LOCATION OST KS OK

Established Series
Rev. JCW, PRF
05/2011

OST SERIES

The Ost series consists of very deep well drained soils that formed in alluvium. Ost soils are on paleoterraces in river valleys of the Great Bend Sand Plains (MLRA 79). Slopes range from 0 to 8 percent. Mean annual precipitation is about 740 millimeters (29 inches) and the mean annual temperature is about 13 degrees C (56 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Udic Argiustolls

TYPICAL PEDON: Ost loam on a east facing, convex, 1 percent slope in cropland. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 20 centimeters (0 to 8 inches); dark grayish brown (10YR 4/2), interior, loam, very dark grayish brown (10YR 3/2), interior, moist; weak fine granular structure; hard, friable, slightly sticky and slightly plastic; common fine roots throughout; 21.0 percent clay; noneffervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; moderately alkaline; abrupt smooth boundary. (13 to 30 centimeters (5 to 12 inches) thick)

Bt1--20 to 30 centimeters (8 to 12 inches); brown (7.5YR 4/2), interior, loam, dark brown (7.5YR 3/2), interior, moist; weak coarse prismatic structure parting to moderate fine subangular blocky structure parting to moderate very fine subangular blocky; hard, firm, sticky and plastic; common fine roots throughout; 26.0 percent clay; few distinct continuous clay films on vertical and horizontal faces of peds; noneffervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; slightly alkaline; clear wavy boundary.

Bt2--30 to 46 centimeters (12 to 18 inches); reddish brown (5YR 5/3), interior, loam, reddish brown (5YR 4/4), interior, moist; weak coarse prismatic structure parting to moderate fine subangular blocky structure parting to moderate very fine subangular blocky; hard, firm, sticky and plastic; common fine roots throughout; 26.0 percent clay; few distinct continuous clay films on vertical and horizontal faces of peds and very few faint patchy skeletans on faces of peds and in pores; slightly effervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; moderately alkaline; clear wavy boundary. (Combined thickness of Bt horizons 10 to 41 centimeters (4 to 16 inches) thick)

Bk1--46 to 58 centimeters (18 to 23 inches); light brown (7.5YR 6/4), interior, clay loam, reddish brown (5YR 4/4), interior, moist; weak coarse prismatic structure parting to moderate fine subangular blocky structure parting to moderate very fine subangular blocky; hard, firm, sticky and plastic; common fine roots throughout; 29.0 percent clay; common coarse irregular carbonate masses and common coarse irregular carbonate concretions; violently effervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; moderately alkaline; gradual wavy boundary.

Bk2--58 to 97 centimeters (23 to 38 inches); light brown (7.5YR 6/4), interior, clay loam, light brown (7.5YR 6/4), interior, moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, firm, sticky and plastic; common fine roots throughout; 27.0 percent clay; many coarse irregular carbonate masses throughout and many coarse irregular carbonate concretions throughout; violently effervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; moderately alkaline; gradual wavy boundary. (Combined thickness of Bk horizons 0 to 61 centimeters (0 to 24 inches) thick)

BCk--97 to 137 centimeters (38 to 54 inches); 50 percent pink (7.5YR 7/4), interior, and 50 percent light reddish brown (5YR 6/4), interior, loam, 50 percent light brown (7.5YR 6/4), interior, and 50 percent reddish brown (5YR 5/4), interior, moist; few fine prominent yellowish brown (10YR 5/6) moist irregular redoximorphic concentrations throughout; weak medium prismatic structure parting to moderate medium subangular blocky; hard, firm, slightly sticky and slightly plastic; 23.0 percent clay; many coarse irregular carbonate masses throughout; violently effervescent throughout (HCl, 1 normal); 1 percent subrounded mixed gravel; moderately alkaline; gradual wavy boundary. (0 to 76 centimeters (0 to 30 inches) thick)

C--137 to 200 centimeters (54 to 80 inches); light gray (2.5Y 7/2), interior, loam, light brownish gray (2.5Y 6/2), interior, moist; few fine prominent yellowish brown (10YR 5/6) moist irregular redoximorphic concentrations throughout; massive; hard, friable, slightly sticky and slightly plastic; 21.0 percent clay; many coarse irregular carbonate masses throughout and many coarse irregular carbonate concretions throughout; violently effervescent throughout (HCl, 1 normal); 2 percent subrounded mixed gravel; moderately alkaline.

TYPE LOCATION: Reno County, KS; about 1.6 kilometers (1 mile) south of Arlington; located about 98 meters (320 feet) north and 503 meters (1650 feet) west of the southeast corner of sec. 16, T. 25 S., R. 8 W.; Pretty Prairie SW USGS quad; lat. 37 degrees 52 minutes 11 seconds N. and long. 98 degrees 12 minutes 6 seconds W.

