LOCATION KRENTZ AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal over cindery, mixed, superactive, thermic Vitrandic Haplocambids
TYPICAL PEDON: Krentz gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.) 80 to 95 percent of the surface is covered with cinders
A--0 to 1 inch; brown (7.5YR 4/3) gravelly loam, dark brown (7.5YR 3/3) moist; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common fine vesicular pores; 30 percent cinders; noneffervescent; neutral (pH 7.2); clear smooth boundary. (1 to 4 inches thick)
Bw1--1 to 10 inches; brown (7.5YR 4/2) very gravelly loam, dark brown (7.5YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; many very fine and fine roots; common fine tubular pores; 40 percent cinders; noneffervescent; slightly alkaline (pH 7.6); clear smooth boundary.
Bw2--10 to 21 inches; brown (7.5YR 5/3) very gravelly loam, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, moderately sticky and moderately plastic; many very fine and fine roots; few fine tubular pores; 50 percent cinders; noneffervescent; slightly alkaline (pH 7.6); abrupt wavy boundary. (Combined thickness of Bw horizons is 15 to 25 inches thick)
Bk--21 to 37 inches; brown (7.5YR 5/3) extremely gravelly sandy loam, dark brown (7.5YR 3/3) moist; massive; soft, very friable, moderately sticky and moderately plastic; many very fine and fine roots; few fine irregular pores; many calcium carbonate coatings on rock fragments; 65 percent cinders; strongly effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (15 to 25 inches thick)
Ck--37 to 60 inches; pink (7.5YR 7/3) and light brown (7.5YR 6/4) extremely gravelly sand and loamy sand, brown (7.5YR 4/3) moist; massive; very hard and brittle; firm; nonsticky and nonplastic; many fine vesicular pores; common fine calcium carbonate filaments; 80 percent cinders and 10 percent cobble size cinders; strongly effervescent; slightly alkaline (pH 7.8).
TYPE LOCATION: Cochise County, Arizona; located at a latitude of 31 degrees, 26 minutes, 18 seconds North and longitude of 109 degrees, 18 minutes, 40 seconds West; 500 feet north and 800 feet east of the southwest corner of section 8, Township 23 S., Range 30 E.
RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of soil moisture control section during July - September and December - February. Driest during May and June. Ustic aridic soil moisture regime.
Soil temperature: 62 to 69 degrees F.
Rock fragments: 30 to 90 percent cinders and cobble size cinders
Reaction: neutral to slightly alkaline
Clay content: 10 to 30 percent in the upper part and less than 10 percent in the lower part
Organic matter content: 1 to 3 percent
A horizon
Hue: 5YR, 7.5YR
Value: 2.5 through 4, dry or moist
Chroma: 2 through 4, dry or moist
Texture: sandy loam, loam
Bw horizon
Hue: 5YR, 7.5YR
Value: 2.5 through 5 dry, 2.5 or 3 moist
Chroma: 2 through 6, dry or moist
Texture: loam, sandy clay loam
Bk horizon
Hue: 5YR, 7.5YR
Value: 3 through 5, dry or moist
Chroma: 2 through 4, dry or moist
Texture: sandy loam, loam
C horizon
Hue: 5YR, 7.5YR
Value: 4 through 7, dry or moist
Chroma: 3 or 4, dry or moist
Texture: sand, loamy sand
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Krentz soils are in the Chihuahuan desert on cinder cones at elevations of 3,800 to 5,200 feet. Slopes range from 15 to 55 percent. These soils formed in slope alluvium and residuum from cinders. The mean annual precipitation is 12 to 16 inches and occurs as thunderstorms during July to September and as gentle rains during December to February. The mean annual air temperature is 60 to 67 degrees F. The frost-free period is 180 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Boss, Paramore, Epitaph, and Outlaw soils. Boss soils are very shallow and shallow on cinder cones. Epitaph soils have a petrocalcic horizon. Outlaw soils are very deep. Paramore soils are moderately deep.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes sideoats grama, and other annual grasses and forbs.
DISTRIBUTION AND EXTENT: Southeastern Arizona portion of the Chihuahuan desert. MLRA is 41. Krentz soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona. Soil survey of Cochise County, Arizona, Douglas-Tombstone Part; San Bernardino Valley Interim Report, 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 1 inch (A horizon)
Cambic horizons - The zone from 1 to 21 inches (Bw1, Bw2 horizons)
Vitrandic feature - The control section contains greater than 60 percent by weight cinders.
Krentz was first proposed in 1959 in the Whitewater Draw portion of the Sulphur Springs Valley area soil survey of Cochise County, Arizona. The original Official Series Description was updated to reflect current soil taxonomy, to clearly define the range of characteristics, and to improve interpretations. The central concept, definition, and historical importance of the series was preserved.
Classified according to Soil Taxonomy Second Edition, 1999