LOCATION COY TX

Established Series
MLG-CKH-JBA
11/2016

COY SERIES

The Coy series consists of very deep, well drained, slowly permeable soils that developed in calcareous clayey alluvium derived from mudstone. These soils are on nearly level to moderately sloping terrace remnants and broad flats associated with drainage ways. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 737 mm (29 in) and the mean annual air temperature is about 21.7 degrees C (71 degrees F).

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Pachic Vertic Argiustolls

TYPICAL PEDON: Coy clay loam in cropland; elevation is 131 meters (430 feet).
(Colors are for dry soil unless otherwise stated.)

Ap--0 to 15 cm (0 to 6 in); dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; weak fine granular and subangular blocky structure; hard, firm; many fine roots; common wormcasts and insect tunnels; 3 mm (1/8 in) gray (10YR 6/1) surface crust; very slightly effervescent; moderately alkaline; clear smooth boundary. Thickness is 10 to 28 cm (4 to 11 in)

Bt1--15 to 30 cm (6 to 12 in); dark gray (10YR 4/1) clay loam, very dark gray (10YR 3/1) moist; weak coarse prismatic parting structure to moderate fine subangular blocky; hard, firm; many fine roots; many wormcasts and insect tunnels; few clay films on surface of peds; slightly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 10 to 25 cm (4 to 10 in)

Bt2--30 to 64 cm (12 to 25 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; weak medium prismatic parting to moderate fine blocky structure; very hard, firm; common fine roots; common wormcasts and insect tunnels; common pressure faces; few clay films on surface of peds; slightly effervescent; moderately alkaline; gradual wavy boundary. Combined thickness of Bt horizons is 20 to 76 cm (8 to 30 in)

Btk--64 to 102 cm (25 to 40 in); dark grayish brown (10YR 4/2) clay, very dark grayish brown (10YR 3/2) moist; moderate fine and medium blocky structure; very hard, firm; common pressure faces; few clay films on surface of peds; few fine and very fine nodules of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 25 to 64 cm (10 to 25 in)

Bk--102 to 140 cm (40 to 55 in); brown (10YR 5/3) clay, brown (10YR 4/3) moist; moderate medium blocky structure; very hard, firm; few vertical cracks 6 mm (1/4 in) wide filled with dark grayish brown (10YR 4/2) clay; common pressure faces; common masses and fine nodules of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 25 to 51 cm (10 to 20 in)

Bky--140 to 203 cm (55 to 80 in); grayish brown (10YR 5/2) and brownish yellow (10YR 6/6) clay, dark grayish brown (10YR 4/2) and yellowish brown (10YR 5/6) moist; weak medium blocky structure; very hard, firm; few dark grayish brown vertical streaks; few fine nodules of calcium carbonate; common fine crystals of gypsum; few fragments of mudstone; strongly effervescent; moderately alkaline.

TYPE LOCATION: Wilson County, Texas; from the intersection of U. S. Highway 181 and Texas Highway 97 in Floresville; 4.5 miles south on U. S. Highway 181; 300 feet north of petroleum service station; 150 feet east in cultivated field.
USGS topographic quadrangle: Poth, Texas;
Latitude: 29 degrees, 5 minutes, 22.5 seconds N;
Longitude: 98 degrees, 5 minutes, 44.7 seconds W;
Datum: WGS 84.

RANGE IN CHARACTERISTICS:
Soil Moisture: A typic ustic moisture regime. The soil moisture control section is dry in some or all parts for more than 90 days but less than 180 cumulative days in normal years.
Mean annual soil temperature: 22 to 23 degrees C (72 to 74 degrees F)
Thickness of Mollic epipedon: 51 to 114 cm (20 to 45 in)
Thickness of Argillic horizon: 51 to 127 cm (20 to 50 in)
Vertic properties: When dry, the soil has cracks up to 5 cm (2 in) wide at the surface that extend to depths of more than 100 cm (40 in).
Depth to Calcic horizon: 89 to 152 cm (35 to 60 in)

A horizon
Hue: 10YR
Value: 2 to 4
Chroma: 1 or 2
Texture: sandy clay loam, clay loam, or clay
Clay content: 25 to 45 percent
Silt content: 20 to 35 percent
Calcium carbonate equivalent: 0 to 5 percent
Effervescence: very slight to strong
Reaction: slightly alkaline to moderately alkaline

BA horizon (where present)
Hue: 10YR
Value: 2 to 4
Chroma: 1 or 2
Texture: sandy clay loam, clay loam, or clay
Clay content: 25 to 45 percent
Silt content: 20 to 35 percent
Calcium carbonate equivalent: 0 to 5 percent
Effervescence: slight to strong
Reaction: slightly alkaline to moderately alkaline

Bt horizons
Hue: 10YR
Value: 3 to 6
Chroma: 1 to 4
Texture: clay loam, sandy clay, or clay
Clay content: 35 to 60 percent
Identifiable secondary calcium carbonate: 0 to 3 percent; masses, threads, and nodules throughout
Calcium carbonate equivalent: 0 to 10 percent
Effervescence: slight to strong
Reaction: slightly alkaline to moderately alkaline

