LOCATION STRONGHURST IL+IA WIEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aeric Endoaqualfs
TYPICAL PEDON: Stronghurst silt loam on a nearly level slope in a cultivated field at an elevation of 220 meters (721 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 18 cm (0 to 7 inches); dark gray (10YR 4/1) silt loam, gray (10YR 6/1) dry; weak medium granular structure; friable; common roots; neutral; clear smooth boundary. [15 to 30 cm (6 to 12 inches) thick]
E--18 to 28 cm (7 to 11 inches); dark grayish brown (10YR 4/2) silt loam; weak fine subangular blocky structure; friable; common roots; few fine and medium dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; slightly acid; clear smooth boundary. [10 to 25 cm (4 to 10 inches) thick]
BE--28 to 38 cm (11 to 15 inches); dark grayish brown (10YR 4/2) silty clay loam; moderate fine subangular blocky structure; firm; common roots; common faint light brownish gray (10YR 6/2) clay depletions on faces of peds; few dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; strongly acid; clear smooth boundary. [8 to 23 cm (3 to 9 inches) thick]
Bt1--38 to 56 cm (15 to 22 inches); grayish brown (10YR 5/2) silty clay loam; moderate fine and medium subangular blocky structure; firm; few roots; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; few fine distinct dark yellowish brown (10YR 4/4) masses of iron in the matrix; common dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; strongly acid; gradual smooth boundary.
Bt2--56 to 74 cm (22 to 29 inches); brown (10YR 5/3) silty clay loam; moderate fine and medium subangular blocky structure; firm; few roots; many faint dark grayish brown (10YR 4/2) clay films on faces of peds; common medium distinct yellowish brown (10YR 5/6) masses of iron and common medium faint dark grayish brown (10YR 4/2) iron depletions in the matrix; many dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; strongly acid; gradual smooth boundary.
Bt3--74 to 89 cm (29 to 35 inches); brown (10YR 5/3) silty clay loam; weak coarse subangular blocky structure; firm; few roots; common distinct dark gray (10YR 4/1) clay films on faces of peds and on surfaces along root channels; many medium faint dark yellowish brown (10YR 4/4) and many medium distinct yellowish brown (10YR 5/6) iron masses in the matrix; many dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; strongly acid; gradual smooth boundary.
Bt4--89 to 119 cm (35 to 47 inches); pale brown (10YR 6/3) silty clay loam; weak coarse subangular blocky structure; friable; few faint dark grayish brown (10YR 4/2) clay films on faces of peds and on surfaces along root channels; many medium distinct yellowish brown (10YR 5/6) masses of iron in the matrix; many dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; moderately acid; gradual wavy boundary. [Combined thickness of the Bt horizon is 69 to 119 cm (27 to 47 inches)]
C--119 to 152 cm (47 to 60 inches); mixed pale brown (10YR 6/3) and yellowish brown (10YR 5/6) silt loam; massive; friable; many soft dark reddish brown (5YR 3/2) concretions of iron and manganese oxides in the matrix; moderately acid.
TYPE LOCATION: Mercer County, Illinois; about 1.25 miles north of Millersburg; 1,440 feet north and 200 feet east of the southwest corner of sec. 26, T. 15 N., R. 4 W. USGS Buffalo Prairie quadrangle; latitude 41 degrees, 15 minutes, 43 seconds N., longitude 90 degrees, 49 minutes, 20 seconds W., NAD 83
RANGE IN CHARACTERISTICS: The depth to the base of soil development is greater than 107 cm (42 inches). The depth to the top of the argillic horizon ranges from 15 to 61 cm (6 to 24 inches). The series control section ranges from strongly acid to neutral. The average sand content is less than 10 percent throughout the series control section.
The Ap or A horizon has value of 3 to 6, and chroma of 1 or 2.
The E horizon has value of 4 to 6, and chroma of 2 or 3.
The Bt or Btg horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 4. It is silty clay loam or silt loam. Average clay content ranges from 28 to 32 percent. Individual subhorizons have as low as 24 percent clay or as high as 35 percent clay.
The C or Cg horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 1 to 4. It is silt loam or silty clay loam. Average clay content ranges from 20 to 29 percent. A loamy substratum phase is recognized.
COMPETING SERIES: These are the
Aptakisic,
Caseyville,
Creal,
Fitchville,
Iva,
Kendall,
Starks,
Waynetown, and
Yeddo series.
Aptakisic, Kendall, and Starks soils average more than 10 percent sand in the lower 1/3 of the control section. Creal soils have a depth to the top of the argillic horizon of greater than 61 cm (24 inches). Caseyville and Iva soils average more than 12 degrees C (54 degrees F) in the soil temperature control section. Fitchville soils contain stratification in the lower 1/3 of the series control section. Waynetown soils contain 15 to 30 percent rock fragment in the lower 1/3 of the series control section. Yeddo soils contain carbonates at a depth of 66 to 140 cm (26 to 55 inches).
GEOGRAPHIC SETTING: Stronghurst soils are on nearly level or gently sloping benches and ridges of till plains. Slope gradients range from 0 to 6 percent. The soils formed in loess. The mean annual precipitation ranges from 760 to 0170 mm (30 to 42 inches), mean annual temperature ranges from 7 to 12 degrees C (45 to 53 degrees F), and frost free period ranges from 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atterberry, Downs, Fayette, New Vienna, Rozetta and Traer soils. The somewhat poorly drained Stronghurst soils are in a drainage sequence with the well drained Fayette soils, the moderately well drained Rozetta soils, and the poorly drained Traer soils. Downs, New Vienna and Atterberry soils have thin dark surface layers. Downs and New Vienna soils are slightly higher on the landscape and Atterberry soils are on similar positions nearby.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. The potential for surface runoff is low or medium. Saturated hydraulic conductivity is 4.23 to 14.11 micrometers per second (moderate permeability).
USE AND VEGETATION: Stronghurst soils are used mostly for growing crops such as corn, soybeans, small grain, and meadow. Some areas are in pasture and woodland. Native vegetation is hardwood forest.
DISTRIBUTION AND EXTENT: Illinois, Wisconsin, and Iowa. LRR's K and M, MLRA?s 95B, 105, 108, and 115C. The extent is moderate (about 60,000 acres correlated to date).
MLRA OFFICE RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Henderson County, Illinois, 1947.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
ochric epipedon - from a depth of 0 to 38 cm (0 to 15 inches) (Ap, E and BE horizon);
albic horizon - from a depth of 18 to 28 (7 to 11 inches) (E
horizon);
argillic horizon - from a depth of 38 to 119 cm (15 to 47 inches) (Bt1, Bt2, Bt3, and Bt4 horizons).