LOCATION DAVILLA                 TX

Established Series
MRJ-RMR-RM
08/2017

DAVILLA SERIES

The Davilla series consists of very deep to loamy alluvium, moderately well drained, very slowly permeable soils that formed in loamy alluvium of Pleistocene age derived from mudstone. These nearly level soils are on treads of Pleistocene stream terraces. Slopes range from 0 to 2 percent. Mean annual precipitation is about 938 mm (36.92 in) and the mean annual air temperature is about 20.2 degrees C (68.4 degrees F).

TAXONOMIC CLASS: Fine-loamy, siliceous, superactive, thermic Udic Haplustalfs

TYPICAL PEDON: Davilla loam--in an area of Wilson-Davilla complex on a 0.5 percent convex slope in a rangeland field. (Colors are for dry soil unless otherwise stated.)

Ap--O to 25 cm (0 to 10 in); brown (7.5YR 4/3) loam, dark brown (7.5YR 3/4) moist; weak fine granular structure when moist, massive structureless when dry; very hard, friable; few fine roots; few wormcasts; 1 percent 2 to 10 mm quartzite fragments; slightly acid; clear wavy boundary. (Thickness is 15 to 46 cm [6 to 18 in])

Bt1--25 to 61 cm (10 to 24 in); brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; weak fine and medium angular blocky structure; very hard, firm; few fine roots; few fine pores; few wormcasts; 25 percent distinct clay films on all faces of peds; few fine distinct light gray (10YR 7/1) iron depletions and 1 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron, sharp and 1 percent fine iron-manganese concretions; 1 percent 2 to 5 mm quartzite fragments; neutral; gradual wavy boundary.

Bt2--61 to 86 cm (24 to 34 in); brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; weak medium angular blocky structure; very hard, firm; few fine roots; few fine pores; 25 percent distinct clay films on all faces of peds; 10 percent fine distinct light gray (10YR 7/1) iron depletions and 1 percent fine prominent reddish yellow (5YR 6/6) masses of oxidized iron, sharp and 1 percent fine iron-manganese concretions; 1 percent 2 to 5 mm quartzite fragments; neutral; gradual wavy boundary. (Thickness of the Bt horizon is 46 to 178 cm [18 to 70 in])

Btg1--86 to 112 cm (34 to 44 in); light brownish gray (10YR 6/2) clay loam, grayish brown (10YR 5/2) moist; weak medium angular blocky structure; very hard, firm; few fine roots; few fine pores; 25 percent distinct clay films on all faces of peds; 1 percent fine distinct light gray (10YR 7/1) clay depletions, 20 percent fine prominent reddish yellow (7.5YR 6/8) masses of oxidized iron, sharp and 1 percent fine iron-manganese concretions; 1 percent 2 to 5 mm quartzite fragments; slightly alkaline; gradual wavy boundary.

Btg2--112 to 127 cm (44 to 50 in); gray (10YR 6/1) clay loam, gray (10YR 5/1) moist; weak medium angular blocky structure; extremely hard, very firm; 25 percent distinct clay films on all faces of peds; 20 percent fine prominent brownish yellow (10YR 6/6) masses of oxidized iron, sharp and 1 percent fine iron-manganese concretions; 1 percent 2 to 5 mm quartzite fragments; slightly alkaline; gradual wavy boundary.

Btg3--127 to 152 cm (50 to 60 in); gray (10YR 6/1) clay loam, gray (10YR 5/1) moist; weak medium angular blocky structure; extremely hard, very firm; 25 percent faint clay films on all faces of peds; 1 percent fine prominent brownish yellow (10YR 6/6) masses of oxidized iron, sharp and 1 percent fine iron-manganese concretions; 1 percent fine carbonate concretions; 1 percent 2 to 5 mm quartzite fragments; slightly alkaline; gradual wavy boundary.

