LOCATION ELMENDORF TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Pachic Vertic Argiustolls
TYPICAL PEDON: Elmendorf clay loam, on a south-facing slope, 1 percent slope in a cultivated field at an elevation of 138 m (455 ft). (Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 cm (0 to 6 in); dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; hard, friable; common roots; slightly alkaline; abrupt smooth boundary. (0 to 25 cm [0 to 10 in] thick)
A--15 to 28 cm (6 to 11 in); dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak moderate subangular blocky structure; hard, friable, sticky; common roots; slightly alkaline; clear wavy boundary. (10 to 31 cm [4 to 12 in] thick)
Bt1--28 to 41 cm (11 to 16 in); very dark gray (10YR 3/1) clay loam, black (10YR 2/1) moist; moderate medium and fine angular blocky structure; hard, firm, sticky; few clay films; common roots; slightly alkaline; diffuse wavy boundary. (combined thickness of the Bt horizons is 38 to 84 cm [15 to 33 in])
Bt2--41 to 97 cm (16 to 38 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium and fine angular blocky structure; very hard, very firm; common clay films; evident pressure faces; few roots; 1 percent of fine calcium carbonate nodules in lower part of horizon; slightly alkaline; gradual wavy boundary.
Btk1--97 to 122 cm (38 to 48 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate medium and fine angular blocky structure; very hard, very firm, sticky; common clay films; evident pressure faces; 6 percent fine calcium carbonate nodules; common coarse distinct grayish brown (10YR 5/2) and yellowish brown (10YR 5/4) masses of oxidized iron; moderately alkaline; slightly effervescent; clear wavy boundary. (combined thickness of the Btk horizons is 69 to 86 cm [27 to 34 in])
Btk2--122 to 158 cm (48 to 62 in); yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; with streaks and pockets of very dark gray (10YR 3/1); weak medium and fine angular blocky structure; extremely hard, very firm, sticky; few clay films; few pressure faces; 3 percent calcium carbonate nodules; strongly effervescent; moderately alkaline; gradual wavy boundary.
By1--158 to 183 cm (62 to 72 in); yellow (10YR 7/6) clay, brownish yellow (10YR 6/6) moist; weak medium blocky structure; very hard, very firm, sticky; contains an estimated 10 percent gray (10YR 5/1) clayey marine shale fragments having a few faint yellowish brown (10YR 5/6) mottles and few fine prominent mottles of yellowish red (5YR 5/6); an estimated 4 percent selenite gypsum crystals; slightly effervescent; moderately alkaline; gradual wavy boundary. (combined thickness of the By horizons is [20 to 99 cm [8 to 39 in])
By2--183 to 229 cm (72 to 90 in); brownish yellow (10YR 6/6) clay, brownish yellow (10YR 6/6) moist; moderate fine blocky structure; very hard, very firm; contains an estimated 30 percent of light olive gray (5Y 6/2) clayey marine shale fragments; an estimated 15 percent crystals of selenite gypsum; slightly effervescent; moderately alkaline; diffuse wavy boundary.
Cy--229 to 243 cm (90 to 96 in); olive yellow (2.5Y 6/6) marine shale with clay texture that is massive and has a few prominent mottles of brownish yellow (10YR 6/6), extremely hard, extremely firm; contains an estimated 15 percent of selenite gypsum crystals; calcareous; moderately alkaline.
TYPE LOCATION: Wilson County, Texas; from the intersection of Texas Highway 181 and Farm Road 541 in Poth, 0.8 mile north on Texas Highway 181, 3 miles east on Farm Road 427 to county road, 0.6 mile north on county road, and 0.12 mile west in a micro-depression in a cultivated field, Poth USGS quad, Latitude: 29 degrees, 6 minutes, 47.85 seconds N; Longitude: 98 degrees, 3 minutes, 59. 48 seconds W, NAD83.
RANGE IN CHARACTERISTICS:
Soil Moisture: An ustic soil moisture regime. The soil moisture control section remains dry in some or all parts for 90 or more but less than 180 cumulative days in normal years. Precipitation falls mostly during the months of April through June and October through November. July through September and January through March are the driest months. When dry, the soil has cracks up to 5 cm (2 in) wide at the surface and extending to depths of more than 127 cm (50 in).
Mean annual soil temperature: 22 to 24 degrees C (72 To 75 degrees F).
