LOCATION LAMBRANCH OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Xeric Haplargids
TYPICAL PEDON: Lambranch gravelly loam - rangeland, on a 2 percent slope at an elevation of 3810 feet. (When described on August 7, 1991 the soil was dry throughout. Colors are for dry soils unless otherwise stated.)
A--0 to 3 inches; grayish brown (10YR 5/2) gravelly loam, dark brown (10YR 3/3) moist; weak very fine granular structure; slightly hard, friable, slightly sticky, nonplastic; common very fine and fine roots; many very fine irregular pores; 20 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (2 to 5 inches thick)
BA--3 to 7 inches; grayish brown (10YR 5/2) clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine and fine tubular pores; 10 percent gravel; slightly alkaline (pH 7.6); gradual smooth boundary. (3 to 8 inches thick)
2Bt1--7 to 14 inches; brown (10YR 5/3) very gravelly clay, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; common very fine and fine roots; many very fine irregular, few very fine and fine tubular pores; common distinct clay films on the faces of peds; 30 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary.
2Bt2--14 to 19 inches; brown (10YR 5/3) very cobbly sandy clay loam, dark brown (10YR 4/3) moist; massive; hard, firm, moderately sticky and moderately plastic; very few very fine roots; many very fine irregular pores; common distinct clay films on coarse fragments; 35 percent gravel, 20 percent cobbles; slightly alkaline (pH 7.6); clear wavy boundary. (This horizon is absent in some pedons.)
2Bt3--19 to 27 inches; dark brown (10YR 4/3), very gravelly clay, dark brown (10YR 4/3) moist, massive; hard, firm, very sticky and very plastic; few very fine roots; common very fine and fine irregular pores; common distinct clay films on coarse fragments; 45 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.8); gradual wavy boundary. (Combined thickness of 2Bt horizon is 14 to 30 inches)
2BC--27 to 60 inches; pale brown (10YR 6/3) very gravelly clay loam, dark brown (10YR 4/3) moist; massive, hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine and fine irregular pores; 40 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.6).
TYPE LOCATION: Harney County, Oregon, about 10 miles southwest of Drewsey, about 600 feet south, 300 feet east of the northwest corner section 17 T.22 S., R.35 E. (Latitude 43 degrees, 39 minutes, 59 seconds N, Longitude 118 degrees, 26 minutes, 55 seconds W)
RANGE IN CHARACTERISTICS: The soils are dry in all parts of the moisture control section for one-half to three-fourths of the time when the soil temperature is 41 degrees F or higher. The mean annual soil temperature is 47 to 51 degrees F. Depth to bedrock is greater than 60 inches. Depth to the base of the argillic horizon is 20 to 40 inches. The particle-size control section averages 35 to 45 percent clay and 35 to 60 percent rock fragments. It is slightly alkaline throughout.
The A horizon has a chroma of 2 dry and 2 or 3 moist.
The 2Bt horizon has a value of 4 or 5 dry or moist, and a chroma of 3 dry, and 2 or 3 moist. Rock fragment content is 20 to 45 percent gravel and, 5 to 25 percent cobbles. It is clay, clay loam, or sandy clay loam with 25 to 45 percent clay.
The 2BC horizon has a value of 6 dry, 4 or 5 moist and chroma of 2 or 3 dry and moist. It is very gravelly clay loam very cobbly loamwith 20 to 35 percent clay. Rock fragment content is 20 to 40 percent gravel and 5 to 20 percent cobbles.
COMPETING SERIES: These are the Clenage, Berning, Bilbo, Havingdon, Maderbak, Pula, Pulcan, Surgem, Tenmile, Vanwyper and Zepham series. Clenage, Havingdon, Maderbak, Pulcan, Surgem, Vanwyper, and Zepham are 20 to 40 inches deep to bedrock. Bilbo soils have carbonates at 20 to 40 inches. Lizzysprings soils have carbonates at 15 to 30 inches. Pula soils have a sola 22 to 40 inches thick and contain 55 to 75 percent coarse fragments in the particle-size control section. Tenmile soils have a mean annual soil temperature of 51 to 56 degrees F. Berning soils are slightly acid to neutral, contain 50 to 75 percent rock fragments in the particle-size control section. The argillic horizon has a base at below 40 inches and the lower part of the argillic horizon contains 15 to 25 percent clay.
GEOGRAPHIC SETTING: Lambranch soils are on alluvial fan terraces and have slopes of 2 to 8 percent. The soils formed in alluvium. Elevations are 3800 to 4100 feet. The climate is characterized by cool, moist winters and hot, dry summers. The mean annual precipitation is 9 to 12 inches. The mean annual air temperature is 45 to 49 degrees F. The frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gumble, Jett, Poall, and Risley series. Gumble soils are shallow over soft bedrock and are on hills. Jett soils are fine-silty and are on stream terraces. Poall soils are in the fine family and are on lake terraces. Risley soils have bedrock between 20 to 40 inches and are on hills.
DRAINAGE AND PERMEABILITY: Well drained, slow permeability.
USE AND VEGETATION: The soils are used for livestock grazing and irrigated hay production. Potential native vegetation is basin big sagebrush, bluebunch wheatgrass, Thurber needlegrass, and basin wildrye.
DISTRIBUTION AND EXTENT: Southeastern Oregon; MLRA 10. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Harney County, Oregon 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Argillic horizon - from 7 to 27 inches (2Bt1, 2Bt2, 2Bt3)
Particle-size control section - from 7 to 27 inches and averages 39 percent clay and 50 percent rock fragments; clayey-skeletal.