LOCATION VERDUN LA+MS TX
Established Series
Rev. JLD
02/2013
VERDUN SERIES
The Verdun series consists of deep, somewhat poorly drained, very slowly permeable soils that contain concentrations of sodium in the subsoil. These soils formed in silty deposits of Pleistocene Age. They are on level, terrace uplands. Slopes range from 0 to 1 percent.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Glossic Natraqualfs
TYPICAL PEDON: Verdun silt loam - bermudagrass and mixed sedge grassland. (Colors are for moist soil unless otherwise stated.)
A--0 to 4 inches; grayish brown (10YR 5/2) silt loam; few fine distinct dark brown (10YR 4/3) mottles; moderate medium granular structure; friable; mildly alkaline; clear wavy boundary. (2 to 6 inches thick)
B/E--4 to 10 inches; brown (10YR 4/3), dark grayish brown (10YR
4/2), and dark gray (10YR 4/1) silty clay loam with thick continuous clay films on peds (Bt); moderate very coarse prismatic structure that parts to moderate medium subangular blocky; friable; tongues up to 10 cm wide and thin layers between peds of grayish brown silt loam (E) make up about 20 percent of horizon; moderately alkaline; clear irregular boundary. (4 to 10 inches thick)
Btn1--10 to 24 inches; brown (10YR 4/3) silty clay loam; common
fine distinct strong brown (7.5YR 5/6) mottles; moderate very coarse prismatic structure that parts to moderate fine subangular blocky; friable; thin layers of light brownish gray (10YR 6/2) silt between prisms; thin patchy very dark gray clay films on some peds; moderately alkaline; gradual wavy boundary. (6 to 18 inches thick)
Btn2--24 to 48 inches; yellowish brown (10YR 5/4) silt loam;
common fine distinct strong brown (7.5YR 5/6) mottles; weak very coarse prismatic structure; friable; common carbonate concretions in lower part; common soft black bodies; few thin patchy clay films; moderately alkaline. (20 to 30 inches thick)
Cn--48 to 60 inches; light olive brown (2.5Y 5/4) silt loam with
few fine faint yellowish brown and light brownish gray mottles; massive, friable; common black stains and soft bodies; few carbonate concretions; moderately alkaline.
TYPE LOCATION: East Baton Rouge Parish, Louisiana; approximately 2.6 miles west of Amite River and 1.1 miles east of intersection of U. S. Highway 190 and Sharp Station Road; 250 feet south of U.S. 190, on a level site at about 50 feet elevation; southwest 1/4 southwest 1/4, sec. 5, T. 7 S., R. 2 E.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 30 to 60 inches or more. Exchangeable sodium ranges from 15 to 50 percent throughout the B horizon.
The A horizon is grayish brown (10YR 5/2), brown (10YR 5/3), dark brown (10YR 4/3, 3/3), or dark grayish brown (10YR 4/2) silt loam.
The E part of the B/E horizon is light brownish gray (10YR 6/2), grayish brown (10YR 5/2), or gray (10YR 5/1, 6/1) silt loam. Tongues of the horizon 1 to 10 cm wide extend into the upper 4 to 10 inches of the B horizon. The A and E horizons range from medium acid through mildly alkaline.
The upper 4 to 10 inches of the Bt horizon is brown (10YR 4/3, 5/3), dark grayish brown (10YR 4/2), dark gray (10YR 4/1), or grayish brown (10YR 5/2; 2.5Y 5/2), silty clay loam with mottles in shades of brown, yellow, or red. Peds are coated with thick dark gray (10YR 4/1) very dark gray (10YR 3/1), or very dark grayish brown (10YR 3/2) clay films. Prisms are surrounded by tongues and interfingers of silt loam. At depths of 4 to 10 inches below its upper boundary the B horizon and the BC horizon are yellowish brown (10YR 5/4), brown (10YR 5/3, 4/3), dark yellowish brown (10YR 3/4), olive brown (2.5Y 4/4), or light olive brown (2.5Y 5/4, 5/6) silty clay loam or silt loam. Mottles are in shades of brown and gray. Some peds have thin discontinuous silt coats. The Btn and Bcn horizons typically are neutral to moderately alkaline throughout, but reaction ranges to medium acid in some pedons. Carbonate concretions are few or common or many in most pedons.
The Cn horizon is in shades of brown in 10YR or 2.5Y hue. Grayish mottles are present in some pedons. It is silt loam or silty clay loam and moderately alkaline or strongly alkaline. Carbonate concretions are present in most pedons.
COMPETING SERIES: These are the
Bonn series in the same family and the
Brimstone,
Deerford,
Foley,
Grubbs,
Hillemann,
Lafe, McCrory, and
Rosella series. Bonn soils have dominant chromas of 2 or less throughout the B horizon. Brimstone, Deerford, and Foley soils have upper Bt horizons with less than 15 percent exchangeable sodium and Foley soils are dominantly 1 or 2 chroma in the B horizon. Grubbs soils have more than 35 percent clay in the upper 20 inches of the B horizon. Hillemann soils have red, acid, silty clay upper B horizons. Lafe soils have strongly acid through slightly acid A horizons and the calcium-magnesium ratio of the B horizons is less than 1. McCrory soils have dominantly gray sandy clay loam B horizons. Rosella soils have more than 15 percent sand coarser than very fine sand in the upper 20 inches of the Bt horizon.
GEOGRAPHIC SETTING: Verdun soils formed in loess or loess-like deposits on nearly level Pleistocene terraces. Slopes are slightly convex to level and typically less than 1 percent. Near the type location the mean annual temperature is about 67.5 degrees F, and the average annual rainfall is 54.5 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Bonn,
Deerford, and
Lafe series and
Calhoun,
Essen,
Fountain, and
Olivier series. Calhoun and Olivier soils are acid and lack natric horizons. Essen and Fountain soils lack natric horizons.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow surface runoff; very slow permeability. Seasonal high water table is perched at depths of 0.5 to 1.0 feet, December through April.
USE AND VEGETATION: Predominantly unimproved pasture or poor quality hardwoods.
DISTRIBUTION AND EXTENT: Louisiana, Arkansas, Tennessee, and possibly Mississippi and Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: AUBURN, ALABAMA
SERIES ESTABLISHED: Livingston Parish, Louisiana, 1931.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 4 inches.
Natric horizon - the zone from 4 to 48 inches.
National Cooperative Soil Survey
U.S.A.