LOCATION COGSWELL AZEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Ustic Haplocalcids
TYPICAL PEDON: Cogswell clay loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 12 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; weak medium granular and subangular blocky structure; hard, friable, slightly sticky and plastic; common fine roots; common fine and medium tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (8 to 14 inches thick)
A--12 to 26 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; hard, friable, sticky and plastic; common fine roots; common fine interstitial and tubular pores; strongly effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (12 to 24 inches thick)
Bk--26 to 46 inches; light brown (7.5YR 6/4) heavy clay loam, brown (7.5YR 4/4) moist; massive; hard, friable, sticky and plastic; common to many fine interstitial and few fine tubular pores; violently effervescent; many fine and medium very pale brown (10YR 8/3), light yellowish brown (10YR 6/4) and light brownish gray (10YR 6/2) soft lime masses and lime filaments; pale brown (10YR 6/3), very pale brown (10YR 8/4) and grayish brown (10YR 5/2) moist; common to many angular hard lime fragments that range up to about 1/2 to 1 inch in diameter; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 24 inches thick)
Btkb--46 to 60 inches; mottled strong brown (7.5YR 5/6), reddish yellow (7.5YR 6/6) and white (7.5YR 8/1) clay loam, strong brown (7.5YR 5/6) and light gray (7.5YR 7/1) moist; moderate fine and medium prismatic structure; hard, friable, slightly sticky and plastic; common fine interstitial pores; common thin clay films on peds; violently effervescent; many medium to coarse very pale brown (10YR 8/2) and light gray (10YR 7/2) soft lime masses and lime filaments; moderately alkaline (pH 8.4); clear wavy boundary.
TYPE LOCATION: Cochise County, Arizona; in silo pit 500 feet south and 300 feet east of the NW corner of sec. 4, T.13S., R.24E.
RANGE IN CHARACTERISTICS:
Soil moisture: Ustic aridic moisture regime.
Depth to calcic horizon: 18 to 38 inches
Calcium carbonate equivalent: 15 to 50 percent (dominantly 15 to 40 percent)
Clay content: averages more than 35 percent clay
A horizons
Hue: 10YR or 7.5YR
Value: 3, 4 or 5 dry or moist
Chroma: 2 or 3 dry and moist
Texture: dominantly clay loam, but range from loam to clay.
Bk horizon
Hue: 10YR or 7.5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 3 or 4
Texture: clay loam or clay
Reaction: slightly to strongly alkaline
Effervescence: slight to violent
The Bk horizon has a thin discontinuous platy, weakly cemented lime layer on its upper surface in some pedons.
Btkb horizon is absent in some pedons, however where it occurs, it usually has more than 15 percent calcium carbonate.
COMPETING SERIES: There are no competitors.
GEOGRAPHIC SETTING: Cogswell soils are on level to nearly level flood plains, alluvial fans, broad swales or valley plains and old lake margins. Slopes range from 0 to 2 percent, but are dominantly less than one percent. These soils formed in mixed alluvium from acid and basic igneous rocks with some influence from sedimentary rocks. Cogswell soils are at elevations of 4,000 to 4,600 feet in a warm semiarid continental climate. The mean annual temperature ranges from 59 degrees to 67 degrees F. The frost-free season ranges from 155 to 230 days. The mean annual precipitation ranges from 10 to 16 inches and occurs as thundershowers from July through September and as gentle fall and winter rains.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Duncan, Elfrida, Frye, Gothard, Guest, Karro, McAllister, Pima, and Riveroad soils. Duncan, Frye, Gothard and McAllister soils have argillic horizons. Elfrida, Karro, and Riveroad soils are fine-loamy. Guest soils do not have calcic horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; slow permeability.
USE AND VEGETATION: Used mostly for irrigated crops such as cotton, alfalfa, grain and truck crops. Present vegetation is mesquite, tobosa, alkali sacaton, snakeweed, burrograss, annual weeds and grasses.
DISTRIBUTION AND EXTENT: Southeastern Arizona. The soils are inextensive. MLRA 41.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Sulphur Spring Valley Area, Arizona, 1948.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 26 inches (Ap and A horizons)
Calcic horizon - The zone from 26 to 46 inches (Bk horizon)
The Cogswell soils were formerly classified as Reddish Brown soils. They were also classified as Calcisols and Pachic Calciustolls.
Classified according to Soil Taxonomy Second Edition, 1999.