LOCATION SPANTARA           NM+TX

SPANTARA SERIES

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Aridic Haplustalfs

TYPICAL PEDON: Spantara fine sand on concave, 1 percent slope in rangeland at an elevation of 4,326 feet. (Colors are for dry soil unless otherwise stated.)

A1--0 to 3 inches; dark yellowish brown (10YR 4/4) fine sand, dark brown (10YR 3/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common fine roots; few fine and medium pores; neutral; abrupt smooth boundary. (2 to 6 inches thick)

A2--3 to 10 inches; brown (10YR 5/3) fine sand, dark yellowish brown (10YR 4/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine roots; few fine and medium pores; neutral; abrupt smooth boundary. (Combined thickness of the A horizons is 8 to 18 inches.)

Bt1--10 to 17 inches; brown (7.5YR 5/4) fine sand, strong brown (7.5YR 5/6) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine roots; few fine and medium pores; few faint clay films on surfaces of peds; slightly alkaline; clear smooth boundary.

Bt2--17 to 24 inches; reddish brown (5YR 5/3) loamy fine sand, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine roots; common fine and medium pores; many prominent clay films on surfaces of peds; slightly alkaline; clear smooth boundary.

Bt3--24 to 34 inches; reddish brown (5YR 4/4) fine sandy loam, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few fine roots; common fine and medium pores; many prominent clay films on surfaces of peds; slightly alkaline; clear smooth boundary.

Bt4--34 to 45 inches; reddish brown (5YR 5/4) fine sandy loam, yellowish red (5YR 5/6) moist; moderate medium subangular blocky structure; hard, friable, nonsticky and nonplastic; few fine roots; common fine and medium pores; many distinct clay films on surfaces of peds; moderately alkaline; clear smooth boundary.

Bt5--45 to 80 inches; reddish brown (5YR 5/4) loamy fine sand, yellowish red (5YR 5/6) moist; weak medium subangular blocky structure; hard, friable; nonsticky and nonplastic; few fine and medium pores; common distinct clay films on surfaces of peds; few fine irregularly shaped masses of calcium carbonate; slightly effervescent; moderately alkaline. (Combined thickness of Bt horizons is 30 to more than 60 inches.)

TYPE LOCATION: Curry County, New Mexico; 1,000 feet south and 50 feet east of the northwest corner of sec. 17, T. 2 N., R. 32 E.; Tule Lake, New Mexico USGS quad; Latitude: 34 degrees, 24 minutes, 10 seconds N.; Longitude: 103 degrees, 36 minutes, 58 seconds W., 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 180 to 270 days, cumulative, in normal years. November through April are the driest months. These soils are intermittently moist in May through October.

Mean annual soil temperature: 62 to 64 degrees F.
Depth to argillic horizon: 10 to 25 inches.
Depth to secondary carbonates: 25 to 60 inches.
Solum thickness: more than 80 inches.
Particle-size control section: less than 18 percent silicate clay.
Clay content decreases by more than 20 percent from the maximum within 60 inches of the surface.

A horizons:

Hue: 5YR, 7.5YR, 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 to 6
Texture: fine sand, loamy fine sand
Effervescence: none
Reaction: neutral

Bt horizons:

Hue: 5YR, 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 to 6
Texture: fine sand (in the upper part), loamy fine sand, fine sandy loam, sandy clay loam
Calcium carbonate equivalent: 0 to 15 percent
Clay content: 5 to 20 percent
Effervescence: very slight to slight
Reaction: neutral to moderately alkaline

A Btk horizons is present in some pedons. Where present:

Hue: 7.5YR, 10YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 4 to 8
Texture: loamy fine sand, fine sandy loam
Calcium carbonate equivalent: 1 to 5 percent
Clay content: 10 to 20 percent
Effervescence: strong or violent
Reaction: slightly alkaline or moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Similar soils are the Ady, Amarillo, Amarose, Ariser, Brownfield, and Patricia
series.

Ady and Amarose series: have a fine-loamy particle-size class.
Amarillo and Patricia series: have an argillic horizon and a fine-loamy particle-
size class.
Ariser series: has an argillic horizon and a fine-loamy particle-size class.
Brownfield series: has an arenic surface horizon and a loamy particle-size class.

GEOGRAPHIC SETTING:
Parent material: sandy eolian and alluvial sediments of the Blackwater Draw
Formation of Pleistocene age.
Landform: level to slightly undulating plains.
Slopes: 1 to 5 percent.
Mean annual temperature: 60 to 62 degrees F.
Mean annual precipitation: 15 to 17 inches.
Frost-free period: 180 to 200 days.
Elevation: 4,000 to 5,300 feet.
Thornthwaite annual P-E Index Values: 23 to 28.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Amarillo, Amarose, Brownfield, Nutivoli, Patricia and Yikes series.

Amarillo, Amarose, Brownfield, and Patricia series: are in similar landscape
positions.
Nutivoli and Yikes series: occur on sand dunes and, in addition, Nutivoli soils do
not have an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained. Moderate permeability. Surface 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 cropland but also used as native rangeland. Principal crops grown are cotton and grain sorghum. Climax vegetation is tall and mid grasses, with tall grasses tending to dominate. This site is dominated by little bluestem and sand bluestem along with taller dropseed species. The remainder is mid and short grasses such as sideoats grama, sand dropseed, hooded windmillgrass, sand lovegrass, sand paspalum, fall witchgrass, hairy grama, needle and thread, and perennial threeawn. Sand sage, shinoak, and skunkbush are also present. This soil has been correlated to the Sandy (077CY035TX) range site in Texas.

DISTRIBUTION AND EXTENT: Southern part of the High Plains of Texas and east-central New Mexico (sub MLRA 77C). The soil is of moderate extent.

MLRA OFFICE RESPONSIBLE: Temple, Texas

SERIES PROPOSED: Curry County, New Mexico; 1998.

REMARKS: The Spantara series was formerly included in the Springer series.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon: 0 to 10 inches. (A horizons)

Argillic horizon: 10 to 80 inches. (Bt1, Bt2, Bt3, Bt4 horizons)

ADDITIONAL DATA: NSSL - S90NM-009-001 (Curry Co.), S96NM-041-001 and S96NM-041-002 (Roosevelt Co.)

Taxonomic version: Keys to Soil Taxonomy, Eighth Edition, 1998