Depth to secondary calcium carbonate: 41 to 137 cm (16 to 54 in)
A and BA(where present) Horizon
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 or 2
Texture: loam, sandy clay loam, or clay loam
Reaction: slightly acid to slightly alkaline
Bt Horizons
Hue: 10YR or 2.5Y
Value: 2 to 4
Chroma: 1 or 2
Texture: clay loam or clay
Clay content (upper 20 inches of Bt): 35 to 50 percent
Reaction: slightly acid to slightly alkaline
Btk Horizons
Hue: 10YR, 5Y, or 2.5Y
Value: 4 to 6
Chroma: 1 to 6
Texture: clay loam or clay
Clay content: 35 to 55 percent
Redoxconcentrations: shades of brown, yellow, gray or red
Identifiable secondary carbonate: 2 to 10 percent, films and threads, masses, or cemented nodular concretions
Reaction: neutral to moderately alkaline
By Horizons
Hue: 10YR, 5Y, or 2.5Y
Value: 5 to 7
Chroma: 3 to 8
Texture: clay loam, sandy clay loam or clay
Clay content: 30 to 50 percent
Redox concentrations: shades of brown, yellow, gray or red
Gypsum: 0 to 15 percent by volume selenite crystals
Reaction: neutral to moderately alkaline
Salinity: slightly saline to strongly saline
Cy Horizon
(Variegated matrix)
Hue: 7.5YR to 5Y
Value: 4 to 7
Chroma: 1 to 6
Texture: clayey marine shale or interbedded loamy material and shale containing
0 to 25 percent selenite crystals and other salts.
COMPETING SERIES: This is the Coy (TX) series in the same family. Similar soils are the Cranell (TX), Dacosta (TX), Grail (ND), and Laparita (TX) series. (The Cranell and Laparita series would compete in the same family once these soils have been updated to the current keys to soil taxonomy.)
Coy soils: are calcareous throughout .
Cranell soils: do not contain gypsum crystals.
Dacosta soils: are in the udic moisture regime and have a mollic epipedon that is less than 20 inches.
Grail soils: are in the frigid temperature regime and formed in local alluvium from soft siltstone or shale.
Laparita soils: have higher salinity values in the argillic horizon
GEOGRAPHIC SETTING:
Parent material: calcareous, clayey residuum weathered from shale
Landform: microlows in complex soils areas. In areas where slopes are greater than 1 percent, these soils occur as valleys in a complex surface of valleys and swells that are perpendicular to the slope contours.
Slope: 0 to 5 percent
Mean annual air temperature range: 21 to 23 degrees C (70 to 73 degrees F).
Mean annual precipitation range: 652 to 918 cm (26 to 36 in)
Precipitation Pattern: Precipitation falls mostly during the months of April through June and October through November. July through September and January through March are the driest months.
Frost-free period: 270 to 290 days
Elevation: 46 to 229 m (150 to 750 ft)
Thornthwaite annual P-E indices: 40 to 50
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Clareville, Coy, Denhawken, Laparita, Marcelinas, and Monteola series.
Clareville and
Laparita soils occur at lower elevations.
Coy,
Denhawken,
Marcelinas, and
Monteola soils occur on similar surfaces.
Denhawken soils lack mollic epipedons and usually occur on micro ridges or knolls in a complex with Elmendorf soils.
Monteola soils are clayey throughout and have intersecting slickensides.
DRAINAGE AND PERMEABILITY: well drained. Permeability is very slow. Runoff is slow on 0 to 1 percent slopes, medium on 1 to 3 percent slopes, and high on 3 to 5 percent slopes.
USE AND VEGETATION: Used for crop production and livestock grazing. Main crops are grain sorghum, cotton, corn, and small grains. Livestock grazing areas are mostly improved bermudagrass. Native vegetation consists of mainly mesquite, cacti, live oak, little bluestem, tricloris, sideoats grama, lovegrass, Arizona cottontop, and vine-mesquite. (Ecological site name: Blackland 25-35" Pz; Ecological site number: R083AY379TX)
DISTRIBUTION AND EXTENT: Northern Rio Grande Plain, Blackland Prairie and Claypan Major Land Resource Areas of Texas; LRR I; MLRA 83; the series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Wilson County, Texas; 1972.
REMARKS: The series was formerly included with the Clareville, Heiden, and Burleson soils.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 122 cm (0 to 48 in). (Ap, A, Bt1, Bt2, and Btk1 horizons)
Argillic horizon: 41 to 122 cm (16 to 48 in). (Bt2, Btk1, and Btk2 horizons)
Vertic feature: pressure faces below a depth of 16 inches and cracks to the surface when dry.
ADDITIONAL DATA: NSSL data on pedon 93P0594 from Gonzales County, Texas.
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006.