LOCATION HOBCAN AZ
Established Series
Rev. AAD/DEW/PDC
09/2015
HOBCAN SERIES
The Hobcan series consists of very deep, well drained soils that formed in mixed alluvium from sedimentary and igneous formations. Hobcan soils are on alluvial fans and fan terraces and have slopes of 1 to 5 percent. The mean annual precipitation is about 8 inches and the mean annual air temperature is about 66 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Typic Calcigypsids
TYPICAL PEDON: Hobcan very fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; reddish yellow (5YR 6/6) very fine sandy loam, yellowish red (5YR 5/6) moist; weak thin platy structure; soft, very friable, slightly sticky and nonplastic; common very fine and few fine roots; many fine and very fine vesicular and common very fine tubular pores; slightly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 2 inches thick)
Bk--1 to 8 inches; reddish yellow (5YR 6/6) very fine sandy loam, yellowish red (5YR 5/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine and few fine roots; common fine and very fine tubular pores; slightly effervescent, common fine rounded calcium carbonate nodules, 16 percent calcium carbonate equivalent; 5 percent crystalline gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (6 to 14 inches thick)
Bky1--8 to 15 inches; reddish yellow (5YR 6/6) fine sandy loam, yellowish red (5YR 5/6) moist; massive; slightly hard, friable, slightly sticky and nonplastic; many very fine and common fine roots; common fine and very fine tubular pores; slightly effervescent, common fine rounded calcium carbonate nodules, 19 percent calcium carbonate equivalent; 10 percent crystalline gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (4 to 10 inches thick)
Bky2--15 to 33 inches; reddish yellow (5YR 6/6) loam, yellowish red (5YR 5/6) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine tubular pores; slightly effervescent, common fine rounded calcium carbonate nodules, 15 percent calcium carbonate equivalent; 15 percent crystalline gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 12 inches thick)
Bky3--33 to 42 inches; reddish yellow (5YR 6/6) loam, yellowish red (5YR 4/6) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine and very fine tubular pores; slightly effervescent, common fine rounded calcium carbonate nodules, 19 percent calcium carbonate equivalent; 15 percent crystalline gypsum; moderately alkaline (pH 8.0); abrupt smooth boundary. (8 to 12 inches thick)
Bky4--42 to 51 inches; reddish yellow (5YR 6/6) loam, yellowish red (5YR 4/6) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; common fine and very fine tubular pores; slightly effervescent, few fine rounded calcium carbonate, 13 percent calcium carbonate equivalent; 5 percent crystalline gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 12 inches thick)
Bky5--51 to 63 inches; reddish yellow (5YR 6/6) very fine sandy loam, yellowish red (5YR 4/6) moist; massive; slightly hard, friable, slightly sticky and nonplastic; few very fine and fine roots; common fine and very fine tubular pores; slightly effervescent, few fine rounded calcium carbonate nodules, 19 percent calcium carbonate equivalent; 5 percent crystalline gypsum; moderately alkaline (pH 8.0).
TYPE LOCATION: Mohave County, Arizona; 1000 feet south of the Arizona State Line and about 9 miles west of Hurricane Cliffs; 2600 feet north and 1800 feet east of the southwest corner of section 34, T.42 N., R.11 W.; 113 degrees, 28 minutes and 22 seconds west longitude and 36 degrees, 59 minutes and 52 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-February. Driest during May and June. Typic aridic soil moisture regime.
Rock Fragments: less than 15 percent
Soil Temperature: 59 to 72 degrees F.
Organic Matter: Less than .5 percent in the surface horizon
Depth to Calcic horizon: 1 to 4 inches
Depth to Gypsic horizon: 8 to 16 inches. Percent gypsum x the thickness in centimeters is less than 3000.
Reaction: slightly or moderately alkaline
A horizon
Hue: 5YR, 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 through 6, dry or moist
Bk horizon
Hue: 5YR, 7.5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 4 through 6, dry or moist
Texture: very fine sandy loam, fine sandy loam (5 to 18 percent clay)
Calcium carbonate equivalent: 15 to 25 percent
Bky horizon
Hue: 5YR, 7.5YR
Value: 5 through 7 dry, 4 through 6 moist
Chroma: 4 through 6, dry or moist
Texture: very fine sandy loam, fine sandy loam, loam (5 to 18 percent clay)
Calcium carbonate equivalent: 15 to 25 percent
Gypsum: 5 to 20 percent, any one horizon may range to 30 percent
COMPETING SERIES: This is the
Monahans (TX) series. Monahans soils are 16 to 36 inches to a gypsic horizon, are moist in the control section for considerably longer periods due to a much higher rainfall component and do not occur in the
Mohave Desert.
GEOGRAPHIC SETTING: Hobcan soils are on alluvial fans and fan terraces and have slopes of 1 to 5 percent. These soils are formed in mixed alluvium derived from sedimentary formations. Elevations range from 1600 to 4500 feet. The mean annual precipitation is 6 to 9 inches. The mean annual air temperature is 57 to 70 degrees F. The frost-free period is 180 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Gypill and
Nikey soils. Gypill soils are on eroding hills, average more than 40 percent gypsum, and are shallow to interbedded shale and gypsum. Nikey soils are very deep calcareous soils on fan terraces and contain small amounts of gypsum.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability. Flooding is none to rare.
USE AND VEGETATION: Hobcan soils are used for livestock grazing. The present vegetation is big galleta, yucca, creosotebush, ratany and white bursage.
DISTRIBUTION AND EXTENT: Northwestern Arizona. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Shivwits Area, Arizona, Part of Mohave County; 1994.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 1 inch (A horizon)
Calcic horizon - The zone from 1 to 42 inches (Bk, Bky1, Bky2, Bky3 horizons)
Gypsic horizon - The zone from 8 to 42 inches (Bky1, Bky2, Bky3 horizons)
Formerly classified Calcic Gypsiorthids.
Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 5/2006. ET
National Cooperative Soil Survey
U.S.A.