Btg4--152 to 203 cm (60 to 80 in); light gray (10YR 7/1) clay loam; gray (10YR 6/1) moist; weak medium angular blocky structure; extremely hard, very firm; 25 percent faint clay films on all faces of peds; 1 percent fine prominent brownish yellow (10YR 6/8) masses of oxidized iron, clear and 1 percent fine iron-manganese concretions; 1 percent fine carbonate concretions; 1 percent 2 to 5 mm quartzite fragments; slightly alkaline. (Thickness of the Btg horizon is 0 to 117 cm [0 to 46 in])

TYPE LOCATION: Milam County, Texas; from junction of Farm Road 487 and Farm Road 437 in Davilla, Texas; approximately 3.6 miles southeast on Farm Road 487; approximately 50 ft north into brushy rangeland pasture.
USGS topographic quadrangle: Davilla, TX;
Latitude: 30 degrees, 45 minutes, 43.17 seconds North;
Longitude: 97 degrees, 13 minutes, 39.47 seconds West.
Datum: WGS84

RANGE IN CHARACTERISTICS:
Solum depth: greater than 203 cm (80 in)
Soil Moisture: dry in some or all parts of the soil moisture control section, for 90 or more cumulative days and moist, in some part, either for more than 180 cumulative days per year, or for 90 or more consecutive days in normal years; ustic soil moisture regime that borders on udic
Mean annual soil temperature: 15 to 22 degrees C (59 to 72 degrees F)
Depth to argillic horizon: 15 to 23 cm (6 to 9 in)
Depth to secondary calcium carbonate: 66 to 99 cm (26 to 39 in)
Depth to redox concentrations: 15 to 23 cm (6 to 9 in)
Depth to redox depletions: 15 to 99 cm (6 to 39 in)
Surface fragments: amount-0 to 2, size-fine, medium, or coarse, kind-quartzite or ironstone nodules

Particle-size control section (weighted average)
Clay content: 27 to 35 percent
Rock fragments: 0 to 12 percent

A Horizon
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 2 to 4
Texture: very fine sandy loam or loam
Clay content: 7 to 20 percent
Rock fragments: amount-0 to 10; size-fine, medium, or coarse; kind-quartzite or ironstone nodules
Electrical conductivity (decisiemens per meter): 0 to 2
Effervescence: none
Reaction: slightly acid to neutral (6.1 to 7.3)

Bt Horizon (upper part)
Hue: 7.5YR, 1OYR or 2.5Y
Value: 4 to 7
Chroma: 2 to 6
Texture: sandy clay loam or clay loam
Clay content: 27 to 35 percent
Redox concentrations: amount-0 to 20, size-fine or medium, contrast-distinct or prominent, boundary-sharp, shades-red, gray, brown, or yellow
Redox depletions: amount-0 to 2, size-fine, contrast-faint, boundary-sharp or clear, shades-gray
Iron-manganese nodules: amount-0 to 2; size-fine; kind-Iron-manganese nodules
Rock fragments: amount-0 to 10; size-fine, medium, or coarse; kind-quartzite or ironstone nodules
Calcium carbonate equivalent: 0 to 5 percent
Electrical conductivity (decisiemens per meter): 0 to 2
Effervescence: none to very slight
Reaction: slightly acid to slightly alkaline (6.1 to 7.8)

Btg, BCt, or Bt Horizon (lower part)
Hue: 1OYR to 5Y
Value: 3 to 7
Chroma: 1 to 4
Texture: sandy clay loam, clay loam, or clay
Clay content: 27 to 42 percent
Redox concentrations: amount-0 to 20, size-fine or medium, contrast-faint, distinct, or prominent, boundary-sharp or clear, shades-red, gray, brown, or yellow
Redox depletions: amount-0 to 2, size-fine, contrast-faint, boundary-sharp or clear, shades-gray
Iron-manganese nodules: amount-0 to 2; size-fine; kind-Iron-manganese nodules
Rock fragments: amount-0 to 12; size-fine, medium, or coarse; kind-quartzite or ironstone nodules
Identifiable secondary carbonate: amount-0 to 2, size-fine or medium, kind-masses or concretions
Calcium carbonate equivalent: 0 to 15 percent
Electrical conductivity (decisiemens per meter): 0 to 2
Sodium Adsorption Ratio: 0 to 4
Effervescence: none to strong
Reaction: slightly acid to moderately alkaline (6.1 to 8.4)

COMPETING SERIES: There are no series in the same family. Similar soils are the Bremond, Bastsil, Chazos, and Gredge series.
Bremond, Chazos, and Gredge soils: have a fine particle-size control section
Bastsil soils: have no clay decrease by more than 20 percent of the maximum clay content within 150 cm (60 in) from the soil surface and are in the active cation exchange capacity activity class

