LOCATION MANCO TXEstablished Series
TAXONOMIC CLASS: Fine-silty, siliceous, active, acid, thermic Fluvaquentic Endoaquepts
TYPICAL PEDON: Manco silt loam--native pastureland. (Colors are for moist soil unless otherwise stated)
A--0 to 3 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine subangular blocky structure; friable, slightly hard; many very fine and fine roots; few fine pores; many fine distinct yellowish red and reddish brown masses of iron accumulation along root channels; extremely acid; abrupt smooth boundary. (3 to 8 inches thick)
Bw--3 to 11 inches; grayish brown (10YR 5/2) loam; weak medium subangular blocky structure; friable, slightly hard; common very fine, fine and few coarse roots; few fine pores; common fine and medium distinct strong brown (7.5YR 5/8) masses of iron accumulation; common fine yellowish red (5YR 5/6) masses of iron accumulation along root channels; few very thin bedding planes; extremely acid; abrupt smooth boundary. (4 to 13 inches thick)
Bg1--11 to 19 inches; gray (10YR 5/1) loam; moderate medium and coarse prismatic structure parting to weak medium subangular blocky; friable, slightly hard; common very fine and fine roots; few fine pores; common thin discontinuous bedding planes; many medium distinct dark reddish brown (5YR 3/4) masses of iron accumulation; few fine dark reddish brown (5YR 3/3) masses of iron accumulation along root channels; very strongly acid; abrupt smooth boundary.
Bg2--19 to 27 inches; dark gray (10YR 4/1) silt loam; moderate medium and coarse prismatic structure parting to weak medium and coarse subangular blocky; friable, slightly hard; few very fine and fine roots; common fine pores; common medium distinct brown (10YR 4/3) masses of iron accumulation; common reddish brown (5YR 4/3) masses of iron accumulation along root channels; very strongly acid; clear smooth boundary.
Bg3--27 to 42 inches; gray (10YR 5/1) silty clay loam; moderate medium and coarse prismatic structure parting to weak medium and coarse subangular blocky; firm, very hard; few very fine and fine roots; few fine pores; many medium distinct strong brown (7.5YR 5/6) and common medium distinct reddish brown (5YR 4/4) masses of iron accumulation; few fine iron-manganese concretions; common fine reddish brown (5YR 4/3) coatings along root channels; common crawfish krotovinas; extremely acid; gradual smooth boundary.
Bg4--42 to 63 inches; gray (10YR 5/1) clay loam; moderate medium and coarse prismatic structure parting to weak medium and coarse subangular blocky; firm, very hard; few very fine and fine roots; common fine and medium pores; common medium and coarse distinct yellowish brown (10YR 5/4) masses of iron accumulation; common reddish brown (5YR 4/3) iron accumulations along root channels; few fine iron-manganese concretions; common crawfish krotovinas; extremely acid; clear smooth boundary. (Combined thickness of the Bg subhorizons is 27 to 60 inches or more)
Bg5--63 to 80 inches; gray (10YR 6/1) clay loam; moderate medium and coarse prismatic structure part to weak medium and coarse subangular blocky; firm, very hard; few very fine and fine roots; common fine pores; common fine and medium distinct yellowish brown (10YR 5/6) and many medium prominent dark red (10R 3/6) masses of iron accumulation; few red (10R 4/6) masses of iron accumulation that are brittle in the center; common fine dark yellowish brown (10YR 4/4) masses of iron accumulation around pores; common crawfish krotovinas; extremely acid.
