LOCATION POSEY                   TX+NM

Established Series
Rev. ERB-RM-TCB
09/2022

POSEY SERIES

The Posey series consists of very deep, well drained, moderately permeable soils that formed in calcareous, loamy eolian deposits from the Blackwater Draw Formation of Pleistocene age. These soils are on nearly level to strongly sloping plains, playa slopes, and draws. Slope ranges from 0 to 12 percent. The mean annual precipitation is 483 mm (19 in) and the mean annual temperature is 16 degrees C (61 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Calcidic Paleustalfs

TYPICAL PEDON: Posey fine sandy loam, on an east-facing, slightly concave, nearly level plain, 1.5 percent slope in cropland at an elevation of about 1,000 m (3,280 ft). (Colors are for dry soil unless otherwise noted.)

Ap--0 to 25 cm (0 to 10 in); reddish brown (5YR 5/4) fine sandy loam, reddish brown (5YR 4/4) moist; weak fine and medium granular structure; soft, friable; few fine roots; about 10 percent calcium carbonate by volume in the form of nodules and finely disseminated carbonates; violently effervescent; moderately alkaline; abrupt smooth boundary. (13 to 38 cm [5 to 15 in] thick)

Btk--25 to 46 cm (10 to 18 in); reddish brown (5YR 5/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, friable; few distinct clay films on faces of peds; few medium roots; common medium root channels; common wormcasts; about 30 percent calcium carbonate by volume in the form of nodules, masses, and finely disseminated carbonates; violently effervescent; moderately alkaline; gradual wavy boundary. (13 to 30 cm [5 to 12 in] thick)

Btkk--46 to 99 cm (18 to 39 in); light reddish brown (5YR 6/4) sandy clay loam; reddish brown (5YR 5/4) moist; weak coarse prismatic structure parting to moderate fine subangular blocky; very hard, firm; few faint clay films on faces of peds; few fine roots; common fine root channels; few wormcasts; about 55 percent calcium carbonate by volume as masses, nodules, and finely disseminated carbonates; violently effervescent; moderately alkaline; gradual wavy boundary. (38 to 76 cm [15 to 30 in] thick)

B'tk--99 to 203 cm (39 to 80 in); reddish yellow (5YR 6/6) sandy clay loam, yellowish red (5YR 5/6) moist, weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm; few fine roots; common fine root channels; few distinct clay films in root channels; sand grains coated and bridged with clay; about 20 percent calcium carbonate by volume as masses, nodules, and finely disseminated carbonates; violently effervescent; moderately alkaline

TYPE LOCATION: Lubbock County, Texas; 300 ft east of southwest corner of sec. 33, Block D, L and SV RR Co. survey, or 1 mile south of New Deal and 2 miles west in cropland; Latitude: 33 degrees, 42 minutes, 31 seconds N; Longitude: 101 degrees, 52 minutes, 09 seconds, W; New Deal, Texas USGS quad; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture
control section is dry in some or all parts for more than 180 but less than 220
days, cumulative, in normal years. July through August and December through
February are the driest months. These soils are intermittently moist in
September through November and March through June.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Depth to secondary calcium carbonate: 13 to 25 cm (5 to 10 in).
Depth to calcic horizon: 20 to 60 cm (8 to 24 in).
Solum thickness: more than 203 cm (80 in).
Surface fragments: 0 to 5 percent, gravel size, strongly cemented carbonate nodules.
Particle-size control section: 18 to 35 percent silicate clay.

A horizon:
Hue: 5YR to 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 2 to 4
Texture: fine sandy loam and loam.
Rock fragments: 0 to 2 percent, gravel size, strongly cemented carbonate nodules.
Effervescence: strong or violent
Reaction: moderately alkaline
Note: Epipedons with moist values and chromas less than 3.5 are less than 18 cm (7 in) thick.

Btk horizons:
Hue: 2.5YR to 7.5YR
Value: 4 to 7, 3 to 6 moist
Chroma: 3 to 6
Texture: sandy clay loam, clay loam Rock fragments: 0 to 10 percent, gravel size, strongly cemented carbonate nodules.
Secondary calcium carbonate: 5 to 45 percent by volume as films, filaments, masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 3 to 35 percent
Effervescence: strong or violent
Reaction: moderately alkaline
Note: The upper part of the Btk horizon contains about 3 to 25 percent carbonates and that increases to about 30 to 60 percent with depth.

