LOCATION TULCH IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Xeric Haplocambids
TYPICAL PEDON: Tulch silt loam--on a northwest facing slope of 1 percent under rangeland vegetation at 3,440 feet elevation. (Colors are for dry soil unless otherwise stated.) When described on November 15, 1983, the soil profile was dry.
A--0 to 3 inches; brown (10YR 5/3) silt loam, dark brown (10YR 3/3) moist; moderate medium platy structure; soft, very friable; common very fine and fine roots; many fine and very fine tubular pores; neutral (pH 7.0); clear smooth boundary. (3 to 10 inches thick)
BA--3 to 9 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine and very fine tubular pores; mildly alkaline (pH 7.4); gradual wavy boundary. (0 to 7 inches thick)
Bw1--9 to 16 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine tubular pores; mildly alkaline (pH 7.4); clear wavy boundary. (7 to 24 inches thick)
Bw2--16 to 34 inches; pale brown (10YR 6/3) silty clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard firm, slightly sticky and plastic; common very fine and fine roots; common fine tubular pores; 10 percent durinodes; mildly alkaline (pH 7.5); gradual wavy boundary. (0 to 18 inches thick)
Bw3--34 to 38 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; hard firm, sticky and plastic; few very fine and fine roots; few fine tubular pores; slightly effervescent; (5 percent calcium carbonate); moderately alkaline (pH 8.0); gradual wavy boundary. (0 to 4 inches thick)
Bk--38 to 70 inches; very pale brown (10YR 7/3) silty clay loam, brown (10YR 5/3) moist; massive; very hard, firm, sticky and plastic; few very fine roots; few fine tubular pores; strongly effervescent, lime in filaments; (12 percent calcium carbonate); moderately alkaline (pH 8.4). (30 to 40 inches thick)
TYPE LOCATION: Twin Falls County, Idaho; about 15 miles southeast of Buhl, Idaho; in the northeast 1/4, southwest 1/4, southeast 1/4 of section 14, T. 8 S., R. 12 E.
RANGE IN CHARACTERISTICS:
Soil temperature - 50 to 52 degrees F.
Depth to carbonates - 26 to 40 inches or more
Depth to bedrock - greater than 60 inches
Control section - clay: 18 to 30 percent
A horizon
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Bw horizon
Value - 5 through 7 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Texture - SIL or SICL Clay - 18 to 30 percent
Bk horizon
Value - 6 or 7 dry, 4 or 5 moist
Texture - VFSL, SIL, or SICL
Clay - 16 to 30 percent
Durinodes - 0 to 20 percent
Calcium carbonate - 5 to 15 percent
COMPETING SERIES: These are the Elvedere (T), Loughty (T), Luce (T), and the McLoughlin series. Elvedere soils have a Bk horizon above 26 inches. Loughty soils have free carbonates in the cambic horizon. Luce soils have a weakly to moderately cemented layer at depths from 16 to 36 inches. McLoughlin soils are moderately saline to strongly saline throughout.
GEOGRAPHIC SETTING: Tulch soils are on nearly level stream terraces and larger drainageways. These soils formed in old alluvium from mixed sources. Slopes are 0 to 2 percent. Elevations are 3,000 to 4,000 feet. The average annual precipitation is 8 to 10 inches. The average annual temperature is 48 to 50 degrees F. and the frost free season is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blacknest, Chuska, Dolman, Purdam, Rakane, Sluka, and Yahoo soils. Blacknest soils have fine loamy argillic horizons. Chuska and Yahoo soils are shallow to a duripan. Dolman, Purdam, Rakane, and Sluka soils are moderately deep to a duripan. All associated soil s are found on higher terraces.
DRAINAGE AND PERMEABILITY: Well drained, runoff slow; permeability is moderately slow.
USE AND VEGETATION: Tulch soils are used for rangeland and irrigated crops. Native vegetation is basin big sagebrush, basin wildrye, and Sandberg bluegrass. Irrigated crops are mainly wheat, barley, sugar beets, potatoes, beans, and alfalfa hay.
DISTRIBUTION AND EXTENT: Tulch soils are of small extent in south central Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Twin Falls County, Idaho, 1984. The name is from a nearby gulch.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the soil surface to 3 inches (A horizon)
Cambic horizon - the zone from 9 to 38 inches (Bw1, Bw2, and Bw3 horizons)
Particle size control section - the zone from 10 to 40 inches (Bw1, Bw2, Bw3, and part of the Bk horizon)