LOCATION HARVARD IL

Established Series
Rev. JWS-AAC
01/2011

HARVARD SERIES

The Harvard series consists of deep, well drained soils formed in loess or other silty material and in the underlying stratified loamy outwash or alluvial sediments. They are on outwash plains, stream terraces, and alluvial fans. Slope ranges from 0 to 10 percent. Mean annual air temperature is about 10.0 degrees C (50 degrees F), and mean annual precipitation is about 889 mm (35 inches).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Mollic Hapludalfs

TYPICAL PEDON: Harvard silt loam - with a 3 percent west-facing slope in a cultivated field at an elevation of about 832 feet. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 18 cm (0 to 7 inches); very dark grayish brown (10YR 3/2) silt loam, grayish brown (10YR 5/2) dry; weak thick platy structure parting to weak fine subangular blocky; friable; few very fine roots; few dark yellowish brown (10YR 4/4) mixing of subsoil material in the lower part; neutral; clear smooth boundary. [18 to 25 cm (7 to 10 inches) thick]

Bt1--18 to 36 cm (7 to 14 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular blocky structure; friable; few very fine roots; few distinct very dark grayish brown (10YR 3/2) organo-clay films on face of peds and linings in the pores; slightly acid; clear smooth boundary.

Bt2--36 to 56 cm (14 to 22 inches); dark yellowish brown (10YR 4/4) silty clay loam; weak fine prismatic structure parting to moderate fine subangular blocky; friable; few very fine roots; few distinct brown (10YR 4/3) clay films on faces of peds; slightly acid; clear smooth boundary.

Bt3--56 to 81 cm (22 to 32 inches); dark yellowish brown (10YR 4/4) silty clay loam; moderate medium prismatic structure parting to moderate medium subangular blocky; friable; common distinct brown (10YR 4/3) clay films on faces of peds; slightly acid; clear smooth boundary.

Bt4--81 to 94 cm (32 to 37 inches); yellowish brown (10YR 5/4) silt loam; weak coarse subangular blocky structure; friable; few distinct brown (10YR 4/3) clay films on faces of peds; neutral; clear smooth boundary. [Combined thickness of the Bt horizon is 25 to 81 cm (10 to 32 inches).]

2Bt5--94 to 114 cm (37 to 45 inches); yellowish brown (10YR 5/4) clay loam; weak coarse subangular blocky structure; friable; few distinct brown (10YR 4/3) clay films on faces of peds; neutral; abrupt smooth boundary. [13 to 76 cm (5 to 30 inches) thick]

2C--114 to 152 cm (45 to 60 inches); dark yellowish brown (10YR 4/4) and yellowish brown (10YR 5/6) stratified sandy loam, loam, and loamy sand; massive; very friable; slightly acid.

TYPE LOCATION: Knox County, Illinois; about 16 miles southeast of Galesburg; 2,300 feet east and 1,320 feet south of the northwest corner of sec. 16, T. 9 N., R. 3 E; USGS Maquon topographic Quadrangle; lat. 40 degrees 46 minutes 4 seconds N., long. 90 degrees 10 minutes 5 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Depth to the base of soil development: commonly 102 127 cm (40 to 50 inches) in thickness, but ranges from 84 to more than 152 cm (33 to more than 60 inches).
Average content of clay in the particle-size control section: between 27 and 35 percent
Average content of fine sand or coarser in the particle-size control section: less than 15 percent
Depth to horizons with more than 15 percent sand: commonly 61 to 102 cm (24 to 40 inches) in thickness but ranges from 51 to 102 cm (20 to 40 inches).

Ap or A horizon:
Hue: 10YR
Value: 2 or 3 (4 or 5 dry)
Chroma: 1 to 3
Texture: silt loam
Reaction: strongly acid to slightly alkaline

E horizon (Where it occurs):
Hue: 10YR
Value: 4 or 5
Chroma: commonly 3, but ranges from 2 to 4.
Reaction: strongly acid to neutral

Bt horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 3 or 4
Texture: dominantly silty clay loam, but some subhorizons are silt loam in some pedons.
Reaction: strongly acid to neutral

2Bt, and/or 2BC horizons:
Hue: 7.5YR or 10YR
Value: 4 or 5
Chroma: 2 to 6
Texture: silty clay loam, clay loam, silt loam, loam, sandy loam or sandy clay loam and is stratified in many pedons.
Clay content: 15 to 35 percent
Silt content: averages more than 50 percent
Reaction: moderately acid to slightly alkaline

