LOCATION TERRETON IDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, calcareous, frigid Typic Torriorthents
TYPICAL PEDON: Terreton silty clay loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 6 inches; light brownish gray (10YR 6/2) silty clay loam, olive brown (2.5Y 4/3) moist; very weak medium subangular blocky structure, moderate very thin platy in upper 2 inches; hard, firm, slightly sticky, slightly plastic; many very fine and few fine and medium roots; common very fine tubular pores in the lower 4 inches; moderately calcareous; moderately alkaline (pH 8.2); abrupt smooth boundary. (5 to 10 inches thick)
C1--6 to 10 inches; light brownish gray (10YR 6/2) clay, olive brown (2.5Y 4/4) moist; weak medium prismatic structure that parts to weak medium and fine subangular blocky structure; hard, friable, sticky and plastic; tubular pores; strongly calcareous, few fine lime veins and splotches in lower part; mildly alkaline (pH 8.0); clear smooth boundary. (0 to 4 inches thick)
C2--10 to 31 inches; light gray (10YR 6/1) clay, light olive brown (2.5Y 5/3) moist; laminated and parts to weak medium and fine subangular blocky structure; hard, firm, sticky and plastic; common very fine and few fine roots; many dead roots and cracks between peds; many very fine tubular pores; strongly calcareous, common lime veins and splotches; mildly alkaline (pH 8.0); gradual smooth boundary. (12 to 30 inches)
IIC3--31 to 51 inches; light brownish gray (2.5Y 6/2) silty clay loam, light olive brown (2.5Y 5/3) moist; massive; common very fine and few fine brown (2.5Y 5/3) moist; massive; common very fine and few fine roots; many very fine tubular pores; strongly calcareous; mildly alkaline (pH 7.9); gradual smooth boundary. (0 to 20 inches thick)
IIIC4--51 to 62 inches; light gray (2.5Y 7/2) clay with spots of gray (N 6/), light olive brown (2.5Y 5/3) moist; massive; hard, firm, sticky and very plastic; 1 to 3 inch lenses of sandy loam and loam that are gray (10YR 5/1) and grayish brown (2.5Y 5/2) moist; strongly calcareous; mildly alkaline (pH 7.9).
TYPE LOCATION: Jefferson County, Idaho; 4 mile east and 2 miles north of Terreton; 10 feet north of road; 528 feet east of the SW corner of section 3, T.6N., R.33E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 43 to 46 degrees F. and the mean summer temperature at a depth of 20 inches ranges from 62 to 65 degrees F. The 10 to 40 inch control section ranges from heavy silty clay loam to clay and averages 35 to 50 percent clay and less than 15 percent rock fragments. There is a continuous zone of free carbonates in all parts of the fine earth fraction between depths of 10 and 20 inches. The A horizon has hue of 2.5Y or 10YR and chroma of 2 or 3. When plowed, the Ap horizon is commonly moderately or strongly calcareous. The lower part of the control section is stratified in some pedons. Mottles or other evidence of wetness are below 40 inches in some pedons.
COMPETING SERIES AND THEIR DIFFERENTIAE: These are the Dollard, Monteview, Ragtown, and Sunburst series. Dollard and Sunburst soils are dry in all parts of the moisture control section less than 3/4 of the time (cumulative) that the soil temperature at a depth of 20 inches is 41 degrees F. or more. Monteview soils average 27 to 35 percent clay in the control section. Ragtown soils have mean annual temperature warmer than 47 degrees F.
GEOGRAPHIC SETTING: The Terreton soils are in level to sloping old lake bottoms at elevations of 4,800 to 4,900 feet. Slopes range up to 8 percent. The soils formed in clayey and silty lacustrine deposits. The semiarid climate has an average frost free season of 90 to 105 days and a mean annual precipitation of 7 to 9 inches. including 1.5 to 3 feet of snowfall. Maximum precipitation falls in May and June.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bereniceton soils and the competing Monteview soils. Bereniceton soils average 18 to 27 percent clay in the control section.
DRAINAGE AND PERMEABILITY: Well drained; very slow runoff; slow permeability. Slight influence from excess water. A water table is below a depth of 40 inches in some pedons.
USE AND VEGETATION: Used for irrigated hay, grain, and pasture and as range. The natural vegetation is mainly big sagebrush, rabbitbrush, and dropseed, Elymus species, horsebrush, and winterfat.
DISTRIBUTION AND EXTENT: Central southeastern Idaho. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County, Idaho, 1972.
REMARKS: These soils were classified formerly as Alluvial soils. They may fit better in Ustic Torriorthents.