LOCATION MIDLAND                 LA+AR TX

Established Series
JJD-DRM-RM
05/2014

MIDLAND SERIES

The Midland series consists of very deep, poorly drained, very slowly permeable soils formed in loamy and clayey sediments of late Pleistocene age. These nearly level soils occur on low concave terraces above stream channels on coast plains. Slope ranges from 0 to 1 percent. Mean annual precipitation is about 1574 mm (62 in), and mean annual air temperature is about 20 degrees C (68 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Chromic Vertic Epiaqualfs

TYPICAL PEDON: Midland silty clay loam--on a broad, nearly level area in a cultivated rice field at an elevation of 3 m (10 ft). (Colors are for moist soil unless otherwise stated.)

Ap--0 to 23 cm (0 to 9 in); dark grayish brown (10YR 4/2) silty clay loam, weak fine granular structure; friable, many very fine and fine roots; few fine prominent strong brown (7.5YR 4/6) oxidation stains around roots, moderately acid; clear smooth boundary. (8 to 38 cm [3 to 15 in] thick)

Btg--23 to 48 cm (9 to 19 in); dark gray (10YR 4/1) silty clay; moderate medium angular blocky structure, firm; many very fine and fine roots; few faint clay films on surfaces of peds; few fine moderately cemented black and brownish iron-manganese concretions; many fine and medium prominent strong brown (7.5YR 5/8) masses of iron accumulation; moderately acid; gradual wavy boundary. (13 to 38 cm [5 to 15 in] thick)

Btkg--48 to 81 cm (19 to 32 in); gray (10YR 5/1) silty clay; moderate medium angular blocky structure; firm; few fine roots; few faint clay films on surfaces of peds; few fine moderately cemented black and brownish iron-manganese concretions; many coarse prominent strong brown (7.5YR 4/6) masses of iron accumulation; few fine calcium carbonate concretions; neutral; gradual wavy boundary. (25 to 51 cm [10 to 20 in] thick)

Btkssgl--81 to 107 cm (32 to 42 in); gray (10YR 5/1) silty clay; moderate medium angular blocky structure; firm; few distinct slickensides 6 in across; few faint clay films on surfaces of peds; few fine moderately cemented black and brownish iron-manganese concretions; many fine prominent strong brown (7.5YR 4/6) and yellowish brown (10YR 5/8) masses of iron accumulation; few fine calcium carbonate concretions; neutral; gradual wavy boundary. (13 to 51 cm [5 to 20 in] thick)

Btkssg2--107 to 203 cm (42 to 80 in); gray (10YR 6/1) silty clay; weak medium angular blocky structure; firm; few distinct slickensides 6 in across; few faint clay films on surfaces of peds; many medium and coarse moderately cemented iron-manganese accumulations; many coarse prominent yellowish brown (10YR 5/8) masses of iron accumulation; few fine calcium carbonate concretions; slightly alkaline.

TYPE LOCATION: Acadia Parish, Louisiana; about 1.6 miles northwest of Morse; 0.5 mile north of LA Highway 92; 1600 ft west of Lazy Point Canal, and 75 ft north of parish road P5-13; 2500 feet south and 1750 feet east of the northwest corner of sec. 57, T. 10 S., R. 2 W.; USGS Mermentau, LA. topographic quadrangle; Lat. 30 degrees, 8 minutes, 54 seconds N.; Long. 92 degrees 31 minutes 37 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
The thickness of the solum is more than 203 cm (80 in). Slickensides or wedge shaped peds range from 17 to 132 cm (41 to 52 in)102 cm of the soil surface. COLE values in the upper 51 cm (20 in) of the B horizon range from about 0.06 to 0.08.

