LOCATION BUCKHART IL

Established Series
RT
09/2021

BUCKHART SERIES

The Buckhart series consists of very deep, moderately well drained soils formed in loess on ground moraines. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 914 millimetrs (36 inches) and mean annual air temperature is about 11 degrees C (52 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Oxyaquic Argiudolls

TYPICAL PEDON: Buckhart silt loam, 2 to 5 percent slopes, on a south-facing slope in a cultivated field at an elevation of about 184 meters (603 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 centimeters (0 to 8 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate medium granular structure; friable; few very fine roots; moderately acid; clear smooth boundary.

A--20 to 38 centimeters (8 to 15 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; moderate fine subangular blocky structure parting to moderate medium granular; friable; few very fine roots; moderately acid; clear smooth boundary. (Combined thickness of the A horizons is 2r to 51 cm or 10 to 20 inches)

Bt1--38 to 66 centimeters (15 to 26 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure parting to moderate medium granular; friable; few very fine roots; many distinct brown (10YR 4/3) clay films on faces of peds and few distinct very dark grayish brown (10YR 3/2) organic coatings in root channels and/or pores; slightly acid; clear smooth boundary.

Bt2--66 to 94 centimeters (26 to 37 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure; friable; few very fine roots; many distinct dark grayish brown (10YR 4/2) clay films on faces of peds; few fine irregular distinct strong brown (7.5YR 5/6) masses of oxidized iron along pores and few fine irregular distinct light brownish gray (2.5Y 6/2) iron depletions along pores; neutral; clear smooth boundary.

Bt3--94 to 132 centimeters (37 to 52 inches); brown (10YR 5/3) silt loam; weak medium subangular blocky structure; friable; few very fine roots; common distinct dark grayish brown (10YR 4/2) clay films on faces of peds; common fine irregular prominent strong brown (7.5YR 5/6) masses of oxidized iron along pores and few fine spherical prominent black (7.5YR 2.5/1) iron-manganese nodules throughout and common fine fiant irregular light brownish gray (2.5Y 6/2) iron depletions along pores; slightly acid; clear smooth boundary. (Combined thickness of the Bt horizons is 63 to 102 cm or 25 to 40 inches)

BCt--132 to 170 centimeters (52 to 67 inches); light olive brown (2.5Y 5/3) silt loam; weak coarse subangular blocky structure; friable; few very fine roots; few distinct dark grayish brown (10YR 4/2) clay films in root channels and/or pores; common fine irregular prominent strong brown (7.5YR 5/6) masses of oxidized iron along pores and common fine irregular light brownish gray (2.5Y 6/2) iron depletions along pores and few fine spherical prominent black (7.5YR 2.5/1) iron-manganese nodules throughout; neutral; gradual smooth boundary. (5 to 20 inches thick)

C--170 to 203 centimeters (67 to 80 inches); yellowish brown (10YR 5/4) silt loam; massive; friable; common medium irregular distinct strong brown (7.5YR 5/6) masses of oxidized iron throughout and common medium irregular distinct light brownish gray (2.5Y 6/2) iron depletions throughout and few fine spherical prominent black (7.5YR 2.5/1) iron-manganese nodules throughout; neutral.

TYPE LOCATION: Christian County, Illinois, approximately 360 feet west and 540 feet north of the southeast corner of sec. 24, T. 14 N., R. 3 W.; USGS GROVE CITY, IL. topographic quadrangle; lat. 39 degrees 38 minutes 30 seconds N. and long. 89 degrees 22 minutes 25 seconds W; UTM Zone 16, 296316 easting and 4390685 northing, NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: 25 to 51 centimeters (10 to 20 inches)
Depth to the base of the argillic horizon: 102 to 140 centimeters (40 to 55 inches)
Thickness of loess: greater than 203 centimeters (80 inches)
Particle-size control section: averages 27 to 35 percent clay
Sand content: less than 7 percent throughout the series control section
Depth to carbonates, where present: greater than 102 centimeters (40 inches)
Mean annual soil temperature:11 to 13 degrees C. ( 52 to 56 degrees F.)
Other features: Redoximorphic depletions with chroma of 2 or less are not present in the 15 centimeters (6 inches) immediately below the mollic epipedon.