GEOGRAPHIC SETTING:
Parent material: loamy alluvium of Pleistocene age derived from mudstone
Landscape: Inland dissected coastal plains
Landform: stream terraces
Microfeature: Davilla soils are on the mounds. The surface is typically mounded. The mounds are oval and range from 6.1 to about 24.4 m (20 to about 80 ft) in diameter. They are about 15 to 46 cm (6 to 18 in) above the associated intermound areas except where cultivation has smoothed and leveled the surface. They are typically mapped in a complex with another soil.
Slope: 0 to 2 percent
Mean annual precipitation: 813 to 1016 mm (32 to 40 in)
Thornthwaite P-E Index: 54 to 64
Mean annual air temperature: 18.8 to 20.5 degrees C (66 to 69 degrees F)
Frost-free period: 236 to 275 days
Elevation: 87.1 to 174.4 m (286 to 573 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Benchley, Chazos, Crockett, Edge, Gause, Gredge, Luling, and Wilson series.
Benchley, Crockett, Edge, and Luling soils: have a solum that is underlain by geologic materials within a depth of 150 cm (60 in) and they have fine-textured control sections. They are slightly higher in the landscape and are on nearby uplands.
Chazos and Gause soils: have fine textured control sections, are on similar stream terrace positions, and have a loamy fine sand epipedon
Gredge soils: have fine-textured control sections, are on similar stream terrace positions, and have an argillic horizon with reddish matrix colors
Wilson soils: have fine-textured control sections, are on similar stream terrace positions, have a very dark gray upper argillic horizon, and are mapped in complex with Davilla soils. Wilson usually occurs on slightly lower intermound positions.

DRAINAGE AND PERMEABILITY:
Drainage class: Moderately well
Permeability: Very slow.
Runoff: high on slopes less than 1 percent and very high on slopes of 1 to 2 percent.
Wetness: The soil has masses of redoximorphic features, which are considered to be mainly relict features. During wet years these soils may be saturated long enough to develop aquic soil conditions in some subhorizons. However, in most years they do not have aquic soil conditions.

USE AND VEGETATION: Used for improved pasture with coastal Bermuda grass and Bahia grass being the dominant improved grasses grown. Some areas are cropped to small grains, corn, or grain sorghum. Some areas are in rangeland. Native vegetation consists of medium and tall grasses such as big bluestem, sideoats grama, silver bluestem, Texas wintergrass, Florida paspalum, little bluestem, and yellow indiangrass and scattered trees such as elm, hackberry, mesquite and post oak.

DISTRIBUTION AND EXTENT: South central, Texas; Land Resource Region J - Southwestern Prairies Cotton and Forage Region; Texas Blackland Prairies, Northern and Southern Parts (MLRAs 86A and 86B) and Texas Claypan Area, Southern Part (MLRA 87A); the series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Temple, Texas

SERIES PROPOSED: Milam County, Texas, 1988. The name is from a small community in Western Milam County close to the type location.

REMARKS: Classification changed (2/94) from Aquic subgroup to Udic subgroup based on changes in aquic soil definitions and moisture data from similar soils. These soils were previously included with the Crockett series.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 25 to 75 cm (10 to 30 in) (Bt1 and Bt2 horizons)
Ochric epipedon: 0 to 25 cm (0 to 10 in). The soil is massive and hard when dry. (A horizon)
Argillic horizon: 25 to 203 cm (10 to 80 in). (Bt1, Bt2, Btg1, Btg2, Btg3, Btg4 horizons)
Redoximorphic concentrations: 25 to 203 cm (10 to 80 in). (Bt1, Bt2, Btg1, Btg2, Btg3, and Btg4 horizons)
Redoximorphic depletions: 25 to 86 cm (10 to 34 in). (Bt1 and Bt2 horizons)
Other features: Most pedons are underlain with beds of sand and/or gravel below a depth of 3 m (10 ft).

ADDITIONAL DATA: TAMU/KSSL Data from 4 pedons shows the weighted average clay content of the control section ranges from 28 to 34 percent. However, the field texture method suggests a fine family.

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

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National Cooperative Soil Survey
U.S.A.