LOCATION WOLCO OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Pachic Argiustolls
TYPICAL PEDON: Wolco silty clay loam - rangeland.
(Colors are for dry soil unless otherwise
stated.)
A1-- 0-14 inches, dark gray (10YR 4/1) silty clay loam,
black (10YR 2/1) moist; moderate medium granular structure; hard,
friable; medium acid; gradual smooth boundary. (9 to 17 inches
thick)
B1-- 14-21 inches, very dark grayish brown (10YR 3/2)
silty clay loam, very dark brown (10YR 2/2) moist; weak medium
subangular blocky structure parting to strong medium granular
structure; very hard, firm; slightly acid; gradual smooth
boundary. (4 to 8 inches thick)
B21t-- 21-36 inches, coarsely mottled brown (7.5YR 5/2),
yellowish red (5YR 5/6), and dark grayish brown (10YR 4/2) silty
clay, dark brown (7.5YR 4/2), yellowish red (5YR 4/6), and very
dark grayish brown (10YR 3/2) moist; moderate medium blocky
structure parting to strong medium granular structure; extremely
hard, very firm; nearly continuous clay films or pressure faces on
faces of peds; few fine black concretions; few fragments of chert
from 2 mm. to 75 mm. in diameter; neutral; gradual smooth
boundary. (9 to 15 inches thick)
B22t-- 36-55 inches, coarsely mottled yellowish red (5YR
5/6) and grayish brown (10YR 5/2) silty clay, yellowish red (5YR
4/6) and dark grayish brown (10YR 4/2) moist; moderate medium
blocky structure; extremely hard, very firm; nearly continuous
clay films or pressure faces on faces of peds; few fine black
concretions; about 10 percent by volume of fragments of chert from
2 mm. to 75 mm. in diameter; moderately alkaline; clear irregular
boundary. (0 to 19 inches thick)
R-- 55-60 inches, hard limestone bedrock; coarsely
fractured.
TYPE LOCATION: Osage County, Oklahoma; about 1.5 miles west and
2.5 miles north of Foraker; 1800 feet north and 30 feet west of
the southeast corner of sec. 13, T. 28 N., R. 6 E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to hard
limestone or chert bedrock range from 40 to 60 inches.
The A horizon is very dark grayish brown (10YR 3/2), dark gray (N
4/ ; 10YR 4/1), or dark grayish brown (10YR 4/2). It is silt loam
or silty clay loam and medium acid or slightly acid.
The B1 horizon is brown to dark brown (7.5YR 4/2), very dark
grayish brown (10YR 3/2), or dark grayish brown (10YR 4/2).
Some pedons have a B1 horizon with mottles of red or brown. It is
medium acid or slightly acid.
The B2t horizons are dark reddish gray (5YR 4/2), reddish brown
(5YR 4/3, 5/3, 4/4, 5/4), yellowish red (5YR 4/6, 5/6), or brown
or dark brown (7.5YR 4/2, 5/2, 4/4, 5/4). Mottles of gray, brown,
or red occur in most pedons. Some matrix colors are coarsely
mottled. These horizons are silty clay loam or silty clay with
the clay content of the control section ranging from 35 to 50
percent. Fragments of limestone or chert and calcium carbonate
concretions from 2 mm. to 75 mm. in diameter, make up from 0 to 15
percent by volume. Fragments of limestone or chert greater than
75 mm. in diameter make up from 0 to 10 percent by volume. The
B2t horizons range from medium acid to moderately alkaline.
Some pedons have B3 horizons that have color, texture, and content
of fragments similar to the B2t horizons. The B3 horizon ranges
from neutral to moderately alkaline.
The R layer is hard limestone and is fractured at intervals from 1
to 6 feet.
Competing Series: These are the Abilene,
Blanket, Brewer, Corbin, Cutter, Dale, Dodson, Grant, Kingfisher,
McLain, Pond Creek, St. Paul, Scullin, and Vanoss series.
Abilene, Blanket, Brewer, Cutter, Dodson, and McLain soils are
more than 60 inches thick to bedrock. Corbin, Pond Creek and St.
Paul soils have sola more than 60 inches thick and lack wetness
mottles within 1 to 2 feet of the soil surface. Dale soils lack
B2t horizons. Grant, Kingfisher, Scullin, and Vanoss soils have
mollic epipedons less than 20 inches thick. In addition, Scullin
soils have sola 20-40 inches thick over limestone bedrock.
GEOGRAPHIC SETTING: The Wolco soils are on nearly level to very gently sloping uplands. Slope gradients are 0 to 3 percent. They have
formed in material weathered from shale and limestone. The
climate is dry subhumid or moist subhumid. Average annual
precipitation ranges from 32 to 40 inches; mean annual temperature
ranges from 57 degrees to 64 degrees F.; Thornthwaite P-E indices
range from 54 to 64. A perched water table ranges from 1.5 to 3.0
from December through April.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Corbin series and the Shidler series. Shidler soils have less than 35 percent
clay in the control section, lack argillic horizons, and have hard
limestone between 4 and 20 inches below the soil surface.
Drainage and Permeability: Moderately well drained; slow to
medium runoff; slow permeability.
USE AND VEGETATION: Mainly used for native range and native hay
meadows. Some areas are cultivated to small grains, grain
sorghums, soybeans, and alfalfa. Tame pastures have been
established on some old cultivated fields. Native vegetation is
mainly mid and tall grass
prairie.
DISTRIBUTION AND EXTENT: North central Oklahoma and possibly in
south central Kansas. The series is of moderate extent.
SERIES ESTABLISHED: Osage County, Oklahoma; 1975.
REMARKS: The Wolco soils were formerly included with the Labette
soils and classified in the Brunizem great soil group.