Btkk horizons:
Hue: 2.5YR to 7.5YR
Value: 4 to 8, 3 to 7 moist
Chroma: 1 to 4
Texture: sandy clay loam, clay loam
Rock fragments: 0 to 5 percent, gravel size, strongly cemented carbonate nodules.
Secondary calcium carbonate: 50 to 70 percent by volume as masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 40 to 60 percent
Effervescence: violent
Reaction: moderately or strongly alkaline

COMPETING SERIES: There are no other series in this family. Similar soils include the Amarillo, Arvana, Bovina, Estacado, Mansker, Midessa, Plemons, and Tulia series.
Amarillo soils: have a calcic horizon between 76 and 150 cm (30 and 60 in) and are non-effervescent in the upper argillic horizon.
Arvana soils: have a petrocalcic horizon between 50 and 100 cm (20 and 40 in).
Bovina and Estacado soils: have mollic epipedons.
Plemons soils: have a fine-silty particle-size class and formed in sediments derived from the Ogallala Formation of Miocene-Pliocene age.
Midessa soils: have a cambic horizon and do not have an argillic horizon.
Mansker and Tulia soils: have carbonatic mineralogy; in addition Mansker soils have a mollic epipedon.

GEOGRAPHIC SETTING:
Parent material: calcareous, loamy eolian deposits from the Blackwater Draw Formation of Pleistocene age.
Landform: nearly level to strongly sloping plains, playa slopes, and draws.
Slopes: 0 to 12 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 63 degrees F).
Mean annual precipitation: 406 to 533 mm (16 to 21 in).
Elevation: 792 to 1,463 m (2,600 to 4,800 ft).
Frost-free period: 185 to 220 days.
Thornthwaite annual P-E Index Values: 25 to 36

GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar Amarillo, Arvana, Bovina (T), Mansker, Midessa, and Tulia soils and the Drake, Patricia, Potter, Sharvana, and Tokio soils.
Amarillo, Arvana, Bovina, Mansker, Midessa, and Tulia soils are on similar landscape positions.
Drake soils are on higher landscape positions and do not have an argillic horizon.
Patricia soils are on slightly higher landscape positions and have a calcic horizon between 150 and 203 cm (60 and 80 in).
Potter soils are on lower landscape positions and have carbonatic mineralogy and a loamy-skeletal particle-size class.
Sharvana soils are on similar landscape positions but have a petrocalcic horizon within 50 cm (20 in).
Tokio soils are on slightly lower landscape positions, have a calcic horizon between 50 to 100 cm (20 to 40 in), and are noneffervescent in the upper argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained and moderate permeability. Surface runoff is negligible on less than 1 percent slopes, low on 1 to 5 percent slopes, and medium on 5 to 12 percent slopes.

USE AND VEGETATION: Widely used for dryland and irrigated crop production. Principal crops grown are cotton, grain sorghum, and wheat. Climax native vegetation is mainly mid and short grasses and includes blue grama, sideoats grama, and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, galleta or tobosa, silver bluestem, wild alfalfa, and prairie clover with a light to moderate overstory of mesquite. This soil has been correlated to the High Lime (R077CY026TX) ecological site in MLRA-77C.

DISTRIBUTION AND EXTENT: Southern High Plains, Southern Part (MLRA 77C in LRR H) of west Texas and eastern New Mexico. The series is of moderate extent.

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

SERIES ESTABLISHED: Hale County, Texas; 1969.

REMARKS: This is a Benchmark Series.
Posey series was formerly included in the Mansker and Veal series.
Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 25 cm (0 to 10 in). (Ap horizon)
Argillic horizon: 25 to 203 cm (10 to 80 in). (Btk, Btkk, B'tk horizons)
Calcic horizon: 46 to 99 cm. (18 to 39 in) (Btkk, B'tk horizons)
Plugged (kk) horizon: 46 to 99 cm (18 to 39 in) (Btkk1, Btkk2)

Note: the kk feature is defined as pedogenic carbonate accumulation that is characterized by laterally continuous carbonates that have engulfed rock, sand, silt, and clay particles; plugged the macroporosity of the soil horizon with 50 percent or more calcium carbonate; and obliterated the original soil structure.

ADDITIONAL DATA: KSSL data available: S90NM-009-005 (Curry County, New Mexico); S2019TX305005, S2019TX305006 (Lynn County, Texas); S2019TX219007 (Hockley County, Texas).

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

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National Cooperative Soil Survey
U.S.A.