LOCATION ARVANA                  TX+NM

Established Series
Rev. TCB-JKA-RM
09/2014

ARVANA SERIES


The Arvana series consists of soils that are moderately deep to a petrocalcic horizon. They are well drained, moderately permeable soils derived from loamy eolian deposits from the Blackwater Draw Formation of Pleistocene age. Arvana soils are on nearly level to gently sloping plains and playa slopes. Slope ranges from 0 to 5 percent. The mean annual precipitation is about 483 mm (19 in) and the mean annual air temperature is about 16 degrees C (60 degrees F).

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

TYPICAL PEDON: Arvana fine sandy loam, on southwest-facing, nearly level plain, 1 percent slope in a cultivated field at an elevation of about 1,116 m (3,660 ft). (Colors are for dry soil unless otherwise stated.)

Ap--0 to 20 cm (0 to 8 in); brown (7.5YR 4/4) fine sandy loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable; many fine and very fine roots; many fine tubular pores; few worm casts; noneffervescent; moderately alkaline; abrupt smooth boundary. (15 to 41 cm [6 to 16 in] thick)

Bt1--20 to 41 cm (8 to 16 in); reddish brown (5YR 4/4) sandy clay loam, dark reddish brown (5YR 3/4) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; few fine roots; many fine tubular pores; few worm casts; common faint clay films on ped surfaces; noneffervescent; moderately alkaline; gradual smooth boundary. (15 to 30 cm [6 to 12 in] thick)

Bt2--41 to 61 cm (16 to 24 in); reddish brown (5YR 5/4) sandy clay loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure, parting to moderate medium subangular blocky; hard, firm; few very fine roots; few fine tubular pores; few worm casts; common faint clay films on ped surfaces; noneffervescent; moderately alkaline; clear wavy boundary. (15 to 38 cm [6 to 15 in] thick)

Bt3--61 to 71 cm (24 to 28 in); yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; weak coarse prismatic structure parting to weak medium subangular blocky; hard, firm; few fine tubular pores; few worm casts; few faint clay films on ped surfaces; few fine films and threads of calcium carbonate in pores and on ped surfaces; slightly effervescent; moderately alkaline; abrupt wavy boundary. (10 to 30 cm [4 to 12 in] thick)

Bkm--71 to 97 cm (28 to 38 in); pinkish white (5YR 8/2) indurated layer containing a few fractures; laminar in the upper and pisolitic structure below the laminae; becomes softer below the pisolitic layer; moderately alkaline. (15 to 61 cm [6 to 24 in] thick)

BCk--97 to 152 cm (38 to 60 in); pink (5YR 8/3) loam, pink (5YR 7/4) moist; few fine and medium reddish yellow (5YR 6/6) mottles; weak fine and medium subangular blocky structure; hard, firm; few worm casts and large tubular pores; about 60 percent calcium carbonate in the form of films, masses, and concretions; violently effervescent; moderately alkaline; diffuse wavy boundary. (30 to 91 cm [12 to 36 in] thick)

2Btk--152 to 203 cm (60 to 80 in); reddish yellow (5YR 6/6) clay loam, yellowish red (5YR 5/6) moist; weak fine and medium subangular blocky structure; hard, firm; common fine tubular pores; few worm casts; few faint clay films on ped surfaces; about 30 percent calcium carbonate in the form of films, threads, and masses; violently effervescent; moderately alkaline.

TYPE LOCATION: Hockley County, Texas; 3 miles south of Pep on State Highway 303;
2 miles west on county road; 1,500 ft south and 30 ft east of the northwest corner of labor 16, league 702. Pep, Texas USGS quad; Latitude: 33 degrees, 46 minutes, 21 seconds N.; Longitude: 102 degrees, 35 minutes, 44 seconds W., NAD 1983.

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. October through March are the driest months.
These soils are intermittently moist in April through September.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Depth to secondary carbonates: 25 to 76 cm (10 to 30 in).
Depth to petrocalcic horizon: 50 to 100 cm (20 to 100 in).
Solum thickness: more than 203 cm (80 in).
Particle-size control section: 18 to 35 percent silicate clay.

A horizon:
Hue: 5YR or 7.5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 2 to 4
Texture: loamy fine sand, fine sandy loam
Effervescence: none to slight
Reaction: neutral to moderately alkaline

Bt horizon: (or Btk horizon, where present)
Hue: 2.5YR or 5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 to 8
Texture: sandy clay loam, loam
Visible calcium carbonate: few to many, fine films, filaments, and masses
Effervescence: none to strong
Reaction: neutral to moderately alkaline

Bkkm horizon:
Dominantly 15 to 30 cm (6 to 12 in) thick, but ranges up to 61 cm (24 in) in some pedons. Indurated caliche layer containing a few fractures, it is laminar in the upper part with pisolitic structure below the laminae; becomes softer below the pisolitic layer.

