LOCATION LA ROCO IDEstablished Series
TAXONOMIC CLASS: Fine-silty, carbonatic, frigid Oxyaquic Calcixerolls
TYPICAL PEDON: La Roco silty clay loam, hayland; on a 1 percent slope at 5,945 feet elevation. (Color is for air dry soil unless otherwise noted.)
A1--0 to 2 inches; grayish brown (2.5Y 5/2) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; strong very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine irregular pores; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 10 inches thick)
A2--2 to 11 inches; grayish brown (2.5Y 5/2) silty clay loam, very dark grayish brown (2.5Y 3/2) moist; moderate coarse and medium subangular blocky structure parting to moderate medium and fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common medium, fine, and very fine roots; common very fine and few fine irregular and few fine tubular pores; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 10 inches thick)
Bk1--11 to 20 inches; very pale brown (10YR 8/2) silty clay loam, pale brown (10YR 6/3) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium and very fine and few fine roots; common very fine and few fine tubular pores; common soft masses of lime; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 20 inches thick)
Bk2--20 to 26 inches; very pale brown (10YR 8/2) silt loam, very pale brown (10YR 7/3) moist; moderate thick and medium platy structure parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few medium and fine roots; common very fine tubular pores; many large soft masses of lime; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (5 to 20 inches thick)
Bk3--26 to 34 inches; very pale brown (10YR 7/4) silt loam, light yellowish brown (10YR 6/4) moist; moderate thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common fine and very fine tubular pores; common soft masses and threads of lime; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 15 inches thick)
Bk4--34 to 42 inches; very pale brown (10YR 7/3) silt loam; light yellowish brown (10YR 6/4) moist; few very fine distinct yellowish brown (10YR 5/6) moist redox concentrations; weak coarse and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine and few tubular pores; about 10 percent very hard calcium carbonate nodules; violently effervescent; moderately alkaline (pH 8.1); abrupt smooth boundary. (0 to 15 inches thick)
2Cg1--42 to 49 inches; light yellowish brown (10YR 6/4) fine sandy loam, yellowish brown (10YR 5/4) moist; few fine distinct yellowish brown (10YR 5/6) moist redox concentrations and few fine prominent gray (2.5Y 5/1) moist redox depletions; massive; slightly hard, very friable, non-sticky and non-plastic; few very fine roots; common very fine and few fine tubular pores; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 20 inches thick)
2Cg2--49 to 59 inches; yellowish brown (10YR 5/4) very fine sandy loam, dark yellowish brown (10YR 4/4) moist; few medium distinct dark yellowish brown (10YR 4/6) moist redox concentrations and common medium and fine prominent gray (2.5Y 5/1) moist redox depletions; massive; soft, very friable, non-sticky and non-plastic; few very fine roots; few very fine tubular and few fine vesicular pores; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 20 inches thick)
3C--59 to 62 inches; pink (7.5YR 7/4) extremely gravely loamy sand, brown (7.5YR 4/4) moist; single grain; loose, non-sticky and non-plastic; many very fine irregular and few fine vesicular pores; 75 percent gravel; slightly effervesent; moderately alkaline (pH 8.0).
TYPE LOCATION: Bear Lake County, Idaho; about 1.5 miles south of Dingle; about 1,400 feet west and 500 feet south of the northeast corner of sec. 23, T. 14 S., R. 44 E.; USGS Dingle 7.5 minute topographic quadrangle; latitude 42 degrees 11 minutes 46 seconds north, longitude 111 degrees 16 minutes 18 seconds west, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture control section - usually moist, dry in all parts for 45 consecutive days or more in the four months following the summer solstice. Xeric moisture regime.
Mollic epipedon thickness - 7 to 20 inches
Depth to 2Cg1 horizon - 40 to 55 inches
Redox concentrations and saturation occurs between 30 and 40 inches for 30 or more cumulative days per year in 6 out of 10 years
Average annual soil temperature - 42 to 46 degrees F. Frigid soil temperature regime.
Particle-size control section:
Total clay content (average) - 27 to 36 percent
Carbonate clay content (average) - 8 to 18 percent
Rock Fragments - 0 to 15 percent gravel
A horizons (when cropped, Ap horizon(s) range from 7 to 12 inches thick)
Hue - 10YR or 2.5Y
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 1 to 3 dry or moist
Texture - SIL or SICL
Rock fragments - 0 to 10 percent, gravel
Calcium carbonate equivalent - 15 to 40 percent
Reaction - pH 7.4 to 8.4
Bk horizons
Hue - 10YR or 2.5Y
Value - 5 to 8 dry, 4 to 7 moist
Chroma - 2 to 4 dry, 2 or 3 moist
Textures - SIL or SICL
Rock fragments - 0 to 15 percent gravel
Calcium carbonate equivalent - 40 to 60 percent
Reaction - pH 7.8 to 8.8
2Cg horizons
Hue - 10YR, 2.5Y or 5Y
Value - 5 to 7 dry, 4 to 6 moist
Chroma - 1 to 4 dry or moist
Textures (can be stratified) - loam, sandy loam, fine sandy loam, very fine sandy loam or their gravelly or very gravelly analogues
Rock fragments - 0 to 60 percent gravel
Calcium carbonate equivalent - 1 to 15 percent
Reaction - pH 7.4 to 8.4
3C horizon (when present)
Hue - 7.5YR or 10YR
Value - 5 to 7 dry, 4 or 5 moist
Chroma - 2 to 4 dry or moist
Textures (can be stratified) - gravelly loamy sand, gravelly sand, gravelly loamy coarse sand, gravelly coarse sand or their very or extremely gravelly analogues
Rock fragments - 15 to 80 percent gravel
Calcium carbonate equivalent - 1 to 10 percent
Reaction - pH 7.4 to 8.4
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform: flood plains and flood plain steps
Elevation: 4,700 to 6,400 feet
Slope: 0 to 2 percent
Parent material: mixed alluvium
Climate: long, cold winters; moist springs; warm, dry summers
Average annual precipitation: 12 to 18 inches
Average annual air temperature: 39 to 45 degrees F
Frost-free period: 70 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bear Lake, Blackotter, Bloomington, Chesbrook, Dinswamp, Lago, Merkley and Nuffer soils. Bear Lake, Blackotter and Chesbrook soils occur on similar landscape positions and are poorly drained. Bloomington and Dinswamp soils occur on lake plains and lake terraces and are very poorly drained. Lago soils occur on similar landscape positions and are not carbonatic. Merkley soils occur on similar landscape positions, are moderately well drained, are not carbonatic and are coarse-silty. Nuffer soils occur on similar landscape positions, have a pachic epipedon and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; negligible to low runoff; moderate permeability. It is frequently flooded for short durations during the period April through May in most years, and at other times following periods of intense rainfall.
USE AND VEGETATION: Mainly used for cropland, pastureland and hayland. The potential natural vegetation is mainly saltgrass, bluegrasses, cheatgrasses, and in places rabbitbrush, shrubby cinquefoil, bluebunch wheatgrass, western wheatgrass, sedges, rushes, giant wildrye, alkali cordgrass, willow, basin big sagebrush, threetip sagebrush and/or forbs.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils of this series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bear Lake County, Idaho, 2008.
REMARKS: Diagnostic horizons and features present in this series are:
Mollic epipedon - the zone from the surface of the soil to 11 inches (A1 and A2 horizons)
Calcic horizon - the zone from the 11 to 42 inches (Bk1, Bk2, Bk3, and Bk4 horizons)
ADDITIONAL DATA: This soil was sampled for analysis at the NSSL, Lincoln, NE. Soil Survey sample number - S90ID007006