LOCATION SALEM OREstablished Series
TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Pachic Ultic Argixerolls
TYPICAL PEDON: Salem gravelly silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 9 inches; very dark brown (10YR 2/2) gravelly silt loam, dark grayish brown (10YR 4/2) dry; weak medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine tubular pores; 15 percent gravel; slightly acid (pH 6.2); gradual smooth boundary. (6 to 16 inches thick)
Bt--9 to 18 inches; very dark brown (10YR 2/2) gravelly silty clay loam, brown (10YR 4/3) dry; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many roots; many fine and very fine tubular pores; few faint and distinct clay films; 15 percent gravel; slightly acid (pH 6.4); abrupt smooth boundary. (6 to 20 inches thick)
BCt--18 to 30 inches; dark brown (10YR 3/3) very gravelly clay loam, brown (10YR 5/3) dry; massive; hard, firm, slightly sticky and moderately plastic; common roots; common fine and very fine irregular pores; faint clay coatings on sand grains; 45 percent gravel; neutral (pH 6.6); clear smooth boundary. (0 to 14 inches thick)
2C--30 to 60 inches; grayish brown (10YR 5/2) stratified extremely gravelly sand to very gravelly loamy sand, pale brown (10YR 6/3) dry; single grain; loose; few roots; many irregular pores; 55 percent gravel; slightly acid (pH 6.2); many feet thick.
TYPE LOCATION: Marion County, Oregon; about 2,050 feet east and 1,600 feet north of the SW corner of section 14, T. 9 S., R. 2 W. Willamette Meridian; Turner, Oregon USGS quad. Latitude 44 degrees, 47 minutes, 05 seconds N., and Longitude 122 degrees, 53 minutes, 58 seconds W.; NAD 27.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry in all parts of the soil between depths of 4 and 12 inches for 45 to 60 consecutive days within the 3-month period following the summer solstice in most years. The mean annual soil temperature ranges from 52 to 55 degrees F. The thickness of the sola and depth to very gravelly sand horizons range from 20 to 35 inches. Depth to bedrock is many feet. The amount of coarse fragments in the A and B horizons ranges from 10 to 60 percent with a weighted average of less than 35 percent in the argillic horizon. The mollic epipedon is 20 to 30 inches thick.
The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It has weak to moderate granular or subangular blocky structure. It has 0 to 35 percent gravel and 0 to 5 percent cobbles. Reaction is slightly acid or moderately acid.
The Bt horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry to 20 inches or more and 2 to 4 moist and dry below 20 inches. Texture is gravelly silty clay loam, gravelly clay loam or gravelly sandy clay loam with 25 to 35 percent clay. It has 15 to 35 percent gravel and 0 to 5 percent cobbles. Clay films range from few to common, faint or distinct. Reaction is slightly acid or neutral.
The BCt horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 to 6 dry, and chroma of 3 or 4 moist and dry. Texture is gravelly silty clay loam, gravelly or very gravelly clay loam or gravelly or very gravelly sandy clay loam with 25 to 35 percent clay. It has 20 to 50 percent gravel and 0 to 10 percent cobbles. Clay films are mostly bridging and coatings on fragments but few to common faint films occur on faces of peds. Reaction is slightly acid or neutral.
The 2C horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 2 to 4 moist and dry. Texture is very gravelly sand, very gravelly loamy sand, extremely gravelly sand or extremely gravelly loamy sand and is typically stratified. It is massive or single grain and hard or loose. It has 35 to 65 percent gravel and 5 to 10 percent cobbles. Reaction is slightly acid or neutral.
COMPETING SERIES: There are no competing series. Similar soils are the Briedwell, Hillsboro, and Oxlay series in other families. Briedwell, Hillsboro, and Oxley soils lack contrasting textures within 40 inches of the surface. Briedwell soils also lack argillic horizons. Clackamas soils are fine-loamy and Oxley soils are loamy-skeletal.
GEOGRAPHIC SETTING: The Salem soils are on valley terraces at elevations of 100 to 800 feet. Slope gradients range from 0 to 12 percent. The soils formed in loamy mixed alluvium over sandy and gravelly alluvium. The climate is characterized by having dry, cool summers and cool, wet winters. The mean annual precipitation is 40 to 60 inches. The mean January temperature is 39 to 40 degrees F. and mean July temperature is 65 to 67 degrees F. The mean annual temperature is 50 to 54 degrees F. The frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coburg, Courtney, Malabon and Sifton soils and the competing Clackamas and Oxley soils. Sifton soils are ashy and have thick black gravelly loam A horizons over dark brown gravelly loam cambic horizons. Sifton soils are on higher terraces. Coburg soils are moderately well drained and clayey. The Courtney soils are poorly drained and are in depressions on terraces. The Coburg and Malabon soils are fine textured. In addition, Coburg soils are moderately well drained. Coburg and Malabon soils are on lower terraces. Clackamas and Oxley soils are on lower terraces.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability over very rapid permeability.
USE AND VEGETATION: Salem soils are used for production of cereal grain, corn, pole beans, berries, orchards, pasture and hay. The native vegetation is pondarosa pine, Douglas-fir, Oregon white oak, bigleaf maple, wild rose, annual and perennial grasses.
DISTRIBUTION AND EXTENT: Salem soils are distributed throughout the Willamette Valley and tributary valleys in western Oregon; MLRA 2. These soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Marion County, Oregon, 1903.
REMARKS: Diagnostic horizons and features include:
Mollic epipedon - the zone from 0 to 30 inches (Ap, Bt, and BCt horizons)
Argillic horizon - the zone from 9 to 30 inches (Bt and BCt horizons)