LOCATION CADDO LA+AR

Established Series
Rev. JJD-JKW-RM
08/2018

CADDO SERIES

The Caddo series consists of very deep, poorly drained soils. These nearly level soils formed in fluviomarine deposits derived from the Intermediate Terraces Formation of Pleistocene age. Slope ranges from 0 to 3 percent. Mean annual air temperature is about 19.5 degrees C (67 degrees F), and mean annual precipitation is about 1549 mm (61in).

TAXONOMIC CLASS: Fine-silty, siliceous, active, thermic Typic Glossaqualfs

TYPICAL PEDON: Caddo silt loam in an area of Caddo-Messer complex, 0 to 1percent slopes; in woodland (Colors are for moist soil unless otherwise stated.)

A--0 to 13 cm, (0 to 5 in); grayish brown (10YR 5/2), silt loam, dry; weak fine granular structure; friable; common coarse roots and many fine roots; common fine interstitial pores; 1 percent fine very dark brown (10YR 2/2) iron-manganese concretions; very strongly acid; abrupt smooth boundary. (8 to 20 cm [3 to 8 in] thick)

Eg1--13 to 43 cm, (5 to 17 in); light brownish gray (10YR 6/2), silt loam; weak medium subangular blocky structure; friable; common fine roots; few fine low continuity tubular pores; 1 percent fine very dark brown (10YR 2/2) iron-manganese concretions and 5 percent medium prominent yellowish brown (10YR 5/8), moist, masses of oxidized iron with clear boundaries lining pores; very strongly acid; clear wavy boundary. (combined thickness of the Eg horizons is 33 to 86 cm [13 to 17 in])

Eg2--43 to 74 cm, (17 to 29 in); light brownish gray (10YR 6/2), silt loam; weak medium subangular blocky structure; friable; brittle; fine roots; fine low continuity tubular pores; 1 percent fine black (10YR 2/1) iron-manganese concretions; 10 percent coarse prominent yellowish brown (10YR 5/8), moist, masses of oxidized iron with clear boundaries lining pores; very strongly acid; abrupt irregular boundary.

Btg/E--74 to 130 cm, (29 to 51 in); light brownish gray (10YR 6/2), silt loam; moderate coarse prismatic structure parts to moderate coarse subangular blocky; firm; few fine roots; common fine low continuity tubular pores; 30 percent discontinuous clay films on vertical faces of peds; about 25 percent tongues of silt loam (E), 1 to 10 centimeters wide; 1percent fine and medium plinthite nodules; 1 percent medium black (10YR 2/1) manganese masses; 10 percent medium prominent yellowish brown (10YR 5/8), moist, masses of oxidized iron with clear boundaries in matrix; 20 percent coarse prominent red (2.5YR 4/8), moist, masses of oxidized iron with sharp boundaries in matrix; strongly acid; gradual wavy boundary. (23 to 58 cm [9 to 23 in] thick)

Btg1--130 to 163 cm, (51 to 64 in); light brownish gray (10YR 6/2), silt loam; moderate medium subangular blocky structure; firm; fine low continuity tubular pores; 40 percent discontinuous clay films on vertical faces of peds; 1 percent medium black (10YR 2/1) manganese masses and 15 percent medium prominent red (2.5YR 4/8), moist, masses of oxidized iron with sharp boundaries in matrix and 25 percent coarse prominent strong brown (7.5YR 5/8), moist, masses of oxidized iron with clear boundaries in matrix; strongly acid; gradual wavy boundary. (combined thickness of the Btg horizons is 39 to 79 cm [15 to 31 in])

Btg2--163 to 203 cm, (64 to 80 in); light brownish gray (10YR 6/2), silt loam; weak coarse subangular blocky structure; firm; fine low continuity tubular pores; common faint clay films on vertical faces of peds; 1 percent medium prominent red (2.5YR 4/8), moist, masses of oxidized iron with sharp boundaries in matrix and 1 percent medium black (10YR 2/1) manganese masses and 25 percent coarse prominent strong brown (7.5YR 5/8), moist, masses of oxidized iron with clear boundaries in matrix; strongly acid.

TYPE LOCATION: Calcasieu Parish, LA; from the intersection of Louisiana state highway 12 and Louisiana state highway 389 in De Quincy, about 9.5 miles southwest on Louisiana state highway 12 to Lucas, LA; 1 mile east and 1 mile south on area between mounds in forest.

