LOCATION FALBA                   TX

Established Series
Rev. ACT-RMR-JAW
02/2018

FALBA SERIES

The Falba series consists of moderately deep, moderately well drained, very slowly permeable soils that formed in interbedded clayey residuum derived from tuffaceous sandstone. These nearly level to moderately sloping soils are on broad ridges on inland dissected coastal plains. Slopes range from 0 to 8 percent. Mean annual precipitation is about 1194 mm (47 in) and the mean annual air temperature is about 19.4 degrees C (67 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Aquic Paleustalfs

TYPICAL PEDON: Falba fine sandy loam--pasture. (Colors are for moist soil unless otherwise stated.)

Ap--0 to 13 cm (0 to 5 in); brown (10YR 5/3) fine sandy loam, pale brown (10YR 6/3) dry; few fine distinct yellowish brown mottles; weak platy structure; hard, very friable; common fine roots; very strongly acid; abrupt smooth boundary. (8 to 20 cm [3 to 8 in] thick)

E--13 to 18 cm (5 to 7 in) grayish brown (10YR 5/2) fine sandy loam, light brownish gray (10YR 6/2) dry; common fine distinct yellowish brown mottles; massive; hard, very friable; few fine roots; amplitude of the contact between the E and the Bt horizon is about 5 inches across a horizontal distance of two ft; very strongly acid; abrupt wavy boundary. (0 to 15 cm [0 to 6 in] thick)

Bt1--18 to 43 cm (7 to 17 in); dark grayish brown (10YR 4/2) clay, grayish brown (10YR 5/2) dry; common fine and medium distinct yellowish brown (10YR 5/6) mottles; few fine prominent strong brown and yellowish red mottles; weak coarse prismatic structure parting to moderate medium and fine angular blocky; extremely hard, very firm; few fine roots, some of which are concentrated between prisms; few shiny pressure faces on the peds; very strongly acid; gradual wavy boundary. (15 to 38 cm [6 to 15 in] thick)

Bt2--43 to 61 cm (17 to 24 in); dark grayish brown (10YR 4/2) on the outside of the peds and grayish brown (2.5Y 5/2) on the inside of the peds; clay; light brownish gray (10YR 6/2) dry; few medium distinct strong brown (7.5YR 5/6) mottles associated with strongly cemented black nodules; weak coarse prismatic structure parting to moderate medium and coarse blocky; extremely hard, very firm; few fine roots between prisms; few very fine sand pockets about 1 cm in diameter between some peds; few shiny pressure faces; very strongly acid; clear wavy boundary. (15 to 43 cm [6 to 17 in] thick)

BCt--61 to 84 cm (24 to 33 in); about 65 percent light brownish gray (2.5Y 6/2) sandy clay loam, light gray (2.5Y 7/2), dry; few medium prominent strong brown (7.5YR 5/6) mottles; weak coarse and medium angular blocky structure; very hard, very firm; dark grayish brown (10YR 4/2) thick continuous clay films between the blocks; few fine roots; few lenses of loam that may be partially weathered tuffaceous fine sandstone; 35 percent soft tuffaceous sandstone fragments from 1 to 10 cm across the long axis; few strongly cemented iron concretions up to about 1.5 cm in diameter; few soft white masses; very strongly acid; abrupt wavy boundary. (0 to 25 cm [0 to 10 in] thick)

Cr--84 to 140 cm (33 to 55 in); very pale brown (10YR 7/3) tuffaceous fine sandstone with angular fractures white (10YR 8/1) dry; weakly cemented; few fine roots along fractures in dark thin clay flows; few medium strongly cemented black concretions and few soft red and yellow masses; slightly alkaline.

TYPE LOCATION: Walker County, Texas; from the intersection of Texas Highway 30 and Interstate 45 in Huntsville, 7.7 miles west on Texas Highway 30, north on Farm Road 2550 4.5 miles to the intersection of Farm Road 2550 and Farm Road 1696, 1.3 miles west on Farm Road 1696, 1.4 miles south on Roberts Road and 1056 ft west in pasture. USGS Galilee topographic quadrangle; Longitude: 95 degrees, 43 minutes, 30 seconds North; Latitude: 42 degrees, 31 minutes, 16 seconds West. Datum WGS84.

RANGE IN CHARACTERISTICS:
Soil moisture: An ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than 90 bu less than 150 cumulative days in normal years.
Soil depth: moderately deep, 51 to 102 cm (20 to 40 in) and corresponds to the depth to tuffaceous sandstone, siltstone, or tuffaceous clays.
Depth to paralithic contact: 21 to 102 cm (20 to 40 in)
Depth to albic horizon, where present: 13cm (5 in)
Depth to argillic horizon: 10 to 18 cm (4 to 7 in)
Depth to abrupt textural change: 10 to 18 cm (4 to 7 in)
Depth to secondary calcium carbonates: 61 cm (24 in) (where present)
Depth to redox concentrations, where present: 43 to 84 cm (17 to 33 in)
Depth to redox depletions: 0 to 90 cm (0 to 35 in)
Thickness of ochric horizon: 10 to 18 cm (4 to 7 in)
Vertic features: 18 to 61 cm (7 to 24 in) (where present)

Particle-size control section (weighted average)
Clay content: 35 to 56 percent
Rock fragments: 0 to 35 percent
The COLE may exceed 0.09 in the Btg horizons, but the potential linear extensibility of the soil is less than 6 cm.

