LOCATION BERNOW OKEstablished Series
TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Glossic Paleudalfs
TYPICAL PEDON: Bernow fine sandy loam--forest.
(Colors are for moist soil unless otherwise
stated.)
A1--0 to 7 inches; dark brown (10YR 4/3) fine sandy loam;
weak fine granular structure; hard, friable; neutral; clear smooth
boundary. (3 to 10 inches thick)
A2--7 to 15 inches; yellowish brown (10YR 5/4) fine sandy
loam; weak fine granular structure; hard, friable; neutral, clear
smooth boundary. (3 to 17 inches thick)
B21t--15 to 38 inches; strong brown (7.5YR 5/6) sandy clay
loam; few fine distinct yellowish red mottles; moderate medium
subangular blocky structure; very hard, firm; few thin
discontinuous clay films on faces of peds; medium acid; gradual
smooth boundary. (10 to 36 inches thick)
B22t--38 to 48 inches; strong brown (7.5YR 5/6) sandy clay
loam; common medium distinct yellowish red (5YR 5/6) mottles;
moderate medium subangular blocky structure; very hard, firm; few
thin discontinuous clay films on faces of peds; very strongly
acid; gradual smooth boundary. (10 to 30 inches thick)
B&A'2--48 to 68 inches; coarsely mottled yellowish brown
(10YR 5/6) and strong brown (7.5YR 5/6) sandy clay loam (B part);
weak coarse subangular blocky structure; very hard, firm; 10
percent light gray (10YR 6/1) fine sandy loam (A part) massive;
very friable, slightly hard; few thin discontinuous clay films
bridging sand grains; few fine dark concretions; strongly acid.
TYPE LOCATION: Bryan County, Oklahoma; about 4 miles northeast of
Bokchito; 1200 feet east and 60 feet north of the southwest corner
of sec. 20, T. 6 S., R. 12 E.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more
than 80 inches.
The A1 or Ap horizon is very dark grayish brown (10YR 3/2), dark
brown (10YR 3/3, 4/3), dark grayish brown (10YR 4/2), grayish
brown (10YR 5/2), or brown (10YR 5/3; 7.5YR 4/2, 4/4). Where the
moist value and chroma are less than 3.5 the thickness is less
than 7 inches. Texture is fine sandy loam or loamy fine sand.
Soil reaction ranges from neutral through medium acid.
The A2 horizon is brown (10YR 4/3, 5/3; 7.5YR 5/2, 4/4, 5/4),
yellowish brown (10YR 5/4), pale brown (10YR 6/3), strong brown
(7.5YR 5/6), light brown (7.5YR 6/4), light yellowish brown (10YR
6/4), or reddish yellow (7.5YR 6/6). It is fine sandy loam or
loamy fine sand and ranges from neutral through strongly acid.
The B21t horizon is yellowish brown (10YR 5/4, 5/6, 5/8), brownish
yellow (10YR 6/6), strong brown (7.5YR 5/6, 5/8), reddish yellow
(7.5YR 6/6, 6/8), reddish brown (5YR 5/4), or yellowish red (5YR
4/6, 4/8, 5/6, 5/8). It has mottles in shades of red, brown, or
yellow in some pedons. This horizon is loam, clay loam, or sandy
clay loam and it ranges from slightly acid through very strongly
acid.
The B22t horizon is light yellowish brown (10YR 6/4), yellowish
brown (10YR 5/4, 5/6, 5/8), brownish yellow (10YR 6/6, 6/8),
strong brown (7.5YR 5/6, 5/8), reddish yellow (7.5YR 6/6, 6/8),
reddish brown (5YR 4/4, 5/4), or yellowish red (5YR 4/6, 4/8, 5/6,
5/8). It has mottles in shades of gray, brown, yellow, or red in
most pedons. This horizon is sandy clay loam or clay loam (20 to
32 percent clay). It ranges from medium acid through very
strongly acid. Some pedons contain clean sand grains comprising
less than 2 percent.
The B part of the B&A'2 horizon has the same range in color as the
B2t horizon or is coarsely mottled in shades of red, yellow,
brown, or gray. The A'2 part of the B&A'2 horizon comprises 5 to
15 percent of the matrix and occurs as pockets, vertical streaks,
or ped coatings. The A'2 part is light gray (10YR 6/1, 7/1, 7/2),
light brownish gray (10YR 6/2), white (10YR 8/1, 8/2), pinkish
gray (7.5YR 6/2, 7/2), or pinkish white (7.5YR 8/2) fine sandy
loam. The B&A'2 horizon is strongly acid or very strongly acid.
COMPETING SERIES: These are the Bernaldo and Gallime series and
the closely similar Besner, Evangeline, Naldo, Vesey, and Whakana
series. Bernaldo soils are browner than 5YR hue and have a
perched water table at a depth of 4 to 6 feet. Besner soils are
coarse-loamy, and Evangeline soils are fine-silty. Gallime soils
have an A horizon with a thickness of 20 inches or more. Naldo,
Vesey, and Whakana soils have mixed mineralogy.
GEOGRAPHIC SETTING: Bernow soils are on nearly level through
strongly sloping uplands. Slope ranges from 0 to 12 percent. The
soil formed in material weathered from loamy and sandy sediments.
The climate is warm and subhumid. Thornthwaite annual P-E index
is 62 to 76. Average annual precipitation is about 38 to 46
inches. Mean annual temperature is about 62 degrees to 66 degrees
F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boswell, Hamden,
Larue, and Romia series. Boswell soils are on similar slopes and
have a fine argillic horizon. Hamden soils are on broad slightly
concave ridges and have gray mottles in the upper part of the
argillic horizon. Larue soils are on broad smooth ridges and have
an A horizon with a thickness of 20 inches or more. Romia soils
are mostly on ridgecrests and have sandstone bedrock at a depth of
40 to 60 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff;
moderate permeability.
USE AND VEGETATION: Primarily used for tame pasture plants or
woodland. Bermudagrass is the principal pasture grass. The main
field crops are wheat, grain sorghum, peanuts, soybeans, and
cotton. Native vegetation is mainly oak, with an understory of
grass.
DISTRIBUTION AND EXTENT: Eastern Oklahoma, possibly Arkansas,
Louisiana, and Texas. The series is of moderate extent.
SERIES ESTABLISHED: Bryan County, Oklahoma; 1975.
REMARKS: The Bernow series formerly was included with the
Bernaldo and Naldo series and was classified in the Red-Yellow
Podzolic great soil group.