LOCATION OPRAIRIE LA

Established Series
DCJ,JDS,LEK
10/2018

OPRAIRIE SERIES

The Oprairie series consists of somewhat poorly drained, soils that formed in loess deposits. These soils are on silty upland terraces of Pleistocene age. Slopes range from 0 to 3 percent.

TAXONOMIC CLASS: Fine-silty, mixed, semiactive, thermic Fragiaquic Glossudalfs

TYPICAL PEDON: Typical pedon of Oprairie silt, on a 2 percent slope, in pasture. (Colors are for moist soil unless otherwise stated)

Ap--0 to 5 centimeters (0 to 2 inches); very dark grayish brown (10YR 3/2) silt; weak fine granular structure; friable; many fine and medium roots; common fine prominent yellowish red (5YR 5/6) masses of oxidized iron throughout; extremely acid; clear wavy boundary. (5 to 20 centimeters (2 to 8 inches) thick)

E--5 to 15 centimeters (2 to 6 inches); brown (10YR 5/3) silt; weak fine subangular blocky structure; friable; many fine and medium roots; many fine pores; 22 percent fine prominent irregular yellowish red (5YR 5/6) and yellowish red (5YR 5/8) masses of oxidized iron throughout; extremely acid; gradual wavy boundary. (5 to 25 centimeters (2 to 10 inches) thick)

E/B--15 to 25 centimeters (6 to 10 inches); 80 percent light olive brown (2.5Y 5/3) exterior and 20 percent yellowish brown (10YR 5/6) interior, silt loam; weak medium subangular blocky structure; friable; many fine and medium roots throughout; many fine and medium pores; 22 percent medium prominent irregular strong brown (7.5YR 5/6) masses of oxidized iron throughout; 22 percent medium manganese coatings; 5 percent fine and medium spherical iron-manganese concretions throughout; 1 percent medium prominent irregular brownish yellow (10YR 6/8) masses of oxidized iron throughout; very strongly acid; clear wavy boundary. (0 to 15 centimeters (0 to 6 inches) thick)

Bt--25 to 38 centimeters (10 to 15 inches); yellowish brown (10YR 5/4), silt loam; moderate medium angular blocky structure; firm; many fine roots throughout; many fine pores; 55 percent faint brown (10YR 5/3) clay films on faces of peds; 22 percent medium prominent irregular yellowish red (5YR 5/6) and red (2.5YR 4/6) masses of oxidized iron throughout; 22 percent fine spherical iron-manganese concretions throughout; 1 percent medium distinct irregular light brownish gray (10YR 6/2) iron depletions between peds; very strongly acid; clear irregular boundary. (20 to 38 centimeters (8 to 15 inches) thick)

Bt/E1--38 to 53 centimeters (15 to 21 inches); 70 percent yellowish brown (10YR 5/6) interior and 30 percent pale brown (10YR 6/3) exterior, silty clay loam, silt loam; moderate medium prismatic parting to moderate medium subangular blocky structure; very firm; many fine and medium roots between peds; common very fine and fine pores; 30 percent by volume albic tongues; 55 percent distinct pale brown (10YR 6/3) clay films on faces of peds; 22 percent fine spherical iron-manganese concretions throughout; 1 percent medium prominent irregular red (2.5YR 4/6) masses of oxidized iron throughout; very strongly acid; gradual irregular boundary.

Bt/E2--53 to 71 centimeters (21 to 28 inches); 70 percent yellowish brown (10YR 5/4) interior and 30 percent light olive gray (5Y 6/2) exterior, silt loam; moderate medium prismatic structure; very firm; common fine roots between peds; common fine pores; 30 percent by volume albic tongues; 55 percent prominent reddish brown (5YR 5/4) clay films on faces of peds and 10 percent distinct pale brown (10YR 6/3) silt coats on vertical faces of peds; 22 percent medium prominent irregular red (2.5YR 4/6) masses of oxidized iron throughout; 22 percent fine irregular manganese coatings on faces of peds; 40 percent brittle peds; strongly acid; clear wavy boundary.