USGS topographic quad: Lunita, LA
Latitude: 30 degrees 21 minutes 30.40 seconds north
Longitude: 93 degrees 32 minutes 32.50 seconds west;
Datum: NAD 83

RANGE IN CHARACTERISTICS:
Thickness of the A and E horizons is 46 to 99 cm (18 to 39in)

Particle-size control section (weighted average)
Clay content: 18 to 22 percent
CEC/clay ratio: 0.45 to 0 .55

A Horizon
Hue: 10YR
Value: 4 or 5
Chroma: 1 or 2
Texture: very fine sandy loam, silt loam, or loam
Iron-manganese concretions: amount-0 to 2 percent
Reaction: very strongly acid or strongly acid

Eg Horizon
Hue: 10YR or 2.5Y
Value: 5 or 6
Chroma: 1 or 2
Texture: very fine sandy loam, silt loam, or loam
Redox concentrations: amount-5 to 25 percent, shades-brown or yellow
Iron-manganese concretions: amount-0 to 2 percent
Reaction: very strongly acid or strongly acid

Btg/E Horizon
Hue: 10YR or 2.5Y
Value: 5 to 7
Chroma: 1 or 2
Texture: loam, silt loam, or silty clay loam
Albic tongues: amount- 15 to 25 percent
Redox concentrations: amount-10 to 35 percent, shades-brown, yellow or red
Redox depletions: amount- 0 to 5 percent, shades- gray
Plinthite nodules: 1 to 5 percent
Reaction: very strongly acid or strongly acid

Btg Horizon
Hue: 10YR or 2.5Y
Value: 5 to 7
Chroma: 1 or 2
Texture: loam, silt loam, or silty clay loam
Albic tongues: amount- 0 to 10 percent
Redox concentrations: amount-10 to 40 percent, shades-brown, yellow or red
Plinthite nodules: 0 to 5 percent
Reaction: very strongly acid or strongly acid

COMPETING SERIES: These are the Alikchi (OK), Caneyhead (TX), Evadale (TX), Guyton (LA), Kinder, and Prairieland series.
Alikchi soils: formed in silty material over shale of Pennsylvanian age; have a paralithic contact above 100 cm (40 in).
Caneyhead soils: very poorly drained; do not have plinthite
Evadale soils: do not have plinthite; have more clay in the lower part of the argillic horizon
Guyton, Kinder, and Prairieland soils: do not have plinthite

GEOGRAPHIC SETTING:
Parent material: loamy fluviomarine deposits of Pleistocene age
Landscape: coastal plains
Landform: flats
Slope: 0 to 3 percent
Soil Moisture: An aquic soil moisture regime.
Mean annual soil temperature: 19.9 to 21.7 degrees C (67 to 71 degrees F)
Mean annual air temperature range: 19.3 to 20.1 degrees C (67 to 69 degrees F)
Mean annual precipitation range: 1499 to 1651 mm (59 to 65 in)
Precipitation Pattern: Rainfall is fairly uniform throughout the year.
Frost-free period: 240 to 300 days
Elevation: 22.9 to 46 m (75 to 150 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beauregard (LA), Glenmora (LA), and Messer (LA) series.
Beauregard and Glenmora soils: moderately well drained; on a higher landform
Messer soils: moderately well drained; on pimple mounds
Wrightsville soils: in a fine family; on a similar landform

DRAINAGE AND PERMEABILITY:
Drainage class: Poorly
Permeability class: Slow
Runoff: high
Wetness: soils have endosaturation and aquic conditions during the winter and early spring months in most years.

USE AND VEGETATION: Used for forest land and for grazing. Native vegetation consists of water oak, green ash, rushes and sedges.

DISTRIBUTION AND EXTENT: Western Louisiana and southern Arkansas; Land Resource Region T; MLRA 152B; the series is of extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Caddo Parish, Louisiana; 1906.

REMARKS: The series type location was moved to the current location during the Soil Data Join and Recorrelation initiative. The previous location in Beauregard Parish was in a coarse-silty family according to lab data.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 74 cm (0 to 29.1 in). (A and Eg horizons)
Glossic horizon: 74 to 130 cm (29.1 to 51.2 in). (Btg/E horizon)
Argillic horizon: 74 to 203 cm (29.1 to 80 in). (Btg/E and Btg horizons)

Aquic conditions: 13 to 203 cm (5 to 80 in) during the winter and early spring months

ADDITIONAL DATA: KSSL Data from type location on pedon 81LA019001.

TAXONOMIC VERVION: Keys to Soil Taxonomy, Eleventh Edition, 2010

National Cooperative Soil Survey
U.S.A.