LOCATION BROADWELL IL
Established Series
Rev. JWS-EEV
03/2011
BROADWELL SERIES
The Broadwell series consists of very deep, well drained soils formed in 40 to 60 inches of loess and in the underlying loamy sand or sand on uplands. Slope ranges from 0 to 12 percent. Mean annual temperature is about 11.1 degrees C (52 degrees F), and mean annual precipitation is about 864 mm (34 inches).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Typic Argiudolls
TYPICAL PEDON: Broadwell silt loam - on a gently sloping knoll in a cultivated field at an elevation of 190.5 meters (625 feet) above mean sea levlel. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 23 cm (0 to 9 inches); very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; weak fine granular structure; friable; common very fine roots and few fine roots; moderately acid; clear smooth boundary.
A--23 to 38 cm (9 to 15 inches); very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; moderate fine granular structure; friable; few very fine and fine roots; slightly acid; clear smooth boundary. [Combined thickness of the A horizons is 25 to 51 cm (10 to 20 inches).]
Bt1--38 to 46 cm (15 to 18 inches); dark brown (10YR 3/3) silty clay loam, yellowish brown (10YR 5/4) dry; weak very fine and fine subangular blocky structure; friable; few very fine and fine roots; many faint very dark grayish brown (10YR 3/2) organo-clay films on faces of peds; slightly acid; clear smooth boundary.
Bt2--46 to 64 cm (18 to 25 inches); brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure; firm; few very fine and fine roots; common faint very dark grayish brown (10YR 3/2) organo-clay films on faces of peds; moderately acid; clear smooth boundary.
Bt3--64 to 79 cm (25 to 31 inches); brown (10YR 4/3) silty clay loam; moderate fine subangular blocky structure; firm; few very fine and fine roots; common faint very dark grayish brown (10YR 3/2) clay films in root channels and/or pores and common faint brown (10YR 4/3) clay films on faces of peds; moderately acid; clear smooth boundary.
Bt4--79 to 104 cm (31 to 41 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; firm; few very fine and fine roots; few distinct very dark grayish brown (10YR 3/2) clay films in root channels and/or pores and common faint brown (10YR 4/3) clay films on faces of peds and few distinct light gray (10YR 7/2) silt coatings on faces of peds and in pores; moderately acid; clear smooth boundary.
Bt5--104 to 127 cm (41 to 50 inches); dark yellowish brown (10YR 4/4) silt loam; weak medium and coarse subangular blocky structure; friable; few very fine roots; common faint brown (10YR 4/3) clay films on faces of peds; few distinct light gray (10YR 7/2) silt coatings on faces of peds and in pores; few fine faint brown (10YR 5/3) masses of oxidized iron along micropores; moderately acid; abrupt smooth boundary. [Combined thickness of the Bt horizons is 51 to 102 cm (20 to 40 inches).]
2BC1--127 to 140 cm (50 to 55 inches); dark yellowish brown (10YR 4/4) stratified loamy fine sand and sandy loam; weak coarse subangular blocky structure; very friable; slightly acid; clear smooth boundary. [Combined thickness of the 2Bt and/or 2BC1 horizons is 0 to 36 cm (0 to 14 inches).]
2BC2--140 to 193 cm (55 to 76 inches); stratified yellowish brown (10YR 5/4) and brown (7.5YR 4/4) fine sand and loamy sand; single grain; loose; few distinct dark brown (7.5YR 3/2) organic coatings in pores; three inch band of yellowish brown (10YR 5/6) silt loam starting at 73 inches; neutral; clear smooth boundary. [0 to 76 cm ( 0 to 30 inches) thick]
2C--193 to 203 cm (76 to 80 inches); yellowish brown (10YR 5/4) fine sand; single grain; slightly acid.
TYPE LOCATION: Christian County, Illinois; about 1 mile northwest of Mount Auburn; 2500 feet north and 460 feet west of the center of section 11, T. 15 N., R. 2 W.; U.S.G.S. Mount Auburn topographic quadrangle; lat. 39 degrees 46 minutes 17 seconds N. and long. 84 degrees 16 minutes 51 seconds W., UTM Zone 16, 304645 easting and 4404877 northing, NAD 83.
RANGE IN CHARACTERISTICS:
Thickness of the solum: 114 to 203 cm (45 to 80 inches)
Thickness of loess over the loamy sand or sand: 102 to about 152 cm (40 to about 60 inches)
Thickness of the mollic epipedon: 25 to 51 cm (10 to 20 inches)
The upper 20 inches of the argillic horizon: averages more than 27 percent clay and less than 10 percent sand
Ap or A horizon:
Hue: 10YR
Value: 2 or 3
Chroma: 1 to 3
Texture: silt loam
Reaction: moderately acid to neutral
Other features:
Some pedons have an AB or BA horizon.
