LOCATION STRAWN                  IL+IN MI OH

Established Series
Rev. GRS-AAC
02/2011

STRAWN SERIES

The Strawn series consists of very deep, well drained soils on end moraines and dissected ground moraines. They are moderately permeable in the solum and moderately or moderately slowly permeable in the substratum. Strawn soils formed in loamy, calcareous till. Slope ranges from 2 to 75 percent. Mean annual temperature is about 9.4 degrees C (49 degrees F), and mean annual precipitation is about 864 mm (34 inches).

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 192 meters (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:
Depth to the base of the argillic horizon: 41 to 61 cm (16 to 24 inches)
Depth to carbonates: 36 to 61 cm (14 to 24 inches)
Particle-size control section: averages between 22 and 35 percent clay, 15 and 40 percent sand, and 25 and 63 percent silt.

Ap or A horizon:
Hue: 10YR
Value: 3 to 5
Chroma: 2 to 4
Texture: loam or silt loam and includes silty clay loam or clay loam where eroded
Rock fragment content: 0 to 7 percent
Reaction: moderately acid to neutral
Other features: 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.

E horizon [15 cm (6 nches) or less thick]:
Hue: 10YR
Value: 3 to 5
Chroma: 2 to 4
Texture; silt loam or loam
Rock fragment content: 0 to 7 percent
Reaction: moderately acid to neutral

Some pedons have a BE horizon with textures and colors similar to the E horizon.

Bt horizon:
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 3 to 6
Texture: clay loam, silty clay loam, silt loam or loam
Clay content: 24 to 35 percent
Sand content: 10 to 35 percent
Rock fragment content: 3 to 15 percent
Reaction: moderately acid to slightly alkaline

Some pedons have a BC horizon with textures and colors similar to the Bt horizon.

C horizon:
Hue: 7.5YR, 10YR or 2.5Y
Value: 5 or 6
Chroma: 2 to 6
Texture: loam, clay loam, silt loam or fine sandy loam
Clay content: 15 to 30 percent
Sand content: 15 to 45 percent
Rock fragment content: 3 to 15 percent
Reaction: slightly alkaline or moderately alkaline and contains carbonates.
Calcium carbonate equivalent: 5 to 40 percent

COMPETING SERIES: These are the Amanda, Belmont, Belmore, Caprell, Chili, Cliftycreek, Conestoga, Crouse, Gallman, Greybrook, Hickory, High Gap, Hollinger, Kanawha, Kidder, Kosciusko, Leroy, Lumberton, Mandeville, Martinsville, Military, Mocksville, Ockley, Pignut, Princeton, Relay, Richardville, Riddles, Senachwine, Skelton, Wawaka, Wawasee, and Woodbine series. All of these soils are differentiated by having sola thicker than 61 cm (24 inches) except Belmore, Hollinger, Kidder, LeRoy, Lumberton, Mandeville, Military, Mocksville, Pignut, 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. Hollinger soils do not have carbonates within a depth of 61 cm (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. Lumberton, Mandeville, Military, and Pignut soils have a lithic or paralithic contact within a depth of 151 cm (60 inches). Mocksville soils formed in weathered residuum from metamorphic or igneous rocks. 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 104 to 311 meters (340 to 1,020 feet) above mean 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 14.11 micrometer per second) in the solum and is moderately high to hogh (4.23 to 14.11 micrometers per second) or moderately high ( 1.41 to 4.23 micrometers per second) in the substratum. 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 98, 108A, 108B, 110, 111A, 111B, 111D, and 115C.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) 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 18 cm (7 inches) (Ap horizon); argillic horizon - the zone from approximately 18 to 56 cm (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.

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National Cooperative Soil Survey
U.S.A.