LOCATION TATLUM                  TX

Established Series
GWC-RM
09/2015

TATLUM SERIES

The Tatlum series consists of deep, very poorly drained, very slowly permeable soils that formed in saline loamy fluviomarine deposits. These nearly level to slightly depressional soils are on broad level tidal areas in coastal marshes. Slope range from 0 to 1 percent but are mostly less than 0.5 percent. Mean annual precipitation is about 1245 mm (49 in), and mean annual air temperature is about 20.6 degrees C (69 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, hyperthermic Sodic Hydraquents

TYPICAL PEDON: Tatlum clay loam, on a smooth 0.1 percent slope, at an elevation less than 1 m (3 ft) in grass. (Colors are for moist soil unless otherwise stated.)

Ag--0 to 46 cm (0 to 18 in); gray (10YR 5/1) clay loam; massive; flows easily between fingers and leaves small residue in hand when squeezed; (n-value 1.0) slightly sticky; common fine and medium roots; common medium distinct dark yellowish brown (10YR 4/4) masses of oxidized iron; strongly saline; moderately alkaline; clear smooth boundary. (15 to 51 cm [6 to 20 in] thick)

Cg1--46 to 71 cm (18 to 28 in); gray (10YR 5/1) clay loam; massive; flows with some difficulty between fingers and leaves small residue in hand when squeezed; (n-value 0.8) slightly sticky; strongly saline; moderately alkaline; gradual smooth boundary. (25 to 56 cm [10 to 22 in] thick)

Cg2--71 to 107 cm (28 to 42 in); gray (10YR 5/1) stratified clay loam with few strata of clay; massive; firm, common medium faint gray (N 5/) iron depletions; moderately alkaline; gradual smooth boundary. (25 to 61 cm [10 to 24 in] thick)

Cg3--107 cm to 152 cm (42 to 60 in); gray (N 5/) stratified clay loam and clay; massive; firm, slightly sticky and slightly plastic; common medium prominent strong brown (7.5YR 5/8) masses of oxidized iron; many medium distinct grayish brown (10YR 5/2) iron depletions; few fine black (10YR 2/1) iron-manganese concretions; strongly saline; moderately alkaline.

TYPE LOCATION: Brazoria County, Texas; about 12 miles east of Freeport; from the intersection of Cold Pass and Churchill Bayou and Follets Island, go across Cold Pass at a compass heading of 20 degrees, site is 60 ft north of the bank of Cold Pass. Christmas Point USGS quadrangle; Latitude: 29 degrees 4 minutes 33 seconds N; Longitude: 95 degrees 9 minutes 15 seconds W; WGS 84

RANGE IN CHARACTERISTICS:
Soil moisture: a peraquic moisture regime.
Mean annual soil temperature: 21.7 to 22.8 degrees C (71 to 73 degrees F)
All layers from 20 to 51 cm (8 to 20 in) below the mineral surface have an n-value of more than 0.7. The n-value is less than 0.7 at some depth between 51 and102 cm (20 and 40 in) from the mineral surface.
Some pedons have an organic mat of decomposing plant material 3 to 20 cm (1 to 8 in) thick on the soil surface.
Reaction ranges from neutral through moderately alkaline throughout the pedon.
The electrical conductivity ranges from 25 to 90 mmhos and the exchangeable sodium is more than 30 percent throughout the control section.
The sand fraction is mainly very fine sand throughout the control section.
Clay content in the control section averages 18 to 35 percent.

Ag horizon:
Hue: N through 10YR
Values: 2 to 5
Chromas: 1 or less
Texture: fine sandy loam through clay loam, or the mucky counterparts of these textures.
Redox concentrations: amount- few to many; color- shades of brown
Redox depletions: amount- few to many; color- shades of gray

Cg horizons:
Hue: N, 5Y, 5GY, 2.5Y, or 10YR
Values: 4 to 7
Chroma: 2 or less. Where 2 chroma occurs, the horizon always contains redoximorphic features. The hue commonly changes on exposure to air.
Texture:very fine sandy loam through clay. Some pedons have mucky counterparts of these textures. The horizon is generally stratified with heavier textured materials
Redox concentrations: amount- few to many; color- shades of brown
Redox depletions: amount- few to many; color- shades of gray

Some pedons have brown clayey horizons below 102 cm (40 in) which commonly are calcareous.

COMPETING SERIES: There are no series in the same family. Similar soils include the Balize, Barbary, Barrada, Caplen, Follet, Gentilly, Levy, Scatlake, and Tracosa series.
Balize soils: are fluid non-saline mineral soils flooded mostly by fresh water.r
Barbary, Barrada, Caplen, Gentilly, Levy, and Tracosa soils: have more than 35 percent clay in the control section.
Follet and Tracosa soils: have n-values of less than 0.7 between 20 and 51 cm (8 and 20 in) of the soil surface.
Scatlake soils: are in a very-fine family and have n-values greater than 1.0 throughout.

GEOGRAPHIC SETTING:
Parent material: loamy eolian deposits and loamy stormy washover fluviomarine deposits from mixed sources
Landscape: barrier islands
Landform: shallow depressional barrier flats
Slope: 0 to 1 percent but mainly less than 0.5 percent
Mean annual precipitation: 1,016 to 1,321 (40 to 52 in)
Mean annual air temperature: 20.6 to 21.7 degrees C (69 to 71 degrees F)
Frost-free period: 300 to 335
Elevation: less than 1 m (3 ft)
Thornthwaite P-E Index: exceeds 50

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caplen, Follet, and Tracosa series and the Harris, Mustang, Narta, Placedo, and Veston series.
All of these soils except Caplen have n-value of less than 0.7 within 20 to 51 cm (8 to 20 in) of the soil surface.
Follet and Tracosa soils: are on similar landscapes.
Harris, Mustang, Narta, Placedo, and Veston soils: occur on a slightly higher position and have a water table that is below the soil surface at least some time during the year.
Caplen soils: are slightly higher.

DRAINAGE AND PERMEABILITY: Tatlum soils are very poorly drained. Runoff is negligible. Permeability is very slow. A permanent water table is at or slightly above the soil surface at low tides to 30 cm (12 in) above the surface during high tides. They are permanently saturated with sea water.

USE AND VEGETATION: Used mainly as wildlife land. A few areas are grazed by livestock where the vegetation adds enough strength to the surface for support. Native vegetation is dominated by smooth cordgrass. Other plants include Salicornia and Batis species.

DISTRIBUTION AND EXTENT: Along the Upper Gulf Coast in southeast Texas. LRR T; MLRA 150B (Gulf Coast Saline Prairies). Small extent.

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

SERIES ESTABLISHED: Brazoria County, Texas; 1978.

REMARKS: These soils were formerly classified as a miscellaneous land type, Tidal flat, or were included with the Veston series. This soil has halic properties as described by J. R. Coover, et al., in SSSA Proceedings, 1975. These soils were reclassified to Sodic Hydraquents in 2015 in accordance with the Keys to Soil Taxonomy, Twelfth Edition, 2014.

Diagnostic horizons and features recognized in this pedon are:

Peraquic moisture regime n-value greater than 0.7

ADDITIONAL DATA: KSSL data on pedon S1978TX039096 at the type location.

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

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National Cooperative Soil Survey
U.S.A.