LOCATION KERRVILLE               TX

Established Series
Rev. WHD-WJG-MLG
11/2013

KERRVILLE SERIES

The Kerrville series consists of soils that are well drained, moderately permeable, and moderately deep to indurated limestone bedrock that is interbedded with weakly cemented limestone. These soils formed in residuum derived from limestone of Cretaceous age. These very gently sloping to very steep soils occur on summits, shoulders, and backslopes of ridges on dissected plateaus. Slope ranges from 1 to 60 percent. Mean annual precipitation is about 711 mm (28 in) and mean annual air temperature is about 19 degrees C (67 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, thermic Typic Calciustepts

TYPICAL PEDON: Kerrville gravelly clay loam, in rangeland.
(Colors are for dry soil unless otherwise stated.)

A--0 to 20 cm (0 to 8 in); pale brown (10YR 6/3) gravelly clay loam, brown (10YR 5/3) moist; weak fine subangular blocky structure parting to moderate fine granular; hard, firm; many fine roots; many wormcasts; 20 percent weakly to strongly cemented angular limestone gravel; violently effervescent; moderately alkaline; clear wavy boundary. Thickness 8 to 30 cm (3 to 12 in)

Bk1--20 to 38 cm (8 to 15 in); very pale brown (10YR 7/4) clay loam, light yellowish brown (10YR 6/4) moist; weak fine subangular blocky structure; hard, firm; few fine roots; many wormcasts; many noncemented and weakly cemented calcium carbonate masses; 10 percent weakly to strongly cemented limestone gravel; violently effervescent; moderately alkaline; clear wavy boundary. Thickness is 10 to 41 cm (4 to 16 in)

Bk2--38 to 61 cm (15 to 24 in); light yellowish brown (10YR 6/4) extremely gravelly clay loam; weak fine subangular blocky structure; hard, firm; 75 percent very pale brown (10YR 8/2) fragments of limestone with 65 percent weakly and strongly cemented and 10 percent noncemented gravel and flagstones; few fine roots; common wormcasts; violently effervescent; moderately alkaline; abrupt smooth boundary. Thickness is 10 to 51 cm (4 to 20 in)

R--61 to 76 cm (24 to 30 in); coarsely fractured indurated limestone bedrock interbedded with weakly cemented limestone; massive fractures mostly more than 25 cm (10 in) apart.

TYPE LOCATION: Kerr County, Texas; from the intersection of Texas Highway 16 and Loop 534 in Kerrville, 2.8 miles south on Loop 534, 0.4 mile east on paved road, 0.3 mile northeast on sanitary landfill road, 0.3 mile northeast on ranch road and across north end of pit to northeast corner of city property, and 120 feet north of road, in rangeland.
USGS topographic quadrangle: Legion, TX; Latitude: 30 degrees, 2 minutes, 1.9 seconds N; Longitude: 99 degrees, 6 minutes, 13.8 seconds W; Datum: NAD83.

RANGE IN CHARACTERISTICS:
Soil moisture: Typic-ustic moisture regime
Depth to lithic contact: 50 to 100 cm (20 to 40 in)
Effervescence: Strongly to violently effervescent
Reaction: Slightly alkaline or moderately alkaline

Particle-size control section (weighted average):
Total clay content: 10 to 30 percent
Carbonate clay content: 2 to 20 percent
Rock and pararock fragments: 15 to 89 percent; 2 to 380 mm; limestone
Calcium carbonate equivalent: 40 to 85 percent in the fine-earth fraction and increases with depth.

A horizon
Hue: 10YR or 2.5Y
Value: 5 to 7 dry, 3 or 4 moist
Chroma: 2 to 4 dry, 2 to 4 moist
Texture: Loam, clay loam, gravelly or very gravelly phases
Rock and pararock fragments: 15 to 60 percent; 2 to 75 mm, limestone

Bw horizon (where present)
Hue: 10YR or 2.5Y
Value: 5 to 8
Chroma: 2 to 4
Texture: Loam, clay loam; very cobbly, very gravelly, cobbly or gravelly phases
Rock and pararock fragments: 15 to 60 percent; 2 to 250 mm, limestone

Bk1 horizon
Hue: 10YR or 2.5Y
Value: 5 to 8
Chroma: 2 to 4
Texture: Loam, clay loam; extremely flaggy, extremely cobbly, extremely gravelly, very flaggy, very cobbly, very gravelly, flaggy, cobbly or gravelly phases
Rock and pararock fragments: 15 to 89 percent; 2 to 75 mm, limestone

Bk2 horizon
Hue: 10YR or 2.5Y
Value: 5 to 8
Chroma: 2 to 4
Texture: Loam, clay loam, and very or extremely, and gravelly, cobbly or flaggy modifiers
Rock and pararock fragments: 50 to 89 percent; 5 to 380 mm, limestone
Identifiable calcium carbonate: nodules, concretion, or masses throughout or around or on bottom of fragments
Other features: Fragments are mostly white (10YR 8/1) but mottles or individual fragments may be yellow (10YR 8/6), brown (10YR 5/3) or gray (10YR 6/1).

