LOCATION BRULE LAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, active, thermic Oxyaquic Paleudults
TYPICAL PEDON: Brule silty clay loam--woodland. (Colors are for moist soil unless otherwise stated.)
A--0 to 6 inches; dark gray (10YR 4/1) silty clay loam; moderate medium subangular blocky structure; firm; many very fine to coarse roots; few fine pores; extremely acid; clear smooth boundary. (3 to 12 inches thick)
AB--6 to 10 inches; dark grayish brown (10YR 4/2) silty clay loam; moderate fine and medium subangular blocky structure; friable; many very fine to coarse roots; few fine pores; extremely acid; clear smooth boundary. (0 to 8 inches thick)
Bw1--10 to 18 inches; brown (10YR 4/3) silt loam; moderate fine and medium subangular blocky structure; friable; many very fine to coarse roots; common very fine and fine pores; common fine and medium rounded black (10YR 2/1) iron-manganese concretions; extremely acid; clear smooth boundary.
Bw2--18 to 24 inches; dark yellowish brown (10YR 4/4) silt loam; weak fine and medium subangular blocky structure; friable; common very fine to medium roots; common very fine and fine pores; common fine and medium irregular dark brown (10YR 3/3) masses of iron-manganese; extremely acid; clear smooth boundary.
Bw3--24 to 30 inches; dark yellowish brown (10YR 4/4) silt loam; weak fine and medium subangular blocky structure; friable; common very fine and fine roots between peds; common very fine and fine pores; common fine irregular very dark gray (10YR 3/1) masses of iron-manganese; very strongly acid; gradual wavy boundary.
Bw4--30 to 37 inches; yellowish brown (10YR 5/4) silt loam; weak fine and medium subangular blocky structure; friable; few very fine and fine roots between peds; common very fine and fine tubular pores; common medium irregular dark yellowish brown (10YR 4/4) masses of iron concentrations with sharp boundaries; common fine irregular black (10YR 2/1) masses of iron-manganese; common medium irregular light olive brown (2.5Y 5/3) iron depletions; very strongly acid; gradual wavy boundary. (combined thickness of the Bw horizons is 20 to 40 inches thick)
2Bt/E--37 to 41 inches; 75 percent light yellowish brown (10YR 6/4) Bt, and 25 percent light gray (10YR 7/1) E, silt loam; moderate medium subangular blocky structure; friable; few very fine and fine roots between peds; few very fine and fine tubular pores; few distinct light gray (2.5Y 7/1) silt coats; very few faint clay films on surfaces of peds; common medium irregular dark yellowish brown (10YR 4/4) masses of iron concentrations with sharp boundaries; many medium irregular yellowish brown (10YR 5/6) masses of iron concentrations with sharp boundaries; common fine irregular black (10YR 2/1) masses of iron-manganese; very strongly acid; gradual wavy boundary. (0 to 10 inches thick)
2Eg/Bt--41 to 54 inches; 70 percent light brownish gray (10YR 6/2) E silt loam, and 30 percent yellowish brown (10YR 5/4) Bt silty clay loam; moderate medium subangular blocky structure; friable; few very fine and fine roots between peds; few very fine and fine tubular pores; few distinct light gray (2.5Y 7/1) silt coats; very few faint clay films on surfaces of peds; many medium and coarse irregular dark yellowish brown (10YR 4/4) masses of iron concentrations with sharp boundaries; common medium and coarse irregular yellowish brown (10YR 5/6) masses of iron concentrations with sharp boundaries; common fine irregular black (10YR 2/1) masses of iron-manganese; very strongly acid; gradual wavy boundary. (0 to 20 inches thick)
2Btg/E--54 to 59 inches; 70 percent light brownish gray (2.5Y 6/2) Bt silty clay loam, and 30 percent light gray (2.5Y 7/1) E silt loam; weak coarse prismatic structure parting to moderate medium subangular blocky; firm; few very fine and fine roots between peds; few very fine to medium tubular pores; many distinct clay films on surfaces of peds; common medium irregular yellowish brown (10YR 5/6) masses of iron concentrations with sharp boundaries; many medium and coarse irregular dark yellowish brown (10YR 4/6) masses of iron concentrations with sharp boundaries; very strongly acid; gradual wavy boundary. (0 to 15 inches thick)
2Btg1--59 to 69 inches; light brownish gray (2.5Y 6/2) silt loam; weak coarse prismatic structure parting to moderate medium subangular blocky; firm; few fine roots between peds; few very fine to medium tubular pores; few distinct light gray (2.5Y 7/1) silt coats on vertical surfaces of peds; many distinct clay films on surfaces of peds; many coarse irregular yellowish brown (10YR 5/6) masses of iron concentrations with sharp boundaries; common medium irregular dark yellowish brown (10YR 4/6) masses of iron concentrations with sharp boundaries; very strongly acid; gradual wavy boundary.
