LOCATION BODCAU LAEstablished Series
TAXONOMIC CLASS: Coarse-silty, siliceous, active, thermic Aquic Paleudults
TYPICAL PEDON: Bodcau silt loam--woodland (Colors are for moist soil unless otherwise stated.)
A--0 to 2 inches; dark grayish brown (10YR 4/2) silt loam; weak fine granular structure; friable when moist, slightly hard when dry; many fine and very fine roots; very strongly acid; clear wavy boundary. (2 to 6 inches thick)
E--2 to 7 inches; brown (10YR 5/3) silt loam; weak fine granular structure; very friable; few fine and very fine roots; common very fine pores; few fine distinct yellowish brown (10YR 5/6) masses of iron accumulation throughout; few black (10YR 2/1) manganese nodules throughout; very strongly acid; clear wavy boundary. (4 to 8 inches thick)
Bt/E1--7 to 20 inches; yellowish brown (10YR 5/4) (B) and brown (10YR 5/3) (E) silt loam; weak medium subangular blocky structure; friable; common fine and very fine roots; common medium pores throughout; about 10 percent faint pale brown (10YR 6/3) pockets and vertical intrusions of albic material (E); many medium and coarse distinct strong brown (7.5YR 5/6) masses of iron accumulation throughout; common medium distinct gray (10YR 5/1) iron depletions throughout; very strongly acid; gradual wavy boundary. (5 to 15 inches thick)
Bt/E2--20 to 37 inches; yellowish brown (10YR 5/4) (B) and pale brown (10YR 6/3) (E) silt loam; weak medium subangular blocky structure; friable; few very fine roots; many medium and coarse vesicular pores; common distinct dark grayish brown (10YR 4/2) clay films on faces of peds, in root channels, and as pore linings; common faint very pale brown (10YR 7/3) silt coatings on faces of some peds (E); common medium distinct yellowish brown (10YR 5/6) masses of iron accumulation throughout; few medium distinct strong brown (7.5YR 5/6) masses of iron accumulation throughout and lining pores; few fine and medium distinct gray (10YR 5/1) iron depletions throughout; very strongly acid; gradual wavy boundary. (12 to 20 inches thick)
Bt/E3--37 to 47 inches; 60 percent yellowish brown (10YR 5/4) (B) and 40 percent very pale brown (10YR 7/3) (E) silt loam; weak medium subangular blocky structure; very friable; few very fine roots; many fine and medium vesicular pores; few distinct strong brown (7.5YR 5/6) masses of iron accumulation throughout; few distinct gray (10YR 6/1) iron depletions throughout; very strongly acid; abrupt wavy boundary. (4 to 12 inches thick)
2Bt/E4--47 to 57 inches; dark gray (10YR 4/1) silty clay loam (2Bt); moderate coarse prismatic structure parting to moderate medium subangular blocky; firm; few very fine roots; few fine pores; about 15 percent very pale brown (10YR 7/3) pockets and vertical intrusions of silt loam between peds (E); many medium and coarse prominent strong brown (7.5YR 4/6 and 7.5YR 5/6) masses of iron accumulation throughout; few fine prominent yellowish red (5YR 4/6) masses of iron accumulation throughout; very strongly acid; clear wavy boundary.
2Bt/E5--57 to 67 inches; 80 percent variegated yellowish brown (10YR 5/6) and grayish brown (10YR 5/2) silty clay loam (Bt), and 20 percent light brownish gray (2.5Y 6/2) pockets and vertical intrusions of silt loam clay depletions (E); moderate coarse prismatic structure parting to moderate medium subangular blocky; very firm; few very fine roots; few fine pores; few medium prominent strong brown (7.5YR 5/6) masses of iron accumulation throughout; extremely acid; gradual wavy boundary.
2Btg/E--67 to 90 inches; 80 percent light olive gray (5Y 6/2) clay loam (2Bt), and 20 percent pockets and vertical intrusions of light yellowish brown (2.5Y 6/3) very fine sandy loam and silt loam clay depletions (E); moderate coarse prismatic structure parting to moderate coarse subangular blocky; very firm; few very fine roots; few fine pores; common fine prominent brownish yellow (10YR 6/8) masses of iron accumulation throughout; few fine prominent yellowish red (5YR 5/6) masses of iron accumulation throughout; extremely acid.
TYPE LOCATION: Bossier Parish, Louisiana; about 12.5 miles east of Benton, La. and about 2 miles south of Bellevue, La. on State Hwy. 157 from the intersection of Bodcau Dam road; then 0.65 miles east on State Hwy. 528 and 78 feet south of the center of Hwy.528 in woods; NW1/4, NE1/4, Sec. 16, T. 19 N., R. 11 W.; Latitude 32 degrees, 38 minutes, 40.5 seconds N., and Longitude 93 degrees, 30 minutes, and 15.2 seconds W.; USGS Bodcau Lake, La. Topographic Quadrangle.