Bt/E3--71 to 107 centimeters (28 to 42 inches); 70 percent yellowish brown (10YR 5/6) interior and 30 percent light brownish gray (2.5Y 6/2) exterior, silt loam; moderate medium prismatic structure; very firm; many fine roots between peds; many fine and medium pores; 30 percent by volume albic tongues; 55 percent prominent brown (7.5YR 5/4) clay films on faces of peds and light brownish gray (2.5Y 6/2) silt coats on vertical faces of peds; 30 percent brittle peds; extremely acid; clear wavy boundary. (Combined thickness of the Bt/E is 25 to 71 centimeters (10 to 28 inches))

B't1--107 to 140 centimeters (42 to 55 inches); yellowish brown (10YR 5/6), silt loam; moderate coarse prismatic structure; firm; common fine roots between peds; many very fine and fine and common medium pores; 55 percent prominent brown (7.5YR 4/4) clay films on faces of peds and 30 percent distinct light gray (2.5Y 7/2) silt coats on faces of peds; 22 percent medium distinct irregular strong brown (7.5YR 5/6) masses of oxidized iron throughout; 22 percent irregular manganese coatings; 5 percent medium prominent irregular red (2.5YR 4/6) masses of oxidized iron throughout; strongly acid; clear wavy boundary.

B't2--140 to 170 centimeters (55 to 67 inches); strong brown (7.5YR 5/6), silt loam; moderate coarse prismatic structure; firm; many fine and medium pores; 2 percent by volume albic tongues; 55 percent faint light gray (2.5Y 7/2) silt coats on faces of peds and 30 percent distinct grayish brown (10YR 5/2) clay films on faces of peds; 22 percent medium distinct irregular yellowish brown (10YR 5/4) masses of oxidized iron throughout; 22 percent fine irregular manganese coatings throughout; 5 percent medium distinct irregular reddish brown (5YR 5/4) masses of oxidized iron throughout; 20 percent brittle peds; strongly acid; diffuse wavy boundary.

B't3--170 to 198 centimeters (67 to 78 inches); strong brown (7.5YR 5/6) and light olive gray (5Y 6/2), silt loam; moderate coarse prismatic structure; firm; many fine and medium pores; 30 percent by volume albic tongues; 55 percent distinct light brownish gray (2.5Y 6/2) clay films on faces of peds; 22 percent medium distinct irregular yellowish brown (10YR 5/4) masses of oxidized iron throughout; 5 percent fine distinct irregular brownish yellow (10YR 6/8) masses of oxidized iron throughout; 1 percent fine manganese coatings lining pores; strongly acid; gradual wavy boundary. (Combined thickness of the Bt horizon is 51 to 99 centimeters (20 to 39 inches))

2Btb/E--198 to 221 centimeters (78 to 87 inches); 70 percent strong brown (7.5YR 5/6) interior and 30 percent light olive gray (5Y 6/2) exterior, silt loam; moderate coarse prismatic structure; firm; many fine and medium pores; 30 percent by volume albic tongues; 55 percent distinct light brownish gray (2.5Y 6/2) clay films on faces of peds; 22 percent fine manganese coatings lining pores; 22 percent fine spherical iron-manganese concretions throughout; strongly acid.

TYPE LOCATION: East Baton Rouge Parish, Louisiana; from the State Capitol Building, 0.8 kilometers (0.5 miles) east of Capital Access Road, then 1.45 kilometers (0.9.mile) east of I-110, then 8.86 kilometers (5.5 miles) northeast of State Highway 67, then 63 meters (210 feet) east of Highway. 135 meters (450 feet) west and 52.5 meters (175 feet) south of the northeast corner of sec. 90, T.6 S., R 1 W, USGS Scotlandville topographic quadrangle; lat. 30 degrees 32 minutes 20.2 seconds N., long. 91 degrees 8 minutes 19.7 seconds W.

