LOCATION SPENLO UT+WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ustic Calciargids
TYPICAL PEDON: Spenlo very fine sandy loam - cultivated (Colors are for air dry soil unless otherwise noted.)
Ap--0 to 6 inches; brown (7.5YR 5/4) very fine sandy loam, dark brown (7.5YR 3/4) moist; weak medium granular structure; soft, very friable, nonsticky, nonplastic; common fine and medium roots; neutral (pH 7.0); clear smooth boundary. (4 to 8 inches thick)
B--6 to 14 inches; yellowish red (5YR 4/6) fine sandy loam, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, plastic common fine and medium roots; common fine and medium pores; neutral (pH 6.6); clear smooth boundary. (3 to 11 inches thick)
Bt1--14 to 27 inches; yellowish red (5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky, plastic; common fine and medium roots; common very fine and fine pores; few thin clay films on faces of peds and in pores; neutral (pH 6.8); clear smooth boundary. (13 to 19 inches thick)
Bt2--27 to 44 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist; moderate medium prismatic structure that parts to moderate medium angular blocky structure; hard, firm, sticky, plastic; common fine roots; common very fine and fine pores; common thin clay films on faces of peds; neutral (pH 7.0); clear wavy boundary. (0 to 17 inches thick)
Btk--44 to 51 inches; red (2.5YR 4/6) sandy clay loam, dark red (2.5YR 3/6) moist, tongued with pink (5YR 7/4) clay loam, reddish yellow (5YR 6/6) moist (like Bk below), moderate medium angular blocky structure; hard, firm, sticky, plastic; few fine roots; common very fine pores; few thin clay films on faces of peds; noncalcareous, but tongues are moderately calcareous and strongly alkaline (pH 8.6); clear wavy boundary. (7 to 21 inches thick)
Bk--51 to 64 inches; pink (5YR 7/4) clay loam, yellowish red (5YR 4/6) moist; massive; hard, firm, slightly sticky, slightly plastic; common very fine and fine pores; strongly calcareous; strongly alkaline (pH 8.8); abrupt wavy boundary. (6 to 7 inches thick)
R--64 inches; Sandstone
TYPE LOCATION: Washington County, Utah; Upper Smith Mesa; southwest 1/4 of the northeast 1/4 of sec. 21, T.40S., R.12W.
RANGE IN CHARACTERISTICS:
Solum thickness: 40 to 56 inches
Mean annual soil temperature: 54 to 58 degrees F.
Mean summer soil temperature: 71 to 76 degrees F.
Soil moisture: The soils are usually dry during the period the soil temperature is above 41 degrees F. They are moist in some part of the moisture control section for 30 to 40 days during the summer months and are dry for 70 to 85 days during the 120 days following the winter solstice. Ustic aridic soil moisture regime.
Some pedons contain up to 20 percent gravel.
A horizon
Hue: 7.5YR or 5YR
Value: 4 or 5 dry
Chroma: 2 through 5
Texture: very fine sandy loam to fine sandy loam and, in places, has a gravelly surface pavement where not cultivated.
Bt horizon
Hue: 5YR or 2.5YR
Value: 3 through 5 dry
Chroma: 4 through 8
Texture: fine sandy clay loam, clay loam, sandy clay loam
Clay content: 25 to 35 percent
Clay films: few to common, thin to moderately thick on faces of peds and in pores
Calcium carbonate: noncalcareous to depths ranging from 35 to 44 inches, with a Btk horizon above the Bk horizon.
Bk horizon
Hue: 5YR or 2.5YR
Value: 6 or 7 dry, 3 or 4 moist
Chroma: 4 through 6
Texture: clay loam or fine sandy clay loam.
COMPETING SERIES: These are the Alvey (UT), Barx (UT), Cabreros (NM), Cerrillos (NM), Clovis (NM), Fernando (NM), Flaco (NM), Horchata (NM), Maysdorf (WY), Millett (AZ), Palabria (NM), Progresso (CO), Sanostee (NM), Scholle (NM), Selpats (WY), Solirec (UT), Threetop (WY), Tuweep (AZ) and Wineg (AZ) series. Alvey soils have hue of 10YR or yellower. Barx soils contain 2.5YR and 5YR hue. Cerrillos soils have a calcic horizon less than 20 inches deep. Clovis soils receive more than half of it annual precipitation between the months of July and October. Fernando soils contain 50 to 80 percent silt in the solum and are mapped in MLRA 51. Cabreros, Flaco, Horchata, Progresso, Sanostee, and Threetop soils are moderately deep over bedrock. Maysdorf soils contain less than 15 percent carbonates in the calcic horizon. Millett soils contain 25 to 75 percent gravel and cobbles in the lower part of the solum. Palabria soils are deep to sandstone. Selpats soils have skeletal lithologic discontinuity at depths ranging from 15 to 39 inches. Scholle soils contain 15 to 35 percent gravel in the control section. Solirec soils receive maximum precipitation in spring and fall. Tuweep soils are formed in alluvium from pyroclastics and basalt. Wineg soils have a MAST of 56 degrees F, and have mixed gravelly alluvium or lacustrine parent material.
GEOGRAPHIC SETTING: Spenlo soils are on gently sloping to strongly sloping old alluvial valleys at elevations of 5,200 to 5,900 feet, Slopes range from 2 to 10 percent. These soils formed in mixed alluvium from sandstone, shale, limestone, and siltstone. The mean annual temperature is 52 to 56 degrees F., and the mean summer temperature is 72 to 76 degrees F. The average annual precipitation is 12 to 14 inches, and the frost-free period is 165 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bond, Lavate, Mathis, and Redbank soils and the competing Clovis soils. Bond soils are 10 to 20 inches deep to bedrock and lack calcic horizons. Lavate soils have mollic epipedons and lack calcic horizons. Mathis soils lack argillic horizons and have very gravelly and cobbly loamy sand control sections. Redbank soils lack argillic and calcic horizons.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff; moderately slow permeability.
USE AND VEGETATION: Used for nonirrigated cropland of wheat and as rangeland. Native vegetation is galleta, black grama, Indian ricegrass, sand dropseed, big sagebrush, pinyon, juniper, serviceberry, and some live oak.
DISTRIBUTION AND EXTENT: Southwestern Utah. MLRA is 35. This series is of minor extent in the Washington Survey area, but extends into adjacent areas.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Washington County, Utah, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 6 inch (Ap horizon)
Argillic horizon - the zone from 14 to 51 inches (Bt and Btk horizons)
Calcic horizon - the zone from 44 to 64 inches (Btk and Bk horizons)
Classified according to Soil Taxonomy Second Edition, 1999
Classification was changed from fine-loamy, mixed, superactive, mesic Ustic Haplargids to fine-loamy, mixed, superactive, mesic Ustic Calciargids in 2003