LOCATION KELLER                  IL

Established Series
Rev. GVB-JWS-CLL
01/2011

KELLER SERIES

The Keller series consists of deep, somewhat poorly drained soils on uplands. They formed in 20 to 40 inches (51 to 102 cm) of loess and the underlying till that contains a strongly developed paleosol. Slope ranges from 2 to 15 percent. Mean annual temperature is about 12.2 degrees C (54 degrees F), and mean annual precipitation is about 965 mm (38 inches).

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

TYPICAL PEDON: Keller silt loam on a northeast-facing slope of 6 percent in a cultivated field at an elevation of 224 meters 9736 feet) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 20 cm (0 to 8 inches); very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; weak fine granular structure; friable; common fine roots throughout; slightly acid; clear smooth boundary.

A--20 to 38 cm (8 to 15 inches); very dark gray (10YR 3/1) silt loam; weak fine granular structure; friable; common fine roots; moderately acid; clear smooth boundary. [Combined thickness of the A horizon is 20 to 38 cm (8 to 15 inches).]

BA--38 to 48 cm (15 to 19 inches); very dark grayish brown (10YR 3/2) silt loam; weak fine subangular blocky structure parting to weak fine granular; friable; common fine roots throughout; common fine continuous tubular pores; common distinct very dark gray (10YR 3/1) organo-clay films on faces of peds; common fine faint irregular brown (10YR 5/3) masses of iron accumulation throughout; slightly acid; clear smooth boundary. [0 to 18 cm (0 to 7 inches) thick]

Btg1--48 to 61 cm (19 to 24 inches); dark grayish brown (10YR 4/2) silty clay loam; weak fine subangular blocky structure; friable; common fine roots throughout; common fine continuous tubular pores; common distinct very dark grayish brown (10YR 3/2) clay films on faces of peds; common fine prominent irregular yellowish brown (10YR 5/6) masses of oxidized iron throughout; common fine faint irregular brown (10YR 5/3) masses of oxidized iron throughout; moderately acid; clear smooth boundary. [Combined thickness of the Bt horizon is 13 to 51 cm (5 to 20 inches).]

2Btg2--61 to 84 cm (24 to 33 inches); dark grayish brown (2.5Y 4/2) silty clay loam; weak medium subangular blocky structure; firm; few fine roots throughout; few fine continuous pores; many distinct dark gray (10YR 4/1) clay films on faces of peds; many fine prominent irregular yellowish brown (10YR 5/6) masses of oxidized iron throughout; common fine and medium faint irregular black (2.5Y 2/1) masses of iron-manganese oxides throughout; moderately acid; clear smooth boundary.

2Btg3--84 to 129 cm (33 to 51 inches); dark grayish brown (2.5Y 4/2) silty clay loam; moderate fine prismatic structure; firm; few fine roots in cracks; few fine constricted tubular pores; many distinct dark gray (10YR 4/1) clay films on faces of peds; common fine prominent rounded white (10YR 8/1) masses of barite throughout; many fine prominent irregular dark yellowish brown (10YR 4/6) masses of oxidized iron throughout; common fine faint rounded black (2.5Y 2/1) iron-manganese concretions throughout; slightly acid; clear smooth boundary.

2Btg4--129 to 155 cm (51 to 61 inches); gray (10YR 5/1) silty clay loam; weak coarse prismatic structure; firm; few fine roots in cracks; few fine constricted tubular pores; common distinct dark gray (10YR 4/1) clay films on faces of peds and in pores; common fine distinct rounded white (10YR 8/1) masses of barite throughout; many fine prominent irregular light olive brown (2.5Y 5/4) masses of oxidized iron throughout; common fine prominent irregular black (2.5Y 2/1) masses of iron-manganese oxides throughout; slightly acid; clear smooth boundary. [Combined thickness of the 2Btg horizon is 13 to 89 cm (5 to 35 inches).]

2BCg--155 to 203 cm (61 to 80 inches); gray (10YR 5/1) silty clay loam; very weak coarse prismatic structure; firm; common fine prominent irregular light olive brown (2.5Y 5/6) masses of oxidized iron throughout; common fine distinct rounded white (10YR 8/1) masses of barite throughout; 6 percent sand; slightly acid. [0 to 38 cm (0 to 15 inches) thick]

TYPE LOCATION: Brown County, Illinois; about 5 miles west of Mt. Sterling; 2,460 feet north and 980 feet east of the southwest corner of sec. 9, T. 1 S., R. 4 W.; Mt Sterling, IL. topographic quadrangle; Lat. 39 degrees 59 mintues 41.2 seconds N. and Long. 90 degrees 52 minutes 13.6 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Depth to the base of the argillic horizon: 127 to 178 cm (50 to 70 inches)
Average content of clay in the particle-size control section: between 27 and 35 percent

Ap, A, and/or AB horizons;
Hue: 10YR
Value: 2 or 3
Chroma: 1 or 2
Texture: silt loam
Reaction: moderatley acid to slightly alkaline

BA horizon (where it occurs):
Hue: 10YR
Value: 3 or 4
Chroma: 1 to 3
Texture: silty clay loam or silt loam
Reaction: strongly acid to slightly acid
Other features:
Some pedons have redoxmorphic features.

Bt or Btg horizon:
Hue: 10YR
Value: 4 to 6
Chroma: 2 to 4
Texture: silty clay loam
Redoxmorphic features:
Hue: 10YR, 7.5YR, 2.5Y or 5Y
Value: 4 to 6
Chroma: 1 to 8, clay films have chroma of 1 or 2.
Reaction: strongly acid or moderately acid in the upper part and is strongly acid to neutral in the lower part.