TYPE LOCATION: Wood County, Texas; from the intersection of State Highway 37 and Farm Road 2088 in Quitman, 9.8 miles east on Farm Road 2088, 700 feet north on pasture road, 800 feet east along levee, 150 feet north in pasture on flood plain of Big Sandy Creek. (Latitude 32N, 49, 58; Longitude 95W, 16, 58)
RANGE IN CHARACTERISTICS: The solum is more than 80 inches thick. Reaction is extremely acid or very strongly acid throughout. Weighted average clay content of the control section ranges from 20 to 34 percent and sand coarser than very fine sand ranges from to 2 to 15 percent. Organic carbon content ranges from 0.2 to 0.5 percent at a depth of 50 inches. These soils are dry in some part of the moisture control section for more than 60 cumulative days in most years. Some pedons have buried A horizons in or below the control section.
The A horizon has hue of 10YR, value of 4 or 5, and chroma of 2 to 6. Most pedons have few to many iron accumulations in shades of brown, yellow, or red. Some pedons have a thin A horizon less than 6 inches thick, with hue of 10YR, value of 3, and chroma of 1 to 3. Texture is loam or silt loam.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 to 6, with few to many iron accumulations in shades of yellow, brown, or red, and iron depletions in shades of gray. Some pedons are variegated in these colors. Most pedons have thin discontinuous bedding planes. Texture is loam, silt loam, clay loam, or silty clay loam.
The Bg horizon has hue of 10YR or 2.5Y, value of 4 to 7, and chroma of 1 or 2, with few to many iron accumulations in shades of brown, yellow, or red. Some pedons have thin discontinuous bedding planes. Texture is loam, silt loam, clay loam, silty clay loam, or sandy clay loam.
COMPETING SERIES: These are the Mathiston and Pophers series of the same family. Other similar soils are the Dreka, Iulus, Mantachie, Mattex, and Socagee series. Mathiston and Mantachie soils are not dry in some part of the moisture control section for 60 cumulative days in most years. In addition, Mantachie soils have a fine-loamy particle size control section. Pophers soils have electrical conductivity of more than 4 mmhos/cm in the lower part of the control section. Socagee soils have dominant chroma of 1. Dreka and Mattex soils have a clayey layer between a depth of 40 and 60 inches. In addition, Dreka soils have a nonacid reaction class. Also, Mattex soils have a fine-loamy particle size control section. Iulus soils have a coarse-loamy particle size control section.
GEOGRAPHIC SETTING: Manco soils are on nearly level floodplains. Slopes are 0 to 1 percent. Mean annual temperature ranges from 64 to 67 degrees F. Frost free days range from 240 to 270 and elevation ranges from 150 to 300 feet above sea level. Mean annual rainfall ranges from 40 to 48 inches and the Thornthwaite P-E index is 64 to 82.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Iulus and Socagee soils and Bibb soils which are on similar flood plains. Bowie, Cuthbert, Kirvin, and Lilbert soils, which have argillic horizons, are above on adjoining uplands.
DRAINAGE AND PERMEABILITY: Manco soils are somewhat poorly drained, and moderately permeable with negligible runoff. An apparent water table is at 1.0 to 1.5 feet for 1 to 3 cumulative months mainly during the winter and spring seasons. These soils flood frequently unless protected. Typically, they flood 2 to 5 times during most years. Duration of flooding is long.
USE AND VEGETATION: Used mainly for woodland or pastureland. Native woodland is mainly sweetgum, water oak, and willow oak. Native grasses include longleaf uniola, Florida paspalum, Virginia wildrye, and various panicums. Improved pastures consists of bahiagrass, common bermudagrass, and tall fescuegrass. Pastures are typically overseeded with white clover.
DISTRIBUTION AND EXTENT: Southern Coastal Plain (MLRA 133B) and Western Gulf Coast Flatwoods (MLRA 152B) of Texas and, possibly, Louisiana. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Wood County, Texas: 1992
REMARKS: These soils were formerly included in the Mantachie series.
Diagnostic Horizons and Features in this pedon:
Ochric epipedon -- 0 to 3 inches
Fluventic feature -- Organic carbon content greater than 0.2 at a depth of 50 inches.
ADDITIONAL DATA: TAMU Soil Characterization Laboratory sample (S89TX-499-005) Wood Co. TX.