LOCATION AGRA OK

Established Series
JEH Rev. JGF:GFS:JLD
02/2016

AGRA SERIES

The Agra series consists of very deep, moderately well drained soils that formed in material weathered from shale or clay, of Pennsylvanian age. These soils are on convex interfluves and side slopes of hillslopes on low hills in the Central Rolling Red Prairies (MLRA 80A). Slopes range from 1 to 5 percent. Mean annual air temperature is about 16 degrees C (61 degrees F), and mean annual precipitation is about 890 mm (35 in).

TAXONOMIC CLASS: Fine, mixed, superactive, thermic Udertic Paleustolls

TYPICAL PEDON: Agra silt loam, on a southeast facing convex slope of 1 percent, in tame pasture at an elevation of 280 m (920 ft). (Colors are for dry soil unless otherwise stated.)

Ap--0 to 18 cm (0 to 7 in); brown (7.5YR 5/2) silt loam, dark brown (7.5YR 3/2) moist; weak very fine granular structure; slightly hard, friable; slightly acid; clear smooth boundary.

A--18 to 28 cm (7 to 11 in); brown (7.5YR 4/2) silt loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; slightly hard, friable; slightly acid, clear smooth boundary. (Combined thickness of the A horizon is 18 to 36 cm [7 to 14 in])

Bt--28 to 41 cm (11 to 16 in); brown (7.5YR 5/2) silty clay loam, brown (7.5YR 4/2) moist; weak medium subangular blocky structure; hard, firm; common distinct clay films on faces of peds; slightly acid; gradual smooth boundary.

Btss1--41 to 76 cm (16 to 30 in); brown (7.5YR 5/4) silty clay, brown (7.5YR 4/4) moist; weak medium prismatic structure parting to moderate medium subangular blocky; very hard, very firm; common distinct brown (7.5YR 4/2) clay films on faces of peds; few distinct slickensides; neutral; gradual smooth boundary.

Btss2--76 to 107 cm (30 to 42 in); light brown (7.5YR 6/4) silty clay, brown (7.5YR 5/4) moist; moderate medium and coarse subangular blocky structure; very hard, very firm; many distinct brown (7.5YR 4/2) clay films on faces of peds; few fine black manganese concentrations; common fine distinct strong brown (7.5YR 5/6), brown (7.5YR 5/4) and light yellowish brown (10YR 6/4) redoximorphic concentrations of iron; common distinct slickensides; moderately alkaline; gradual smooth boundary. (Combined thickness of the Bt horizon is 51 to 127 cm [20 to 50 in])

Btkss--107 to 203 cm (42 to 80 in); variegated gray (N 6/ ), pinkish gray (7.5YR 7/2), light brown (7.5YR 6/4), and reddish yellow (7.5YR 6/6) silty clay; weak coarse subangular blocky structure; very hard, very firm; common distinct clay films on faces of peds; common distinct slickensides; few fine black manganese concentrations; few fine calcium carbonate concretions; moderately alkaline.

TYPE LOCATION: Payne County, Oklahoma; about 2 miles north and one mile west of Yale; 2,000 feet west and 1,050 feet south of the northeast corner of sec. 12, T. 19 N., R. 5 E.

USGS topographic quadrangle: Maramec, OK
Latitude: 36 degrees, 8 minutes, 32 seconds N
Longitude 96 degrees, 43 minutes, 14 seconds W
Datum: NAD 83

Decimal Degrees:
Latitude: 36.1422222
Longitude: -96.7205556

UTM Easting: 705088 m
UTM Northing: 4002130 m
UTM Zone: 14

RANGE IN CHARACTERISTICS:
Depth to bedrock: more than 203 cm (80 in) from the surface
Depth to secondary carbonate: more than 102 cm (40 in)
Clay content of control section (weighted average): 35 to 60 percent
Sand content of control section (weighted average): 0 to 35 percent

Ap and A horizons:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 or 3 dry or moist
Texture: silt loam or loam
Reaction: moderately acid to slightly alkaline

Bt horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 4 dry or moist
Texture: silty clay loam or clay loam
Reaction: moderately acid to slightly alkaline

Btss horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 6 dry or moist
Texture: clay loam, silty clay loam, silty clay, or clay
Redoximorphic features: concentrations of iron and manganese
Other features: few to common slickensides
Reaction: neutral to moderately alkaline

Btkss horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6 dry or moist
Texture: clay, silty clay, silty clay loam, or clay loam
Redoximorphic features: concentrations of iron and manganese, and depletions of iron
Identifiable secondary carbonate: few to common
Gypsum crystals: Some pedons have gypsum crystals
Other features: few to common slickensides
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: These are the Kirkland and Renfrow series.
Kirkland soils: have a mollic epipedon more than 51 cm (20 in) thick.
Renfrow soils: do not have redoximorphic features.

GEOGRAPHIC SETTING:
Parent Material: material weathered from shale or clay of Pennsylvanian age
Landscape: Hills
Landform: convex interfluves and side slopes of low hills
Slope: 1 to 5 percent
Mean annual soil temperature: 14 to 17 degrees C (57 to 63 degrees F)
Mean annual precipitation: 660 to 965 mm (26 to 38 in)
Frost-free period: 200 to 230 days
Elevation: 213 to 457 m (700 to 1500 ft)
Thornthwaite P-E Index: 50 to 64

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coyle, Huska, Lucien, and Steedman series.
Coyle soils: are moderately deep and occur on similar positions
Huska soils: have a natric horizon and are in lower positions
Lucien soils: are shallow and are on crests and upper side slopes
Steedman soils: are moderately deep and are on steeper parts of the landform

DRAINAGE AND PERMEABILITY:
Drainage: moderately well drained
Permeability: slow
Runoff: high to very high
Episaturation: 91 to 122 cm (36 to 48 in) for brief periods during the winter and spring

USE AND VEGETATION: Used mainly for improved pasture or livestock grazing.
Improved pasture is mainly common bermudagrass. Native vegetation is mainly big bluestem, little bluestem, Indiangrass, and switchgrass. Some of the less sloping areas are cultivated to wheat, grain sorghums, and soybeans.

DISTRIBUTION AND EXTENT: North central Oklahoma; Land Resource Region H, MLRA 80A. The series is extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Payne County, Oklahoma, 1983

REMARKS:
These soils were formerly included in the Dennis series.
The OSD was extensively updated as a result of SDJR Initiative (JLD 01/2016).

Diagnostic features and horizons recognized in this soil are:
Mollic epipedon: 0 to 28 cm (0 to 11 in) (Ap and A horizons)
Argillic horizon: 28 to 203 cm (11 to 80 in) (Bt horizons)
Slickensides: 41 to 203 cm (42 to 80 in) (Btss and Btkss horizon)
Redoximorphic features: 76 to 203 cm (30 to 80 in) (Bt3 and Btkss horizons)
Secondary carbonates: 107 to 203 cm (42 to 80 in) (Btkss horizon)
Moisture regime: Udic-Ustic

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014

National Cooperative Soil Survey
U.S.A.