Ap and A horizons:
Hue: 10YR
Value: 2 or 3 (4 or 5 dry)
Chroma: 1 to 3
Texture: silt loam or silty clay loam
Clay content: averages 20 to 30 percent
Reaction: moderately acid to neutral

Some pedons have an AB or a BA horizon, with a hue of 10YR, value 3 or 4 (4 through 6 dry) and chroma of 2 through 4.

Bt or Btg horizons:
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 3 to 6 (2 to 6 in the lower part)
Other features: Redoximorphic features have hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 2 to 8.
Texture: dominantly silty clay loam, but has subhorizons of silt loam
Clay content: averages 27 to 35 percent
Reaction: moderately acid to neutral

BCt, BC or BCg horizons:
Hue: 10YR, or 2.5Y
Value: 5 or 6
Chroma: 2 to 4
Other features: Redoximorphic features have hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 2 to 8.
Texture: dominantly silt loam, but is silty clay loam in some pedons
Clay content: averages 18 to 30 percent
Reaction: neutral to slightly alkaline

C or Cg horizons:
Hue: 10YR or 2.5Y
Value: 5 or 6
Chroma: 2 to 6
Other features: Redoximorphic features have hue of 7.5YR, 10YR, or 2.5Y; value of 4 to 6; and chroma of 2 to 8.
Texture: silt loam
Clay content: averages 18 to 27 percent
Reaction: neutral to moderately alkaline

COMPETING SERIES: These are the Assumption, Aviston, Barrington, Blackberry, Catlin, Clare, Dana, Danabrook, Geryune, Graymont, Harrison, Keltner, Saybrook, and Totanang series. Assumption, Clare, Dana, Danabrook, Geryune, and Graymont soils have subhorizons with more than 7 percent sand within a depth of 40 inches. Aviston soils formed in 60 to 80 inches of loess and have a mean annual soil temperature greater than 56 degrees F. Barrington and Saybrook soils have more than 7 percent sand and carbonates within a depth of 40 inches. In addition, the base of the argillic horizon is at depths less than 40 inches in the Saybrook soils. Blackberry, Catlin and Harrison soils have more than 7 percent sand within depths of 60 inches. Keltner soils have a paralithic contact at depths of 40 to 60 inches. Totanang soils have more than 7 percent sand below depths of 24 inches and more than 15 percent rock fragments in the lower part of the series control section.

GEOGRAPHIC SETTING: The Buckhart soils formed in loess and are on summits on ground moraines. Slope ranges from 0 to 5 percent. Mean annual air temperature ranges from 10 to degrees C (50 to 54 degrees F), mean annual precipitation ranges from 864 to 106 millimters (34 to 40 inches), frost-free period ranges from 160 to 190 days, and elevation ranges from 122 to 244 meters (400 to 800 feet) above sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elkhart, Ipava, Muscatune, Newvienna, Osco, Sable, and Virden soils. The well drained Elkhart soils have carbonates within depths of 102 centimeters (40 inches), are on similar parts of the landscape, and are also on sideslopes along drainageways. The somewhat poorly drained Ipava and Muscatune soils and the poorly drained Sable and Virden soils are on nearly level broad interstream divides on positions at lower elevations, and they form a hydrosequence with the Buckhart soils. In addition, the Ipava and Virden soils have a fine-textured particle size control section. The moderately well drained Newvienna soils are on similar positions on the landscape and have a thinner dark surface layer. The well drained Osco soils are on sideslopes along drainageways.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained. The potential for surface runoff is low. Saturated hydraulic conductivity is moderately high to high (423. to 14.11 micrometers per second). Permeability is moderate. The depth to the top of an apparent seasonal high water table ranges from 61 to 107 centimeters (2 to 3.5 feet) at some time between February and April in most years.

USE AND VEGETATION: Most areas of the Buckhart soils are cultivated. Corn, soybeans, and wheat are the principal crops. Native vegetation is prairie grasses.

DISTRIBUTION AND EXTENT: In Central and western Illinois. The soils are of moderate extent in MLRA 108B.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana

SERIES ESTABLISHED: Christian County, Illinois, 1999. The Buckhart series was named for the township where the type location is located in Christian County.

REMARKS: Buckhart soils were formerly included with the Tama series (Typic Argiudolls). The representative data mapunit for this pedon is DMU ID 44521 for MO-11.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 38 cm (15 inches), (Ap and A horizons). Argillic horizon - the zone from approximately 38 to 132 cm (15 to 52 inches), (Bt1, Bt2, and Bt3 horizons). Udic moisture regime.

National Cooperative Soil Survey
U.S.A.