RANGE IN CHARACTERISTICS: Solum thickness is more than 80 inches. Depth to the 2Bt or 2Bt/E horizon ranges from 45 to 58 inches. Reaction ranges from very strongly acid to extremely acid throughout.
The A or Ap horizon has hue of 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is silt loam, loam or very fine sandy loam.
The E horizon has hue of 10YR, value of 5 or 6, and chroma of 3. Redox concentrations in shades of brown range from few to common, and iron depletions in shades of gray range from none to few. Texture is silt loam, loam or very fine sandy loam.
A BE horizon is present in some pedons. Where present, it has hue of 10YR, value of 4 to 6 and chroma of 3 or 4. Texture is silt loam, loam, or very fine sandy loam.
The Bt/E horizon has hue of 10YR, value of 4 to 6, and chroma of 3 or 4 in the Bt parts, and hue of 10YR, value of 5 or 6, and chroma of 2 or 3 in the E parts. Iron accumulations in shades of brown, and iron or clay depletions in shades of gray range from few to many. Texture is silt loam or loam.
The 2Bt/E or 2Btg/E horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 1 or 2 in the Bt parts, or it is variegated in shades of gray and brown; and it has hue of 10YR or 2.5Y, value of 5 to 7, and chroma of 1 to 3 in the E parts. Iron accumulations in shades of brown, yellow, or red, and iron depletions in shades of gray range from few to many. Texture is silty clay loam, clay loam, or silty clay in the Bt parts, and silt loam, very fine sandy loam, or silty clay loam in the E parts.
COMPETING SERIES: There are no other series in the same family. The Abita, Beauregard, Frizzel, Glenmora, Gurdon, Keithville, Kolin, Sawtown and Timpson series are in closely related families. Beauregard soils have more than 18 percent clay in the upper 20 inches of the argillic horizon and have more than 5 percent plinthite segregations in the subsoil. Frizzell soils have a clay decrease of 20 percent or more from the maximum within a depth of 60 inches and have base saturation more than 35 percent in the lower part of the solum. Gurdon soils have a subsoil layer with more than 10 percent brittle peds, do not have a lithologic discontinuity, and have a semiactive activity class. Abita, Glenmora, Keithville, Kolin and Sawtown soils have a more than 18 percent clay in the upper 20 inches of the argillic horizon and have base saturation more than 35 percent in the lower part of the solum. Timpson soils have base saturation more than 35 percent in the lower part of the solum and are better drained.
GEOGRAPHIC SETTING: Bodcau soils are on broad, level to very gently sloping positions on stream terraces. They formed in Pleistocene age silty alluvial sediments derived from acid soils on tertiary uplands. The mean annual temperature ranges from 60 to 70 degrees F. at the type location. Mean annual precipitation ranges from 45 to 48 inches. Frost free days range from 250 to 275. Elevation ranges from 200 to 245 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related Kolin series, and the Bowie, Gore, Guyton and Wrightsville series. Kolin soils are on similar positions and have a clayey discontinuity within a depth of 36 inches. Bowie soils are on higher positions, formed in Tertiary age marine sediments, and contain more than 5 percent plinthite. Gore soils are on sideslopes along drainageways and are clayey throughout. Guyton and Wrightsville soils are in depressional areas and are gray throughout with aquic conditions in the upper part of the subsoil.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. A saturated zone with its upper boundary at 1 to 2.5 feet is perched above the discontinuity during the winter and early spring months in normal years. Permeability is moderately slow. Runoff is low on the more level slopes, and medium on gently sloping areas.
USE AND VEGETATION: Most of the acreage is in woodland, mainly loblolly pine and mixed hardwoods. A small acreage is used for pasture and homesites.
DISTRIBUTION AND EXTENT: Western Coastal Plain (MLRA 133B) in North Louisiana, and possibly east Texas and southern Arkansas. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES PROPOSED: Bossier Parish, Louisiana; 1997
REMARKS: The Bodcau soils were formerly included with the Stough and Prentiss series in the previously published Bossier Parish Soil Survey (1962).
Diagnostic horizons and features in this pedon include:
Ochric epipedon..... 0 to 7 inches (A and E horizons).
Albic horizon........2 to 7 inches (E horizon).
Argillic horizon.....20 to 90 inches (Bt/E, 2Bt/E, and 2Btg/E horizons).
Intrusions of albic material..7 to 90 inches (Bt/E1 and 2Bt/E horizons).
Lithologic discontinuity......47 inches (top of the 2Bt/E1 horizon).
ADDITIONAL DATA: Laboratory analyses were run on samples from the type location pedon by Louisiana Agricultural Experiment Station (S97LA-015-32).