R horizon
Texture: Indured limestone and/or interbedded with weakly cemented limestone
Horizon thickness: Greater than 25 cm (10 in)
Vertical fractures: Greater than 10 cm (4 in) apart horizontally
Cementation: Strongly cemented or indurated
Identifiable calcium carbonates: in fractures of some pedons

COMPETING SERIES: There are no competing series in the same family. Similar soils are Brackett, Karnes, Real, Rio Frio, Stilskin, and Whitewright series.
Brackett and Whitewright soils: Contain less than 35 percent coarse fragments and do not have a lithic contact within 100 cm (40 in).
Karnes and Rio Frio soils: Have less than 35 percent rock fragments and are deep and very deep alluvial soils on stream terraces.
Real, Stilskin and Whitewright soils: Are less than 50 cm (20 in) to a paralithic contact.

GEOGRAPHIC SETTING:
Parent material: Residuum from weathered indurated limestone bedrock interbedded with weakly cemented limestone of Cretaceous age, such as the Glen Rose Formation.
Landscape: dissected plateaus
Landform: Summits, shoulders, and backslopes of ridges
Slopes: 1 to 60 percent
Precipitation Pattern: The majority of the yearly amount occurs during the fall and spring months. The winter and summer months are normally drier.
Mean annual precipitation: 660 to 864 mm (26 to 34 in)
Thornthwaite annual P-E index: 32 to 52
Mean annual air temperature: 17.8 to 20.0 degrees C (64 to 68 degrees F)
Frost-free period: 220 to 240 days
Elevation: 266.7 to 762 m (875 to 2,200 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are Brackett, Campwood, Denton, Doss, Eckrant, Real, and Tarrant series.
Brackett and Denton soils: occur on backslope positions
Campwood and Doss soils: are very deep alluvial soils and occur on lower stream terraces
Eckrant and Tarrant soils: occur on higher positions
Real soils: occur on similar positions

DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is low on 1 to 5 percent slopes, medium on 5 to 20 percent slopes, and high on 20 to 60 percent slopes.

USE AND VEGETATION: Used entirely as rangeland. The climax plant community is a tall grass and mid grass, oak savannah. The dominant grass is little bluestem. The other grasses are sideoats grama, tall grama, yellow Indiangrass, silver bluestem, slim tridens, pinhole bluestem, cane bluestem, tall dropseed, hairy grama, and perennial threeawns. The dominant forbs include Engelmann daisy, bushsunflower, and sensitive briar. The woody plants include live oak, Texas oak, flameleaf sumac, evergreen sumac, agarito, and greenbriar. With continued over grazing, the site could potentially deteriorate to a plant population of sideoats grama, seep muhly and live oak. If continuous heavy grazing continues for many years, Ashe juniper will increase and form a dense stand with an understory of plants, such as Texas grama, red grama, puff sheath dropseed, Lindheimer muhly, and Texas persimmon.

DISTRIBUTION AND EXTENT: Texas, Southwest Plateaus and Plains Range and Cotton Region, LLR I: Edwards Plateau, Central Part (MLRA 81B), and Edwards Plateau, Eastern Part (MLRA 81C). This series is extensive.

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

SERIES ESTABLISHED: Kerr County, Texas; 1983.

REMARKS: These soils were formerly included in the Brackett series. Brackett soils do not have a lithic contact and have less than 35 percent coarse fragments in the particle size control section.

Classification changed from Typic Ustochrepts to Typic Calciustepts recognizing a calcic in the Bk1 horizon.

The correct classification of the typical pedon as described is loamy rather than loamy-skeletal particle size class. It was not changed from its original classification until a study is completed. The pararock fragments function like rock fragments in the soil for most uses.

Edited 11/2013 (RFG-JRJ): Updated the competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 20 cm (0 to 8 in) (A horizon)
Calcic horizon: 20 to 38 cm (8 to 15 in) (Bk1 horizon)
Lithic contact: 61 cm (24 in) (top of R layer)

ADDITIONAL DATA: National Soil Survey Laboratory data on S63TX171-1
(40A34405-34409), and S63TX031-1 (40A34400-34404).

Taxonomic Version: Keys to Soil Taxonomy, Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.