A, or Ap horizon(s):
Hue: 10YR, 2.5Y
Value: 4 to 8
Chroma: 1 to 3
Texture: fine sandy loam, sandy loam, or loamy fine sand
Rock fragments: 0 to 4 percent, 2 to 75 mm, sandstone
Reaction: strongly acid or very strongly acid

E, or Eg horizon(s), when present:
Hue: 10YR, 2.5Y
Value: 4 to 7
Chroma: 1 to 3
Texture: fine sandy loam, sandy loam, or loamy fine sand
Rock fragments: 0 to 4 percent, 2 to 75 mm, sandstone
Reaction: strongly to very strongly acid
Boundary between A or E horizon and Bt horizon is abrupt and ranges from smooth to wavy

Bt, Btg, BCt, BCtg or C/Btg horizon(s):
Hue: 2.5Y or 10YR
Value: 4 to 7
Chroma: 1 to 2
Texture: clay, sandy clay loam, or clay loam
Clay content: 35 to 50 percent
Clay films: on all faces of peds
Iron-manganese concentrations: 0 to 1 percent, fine to medium, masses or concentrations
Rock fragments: 0 to 35 percent, 0 to 10cm, tuffaceous sandstone, some pedons contain fragments of sandstone
Identifiable secondary carbonates: 0 to 25 percent, soft masses, lower part of horizon
White masses of barite are present in some pedons.

Reaction: very strongly acid to neutral

Many pedons have a transitional Bt/Cr horizon.

Cr, or Crt horizon(s):
Hue: 10YR, 2.5Y
Value: 4 to 8
Chroma: 1 to 4
Identifiable secondary carbonates: 0 to 1 percent, soft masses or concretions
Reaction: slightly alkaline (slightly alkaline to strongly acid)
In some pedons these materials are considered a lithologic discontinuity due to changes in sand to silt ratios.
The Cr or Crt layer ranges from clayey tuff, tuffaceous clay, volcanic ash, fine grained sandstone to siltstone.

COMPETING SERIES: This is the Hassee series in the same family. Similar soils are the Arol, Burlewash, Cadell, Gredge, Lufkin, Flemington, and Shalba series.
Hassee soils: are very deep.
Arol soils: have value of less than 10 cm (4 in) the upper Bt horizon.
Cadell, Chazos, Gredge, Flemington, and Lufkin soils: have sola thicker than 102 cm (40 in). Burlewash soils: are well drained and have higher chroma colors in the Bt horizons.
Shalba soils: have sola less than 51 cm (20 in) thick.
Niotaze soils: have chroma of 2 or more in the Bt horizon and are in cooler climates.
Singleton soils: have less than 60 percent of the matrix occupied by low chroma colors.

GEOGRAPHIC SETTING:
Parent material: clayey residuum derived from tuffaceous sandstone. These materials are interbedded clays, tuffs, ash beds, sandstones, and pyroclastics as typified by the Catahoula Formation
Landscape: inland dissected coastal plains
Landform: convex linear summits on interfluves on broad ridges
Slope: 0 to 8 percent
Mean annual precipitation: 889 to 1143 mm (35 to 45 in)
Mean annual air temperature: 19.4 to 21 degrees C (67 to 70 degrees F)
Frost-free period: 240 to 288 days
Elevation: 39 to 168 m (128 to 550 ft)
Thornthwaite P-E Index: 52 to 72

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arol, Burlewash, Greenvine, Lufkin, Shalba, Singleton, and the Elmina series.
Arol, Lufkin, Shalba and Singleton soils: are on similar landscape positions.
Burlewash and Greenvine soils: are on nearby sloping, convex areas.
Greenvine soils: have vertic properties and lack an argillic horizon.
Elmina soils: are on similar positions, but have sandy surface layers 51 to 102 cm (20 to 40 in)thick.

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, high for 3 to 5 percent slopes and very high on 5 to 8 percent slopes. A fluctuating water table occurs between 18 to 61 cm (7 to 24 in) of the surface during the months January to May and October to December in most years.

USE AND VEGETATION: Mainly pastureland and rangeland. Large acreages were once planted to cotton, but are now unimproved pastures. Improved pastures are coastal bermudagrass. Native vegetation is a post oak savannah. Major grasses being little bluestem, indiangrass, switchgrass, big bluestem and sideoats grama. A few shortleaf pine have encroached this soil in the extreme eastern part of the area of occurrence.

DISTRIBUTION AND EXTENT: South-central Texas; Land Resource Region J - Southwestern Prairies Cotton and Forage Region; MLRA 87A - Texas Claypan Areas, Southern Part. Mainly between the Trinity and Colorado Rivers. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Walker County, Texas; 1975.

REMARKS: Falba soils were formerly included in Lufkin series.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 18 to 58 cm (7 to 22 in)

Ochric epipedon: 0 to 18 cm (0 to 7 in) (A and E horizons)
Albic horizon: 13 to 18 cm (5 to 7 in) (E horizon)
Argillic horizon: 18 to 84 cm (7 to 33 in) (Bt and BCt horizons)

Endosaturation: the zone of saturation at 18 to 61cm (7 to 24in) (Bt1 and Bt2 horizons)
Abrupt textural change: at the upper boundary of the Bt horizon
Redoximorphic depletions: 18 to 61 cm (7 to 24 in) Grayish brown soil color with mottles (Bt1 and Bt2 horizons)
Aquic conditions: 18 to 61cm (7 to 24 in) (Bt1 and Bt2 horizons)
Paralithic contact: 84 cm (33 in)

ADDITIONAL DATA: National Soil Survey Laboratory: 70TX-236- 2(71L009-71L014).

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.

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National Cooperative Soil Survey
U.S.A.