Btk horizons (where present)
Hue: 7.5YR or 10YR
Value: 3 to 6
Chroma: 1 to 4
Texture: clay loam, sandy clay, or clay
Clay content: 35 to 60 percent
Identifiable secondary calcium carbonate: 3 to 10 percent; masses, threads, and nodules throughout
Calcium carbonate equivalent: 5 to 20 percent
Effervescence: slight to violent
Reaction: slightly alkaline to moderately alkaline

Bk or Bky horizon
Hue: 7.5YR or 10YR
Value: 5 to 7
Chroma: 2 to 6
Texture: silty clay, clay, clay loam, sandy clay
Clay content: 35 to 60 percent
Identifiable secondary calcium carbonate: 0 to 10 percent; masses and nodules throughout
Calcium carbonate equivalent: 10 to 30 percent
Gypsum content: 0 to 5 percent; threads and films throughout
Effervescence: strong to violent
Reaction: slightly alkaline to moderately alkaline

BC horizon (where present)
Hue: 7.5YR to 2.5Y
Value: 5 to 7
Chroma: 2 to 6
Texture: silty clay or clay
Clay content: 40 to 60 percent
Identifiable secondary calcium carbonate: 1 to 15 percent; masses, films, and nodules throughout
Calcium carbonate equivalent: 5 to 30 percent
Gypsum content: 0 to 10 percent; threads and films throughout
Effervescence: slight to violent
Reaction: slightly alkaline to strongly alkaline

COMPETING SERIES: This is the Laparita and Elmendorf series in the same family. Similar soils are the Chacon, Clareville, Czar, Marcelinas, Monteola, and Tordia series.
Chacon soils: occur in a slightly drier (aridic-ustic) soil moisture regime
Clareville and Czar soils: do not have vertic properties and are noncalcareous in the surface
Elmendorf soils: are noncalcareous in the A and upper Bt horizons, have very slow permeability, and have redoximorphic features
Laparita soils: are more saline in the upper part
Marcelinas soils: have mixed mineralogy and have mollic epipedons less than 50 cm (20 in) thick
Monteola soils: do not have an argillic horizon
Tordia soils: do not have an argillic horizon

GEOGRAPHIC SETTING:
Parent Material: clayey alluvium derived from calcareous mudstone
Landscape: inland, dissected coastal plain
Landform: hillslopes on remnants of old high terraces
Slope: 0 to 5 percent
Precipitation pattern: June through August and December through February are the driest months. These soils are intermittently moist in September through November and March through May.
Mean annual precipitation: 559 to 889 mm (22 to 35 in)
Thornthwaite annual P-E indices: 31 to 44
Mean annual air temperature: 21.1 to 23.3 degrees C (70 to 74 degrees F)
Frost free period: 270 to 300 days
Elevation: 30.5 to 182.9 m (100 to 600 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Clareville, Elmendorf, Marcelinas, Monteola, Tordia, and Floresville series.
Clareville soils: do not have vertic properties and are noncalcareous in the surface
Elmendorf soils: are noncalcareous in the A and upper Bt horizons, have very slow permeability, and have redoximorphic features
Floresville soils: occur at higher elevation and have hue redder than 10YR
Marcelinas soils: have mixed mineralogy and have mollic epipedons less than 51 cm (20 in) thick
Monteola and Tordia soils: do not have an argillic horizon

DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is medium on less than 1 percent slopes and high on 1 to 5 percent slopes.

USE AND VEGETATION: Mainly used for crop production with some areas used for livestock grazing and wildlife habitat. Cultivated crops are cotton, grain sorghum, and corn. Native grasses include Arizona cottontop, little bluestem, sideoats grama, curlymesquite, and Texas bristlegrass. Woody invaders are whitebrush, spiny hackberry, huisache, and mesquite.

DISTRIBUTION AND EXTENT: Northern and Central Rio Grande Plain of Texas (MLRA 83A, 83C); Land Resource Region I. The series is of moderate extent.

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

SERIES ESTABLISHED: Wilson County, Texas; 1972.

REMARKS: The Coy soils were formerly included with the Monteola series.

Edited 11/2016 (RFG-GWH): Updated competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: 15 to 66 cm (6 to 26 in)
Mollic epipedon: 0 to 102 cm (0 to 40 in). (A and Bt horizons)
Argillic horizon: 15 to 102 cm (6 to 40 in). (Bt horizons)
Calcic horizons: 102 to 140 cm (40 to 55 in). (Bk horizon)
Vertic properties: when dry, the soil has cracks up to 5 cm (2 in) wide at the surface that extend to depths of more than 100 cm (40 in).

ADDITIONAL DATA: KSSL: Pedons ID 92TX297003 & S01TX-131-004; TAMU Soil Characterization Laboratory S82TX-273-001. Lab analysis was performed on 2 pedons at the local project office.

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

National Cooperative Soil Survey
U.S.A.