LOCATION MCLOUGHLIN OREstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Xeric Haplocambids
TYPICAL PEDON: McLoughlin silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap1--0 to 3 inches; very pale brown (10YR 7/1) silt loam, dark brown (10YR 4/3) moist; strong thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine interstitial pores; weakly calcareous in spots; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 6 inches thick)
Ap2--3 to 9 inches; very pale brown (10YR 7/3) silt loam, dark brown (10YR 4/3) moist; moderate fine and medium granular structure; soft, friable, sticky and plastic; many roots; many very fine interstitial pores; weakly calcareous in spots; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 6 inches thick)
B2--9 to 20 inches; very pale brown (10YR 7/3) silt loam, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic structure; hard, friable, sticky and plastic; common large roots; common very fine tubular pores; weakly calcareous; strongly alkaline (pH 8.6); gradual wavy boundary. (8 to 15 inches thick)
C1ca--20 to 28 inches; very pale brown (10YR 7/3) light silty clay loam, yellowish brown (10YR 5/4) moist; massive; hard, friable, sticky and plastic; common large roots; common very fine tubular pores; moderately calcareous; strongly alkaline (pH 8.6); gradual wavy boundary. (5 to 15 inches thick)
C2ca--28 to 50 inches; very pale brown (10YR 7/3) light silty clay loam, yellowish brown (10YR 4/4) moist; massive; hard, friable, sticky and plastic; strongly calcareous; strongly alkaline (pH 8.8); gradual wavy boundary. (10 to 30 inches thick)
C3--50 to 60 inches; stratified silty clay loam and silt loam; similar to above in color and consistence; massive.
TYPE LOCATION: Malheur County, Oregon; 700 feet north of the creek channel; NE1/4 SE1/4 SE1/4 section 2, T. 23 S., R. 46 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 48 to 56 degrees F. In most years the soils are usually dry but are moist between depths of 4 and 12 inches for 45 consecutive days or more within the four-month period following the summer solstice and are moist for 60 consecutive days during the winter. The soils are moderately to strongly saline-alkali throughout. Some profiles are calcareous throughout and others are calcareous only in the lower part of the profile. The solum is silt loam, loam or silty clay loam and has 22 to 35 percent clay and less than 15 percent fine sand and coarser. The solum is stratified with medium and moderately fine textured material washed from adjacent uplands of silty lacustrine sediments. The profile to depth of 40 inches or more has value of 6 or 7 dry, 4 or 5 moist and chroma of 3 or 4 dry and moist. The structure ranges from weak to strong platy and vesicular in the upper few inches of the A horizon and weak or moderate granular or fine or very fine subangular blocky in the lower part of the A horizon and weak to strong prismatic and weak or moderate subangular blocky in the B horizon.
COMPETING SERIES: This is the Luce series. Luce soils have a thin weakly cemented horizon at depth of about 20 inches and lack B horizons.
GEOGRAPHIC SETTING: McLoughlin soils are on nearly level to gently sloping alluvial fans with gradients of 0 to 8 percent, at elevations of 2,100 to 3,500 feet. The soils formed in mixed alluvium from old lacustrine sediments. The climate is semiarid with hot dry summers and cold moist winters. The mean annual temperature is about 46 to 54 degrees F., mean summer temperature is 68 to 72 degrees F., and mean winter temperature is 31 to 33 degrees F. The average annual precipitation ranges from 8 to 10 inches. The frost-free period is 110 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Garbut, Powder, Stanfield and Umapine series. Garbut soils are coarse-silty and lack B horizons. Powder soils have mollic epipedons and are coarse-silty. Stanfield soils have a duripan at depths of 20 to 40 inches. Umapine soils are coarse-silty and very strongly alkaline.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Range in irrigated small grains, alfalfa hay, pasture and occasionally sugar beets. Native vegetation is mainly Atriplex spp., greasewood, saltgrass and annual alkaline-tolerant forbs.
DISTRIBUTION AND EXTENT: Malheur County, Oregon. Over 5,000 feet in Utah. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Malheur County, Oregon, 1975.
NSTH 17, RECLASSIFICATION ONLY, 3/95