LOCATION MAMOU                   LA

Established Series
BAT-CLN-RM
01/2018

MAMOU SERIES

The Mamou series consists of very deep, somewhat poorly drained, slowly permeable soils that formed in loamy fluviomarine deposits of the Prairie Terrace Formation of Pleistocene age. These nearly level to very gently sloping soils occur on elongated deltaic natural levees. . Slope ranges from 1 to 3 percent. Mean annual precipitation is about 1549 mm (61 in), and mean annual air temperature is about 20.6 degrees C (69 degrees F).
TAXONOMIC CLASS: Fine-silty, siliceous, active, thermic Aeric Albaqualfs

TYPICAL PEDON: Mamou silt loam--in pasture on a convex 2 percent side slope; elevation is 17.4 m (57 ft). (Colors are for moist soil unless otherwise stated.)

Ap--0 to 15 cm (0 to 6 in); grayish brown (10YR 5/2) silt loam; weak fine granular structure; friable; common fine roots; few black (10YR 2/1) organic stains; common fine distinct yellowish brown (10YR 5/4) masses of oxidized iron; slightly acid; clear smooth boundary. (Thickness of the Ap horizon is 8 to 20 cm [3 to 8 in])

E--15 to 28 cm (6 to 11 in); yellowish brown (10YR 5/4) silt loam; weak medium subangular blocky structure; friable; few fine roots; common fine pores; common fine distinct grayish brown (10YR 5/2) iron depletions; few medium prominent red (2.5YR 4/6) masses of oxidized iron; slightly acid; abrupt wavy boundary. (Thickness of the E horizon is 8 to 25 cm [3 to 10 in])

Btg1--28 to 48 cm (11 to 19 in); variegated matrix of dark gray (10YR 4/1), very dark gray (10YR 3/1), and dark red (2.5YR 3/6) silty clay loam; surfaces of peds are very dark gray (10YR 3/1); weak coarse prismatic structure parting to strong medium subangular blocky; firm; few fine roots along surface of peds; few fine pores; many prominent clay films on surfaces of peds; few fine black (10YR 2/1) iron-manganese masses; few fine faint brown (10YR 4/3) masses of oxidized iron; slightly acid; clear wavy boundary.

Btg2--48 to 66 cm (19 to 26 in); yellowish brown (10YR 5/4) silty clay loam with dark grayish brown (10YR 4/2) coatings on surface of peds; moderate medium subangular blocky structure; firm; few fine roots; few fine pores; many prominent clay films on surface of peds; many medium black stains on surfaces of peds; few fine black (10YR 2/1) iron-manganese masses; few fine prominent red (2.5YR 5/6) masses of oxidized iron; slightly acid; diffuse wavy boundary. (Combined thickness of the Btg horizon is 25 to 111 cm [10 to 44 in])

C--66 to 163 cm (26 to 64 in); variegated matrix of light yellowish brown (10YR 6/4) and yellowish brown (10YR 5/4) loam; massive; firm; common medium distinct strong brown (7.5YR 5/8) masses of oxidized iron; few medium brown (10YR 4/3) ironstone concretions with red interiors; neutral.

TYPE LOCATION: Evangeline Parish, Louisiana; 5 miles south of Mamou; 1.2 miles west of Fenris Junction, 72 yards south of highway; Eunice North, LA USGS topographic quadrangle; Latitude: 30 degrees 33 minutes 35.7 seconds N; Longitude: 92 degrees 27 minutes 8.2 seconds W;WGS84. NW1/4SE1/4 sec. 2, T. 6 S., R 1 W.

RANGE IN CHARACTERISTICS:
Soil Moisture: an aquic moisture regime
Mean annual soil temperature: 21.1 to 22.2 degrees C (70 to 72 degrees F)
Solum thickness: 51 to 127 cm (20 to 50 in).
Thickness of the A and E horizons to the abrupt textural change: 15 to 46 cm (6 to 18 in)

Weighted average clay content of the A and E horizons: 5 to 15 percent
Weighted average clay content of the argillic horizon: 25 to 35 percent.