RANGE IN CHARACTERISTICS:
Soil moisture regime: An ustic moisture regime bordering on udic.
Soil temperature regime: mesic
Mean annual soil temperature: 13 to 14 degrees C (56 to 58 degrees F).
Particle-size control section clay content: 18 to 34 percent clay
Particle-size control section sand content: 20 to 45 percent sand
Depth to calcic horizon: 45 to more than 200 centimeters (18 to more than 80 inches)
Depth to secondary calcium carbonate: 30 to 71 centimeters (12 to 28 inches)
Thickness of the mollic epipedon: 25 to 40 centimeters (10 to 16 inches)
Thickness of the argillic horizon: 20 to 86 centimeters (8 to 34 inches)
Thickness of the calcic horizon: 0 to 76 centimeters (0 to 30 inches)

Ap horizon:
Hue: 5YR to 10YR
Value: 3 to 5, 2 or 3 moist
Chroma: 1 or 2
Texture: loam or clay loam
Rock fragments: 0 to 3 percent
Calcium carbonate equivalent: 0 to 1 percent
Reaction: slightly acid to moderately alkaline

Bt horizon:
Hue: 5YR to 10YR
Value: 4 or 5, 3 or 4 moist
Chroma: 2 to 4
Texture: loam or clay loam
Rock fragments: 0 to 3 percent
Calcium carbonate equivalent: 0 to 5 percent
Reaction: neutral to moderately alkaline

Bk and BCk horizon:
Hue: 5YR to 10YR
Value: 6 to 8, 4 to 6 moist
Chroma: 4 to 6
Texture: loam, clay loam, sandy clay loam, or sandy loam
Rock fragments: 0 to 3 percent
Calcium carbonate equivalent: 15 to 40 percent
Reaction: slightly alkaline or moderately alkaline

C horizon:
Hue: 10YR or 2.5Y
Value: 4 to 8, or moist
Chroma: 2 to 6
Texture: loam, sandy clay loam, or fine sandy loam
Rock fragments: 0 to 3 percent
Calcium carbonate equivalent: 2 to 14 percent
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Lancaster, Leisy, Loretto, Nalim, Naron, Saltcreek and Shellabarger series.
The Lancaster soils have a paralithic contact within a depth of 100 centimeters (40 inches)..
The Leisy and Loretto soils have a mean annual soil temp less than 12 degrees C (53 degrees F).
Nalim and Naron soils have secondary carbonates occurring below 100 centimeters (40 inches).
Saltcreek soils have a paleosol between 76 to 152 centimeters (30 and 60 inches) and do not have carbonates above 100 centimeters (40 inches)..
Shellabarger soils have secondary carbonates occurring below 86 centimeters (34 inches).

GEOGRAPHIC SETTING:
Parent material: alluvium
Landform: paleoterraces in river valleys
Slopes: 0 to 8 percent
Elevation: 450 to 550 meters (1500 to 1800 feet)
Mean annual air temperature: 13 to 14 degrees C. (55 to 57 degrees F.)
Mean annual precipitation: 640 to 810 millimeters (25 to 32 inches)
Wettest months: Mar - Oct.
Driest months: Nov - Feb.
Frost-free period: 190 to 210 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are Blanket, Bethany, Case, Clark, and Farnum soils.
Blanket, Bethany and Farnum soils have mollic epipedon more than 20 inches (50 centimeters) thick and Blanket and Bethany also have more than 35 percent clay in the particle size control section.
Case soils are on similar landforms and do not have a mollic epipedon or an argillic horizon.
Clark soils are on similar landforms and do not have an argillic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well drained
Runoff: medium to rapid
Saturated hydraulic conductivity: moderately high

USE AND VEGETATION: Most areas are in cropland.
Wheat and sorghum as the principal crops.

DISTRIBUTION AND EXTENT: South Central Kansas. LRR H Great Plains Winter Wheat and Range, MLRA 79 Great Bend Sand Plains. This series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado

SERIES ESTABLISHED: Reno County, Kansas 1964

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 30 centimeters (0 to 12 inches) (Ap, Bt1)
argillic horizon: 20 to 46 centimeters (8 to 18 inches) (Bt1, Bt2)
calcic horizon: 46 to 137 centimeters (18 to 54 inches) (Bk1, Bk2, BCk)

Keys to Soil Taxonomy: Eleventh edition, 2010

ADDITIONAL DATA: Laboratory data S85KS155004 at the following site:
http://ssldata.sc.egov.usda.gov/rptExecute.asp?p=12475&r=1&submit1=Get+Report
OST SERIES
LRR=H
5/22/90
1. Added "very deep" to the first sentence in paragraph 1.
2. Added wet consistence to typical pedon.
3. Added "clay films" to the Bt horizons.
4. Added "calcium carbonate equivalent to the Bt and Bk horizons.
5. Changed "C" horizon to BCk horizon.
6. Removed solum thickness from the range in characteristic.
7. Removed non-competing series from competing paragraph.
Modified format by LRM in 2/2006 to include metric and English conversion and change permeability to saturated hydraulic conductivity.
Changed format in competing series. Changed depths from 203 to 200 cm., changed the precipitation to mm from cm JCW 05/2011.

National Cooperative Soil Survey
U.S.A.