RANGE IN CHARACTERISTICS:
Thickness of the solum ranges from 76 to more than 254 centimeters (30 to 100 inches).
At least 50 percent effective cation-exchange capacity is occupied by exchangeable aluminum in the upper 76 centimeters (30 inches)

Ap horizon:
Hue: 10YR
Value: 3 to 5
Chroma: 1 to 3
Where the value is 3, this horizon is less than 6 inches thick
Texture: silt or silt loam
Reaction: extremely acid to neutral

E horizon, where present:
Hue: 10YR
Value: 5 or 6
Chroma: 3 to 6
Redoximorphic concentrations: in shades of brown, yellow and red
Redoximorphic depletions: in shades of gray with chroma of 2 or less
Texture: silt or silt loam
Reaction: extremely acid to moderately acid

The EB or BE horizon, where present:
Hue: 10YR
Value: 5 or 6
Chroma: 3 to 6
Redoximorphic concentrations: in shades of brown, yellow and red
Redoximorphic depletions: in shades of gray with chroma of 2 or less
Texture: silt loam
Reaction: very strongly acid to moderately acid

Bt horizon and the Bt part of the B/E horizon:
Hue of 10YR or 7.5YR
Value: 4 to 6
Chroma: 3 to 8
Redoximorphic concentrations: in shades of brown, yellow and red
Redoximorphic depletions: in shades of gray with chroma of 2 or less
Texture: silty clay loam or silt loam
Reaction: very strongly acid to moderately acid
E part of B/E horizon:
Hue: 10 YR, 2.5 Y, or 5Y
Value: 5 or 6
Chroma: 2 or 3

2Bt or BC horizons:
Hue: 10YR or 7.5YR
Value: 4 to 6
Chroma: 3 to 8
Texture: silty clay loam or silt loam
Firm and brittle bodies make up 25 to 40 percent of the horizontal cross sections of the Bt and 2Bt horizons
Reaction: very strongly acid to neutral

COMPETING SERIES: There are no other series in the same family.

GEOGRAPHIC SETTING:
Parent material: silty loess deposits
Landform: terraces of Pleistocene age
Flooding: none
Slopes: 0 to 3
Range of mean annual temperature: 155 centimeters (60.9 inches)
Range of mean annual precipitation: 19.8 C(67.7 F)
Precipitation pattern: udic
Frost-free period: 231 to 247

GEOGRAPHICALLY ASSOCIATED SOILS: Calhoun, Deerford, Frost, Gilbert, Jeanerette, Satsuma, Scotlandville, and Verdun soils.
Calhoun, Frost, and Gilbert soils are gray throughout and are on lower landscape positions.
Jeanerette soils have a mollic epipedon.
Deerford and Verdun soils have a natric horizon.
Satsuma soils are on stream terraces and are siliceous with a loamy substratum.
Scotlandville soils are on slightly higher positions and do not have grayish iron depletions in the upper part of the argillic horizon.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: Somewhat poorly
Runoff: low to medium
Saturated Hydraulic Conductivity: moderately low to moderately high

USE AND VEGETATION: Most acreage is used for pasture or urban development.

DISTRIBUTION AND EXTENT: Southeast Louisiana in the Southern Mississippi Valley Silty Uplands (MLRA 134).

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AUBURN, ALABAMA

SERIES ESTABLISHED: East Baton Rouge Parish, Louisiana, 1998. Oprairie soils were formerly included in the Olivier and Loring series.

REMARKS: Diagnostic horizons and features recognized in the typical pedon include:
Ochric Epipedon........... 0 to 38 centimeters (0 to 15 inches) (Ap, E, and E/B horizons
Argillic Horizon.......... 25 to 290 centimeters (10 to 114 inches) (Bt, Bt/E, B't, 2Bt/E, and 2Bt horizons)
Fragic Properties......... 53 to 173 centimeters (21 to 68 inches) (Bt/E2, Bt/E3, B't1 and B't2 horizons)
Glossic horizon........... 38 to 107 centimeters (15 to 42 inches), and 203 to 249 centimeters (80 to 98 inches) (Bt/E and 2Bt/E horizons)
Lithologic Discontinuity...203 centimeters 80 inches (top of the 2Bt/E1 horizon)

ADDITIONAL DATA: Lab analyses were run on samples from the typical pedon by NSSL, Lincoln, Nebraska (S95LA-033-010).

National Cooperative Soil Survey
U.S.A.