LOCATION ANNIS IDEstablished Series
SOIL FAMILY: Fine-silty, mixed, frigid Fluvaquentic Haploxerolls.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Fluvaquentic Haploxerolls
TYPICAL PEDON: Annis silty clay loam, pasture. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches, grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate very fine subangular blocky structure; hard, friable, sticky and plastic; many very fine, fine and medium roots; common very fine and fine interstitial pores; slightly calcareous; moderately alkaline (pH 8.0); abrupt smooth boundary. (6 to 12 inches thick)
A12--7 to 12 inches, grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and fine tubular pores; slightly calcareous; moderately alkaline (pH 8.0); abrupt smooth boundary. (0 to 10 inches thick)
B2--12 to 21 inches, light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; few fine distinct mottles of dark yellowish brown (10YR 4/4) moist; weak coarse prismatic that parts to weak thin and medium platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; many very fine and fine tubular pores; slightly calcareous; moderately alkaline (pH 8.2); gradual wavy boundary. (5 to 15 inches thick)
C1ca--21 to 31 inches, light brownish gray (10YR 6/2) silty clay loam, dark grayish brown (10YR 4/2) moist; few fine distinct mottles of dark yellowish brown (10YR 4/4) moist; weak coarse prismatic that parts to weak very fine and fine subangular blocky structure; hard, friable, sticky and plastic; few very fine and fine roots; many very fine and fine tubular pores; slightly calcareous with few fine lime splotches; moderately alkaline (pH 8.4); clear wavy boundary. (6 to 20 inches thick)
C2ca--31 to 38 inches, light brownish gray (10YR 6/2) silty clay loam, grayish brown (10YR 5/2) moist; many fine distinct mottles of dark brown (10YR 3/3) moist; weak very fine subangular blocky structure; hard, friable, sticky and very plastic; few very fine and fine roots; many very fine and fine tubular pores; moderately calcareous; moderately alkaline (pH 8.4); abrupt wavy boundary. (5 to 12 inches thick)
C3ca--38 to 49 inches, gray (10YR 5/1) silty clay loam, very dark gray (10YR 3/1) moist; few fine prominent mottles of dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky structure; hard, friable, sticky and very plastic; few very fine and fine roots; many very fine and fine tubular pores; moderately calcareous; moderately alkaline (pH 8.4); clear wavy boundary. (5 to 12 inches thick)
C4ca--49 to 60 inches, light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; common medium distinct mottles of dark yellowish brown (10YR 3/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; many very fine and fine tubular pores; strongly calcareous; moderately alkaline (pH 8.4). (6 to 20 inches thick)
TYPE LOCATION: Jefferson County, Idaho; 1 mile north of Menan; 1,000 feet south, 75 feet east of the NW corner of sec. 27, T.5N., R.38E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 42 degrees to 46 degrees F. The soils are mildly or moderately alkaline (pH 7.8 to 8.4). Commonly the soil below depth of 20 inches is stratified silty clay loam, silt loam and fine sandy loam. The soil is usually moist except it is dry in all parts of the 4- to 12-inch depth for more than 45 consecutive days in late summer in more than 7 out of 10 years. The soil control section averages 27 to 35 percent clay and less than 15 percent fine sand or coarser. The profile has an irregular decrease in organic carbon to a level of 0.1 to 0.3 percent within 50 inches of the surface. Mottles are commonly below depth of 20 inches. A fluctuating water table occurs at depths of 3 to 5 feet.
The Ap horizon has value of 4 or 5 dry, 2 or 3 moist and chroma of 1 or 2.
The Cca horizon has hue of 10YR or 2.5Y. Some pedons include strata of loam and sandy loam.
COMPETING SERIES: These are the Blackfoot, East Fork, Heidtman, Parehat and Rose Creek series. Blackfoot soils have 18 to 27 percent clay and more than 15 percent fine sand or coarser in the control section. East Fork, Heidtman and Parehat soils have a mean annual soil temperature between 47 degrees and 59 degrees F. Rose Creek soils have less than 18 percent clay in the control section.
GEOGRAPHIC SETTING: These soils are on river terraces. Elevation is about 4,800 feet. Slopes are between 0 to 1 percent. These soils formed in mixed alluvium. They have an average frost-free period of 100 to 115 days. The mean annual precipitation is 8 to 12 inches including 2 or 3 feet of snowfall.
ASSOCIATED SOILS: These are the competing Blackfoot soils and the Bereniceton and Labenzo soils. Bereniceton soils have an ochric epipedon. Labenzo soils are 20 to 40 inches deep over sand and gravel.
DRAINAGE AND PERMEABILITY: Moderately well drained; very slow runoff; moderately slow permeability.
USE AND VEGETATION: Used mostly for irrigated hay, pasture, small grains and potatoes. The soils are all cultivated.
DISTRIBUTION AND EXTENT: Southeastern Idaho. Series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County, Idaho, 1975.