The particle-size control section averages between 22 to 35 percent clay, 15 to 40 percent sand, and 25 and 63 percent silt.
The Ap or A horizon has hue of 10YR, value of 3 to 5, and chroma of 2 to 4. Pedons with value of 3 and chroma of 2 or 3 are less than 7 inches thick or have dry value of 6 or more. Texture is loam or silt loam and includes silty clay loam or clay loam where eroded. Rock fragment content ranges from 0 to 7 percent. Reaction is moderately acid to neutral.
Some pedons have an E horizon as much as 6 inches in thickness. Where present it has hue of 10YR, value of 3 to 5, and chroma of 2 to 4. Texture is silt loam or loam. Rock fragment content ranges from 0 to 7 percent. Reaction is moderately acid to neutral.
Some pedons have a BE horizon with textures and colors similar to the E horizon.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 to 6. It is clay loam, silty clay loam, silt loam or loam. Clay content ranges from 24 to 35 percent. Sand content ranges from 10 to 35 percent. Rock fragment content ranges from 3 to 15 percent. Reaction is moderately acid to slightly alkaline.
Some pedons have a BC horizon with textures and colors similar to the Bt horizon.
The C horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 5 or 6, and chroma of 2 to 6. It is loam, clay loam, silt loam or fine sandy loam. Clay content ranges from 15 to 30 percent. Sand content ranges from 15 to 45 percent. Rock fragment content ranges from 3 to 15 percent. Reaction is slightly alkaline or moderately alkaline and contains carbonates. Calcium carbonate equivalent ranges from 5 to 40 percent.
COMPETING SERIES: These are the Amanda, Belmont, Belmore, Chenault, Chili, Coggon, Conestoga, Crouse, Fredericktown, Gallman, Greybrook, Hebron, Hickory, High Gap, Hollinger, Kalamazoo, Kanawha, Kidder, Kosciusko, Leroy, Letort, Lumberton, Mandeville, Martinsville, Mifflin, Military, Nodine, Nollville, Ockley, Oglesbet, Owosso, Princeton, Relay, Richardville, Riddles, Senachwine, Sisson, Skelton, Theresa, Wawaka, Wawasee, Woodbine, and Wykoff series. All of these soils are differentiated by having sola thicker than 24 inches except Belmore, Hebron, Hollinger, Kidder, LeRoy, Mandeville, Military, and Relay. Belmore soils have more than 15 percent rock fragments in some layer in the middle or lower part of the series control section. Hebron soils have more than 35 percent clay in the middle part of the series control section. Hollinger soils do not have carbonates within a depth of 24 inches and have a higher content of mica in the series control section. Kidder soils contain more than 35 percent sand coarser than very fine sand in the argillic horizon. Leroy soils have a calcium carbonate equivalent of more than 40 percent in lower part of the series control section. Mandeville and Military soils have a lithic or paralithic contact within a depth of 60 inches. Relay soils have hues yellower than 10YR and contain magnesium-rich rock fragments dominated by gabbro, metagabbro or granodiorite.
GEOGRAPHIC SETTING: Strawn soils are on gently sloping to very steep positions on end moraines and dissected ground moraines. Slope gradients are 2 to 75 percent. Strawn soils formed in loamy calcareous till. Some pedons have a thin mantle of loess. Mean annual precipitation ranges from 737 to 1016 mm (29 to 40 inches), mean annual temperature ranges from 7 to 12 degrees C (45 to 54 degrees F)., frost free period ranges from 160 to 180 days, and elevation ranges from 340 to 1,020 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the well drained Chute, Hennepin, and Senachwine soils. Chute and Hennepin soils do not have argillic horizons, are on similar landforms or nearby slopes, and in places are intricately mixed with Strawn soils. Senachwine soils have thicker sola and are on similar positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff ranges from low to high. Saturated hydraulic conductivity is moderately high to high (4.23 to less than 14.11 micrometer per second). Permeability is moderate in the solum, and is moderate or moderately slow in the substratum.
USE AND VEGETATION: Most areas are used for pasture or woodland. Some less sloping areas are used to grow corn or small grain. The native vegetation is deciduous forest.
DISTRIBUTION AND EXTENT: Northern and central Illinois and Indiana, southwestern Ohio and lower Michigan. The extent is moderate in MLRA's 95B, 108, 110, 111, and 115.
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Boone County, Illinois, 1935.
REMARKS: Diagnostic horizons recognized in this pedon are:ochric epipedon - the layer from the surface of the soil to a depth of 7 inches (Ap horizon);
argillic horizon - the zone from approximately 7 to 22 inches (Bt1 and Bt2 horizons).
Moderately permeable (IL0227), moderately permeable, eroded (IL0337), moderately slowly permeable (IL)0344), and moderately slowly permeable, eroded (IL0345) phases are recognized and some may become new series when the subset soil surveys in which
they are in are updated.