LOCATION NIBLEY UTEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Aquic Argixerolls
TYPICAL PEDON: Nibley silty clay loam - cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark brown (10YR 2/2) moist; weak medium granular structure; hard, firm, sticky, plastic; common fine and few medium root5; few fine pores; noncalcareous; slightly alkaline (pH 7.6); abrupt smooth boundary. (6 to 8 inches thick)
A--7 to 13 inches; dark grayish brown (10YR 4/2) heavy silty clay loam, very dark brown (10YR 2/2) moist; moderate medium granular structure; hard, firm, sticky, plastic; common fine and few medium roots; common fine pores; noncalcareous; slightly alkaline (pH 7.5); abrupt smooth boundary. (0 to 7 inches thick)
Bt--13 to 20 inches; brown (10YR 5/3) silty clay, brown (7.5YR 4/2) moist; moderate medium prismatic structure that parts to moderate medium subangular blocky structure; very hard, very firm, sticky, very plastic; common fine roots; common fine and few medium pores; common thin clay films; slightly calcareous; slightly alkaline (pH 7.7); gradual wavy boundary. (7 to 9 inches thick)
Btk--20 to 32 inches; light gray (10YR 7/2) silty clay, grayish brown (10YR 5/2) moist; few fine distinct strong brown (7.5YR 5/8) mottles; weak medium prismatic structure that parts to moderate medium subangular blocky structure; very hard, very firm, sticky, very plastic; few fine roots; many fine and few medium pores; few thin clay films; strongly calcareous; moderately alkaline (pH 8.0); gradual smooth boundary. (0 to 12 inches thick)
Bk--32 to 43 inches;light gray (10YR 7/2) light silty clay, pale brown (10YR 6/3) moist; common medium distinct strong brown (7.5YR 5/8) mottles weak medium prismatic structure that parts to moderate fine subangular blocky structure; very hard, very firm, sticky, very plastic; few fine roots; many fine and few medium pores; strongly calcareous; strongly alkaline (pH 8.6); clear smooth boundary. (O to 12 inches thick)
C--43 to 58 inches; light gray (2.5Y 7/2) silty clay, light brownish gray (2.5Y 6/2) moist; common medium distinct strong brown (7.5YR 5/8) mottles; massive; very hard, very firm, sticky, and very plastic; common fine pores; strongly calcareous; moderately alkaline (pH 8.3).
TYPE LOCATION: Cache County, Utah; 1/8 mile south and 5/8 mile east of USU Animal Husbandry farm headquarters; 500 feet north and 300 feet east of the SW corner of the NE1/4 sec. 30, T.11N., R.lE.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 10 to 19 inches thick. The combined thickness of the A and Bt horizons range from 16 to 21 inches over the horizon of carbonate accumulation. The mean annual soil temperature ranges from 48 to 50 degrees F. and the mean summer soil temperature at a depth of 20 inches ranges from 62 to 68 degrees F. The soils are usually saturated within a depth of 30 inches when not drained and are not dry in all parts of the 4 to 12 inch section for 60 consecutive days in 7 out of 10 years. The watertable is mainly 30 to 50 inches below the soil surface in the undrained areas and 50 to 60 inches in the drained areas.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and contains 2 to 3 percent organic matter. It has weak to moderate and fine to coarse granular or subangular blocky structure. This horizon is neutral or slightly alkaline. It is 10 to 15 inches thick.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 or 3. It is silty clay loam with more than 35 percent clay or is silty clay. This horizon has weak to moderate, medium prismatic structure. It ranges from neutral to moderately alkaline.
The Btk and Bk horizons have hue of 10YR or 7.5YR, value of 6 or 7 dry, 5 or 6 moist, and chroma of 2 or 3. They are silty clay or silty clay loam. These horizons have weak, medium prismatic to moderate fine to medium subangular blocky structure. They are moderately or strongly alkaline.
The C horizon has hue of 2.5Y, 10YR or 7.5YR, value of 7 or 8 dry, 5 or 6 moist, and chroma of 2 through 4. It ranges from silt loam to silty clay and is moderately or strongly alkaline.
COMPETING SERIES: These are the Center Creek, Collett, Greenson, and Trenton series Center Creek soils have silty clay loam argillic horizons with less than 35 percent clay. Collett soils lack argillic horizons. Greenson soils lack argillic horizons and have silt loam control sections. Trenton soils have natric horizons.
GEOGRAPHIC SETTING: Nibley soils are on nearly level to sloping low and medium lake terraces at elevations of 4,450 to 4,700 feet. Gradients are dominantly 0 to 3 percent and range from 0 to 6 percent. Parent materials are mixed lake sediments. The climate is dry subhumid. The average annual precipitation ranges from 14 to 18 inches. The mean annual temperature ranges from 45 to 47 degrees F. The mean annual summer temperature ranges from 65 to 67 degrees F. The frost-free period ranges from 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Airport and Parleys soils and the competing Collett and Greenson series. Airport soils have chroma of 1 in the mollic epipedon and have natric horizons. Parleys soils lack characteristics associated with wetness within 40 inches and have silty clay loam argillic horizons.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow to medium runoff; slow permeability. Many areas of this soil have been artificially drained.
USE AND VEGETATION: Used for cropland of irrigated alfalfa, sugar beets, small grains, corn silage, and improved pasture. The native vegetation is saltgrass, meadow foxtail, alkali sacaton, some areas of wiregrass or sedges.
DISTRIBUTION AND EXTENT: Northern Utah. This series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cache County, Utah, 1972.