LOCATION SWEET IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Argidic Durixerolls
TYPICAL PEDON: Sweet loam, cultivated. (Colors are for dry soils unless otherwise noted.)
Ap--0 to 7 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine and very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; many very fine pores; slightly acid (pH 6.3); abrupt smooth boundary. (4 to 8 inches thick)
A--7 to 9 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; many very fine interstitial pores; common worm holes and casts; slightly acid (pH 6.4); clear smooth boundary. (1 to 4 inches thick)
ABt--9 to 15 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine pores; few very coarse channels and rodent holes; few faint clay films; thin patchy siliceous speckling on surfaces of peds; neutral (pH 6.9); clear smooth boundary. (2 to 6 inches thick)
Bt1--15 to 21 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium prismatic structure; very hard, firm, moderately sticky and moderately plastic; common fine roots; common very fine tubular pores; many distinct clay films; moderate, thin patchy siliceous speckling on surfaces of peds; slightly acid (pH 6.1); abrupt wavy boundary. (2 to 7 inches thick)
Bt2--21 to 33 inches; brown (7.5YR 5/3) clay loam, dark brown (7.5YR 4/3) moist; moderate medium prismatic structure; extremely hard, very fine, moderately sticky and very plastic; few very fine roots; few very fine tubular pores; very dense; continuous prominent clay films; (pH 6.7); abrupt wavy boundary. (8 to 16 inches thick)
Btk--33 to 38 inches; brown (10YR 5/3) sandy clay loam, brown (10YR 4/3) moist; weak coarse prismatic structure; very hard, very firm, moderately sticky and moderately plastic; few fine roots; few very fine tubular pores; continuous prominent brown (7.5YR 5/3) clay films; about 5 percent fine pebbles; common 2 to 3 mm. calcium carbonate spots and veins; neutral (pH 7.2); abrupt smooth boundary. (4 to 8 inches thick)
Bqm1--38 to 46 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; weak thick plates and weak fine and medium angular blocky structure; extremely hard, extremely firm; very weakly to weakly cemented; few faint clay films; about 5 percent fine pebbles; upper part contains white noncalcareous veins; (pH 7.8); gradual smooth boundary. (3 to 10 inches thick)
Bqm2--46 to 58 inches; brown (10YR 5/3) coarse sandy loam, dark brown (10YR 3/3) moist; massive; weakly to very weakly cemented; extremely hard, extremely firm, few faint clay films; very few very pale brown siliceous veins; slightly alkaline. (1 to 8 inches thick)
TYPE LOCATION: Gem County, Idaho; about 1 mile south of Sweet; 1,450 feet south and 2,250 feet east of the northeast corner of section 10, T.7N., R.1E.; Latitude - 43 degrees, 57 minutes, 42 seconds N.; Longitude - 116 degrees, 19 minutes, 28 seconds W.
RANGE IN CHARACTERISTICS: Depth to the duripan is 20 to 40 inches. The mean annual soil temperature is about 48 to 53 degrees F. The mollic epipedon is 7 to 15 inches thick. The argillic horizon contain 25 to 35 percent clay, more than 15 percent particles coarser than very fine sand and less than 10 percent rock fragments by weighted average. Depth to carbonates is 18 to 36 inches.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma 2 or 3 dry or moist. It is stony, very stony or extremely stony, and is loam, silt loam, or clay loam.
It has 0 to 25 percent stones and 0 to 10 percent gravel.
The Bt and Btk horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 or 4 moist, chroma of 2 or 3 dry and moist. It is clay loam, loam, or sandy clay loam and has moderate or strong prismatic or blocky structure. It has 0 to 5 percent cobbles and 0 to 5 percent gravel.
The weakly to moderately cemented duripan is cemented by silica or silica and calcium carbonate.
COMPETING SERIES: These are no competing series.
GEOGRAPHIC SETTING: Sweet soils are on dissected stream terraces. Slopes range from 0 to 30 percent, with those 3 to 7 percent dominant. The soils formed from medium and moderately coarse textured alluvium weathered from mixed acid igneous and basaltic rocks. In some areas, the upper part of the profile contains an admixture of loess. Elevations are about 2,500 to 5,500 feet. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 10 to 13 inches. The mean annual temperature is 47 to 53 degrees F. Frost-free season is about 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kepler, Newell, Montour, and Ridenbaugh soils. Kepler, Montour, and Ridenbaugh soils have fine textured control sections. Montour and Newell soils lack duripans.
DRAINAGE AND PERMEABILITY: Well drained; medium to slow runoff; permeability is moderately slow, and of the duripan very slow.
USE AND VEGETATION: Mainly cultivated. Some areas are irrigated and produce wheat, barley, alfalfa, and pasture. Nonirrigated areas produce wheat and barley. Vegetation is mainly bluebunch wheatgrass, Sandberg bluegrass, cheatgrass, big sagebrush, Thurber needlegrass, basin wildrye, squirreltail, rabbitbrush, and associated forbs.
DISTRIBUTION AND EXTENT: Southwestern and southcentral Idaho. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Mayfield SCD, Ada and Elmore Counties, Idaho, 1943.
REMARKS: Diagnostic horizons and other features:
Mollic epipedon: 0 to 15 inches
Argillic horizon: 15 to 38 inches
Duripan: 38 to 58 inches weakly cemented
ADDITIONAL DATA: Type location S56-ID-23-25 (1-8) Riverside Lab.