Ap or A Horizon:
Hue: 10YR
Value: 4 or 5
Chroma: 1 or 2
Texture: very fine sandy loam, silt loam, or loam
Redox concentrations: amount-none to common; shades-brown
Redox depletions: amount-none to common; shades-gray
Reaction: very strongly acid to slightly acid (4.5 to 6.5)

E Horizon:
Hue: 10YR
Value: 4 to 6
Chroma: 3 or 6
Texture: very fine sandy loam, silt loam, or loam
Redox concentrations: amount-none to common; shades-yellow or brown
Redox depletions: amount-few to many; shades-gray
Reaction: very strongly acid to slightly acid (4.5 to 6.5)

Btg Horizon:
Colors for ped coatings are:
Hue: 10YR or 2.5Y
Value: 3 to 5
Chroma: 1 or 2

Colors for ped interiors are:
Hue: 7.5YR or 10YR
Value: 3 to 6
Chroma: 4 or 8
Most pedons have a variegated matrix with the same colors
Texture: silt loam or silty clay loam
Redox concentrations: amount-few to many; shades-yellow, brown, or red
Redox depletions: amount-none to many; shades-gray
Iron-manganese concentrations: amount-none to common; kind-masses or concretions
Reaction: very strongly acid to slightly alkaline (4.5 to 7.8)

C Horizon:
Variegated matrix in shades of brown, red, or gray
Texture: loam, silt loam, silty clay loam (some pedons have a thin clayey strata
Redox concentrations: amount-none to common; shades-brown
Reaction: slightly acid to slightly alkaline (6.1 to 7.8)

COMPETING SERIES: There are no other series in this family. Similar soils include the Acadiana, Crowley, Dundee, Homa, Patoutville, Springfield, Tenot, and Zachary series.
Acadiana, Crowley, and Springfield soils: a fine particle-size control section. In addition, Crowley soils do not have chroma of 3 or more in the E or upper Bt horizons.
Dundee, Homa, Springfield, and Tenot soils: in the thermic temperature regime. In addition, Dundee soils do not have an E horizon; Homa soils have a very-fine particle-size control section.
Patoutville soils: are in a superactive family; have less than 10 percent sand in the argillic horizon.
Tenot soils: less than 10 percent sand; sola more than 127 cm (50 in) thick.
Zachary soils: poorly drained; have grayer soil colors in the argillic horizon.

GEOGRAPHIC SETTING:
Parent material: loamy fluviomarine deposits of the Prairie Terrace of Pleistocene age
Landscape: flat coastal plains
Landform: elongated natural levees of relic stream channels
Slope: 1 to 3 percent
Mean annual precipitation: 1397 to 1651 mm (55 to 65 in)
Precipitation Pattern: Precipitation is fairly uniform throughout the year.
Mean annual air temperature: 20 to 21.1 degrees C (68 to 70 degrees F)
Frost-free period: 240 to 270 days
Elevation: 12 to 46 m (40 to 150 ft)
Thornthwaite P-E Index: 68 to 80

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Acadiana, Crowley, and Patoutville series and the Mowata and Kinder series. Acadiana soils: on similar to slightly lower landform
Crowley soils: in a fine family; on nearly level areas on a lower landform
Kinder soils: poorly drained; on nearly level areas on a lower landform.
Mowata soils: poorly drained; on a lower concave landform

DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Permeability is slow. Runoff is very high. Water is perched at depths of 15 cm to 30 cm (0.5 to 1.0 ft) for short periods mostly during the winter and spring.

USE AND VEGETATION: Used mainly for growing cotton, corn, sweet potatoes, rice, soybeans, and pasture. Native vegetation is tall prairie grasses.

DISTRIBUTION AND EXTENT: Gulf Coast Prairie of Southwest Louisiana; Land Resource Region - T; MLRA- 150A; of small extent.

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

SERIES ESTABLISHED: Evangeline Parish, Louisiana; 1970.

REMARKS: These soils were formerly included in the Crowley series.

Diagnostic horizons and features recognized in this pedon are;
Ochric epipedon: 0 to 28 cm (0 to 11 in) (Ap & E horizons).
Abrupt textural change: the contact at 28 cm (11 in) has a clay increase that doubles within 8 cm (3 in).
Argillic horizon: 28 to 66 cm (11 to 26 in) (Btg horizons).
Aeric feature: chroma of 3 or more in more than 40 percent of the argillic horizon to a depth of 76 cm (30 in).

ADDITIONAL DATA: Selected chemical data from the LSU fertility lab pedon number S95LA001147-1 from Acadia Parish.

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

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National Cooperative Soil Survey
U.S.A.