BCkk horizon:
Hue: 2.5YR to 7.5YR
Value: 6 to 8, 5 to 7 moist
Chroma: 1 to 4
Texture: clay loam, loam, sandy clay loam and their gravelly or very gravelly counterparts.
Visible calcium carbonate: about 50 to 80 percent by volume in the form of films, masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 40 to 70 percent
Effervescence: violent
Reaction: moderately or strongly alkaline

2Btk or Btk horizon: (where present)
Hue: 2.5YR to 7.5YR
Value: 4 to 7, 3 to 6 moist
Chroma: 3 to 8
Texture: clay loam, sandy clay loam
Visible calcium carbonate: about 15 to 50 percent by volume in the form of films, masses, nodules, and finely disseminated carbonates
Calcium carbonate by weight: 10 to 40 percent
Effervescence: strong or violent
Reaction: moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Amarillo, Friona, Posey, Sharvana, and Stegall series.
Amarillo and Posey series: do not have a petrocalcic horizon.
Friona series: has a mollic epipedon.
Sharvana series: has a petrocalcic horizon within 51 cm (20 in) of the surface.
Stegall series: has more than 35 percent silicate clays in the particle-size control section.

GEOGRAPHIC SETTING:
Parent material: loamy eolian deposits from the Blackwater Draw Formation of Pleistocene age.
Landform: nearly level to gently sloping plains and playa slopes.
Slopes: 0 to 5 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 63 degrees F).
Mean annual precipitation: 432 to 533 mm (17 to 21 in).
Frost-free period: 185 to 220 days.
Elevation: 792 to 1,555 m (2,600 to 5,100 ft).
Thornthwaite annual P-E Index: 25 to 36.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acuff, Amarillo, Brownfield, Friona, Lenorah, Midessa, Patricia, Portales, Posey, Seagraves, Sharvana, Tokio, and Yellowlake series.
Acuff, Amarillo, Brownfield, and Patricia series: are on slightly higher landscape positions and do not have a petrocalcic horizon.
Friona series: has a mollic epipedon.
Lenorah series: are on lower landscapes in relict valleys, drainageways, and associated salina basins and has a sodium adsorption ratio (SAR) more than 13.
Portales series: is on slightly lower landscape positions and do not have an argillic horizon.
Midessa and Posey series: are on slightly higher landscape positions, are calcareous to the surface, and do not have a petrocalcic horizon.
Seagraves series: are on lower landscape positions and do not have a petrocalcic horizon.
Sharvana series: are on similar landscape positions and have a petrocalcic horizon within 51 cm (20 in) of the surface.
Tokio series: are on similar landscape positions and do not have a petrocalcic horizon.
Yellowlake series: are on lower landscape positions and have a natric horizon.

DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Runoff is negligible on 0 to 1 percent slopes, very low on 1 to 3 percent slopes, and low on 3 to 5 percent slopes.

USE AND VEGETATION: Mainly used for crop production but also used as native rangeland and wildlife habitat. Principal crops grown are cotton, grain sorghum, and wheat. Climax vegetation is mainly short and mid grasses, with mid grasses tending to dominate, with a smaller tall grass compliment. This site is dominated by blue grama with lesser amounts of sideoats grama, buffalograss, little bluestem, gauras, plains zinnia, prairieclover, bundleflower, and wild alfalfa, and ephedra. Woody plants include catclaw sensitivebrier, yucca, and sand sagebrush. Dominant vegetation on the loamy fine sands is sideoats grama, bluestems, and switchgrass, while on the fine sandy loams is sideoats grama, blue grama, buffalograss, and Arizona cottontop. This soil has been correlated to the Sandy Loam (R077CY036TX) and Sandy (R077CY035TX) ecological site in MLRA-77C.

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

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

SERIES ESTABLISHED: Andrews County, Texas; 1941.

REMARKS: This is a Benchmark Series.
Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 20 cm (0 to 8 in). (Ap horizon)
Argillic horizon: 20 to 71 cm (8 to 28 in). (Bt1, Bt2, Bt3 horizons)
Petrocalcic horizon: 71 to 97 cm (28 to 38 in). (indurated to strongly cemented Bkkm horizon)
Calcic horizon: 97 to 203 cm (38 to 80 in). (BCkk, 2Btk horizons)
Carbonate plugged horizon (kk): 71 to 152 cm (28 to 60 in) (Bkkm, BCkk)
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: NSSL data available - Sample number: S04TX-219-002 (Hockley County, Texas); S85TX-329-001 (Midland County, Texas).

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


National Cooperative Soil Survey
U.S.A.