2Btg2--69 to 80 inches; light gray (2.5Y 7/2) silt loam; weak coarse prismatic structure parting to moderate medium subangular blocky; firm; few fine roots between peds; few very fine tubular pores; few prominent light gray (2.5Y 7/1) silt coats on vertical surfaces of peds; few distinct clay films on vertical and horizontal surfaces of peds; many coarse irregular yellowish brown (10YR 5/6) masses of iron concentrations with sharp boundaries; very strongly acid. (combined thickness of 2Btg horizons is 15 to 40 inches)
TYPE LOCATION: Acadia Parish, Louisiana; from Rayne, 4.5 miles north-northwest on LA Highway 367; 200 feet west of LA Highway 367 and 300 feet south of Bayou Plaquemine Brule; (1080 feet west and 2200 feet north of the southeast corner of section 39, T. 8 S., R. 2 E.; Latitude 30N, 18, 36; Longitude 92W, 18, 15).
RANGE IN CHARACTERISTICS:
Solum thickness and rooting depth: more than 80 inches
Soil Moisture: An udic soil moisture regime.
Mean annual soil temperature: 72 to 74 degrees F.
Depth to argillic horizon: 25 to 45 inches
Depth to cambic horizon: 3 to 12 inches
Depth to glossic horizon: 25 to 45 inches
Depth to redox concentrations: 5 to 20 inches
Depth to redox depletions: 30 to 50 inches
Depth to episaturation: 20 to 40 inches for 1 month or more in normal years.
Particle-size control section (weighted average)
Clay content: 18 to 30 percent
Sand content: 3 to 15 percent
CEC/clay ratio: 0.40 to 0.60
A, Ap, AB Horizon
Hue: 7.5YR or 10YR
Value: 3 to 5 (value 3; horizon is less than 7 inches thick)
Chroma: 1 to 4
Texture: silt loam or silty clay loam
Reaction: extremely acid to strongly acid
Bw Horizon
Hue: 7.5YR or 10YR
Value: 3 to 6
Chroma: 3 to 8
Texture: silt loam or silty clay loam
Iron concentrations: color-brown, red, or yellow; amount-few to many; boundary-clear to sharp.
Iron-manganese: form-masses or concretions; amount-few to many
Iron depletions: color-brown or gray with chroma 2 or less below 30 inches; amount-few to common; boundary-clear to sharp
Base saturation: 5 to 25 percent
Reaction: extremely acid to strongly acid
2E Horizon (where present)
Hue: 10YR or 2.5Y
Value: 5 to 7
Chroma: 1 or 2
Texture: silt loam
Clay content: 15 to 27 percent
Iron concentrations: color-brown; amount-few to many; boundary-clear to sharp
Iron-manganese concentrations: form-concretions; color-brown or black; amount-few to many
Base saturation: 5 to 25 percent
Reaction: extremely acid to strongly acid
2Bt/E Horizon (where present)
Part: Bt (70 to 85 percent)
Hue: 10YR
Value: 5 or 6
Chroma: 3 or 4
Part: E (15 to 30 percent)
Hue: 10YR
Value: 6 or 7
Chroma: 1 or 2
Texture: silt loam or silty clay loam
Clay content: 18 to 30 percent
Clay films: amount-very few to common; location-surface of peds; contrast-faint or distinct
Iron concentrations: color-brown; amount-common to many; boundary-clear to sharp
Iron-manganese concentrations: form-masses; color-brown or black; amount-few to common
Iron or clay depletions: color-gray; amount-common to many; boundary-clear
Base saturation: 5 to 25 percent
Reaction: Extremely acid to strongly acid
2Eg/Bt and Btg/E Horizon (where present)
Part: Bt
Hue: 10YR or 2.5Y
Value: 5 or 6
Chroma: 2 to 4
Part: E
Hue: 10YR or 2.5Y
Value: 6 or 7
Chroma: 1 or 2
Texture: silt loam or silty clay loam
Clay content: 18 to 30 percent
Clay films: amount-few to many; location-surface of peds and pore linings; contrast-distinct
Iron concentrations: color-brown; amount-common to many; boundary-clear to sharp
Iron-manganese concentrations: form-masses; color-brown or black; amount-few to common
Iron or clay depletions: color-gray; amount-common to many; boundary-clear
