LOCATION IPAVA IL+IN

Established Series
Rev. JCD-GVB-RT
04/2015

IPAVA SERIES

The Ipava series consists of very deep, somewhat poorly drained soils formed in loess on uplands. Slope ranges from 0 to 5 percent. Mean annual temperature is about 11.7 degrees C (53 degrees F), and mean annual precipitation is about 965 mm (38 inches).

TAXONOMIC CLASS: Fine, smectitic, mesic Aquic Argiudolls

TYPICAL PEDON: Ipava silt loam- nearly level in a cultivated field at an elevation of about 804 feet (245 meters) above mean sea level. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 25 cm (0 to 10 inches); black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; moderate fine and medium subangular blocky structure; friable; moderately acid; abrupt smooth boundary.

A--25 to 46 cm (10 to 18 inches); very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (10YR 5/2) dry; weak fine and medium subangular blocky structure; friable; common distinct black (10YR 2/1) organic coatings on faces of peds; moderately acid; clear smooth boundary. [Combined thickness of the A horizon is 25 to 50 cm (10 to 20 inches).]

BA--46 to 61 cm (18 to 24 inches); brown (10YR 4/3) silty clay loam; moderate fine and medium subangular blocky structure; friable; common distinct very dark gray (10YR 3/1) organic coatings on faces of peds; few fine distinct light brownish gray (2.5Y 6/2) iron depletions in the matrix; few fine distinct yellowish brown (10YR 5/6) masses of oxidized iron in the matrix; moderately acid; clear smooth boundary. [0 to 8 inches (0 to 20 cm) thick]

Btg1--61 to 79 cm (24 to 31 inches); dark grayish brown (10YR 4/2) silty clay; moderate fine prismatic structure parting to moderate fine subangular blocky; firm; common distinct dark gray (10YR 4/1) clay films on faces of peds; few fine distinct light brownish gray (2.5Y 6/2) iron depletions in the matrix; common fine prominent yellowish brown (10YR 5/8) masses of oxidized iron in the matrix; slightly acid; clear smooth boundary.

Btg2--79 to 94 cm (31 to 37 inches); grayish brown (2.5Y 5/2) silty clay loam; moderate medium prismatic structure parting to moderate medium angular blocky; friable; common distinct dark gray (10YR 4/1) clay films on faces of peds; common fine faint light brownish gray (2.5Y 6/2) iron depletions in the matrix; common medium prominent strong brown (7.5YR 5/8) masses of oxidized iron in the matrix; few fine prominent black (7.5YR 2.5/1) very weakly cemented iron-manganese concretions throughout; few fine prominent black (7.5YR 2.5/1) manganese stains on faces of peds; slightly alkaline; gradual smooth boundary. [Combined thickness of the Btg horizon is 25 to 125 cm (10 to 50 inches).]

BCg--94 to 127 cm (37 to 50 inches); grayish brown (2.5Y 5/2) silty clay loam; moderate medium prismatic structure parting to moderate medium angular blocky; friable; few distinct very dark grayish brown (10YR 3/2) organo-clay films as linings in pores and on a few vertical faces of peds; common fine faint light brownish gray (2.5Y 6/2) iron depletions in the matrix; common fine prominent strong brown (7.5YR 5/8) masses of oxidized iron in the matrix; few fine prominent black (7.5YR 2.5/1) very weakly cemented iron-manganese concretions throughout; common fine prominent black (7.5YR 2.5/1) manganese stains on faces of peds; slightly alkaline; clear smooth boundary. [0 to 43 cm (0 to 17 inches) thick]

Cg--127 to 152 cm (50 to 60 inches); light brownish gray (2.5Y 6/2) silt loam; massive; friable; few distinct very dark grayish brown (10YR 3/2) organo-clay films as linings in pores; common fine prominent yellowish brown (10YR 5/8) masses of oxidized iron in the matrix; few fine prominent black (7.5YR 2.5/1) very weakly cemented iron-manganese concretions throughout; few fine prominent black (7.5YR 2.5/1) manganese stains on faces of vertical cleavage planes; moderately alkaline.

TYPE LOCATION: Knox County, Illinois; about 0.25 mile northeast of Oneida; 2,046 feet west and 594 feet north of the southeast corner of sec. 25, T. 13 N., R. 2 E.; USGS Oneida topographic quadrangle; lat. 41 degrees 4 minutes 40 seconds N. and long. 90 degrees 13 minutes 3 seconds W; NAD 27; UTM zone 15 0733740 easting and 4551126 northing, NAD 83.