2Btg or 2Bt horizon:
Hue: 10YR, 2.5Y, 5Y or N (neutral)
Value: 3 to 6
Chroma: 0 to 3
Texture: silty clay loam, clay loam, clay, or silty clay
Redoxmorphic features:
Hue: 10YR, 7.5YR, 2.5Y or 5Y
Value: 4 to 6
Chroma: 1 to 8
Reaction: strongly acid to slightly alkaline

2BCg or 2BC horizon:
Hue: 10YR, 2.5Y, 5Y or N (neutral)
Value: 3 to 6
Chroma: 0 to 3
Texture: silty clay loam, clay loam, clay, or silty clay
Redoxmorphic features:
Hue: 10YR, 7.5YR, 2.5Y or 5Y
Value: 4 to 6
Chroma: 1 to 8
Reaction: strongly acid to slightly alkaline
Other features:
Some pedons do not have this horizon within a depth of 152 cm (60 inches). Some pedons contain buried horizons of the paleosol beneath the modern solum.

COMPETING SERIES: These are the Arrowsmith, Bearpen, Brenton, Edwardsville, Elburn, Grundelein, Hacreek, Harco, Higginsville, Lafayette, Lawndale, Lisbon, Lismod, Loran, Mundelein, Muscatune, Nira, Raub, Rooks, Rowley and Shannondale series. Arrowsmith soils have carbonates within a depth of 102 cm (40 inches) and have less than 27 percent clay in the lower part of the series control section. Bearpen and Rowley soils average less than 27 percent clay in the particle-size control section. Brenton, Elburn, Harco, Lawndale, Lisbon, Lismod, Mundelein, Muscatune, Raub and Shannondale soils average less than 30 percent clay in the lower part of the series control section. In addition, Harco and Mundelein soils contain carbonates within a depth of 102 cm (40 inches). Edwardsville and Higginsville soils have less than 7 percent sand throughout the soil profile. Grundelein and Lafayette soils have more than 15 percent rock fragments in the lower part of the series control section. Hacreek soils have less than 10 percent sand in all horizons above a depth of 152 cm (60 inches). Loran soils have a paralithic contact within a depth of 152 cm (60 inches). Nira soils have less than 5 percent content of sand in the lower third of the series control section. Rooks soils have less than 15 percent sand throughout the soil profile and contains carbonates within a depth of 102 cm (40 inches).

GEOGRAPHIC SETTING: Keller soils are on gently sloping to moderately steep parts of dissected Illinoian and Pre-Illinoian till plains. Slope gradients are 2 to 15 percent. These soils formed in 51 to 102 cm (20 to 40 inches) of loess and the underlying till that contains a strongly developed paleosol. Mean annual temperature varies from 10.0 to 13.9 degrees C (50 to 57 degrees F), mean annual precipitation varies from 889 to 1016 mm (35 to 40 inches), frost free days ranges from 160 to 190 days, and elevation ranges from 122 to 305 meters (400 to 1000 feet) above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Assumption, Coatsburg, Fishhook, Harrison, Ipava, Tama, and Velma soils. The well drained and moderately well drained Assumption soils are on similar parts of the landform position nearby. The poorly drained Coatsburg soils are downslope. Fishhook soils lack a mollic epipedon and are the light colored member of a biosequence with Keller soils. They are on similar parts of the landform positions nearby. Harrison, Ipava, and Tama soils averages less 30 percent clay in the lower one-half of the particle size control section and are upslope on higher side slopes or crests of summits on the landform position. Velma soils are on side slope positions downslope of the Keller soils. They contain more than 15 percent sand in the particle-size control section and less than 30 percent clay in the lower part of the particle-size control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. The seasonal high water table is 15 to 61 cm (0.5 foot to 2.0 feet) below the surface in spring. The potential for surface runoff is medium to high. Concave areas near the heads of drainageways receive water from seepage or surface runoff from upslope. Saturated hydraulic conductivity is moderately high to high (4.23 to 14.11 micrometers per second) in the loess and moderately low to moderately high (0.42 to 1.41 micrometers per second) in the till. Permeability is moderate (0.6 to 2 inches per hour) in the loess and slow (0.06 to 0.2 inches per hour) in the till.

USE AND VEGETATION: Many areas are used for cultivated crops. Corn, soybeans, and small grain are the principal crops. Some areas are used for forages for hay and pasture. Native vegetation is prairie grass.

DISTRIBUTION AND EXTENT: Western Illinois. Extent is moderate in MLRAs 108B, 114B, and 115C. The type location is in MLRA 115C.

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

SERIES ESTABLISHED: Stephenson County, Illinois, 1969.

REMARKS: The 2Bt or 2Btg horizon of the Keller soils is the lower part of a modern solum superimposed upon a Sangamon paleosol in the Illinoian and Pre-Illinioan till. Many of the properties of those horizons are believed to have been inherited from the paleosol. The variability of the properties is related to the geologic truncation of the paleosol before it was buried by loess, and to the extent of modern soil development in the old materials. Calcium and other bases have been replenished through seepage in some pedons after burial by loess. It is difficult to differentiate the properties of the lower part of the modern solum from those of the paleosol in many pedons. Some pedons contain a thin layer of loamy pedisediment between the loess and the till.

Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 48 cm (19 inches), (Ap, A, and BA horizons); argillic horizon - the zone from approximately 48 to 155 cm (19 to 61 inches), (Btg1, 2Btg2, 2Btg3, and 2Btg4).

ADDITIONAL DATA: Data are on file at the NRCS MLRA Office Regional 11.

---

National Cooperative Soil Survey
U.S.A.