Base saturation: 5 to 25 percent
Reaction: Extremely acid to strongly acid
Btg Horizon
Hue: 10YR or 2.5Y
Value: 5 to 7
Chroma: 1 or 2
Texture: silt loam, clay loam, or silty clay loam
Clay content: 20 to 35 percent
Clay films: amount-few to many; location-surface of peds and pore linings; contrast-distinct
Iron concentrations: color-brown; amount-common to many; boundary-clear to sharp
Iron-manganese concentrations: form-masses; color-brown or black; amount-few to common
Iron or clay depletions: color-gray; amount-common to many; boundary-clear
Base saturation: 15 to 35 percent
Reaction: Extremely acid to strongly acid
COMPETING SERIES: There are no other series in the same family. Similar soils are the Cascilla, Falaya, Ouachita, and Weyanoke series. Cascilla and Weyanoke soils are Inceptisols. Ouachita soils have siliceous mineralogy. Falaya and Weyanoke soils have a coarse-silty particle-size control section.
GEOGRAPHIC SETTING:
Parent material: Holocene age silty alluvium.
Landform: nearly level to very gently sloping convex ridges or natural levees on floodplains of major drainageways.
Slope: 0 to 3 percent.
Mean annual air temperature range: 69 to 72 degrees F.
Mean annual precipitation range: 55 to 65 inches.
Frost-free period: 235 to 300 days.
Elevation: less than 5 to 60 feet.
Thornthwaite annual P-E indices: more than 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Acadiana,
Barbary,
Basile,
Crowley,
Duson,
Iota,
Kaplan,
Kinder, and
Vidrine soils.
Barbary soils are Hydraquents, in ponded backswamps, with n-value of more than 0.7 above 40 inches.
Acadiana, Crowley, Duson, Iota, and Kaplan soils are Alfisols and on side slopes above drainageways on higher landscape positions.
Basile soils are Alfisols and on lower elevations in floodplains.
Kinder and Vidrine soils are Alfisols on broad, nearly level, higher, stream divide landscape positions. The Vidrine soils are on circular mounds in a complex with the Kinder soils.
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is moderate. Runoff is negligible on 0 to 1 percent slopes and very low on 1 to 3 percent slopes. Flooding is frequent for very brief to brief periods, unless protected. In some years these soils flood for long duration.
USE AND VEGETATION: Most areas are in woodland with bottomland hardwood species, mainly sweetgum, water oak, sweetbay, overcup oak, and cherrybark oak trees dominant. A few small areas have been cleared and used for improved pasture.
DISTRIBUTION AND EXTENT: LLR T, Southwest Louisiana on the Coast Prairie (MLRA 150A). Brule soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas.
SERIES ESTABLISHED: Acadia Parish, Louisiana; 2000.
REMARKS: Brule soils (pronounced "brew-lay") were formerly included with the Cascilla series. These Ultisols in broad drainageways, associated with Alfisols on adjacent uplands, are presumed to have formed from sediments transported from Tertiary age or other low base status materials (see pg. 63 Holocene age parent materials discussion in 'Landforms and Surface Geology' section by Dr. Bobby Miller; Allen Parish, Louisiana Soil Survey report, Sept. 1980).
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--0 to 10 inches (A and AB horizon)
Cambic horizon--10 to 37 inches (Bw horizons)
Argillic horizon--37 to 80 inches (2Bt/E, 2Eg/Bt, 2Btg/E, and 2Btg horizons)
Glossic horizon--37 to 59 inches (2Bt/E, 2Eg/Bt, 2Btg/E horizons)
ADDITIONAL DATA: Laboratory data from Louisiana Agricultural Experiment Station and NSSL (S96LA-001-004) from Acadia Parish, LA.
TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999.