RANGE IN CHARACTERISTICS:
Thickness of the mollic epipedon: 25 to 50 cm (10 to 20 inches)
Depth to the base of the argillic horizon: 76 to 160 cm (30 to 63 inches)
Depth to carbonates: greater than 102 cm (40 inches)
Average content of clay in the particle-size control section: between 35 and 42 percent
Average content of sand in the series control section: less than 10 percent in all parts

Ap, A, and/or AB horizons:
Hue: 10YR
Value: 2 or 3 (4 or 5 dry)
Chroma: 1 or 2
Texture: silt loam or silty clay loam
Reaction: strongly acid to slightly alkaline depending upon liming practices

BA, Bt, Btg, BC, and/or BCg horizons:
Hue: 7.5YR to 5Y
Value: 3 to 6
Chroma: 2 to 6
Texture: silty clay loam or silty clay, with lower subhorizons of silt loam in some pedons
Depth to maximum clay content: Between 51 and 76 cm (20 and 30 inches)
Reaction: strongly acid in the upper horizons to slightly alkaline in the lower horizons

Cg or C horizon:
Hue: 7.5YR to 5Y
Value: 5 to 7
Chroma: 1 to 8
Texture: silt loam
Average content of clay: between 18 and 25 percent
Reaction: slightly acid to moderately alkaline
Other features:
Some pedons have redoximorphic colors with nearly equal proportions of high and low chroma.

COMPETING SERIES: These are the Biddle, Flanagan, Herrick, Malvern, Rutland, and Timewell series. Biddle soils have 5 to 15 percent exchangeable sodium in the subsoil. Flanagan soils average more than 10 percent sand in the lower part of the series control section. Herrick and Timewell soils have an AE or E horizon or a moist color value more than 3 in the upper part of the control section. Malvern and Rutland soils average more than 25 percent clay in the lower part of the series control section.

GEOGRAPHIC SETTING: Ipava soils are on nearly level to gently sloping broad summits on uplands. A minor acreage has been correlated on stream terraces. Slope gradients typically are between 1 and 3 percent and range from 0 to 5 percent. Ipava soils formed in loess. Mean annual temperature ranges from 10.0 to 13.3 degrees C (50 to 56 degrees F). Mean annual precipitation ranges from 914 to 1,016 mm (36 to 40 inches). Frost-free period ranges from 160 to 190 days. Elevation is 180 to 250 meters (590 to 820 feet) above mean sea level.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckhart, Clarksdale, Denny, Osco, Sable, and Virden soils. Clarksdale soils are on similar landscapes nearby, but are typically nearer the drainageways. The poorly drained Denny soils have albic horizons and are in depressional areas. The well drained Osco and moderately well drained Buckhart soils contain less clay in the subsoil and are more sloping or are on narrower ridges in areas with greater relief. The poorly drained Sable soils contain less clay in the subsoil and are nearby on the parts of the inter-stream divides with lowest relief. The poorly drained Virden soils typically are nearby on the parts of the inter-stream divides with lowest relief.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained. An apparent seasonal high water table is at a depth of 30 to 61 cm (1 to 2 feet) below the surface at some time between January and May in normal years. The potential for surface runoff is low or medium. Saturated hydraulic conductivity is moderately low to moderately high (0.42 to 1.41 micrometers per second). Permeability is moderately slow (0.2 to 0.6 inches per hour).

USE AND VEGETATION: Most areas of this soil are cultivated. Corn, soybeans, and small grain are the principal crops. Native vegetation is prairie grass.

DISTRIBUTION AND EXTENT: MLRAs 108A, 108B, 110, and 115C in Illinois and Indiana. The series is extensive. More than 785,000 acres have been correlated.

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

SERIES ESTABLISHED: Christian County, Illinois, 1946.

REMARKS: Diagnostic horizons recognized in this pedon are:
Mollic epipedon - from the surface to a depth of 46 cm (18 inches) (Ap and A horizons).
Argillic horizon - from a depth of 61 to 94 cm (24 to 37 inches) (Btg1 and Btg2 horizons).

ADDITIONAL DATA: Data on numerous pedons are on file at the Illinois State office.

National Cooperative Soil Survey
U.S.A.