Soil Moisture: An Aquic soil moisture regime.
Mean annual soil temperature: 19.9 to 21.7 degrees C (68 to 71 degrees F)

Particle-size control section (weighted average)
Clay content: 35 to 55 percent

Ap or A (where present) Horizon
Hue: 10YR
Value: 4 or 5
Chroma: 1 or 2
Texture: silt loam or silty clay loam
Redox concentrations: amount-none or few, shades-brown
Reaction: strongly acid to neutral (5.1 to 7.3)

Btg Horizon
Hue: 10YR to 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: silty clay loam, silty clay, or clay
Redox concentrations: amount-few to many, shades-brown, yellow or olive
Reaction: strongly acid to neutral (5.6 to 7.3)

Btkg and Btkssg Horizons
Hue: 10YR to 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: silty clay loam, silty clay, or clay
Slickensides/Pressure faces: amount-none to common; distinctness-faint or distinct
Redox concentrations: amount-few to many, shades-brown, yellow or olive
Identifiable secondary carbonate: amount-few or common; kind-concretions or masses
Reaction: neutral to moderately alkaline (7.3 to 8.4)

BCg Horizon (where present)
Hue: 10YR to 5Y
Value: 4 to 6
Chroma: 1 or 2
Texture: silty clay loam, silty clay, or clay
Redox concentrations: amount-few to many, shades-brown, yellow or olive
Identifiable secondary carbonate: amount-0 to 2 percent, size-, kind-concretions or masses
Reaction: neutral to moderately alkaline (7.3 to 8.4)

COMPETING SERIES: This is the Tensas (LA) series in the same family and the similar Bacliff (TX), Baldwin (LA), Beaumont (TX), Crowley (LA), Edna (TX), Judice (LA), Kaplan (LA), Mowata (LA), and Viterbo (TX) series.
Tensas soils: somewhat poorly drained; formed in Holocene age natural levee sediments; are underlain with loamy materials.
Bacliff, Beaumont, and Judice soils are Vertisols; Judice soils have a mollic epipedon.
Baldwin soils: formed in Holocene age Mississippi River delta sediments; are on slightly better drained convex positions on natural leeves.
Crowley and Edna soils: have an abrupt textural change.
Kaplan soils: have sub-horizons with chroma of more than 2.
Mowata soils: have a glossic horizon.
Viterbo soils: have red masses of iron accumulation in the B horizons; are somewhat poorly drained.

GEOGRAPHIC SETTING:
Parent material: loamy and clayey alluvial sediments of late Pleistocene age; presumed to have been deposited mainly by the Red River with some influence from the Mississippi River
Landscape: coastal plains river valleys
Landform: terraces
Microfeature: open depressions
Slope: 0 to 1 percent but mainly less than 1 percent.
Mean annual precipitation: 1397 to 1651 mm (55 to 65 in)
Precipitation Pattern: Precipitation is uniform throughout the year with slight peaks during the spring and summer months
Mean annual air temperature: 19.3 to 20.1 degrees C (67 to 68 degrees F)
Frost-free period: 235 to 350 days
Elevation: 1.5 to 21.3 m (5 to 70 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Basile (LA), Crowley (LA), Judice (LA), Kaplan (LA), and Mowata (LA) soils.
Basile soils: have a fine-silty particle-size control section; a glossic horizon; on flood plains of drainageways. Crowley and Kaplan soils: somewhat poorly drained; on convex ridges and sideslopes at slightly higher elevations.
Judice and Mowata soils: are in similar positions. Judice soils have a mollic epipedon. Mowata soils have a glossic horizon.

DRAINAGE AND PERMEABILITY: Poorly drained. Very slow permeability. Runoff is high. A water table exists from 6 to 61 cm (0.5 to 2 ft) from the soil surface from November through April in normal years. Some areas are subject to occasional or rare flooding for brief periods.

USE AND VEGETATION: Most of this soil is cultivated and used to grow rice and soybeans, rotated with pasture or used for crayfish aquaculture. A few areas are used for corn, grain sorghum, and wheat. Native vegetation was tall prairie grasses.

DISTRIBUTION AND EXTENT: Southwest Louisiana; Land Resource Region T; MLRA 150A-Gulf Coast Prairies; the series is of large extent.

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

SERIES ESTABLISHED: Acadia Parish, Louisiana; 1948.

REMARKS: Series redescribed and type location moved to site with lab data and centrally located in series province (DRM 1998). Some data indicate these soils may classify as Vertisols.
Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon-0 to 23 cm (0 to 9 in) (Ap horizon).
Argillic horizon-23 to 203 cm (9 to 80 in) (Btg, Btkg, Btkssg1, and Btkssg2 horizons).
Aquic moisture regime.
Vertic feature-Slickensides at 81 cm (32 in).

ADDITIONAL DATA: Laboratory data on the typifying pedon from Acadia Parish by Louisiana Agricultural Experiment Station (S94LA-001-009).

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.