Bt horizon:
Hue: 10YR or 7.5YR
Value: 3 to 5
Chroma: 3 to 6
Texture: dominantly silty clay loam, but is silt loam in the upper or lower parts of some pedons
Reaction: moderately acid or slightly acid in at least one subhorizon, and is neutral in the upper part or in the lower part in some pedons
Other features:
Some pedons do not have redoximorphic features in the lower part of the Bt.
2Bt horizon (where present):
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 4 to 6
Texture: typically stratified clay loam, loam, silt loam, fine sandy loam or loamy sand
Reaction: moderately acid to neutral
2BC horizons:
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 4 to 6
Texture: typically stratified clay loam, loam, silt loam, fine sandy loam or loamy sand, lower part of the 2BC horizon is typically loamy sand or loamy fine sand, but some pedons are fine sand or sand
Reaction: moderately acid to neutral
2C horizon [present above a depth of 152 cm (60 inches) in some pedons]:
Hue: 10YR or 7.5YR
Value: 4 or 5
Chroma: 4 to 6
Texture: fine sand, sand, loamy fine sand or loamy sand
Clay content: 3 to 10 percent
Sand content: 50 to 90 percent and averages more than 80 percent.
Reaction: moderately acid to neutral
COMPETING SERIES: These are the
Ashdale,
Dinsdale,
Douglas,
Elkhart,
Elmont,
Healing,
Lycurgus,
Malcolm,
Meadowbank,
Mendota,
Mickle,
Ogle,
Osco,
Parkway,
Plano,
Proctor,
Richwood,
Ripon,
Sibley (see Remarks),
Sidell,
Tama,
Tecumseh,
Toddville,
Wakenda, and
Waupecan series. Ashdale soils have more than 35 percent clay in the lower part of the series control section. Dinsdale, Meadowbank, Mendota, Proctor and Tecumseh soils have less than 40 inches of loess. Sibley soils have mollic epipedons more than 61 cm (24 inches) in thickness. Douglas, Healing, Ogle, Osco, Parkway, Sidell, Tama, and Wakenda soils have more than 10 percent clay and less than 50 percent sand in the lower part of the series control section. Elkhart soils have carbonates within a depth of 40 inches. Elmont soils have a paralithic contact within a depth of 152 cm (60 inches). Lycurgus soils have more than 10 percent sand in the upper part of the series control section. Malcolm soils formed in noncalcareous interglacial sediments and have sola less than 40 inches. Mickle, Richwood and Toddville soils average less than 27 percent clay in the particle-size control section. Plano soils average 3 percent or more rock fragments and less than 80 percent sand in the lower part of the series control section. Ripon soils have a lithic contact within a depth of 102 cm (40 inches). Waupecan soils contain more than 15 percent rock fragments in the lower part of the series control section and have carbonates within a depth of 152 cm (60 inches).
GEOGRAPHIC SETTING: Broadwell soils are on nearly level to rolling uplands near stream valleys. They formed in 102 to 152 cm (40 to 60 inches) of loess and in the underlying eolian loamy sand or sand. Slope gradients range from 0 to 12 percent. Mean annual temperature ranges from 10.0 to 12.2 degrees C (50 to 54 degrees F), and mean annual precipitation ranges from 813 to 914 mm (32 to 36 inches).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Lawndale,
Pillot,
Sable and
Tama soils. The somewhat poorly drained Lawndale soils are on lower lying or more nearly level areas nearby and form a hydrosequence with Broadwell soils. Tama soils are on similar landscapes nearby where loess is more than 152 cm (60 inches) in the thickness. Pillot soils are nearby where loess is thinner; they have strongly contrasting particle-size class of fine-silty over sandy or sandy-skeletal. Poorly drained Sable soils are nearby in lower lying areas. They have grayer colors throughout.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface water runoff is low on nearly level areas and medium on sloping areas. Saturated hydraulic conductivity is moderately high to high (423. to 14.11 micrometers per second) in the upper part of the solum and high to very high (14.11 to 141.14 micrometers per second) in the lower part and in the substratum. Permeability is moderate in the upper part of the solum and moderately rapid or rapid in the lower part and in the substratum.
USE AND VEGETATION: Most areas are cultivated. Corn, soybeans and small grain are the principal crops. Meadow is grown for hay in some areas. The native vegetation is prairie grasses.
DISTRIBUTION AND EXTENT: Central Illinois in MLRAs 108A, 108B, and 115C. Extent is moderate.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Logan County, Illinois, 1976
REMARKS: Diagnostic horizons and features recognized in this pedon are: Mollic epipedon - the zone from the surface to a depth of 46 cm (18 inches) (Ap, A and Bt1 horizons). Argillic horizon - the zone from approximately 38 to 127 cm (15 to 50 inches) (Bt1, Bt2, Bt3, Bt4 and Bt5 horizons). Udic soil moisture regime.
The 2003 update relocated the typical pedon from Sangamon County, Illinois to a more representative site in Christian County, Illinois. The Sibley soils should be reclassified as Pachic Argiudolls and, therefore would not be a competing series.
National Cooperative Soil Survey
U.S.A.