LOCATION PANITCHEN COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Ustic Torrifluvents
TYPICAL PEDON: Panitchen silty clay loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; light brownish gray (2.5Y 6/2) silty clay loam, dark grayish brown (2.5Y 4/2) moist; weak very thin platy structure parting to weak very fine granular; soft, very friable, nonsticky and slightly plastic; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 8 inches thick)
AC--6 to 15 inches; grayish brown (2.5Y 5/2) silty clay loam, stratified with thin layers of sandy loam, dark grayish brown (2.5Y 4/2) moist; weak, fine and medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 20 inches thick)
Cy1--15 to 34 inches; grayish brown (2.5Y 5/2) silty clay loam, stratified with thin layers of sandy loam, loamy sand and gravelly sandy loam, dark grayish brown (2.5Y 4/2 moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; strongly effervescent; visible gypsum occurring as small and medium crystals in seams; moderately alkaline (pH 8.2); clear wavy boundary. (10 to 30 inches thick)
Cy2--34 to 60 inches; grayish brown (2.5Y 5/2) silty clay loam stratified with thin layers of sandy loam, loamy sand, and gravelly sandy loam, dark grayish brown (2.5Y 4/2) moist; massive; hard, friable, nonsticky and slightly plastic; strongly effervescent; visible gypsum occurring as small crystals on ped faces; moderately alkaline (pH 8.4).
TYPE LOCATION: La Plata County, Colorado; about 2,600 feet east and 1,600 feet south of the northwest corner of Sec. 1, T. 32 N., R. 12 W. U.S.G.S. Pinkerton Mesa quad.; Lat. 37 degrees, 02 minutes, 58 seconds N., and Long. 108 degrees, 6 minutes, 03 seconds W.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 47 to 57 degrees F. Salinity ranges from 2 to 15 mmhos throughout. Coarse fragments average from 0 to 15 percent and are mostly very fine and fine gravel. The soil is typically calcareous to the surface. The moisture control section is dry for 15 consecutive days from May 15 to July 15 when the soil temperature at 20 inches is greater than 41 degrees F. (5 degrees C.). It is not dry in all parts of the moisture control section for at least 45 consecutive days following the summer solstice to October 20, and for at least 90 cumulative days during that period.
The A horizon has hue of 5Y through 10YR, value of 5 through 7, 4 through 6 moist, and chroma of 2 through 4. It is moderately alkaline or strongly alkaline.
The AC horizon, when present, has hue of 5Y through 10YR, value of 5 through 7, 4 through 6 moist, and chroma of 2 through 4. It is moderately alkaline or strongly alkaline.
The C horizon has hue of 5Y through 7.5YR, value of 5 through 7, 4 through 6 moist, and chroma of 2 through 6. It is typically silty clay loam stratified with thin layers of sandy loam, loamy sand, and gravelly sandy loam. The weighted texture of the 10 to 40 inch control section has 18 to 35 percent clay and more than 15 percent fine or coarser sand. Gypsum content ranges from 1 to 5 percent and changes erratically between strata. Exchangeable sodium percent ranges from 2 to 15 and varies between strata. It is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Barnum (WY), Hamburn (NM). Haverdad (WY), Hysham (MT), Manikan (AZ), San Mateo (NM), and Suwanee (nm) series. Barnum soils have hue of 5YR or redder in the C horizon. Hamburn soils contain soluble salts and are in a typic aridic rainfall area, but receive additional moisture from flooding. Haverdad soils receive over one-half of their precipitation during April, May, and June, and are dry in all parts of the moisture control section for at least 60 consecutive days from July 15 to October 25 and for at least 90 consecutive days during this period. Manikan soils have hue of 5YR or 7.5YR. Hysham soils are very strongly alkaline in the particle-size control section, and have very hard or extremely hard Bw horizons. San Mateo and Suwanee soils lack horizons with visible gypsum concentrations of 1 to 5 percent.
GEOGRAPHIC SETTING: Panitchen soils are on drainageways, low terraces, valley bottoms, and on alluvial fans. Slopes are 0 to 6 percent. The soil formed in alluvial material weathered from sandstone and shale. Elevation ranges from 5,000 to 7,400 feet. Mean annual temperature ranges from 45 to 55 degrees F., and mean summer temperature ranges from 60 to 70 degrees F. Mean annual precipitation ranges from 12 to 15 inches and is distributed fairly evenly throughout the year. About half of the precipitation falls between April and September, with May and June being the driest months. PE Index is about 32 at the type location and ranges from 25 to 45 for the series.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckle, Dulce, Florita, Travessilla, and Yenlo soils. Buckle and Yenlo soils have argillic horizons. Dulce and Travessilla soils have bedrock at less than 20 inches. Florita soils have coarse-loamy, particle-size control sections and are less alkaline.
DRAINAGE AND PERMEABILITY: Well drained; moderate runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for rangeland. Native vegetation consists of greasewood, shadscale, big sagebrush, alkali sacaton, Indian ricegrass, western wheatgrass, squirreltail, galleta, and prickly pear.
DISTRIBUTION AND EXTENT: Panitchen soils occur in western Colorado and possibly the southeastern parts of Utah. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: La Plata County, Colorado, 1982.
REMARKS: Diagnostic horizons and features recognized are: an ochric epipedon from 0 to 6 inches; stratification with thin layers of sandy loam in the AC horizon; thin layers of sandy loam, loamy sand and gravelly sandy loam in the Cy horizons; visible accumulations of gypsum in the Cy horizons; and a mesic temperature regime. Last updated by the state 3/95.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Lakewood MLRA office, without review of the soil series property data. The remainder of this document has not been updated.