2C horizon:
Hue: 10YR or 2.5Y
Value: 3 to 6
Chroma: 3 to 6
Texture: dominantly silt loam, loam, sandy loam or clay loam and are stratified. Thin subhorizons (strata) of loamy sand or sand with more than 75 percent sand occur in all pedons.
Average content of clay: 5 to 25 percent
Average content of sand: 30 to 75 percent
Average content of silt: less than 50 percent
Average content of rock gragment: less than 15 percent
Reaction: strongly acid to moderately alkaline and contains carbonates in some pedons at a depth greater than 102 cm (40 inches).

COMPETING SERIES: These are the Batavia, Bowes, Churchtown, Deroin, Downs, Ella, Festina, Frankville, Gladek, Greenbush, Hersey, Juda, Knox, Luana, Mannon, Massbach, Mellott, Mt. Carroll, Myrtle, Nasset, Newhouse, Oak Center, Shelbyville, Watkins, Waubeek, and Yutan series. Batavia soils average more than 50 percent silt in the third part of the series control section. Bowes soils contain more than 15 percent rock fragments in the lower part of the series control section. Deroin, Festina, and Watkins soils average less than 30 percent sand in the lower part of the series control section. Downs, Churchtown, Knox, Mt. Carroll, and Yutan soils average more than 50 percent silt in the lower two parts of the series control section. Ella, Hersey, and Newhouse soils average less than 27 percent clay in the particle-size control section. Frankville and Luana soils have a lithic contact within a depth of 102 cm (40 inches). Gladek soils typically do not have rock fragments in the lower part of the series control section. Greenbush and Mannon soils contain less than 10 percent sand in the lower part of the series control section. Juda, Massbach, Nasset, and Shelbyville soils average more than 25 percent clay in the lower part of the series control section. Mellott, and Waubeek soils do not have subhorizons in the lower part of the series control section with more than 75 percent sand. Myrtle soils have hue of 5YR or redder in the third part of the series control section. Oak Center soils have 18 to 28 percent weighted average of clay content in the particle-size control section.

GEOGRAPHIC SETTING: The Harvard soils typically are on outwash plains or stream terraces and, in some places, are on alluvial fans above the level of flooding. The soils formed in 51 to 102 cm (20 to 40 inches) of loess or other silty material and in the underlying stratified loamy outwash or alluvial sediments of Wisconsinan Age. Slopes range from 0 to 10 percent. Mean annual air temperature ranges from 8.9 to 12.2 degrees C (48 to 54 degrees F), and mean annual precipitation varies from 762 to 1016 mm (30 to 40 inches), frost free days range from 150 to 180 days, and the elevation ranges from 207 to 311 meters (680 to 1020 feet) above sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alvin, Brenton, Camden, Downs, Drummer, Millbrook and Proctor soils. The well drained Alvin soils are on similar landforms that do not have a mantle of loess. The somewhat poorly drained Brenton and Millbrook soils are on slightly lower lying landforms. The well drained Camden and Proctor soils form a biosequence with Harvard soils and are on similar landform positions. The well drained Downs soils are developed entirely in loess and are on higher lying areas. The poorly drained Drummer soils are in depressions or lower lying areas.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is low or medium. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometer per second) in the upper part of the solum and moderately high to high (4.23 to 14.11 micrometer per second) or high ( 14.11 to 42.34 micrometer per second) in the lower part and the substratum. Permeability is moderate in the upper part of the solum and moderate or moderately rapid in the lower part and in the substratum.

USE AND VEGETATION: Most areas are used to grow corn, soybeans, small grain, and forages for hay or pasture. Native vegetation is mixed prairie grasses and hardwood trees.

DISTRIBUTION AND EXTENT: Central and northern Illinois. The extent is moderate; about 27,000 acres have been mapped in MLRAs 95B, 108A, 108B and 115C.

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

SERIES ESTABLISHED: McHenry County, Illinois, 1960.

REMARKS: Diagnostic horizons recognized in this pedon are: ochric epipedon - the zone from the surface of the soil to a depth of 18 cm (7 inches) (Ap horizon); argillic horizon - the zone from about 18 to 114 cm (7 to 45 inches) (Bt1, Bt2, Bt3, Bt4, and 2Bt5 horizons; udic moisture regime.

National Cooperative Soil Survey
U.S.A.