Established Series
Rev: EPM


The Betis series consists of very deep, somewhat excessively drained rapidly permeable, sandy upland soils. They formed in thick sandy sediments of marine deposits. These soils are on broad nearly level to moderately sloping broad interfluves. Slopes are dominantly 2 to 5 percent but range from 0 to 12 percent. Mean annual air temperature is about 20 degrees C (68 degrees F), and mean annual precipitation is about 1118 mm (44 in).

TAXONOMIC CLASS: Sandy, siliceous, thermic Lamellic Paleudults

TYPICAL PEDON: Betis loamy fine sand, on a smooth convex 2 percent slope, in woodland. (Colors are for moist soil unless otherwise stated.)

A--0 to 25 cm (0 to 10 in); brown (10YR 4/3) loamy fine sand; weak fine granular structure; soft, very friable; many medium and coarse roots; strongly acid; clear smooth boundary (10 to 30 cm [4 to 12 in] thick).

Bw1--25 to 94 cm (10 to 37 in); brown (7.5YR 5/4) loamy fine sand, few pockets of pale brown (10YR 6/3); single grained; soft, very friable; many medium and few coarse roots; strongly acid; gradual smooth boundary.

Bw2--94 to 145 cm (37 to 57 in); strong brown (7.5YR 5/6) loamy fine sand that contains common small bodies of very pale brown (10YR 7/3); single grained; soft, very friable; moderately acid; few coarse and fine roots; gradual smooth boundary (Combined thickness of the Bw horizon is 50 to 175 cm [20 to 70 in]).

E and Bt--145 to 203 cm (57 to 80 in); very pale brown (10YR 7/3) loamy fine sand (E), that contains common yellowish brown (10YR 5/6) fine sandy loam (Bt) lamellae 1/4 to 3/4 inch thick; single grained; lamellae are massive; soft, very friable; lamellae have coated sand grains and some clay bridging; moderately acid.

TYPE LOCATION: Nacogdoches County, Texas; from intersection with Loop 224 west of Nacogdoches; 5 miles west along Texas Highway 21 and about 100 feet behind church building. Lake Nacogdoches North USGS quad; Lattitude, 31 degrees, 38 minutes, 27.6 seconds N; Longitude, 94 degrees, 45 minutes, 36 seconds, W. NAD 83.


Soil Moisture: An udic soil moisture regime. The soil is dry in some part of the moisture control section for 75 to 90 cumulative days in most years.

Mean annual soil temperature: 19 to 21 degrees C (67 to 70 degrees F)
Depth to argillic horizon: 61 to 203 cm (24 to 80 in)
Thickness of solum: more than 203 cm (more than 80 in)

Particle-size control section (weighted average)
Clay content: 2 to 15 percent
Base Saturation: 25 to 35 percent

A horizon
Hue: 10YR
Value: 4 or 5
Chroma: 2 to 4
Hue: 7.5YR
Value: 4 or 5
Chroma: 2 or 4
Texture: fine sand or loamy fine sand
Reaction: very strongly acid to moderately acid (4.5 to 6.0) unless limed

E horizon where present
Hue: 10YR
Value: 5 to 7
Chroma: 3
Texture: fine sand or loamy fine sand
Reaction: very strongly acid to moderately acid (4.5 to 6.0) unless limed

Bw horizon
Hue: 7.5YR
Value: 5 or 6
Chroma: 4 to 8
Hue: 10YR
Value: 5
Chroma: 4 to 8
Albic material: few to common randomly distributed pockets of clean sand grains
Texture: fine sand or loamy fine sand
Reaction: very strongly acid to moderately acid (4.5 to 6.0)

E and Bt horizon
E portion
Hue: 10YR
Value: 5 to 7
Chroma: 3 or 4
Bt portion
Hue: 7.5YR or 10YR
Value: 5
Chroma: 6 or 8
Lamella: composite thickness is more than 15 cm (6 in) within a depth of 203 cm (80 in)
Texture: loamy fine sand or fine sandy loam

COMPETING SERIES: There are no other series in the same family. The Bienville, Briley, Darco, Eustis, Flo, Glenpool, Grapeland, Lilbert, Troup and Valdosta series are in closely related families.
Eustis and Valdosta soils: are dry in the moisture control section less than 75 days in most years.
Grapeland soils: have a Bt horizon with hue of 5YR or redder.
Valdosta soils: are restricted to the Hawthorn geologic formation.
Bienville soils: have more than 35 percent base saturation, have a seasonal water table at a depth of 100 to 150 cm (40 to 60 in), and are on terraces.
Briley, Darco, Lilbert, and Troup soils: have a loamy control section
Flo and Glenpool soils: have more than 35 percent base saturation.

Parent material: Sandy marine sediments
Landscape: Coastal Plain
Landform: Interfluve
Slope: 0 to 12 percent but are dominantly 2 to 5 percent
Mean annual air temperature range: 18 to 20 degrees C (65 to 70 degrees F)
Mean annual rainfall range: 1016 to 1219 mm (40 to 48 in)
Frost-free period: 235 to 250 days
Elevation: 122 to 213 m (400 to 700 ft)
Thornthwaite P-E index: Greater than 64

GEOGRAPHICALLY ASSOCIATED SOILS: These are the closely related Briley, Darco, Grapeland and Lilbert series, and the Tenaha and Tonkawa series.
Briley soils: are on slightly higher convex divides.
Darco, Grapeland and Lilbert soils: are on similar landscape positions.
Tenaha soils: are on side slopes of drains and ridges. They have a loamy subsoil beneath a sandy epipedon more than 50 cm (20 in) thick.
Tonkawa soils: are on similar positions and do not have an argillic horizon made up of lamellae.

DRAINAGE AND PERMEABILITY: Betis soils are somewhat excessively drained and rapidly permeable. Runoff on 0-3 percent slopes is negligible, 3-5 percent is very low, and 5-8 percent is low.

USE AND VEGETATION: Used mainly for pastures of improved bermudagrass and for woodland. The principal trees are loblolly pine, shortleaf pine, and longleaf pine. Minor areas are used for crops of peanuts, corn, and watermelon.

DISTRIBUTION AND EXTENT: Eastern Texas, Louisiana, and possibly Oklahoma and Arkansas. The series is of moderate extent.


SERIES ESTABLISHED: Nacogdoches County, Texas; 1976.

REMARKS: The series was reclassified from a Psammentic Paleudult to a Lamellic Paleudult in 1997. The series was updated in 2002 to allow a thin E horizon beneath the surface layer. This soil was formerly included in the Eustis series.

Diagnostic Horizons:

Ochric epipedon - 0 to 94 cm (0 to 37 in).

Argillic horizon - 145 to 203 cm (57 to 80 in).


National Cooperative Soil Survey