LOCATION SPEAKER OR+CA
Established Series
Rev. DKS/AON/TDT
09/2025
SPEAKER SERIES
The Speaker series consists of moderately deep, well drained soils that formed in colluvium weathered from sedimentary and metamorphic rocks. Speaker soils are on low rolling foot slopes and side slopes and have gradients of 2 to 75 percent. The mean annual precipitation is about 45 inches (1140 mm) and the mean annual temperature is about 50 degrees F (10 degrees C).
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Ultic Haploxeralfs
TYPICAL PEDON: Speaker gravelly loam, forested on a 45 percent slope. (Colors are for moist soil unless otherwise noted.)
O--0 to 1 inch (0 to 2 cm); duff layer.
A1--1 to 4 inches (2 to 10 cm); dark brown (7.5YR 3/3) gravelly loam, brown (7.5YR 5/3) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; many irregular pores; 30 percent gravel and cobbles; slightly acid (pH 6.1); abrupt smooth boundary. (2 to 4 inches (5 to 10 cm) thick)
A2--4 to 7 inches (10 to 18 cm); dark brown (7.5YR 3/4) gravelly loam, brown (7.5YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium roots; many very fine and fine tubular pores; 20 percent gravel and cobbles; moderately acid (pH 5.8); clear smooth boundary. (2 to 5 inches 5 to 13 cm) thick)
BA--7 to 14 inches (18 to 36 cm); reddish brown (5YR 4/4) gravelly loam, reddish brown (5YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, sticky and plastic; many fine and common medium roots; many very fine and fine tubular pores; 20 percent gravel; moderately acid (pH 5.8); clear smooth boundary. (4 to 11 inches (11 to 28 cm) thick)
2Bt--14 to 31 inches (36 to 79 cm); yellowish red (5YR 4/6) gravelly clay loam, yellowish red (5YR 5/6) dry; moderate fine subangular blocky structure; hard, firm, sticky and plastic; common medium and coarse roots; common very fine and fine tubular pores; few moderately thick clay films; 20 percent partially weathered gravel; moderately acid (pH 5.6); gradual wavy boundary. (12 to 20 inches (30 to 50 cm) thick)
2Crt--31 to 34 inches (79 to 86 cm); weathered bedrock with common dark red (2.5YR 3/6) clay films and black stains in fractures.
TYPE LOCATION: Josephine County, Oregon; about 1 1/2 miles east from powerline road on Daisy Mountain Road; about 100 feet west and 1,620 feet south of the NE corner of sec. 21, T. 34 S., R. 5 W., Willamette Meridian.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 54 degrees F (8 to 12 degrees C). The soils are usually moist but are dry between depths of 4 and 12 inches (5 to 30 cm) for 60 to 90 consecutive days following the summer solstice. Depth to a paralithic contact and thickness of the solum range from 20 to 40 inches (50 to 100 cm). The particle-size control section averages 0 to 30 percent gravel, 0 to 5 percent cobbles, 25 to 35 percent clay, and more than 15 percent fine sand and coarser but less than 15 percent coarse and very coarse sand. Clean sand and silt coatings are common on faces of peds in the upper part of the B horizon in some pedons.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 through 7 dry, and chroma of 2 through 6 moist and dry. Rock fragments average 5 to 30 percent gravel and 0 to 5 percent cobbles. Reaction is strongly to slightly acid. The horizon has 2 to 4 percent organic matter.
The Bt horizon has hue of 7.5YR or 5YR, value of 4 or 5 moist, 4 through 7 dry, and chroma of 4 through 6 moist and dry. Textures are gravelly clay loam, clay loam, gravelly loam or loam. There are few to common, moderately thick clay films. Stone lines are in some pedons. Reaction is very strongly to moderately acid.
COMPETING SERIES: These are the
Bigridge (MLRA 18 and 22A),
Cohasset (MLRA 22A),
Holland (MLRA 22A),
Hospiter (MLRA 5),
Hotaw (MLRA 22A),
Millerridge (MLRA 22A),
Minniecreek (MLRA 18),
Pasturerock (MLRA 4B),
Sitton (MLRA 2), and
Willakenzie (MLRA 2) soils. Bigridge and Cohasset soils have a paralithic contact between 100 and 150 cm. Holland, Hospiter, Pasturerock, and Sitton soils are very deep. Hotaw soils formed in granodiorite and are dry from about June to October (about 120 days), and have a mean soil temperature of 11 to 15 degrees C. Millerridge soils formed in ultramafic rock and have significant amounts of Magnesium-rich minerals, and have a mean annual soil temperature of 12 to 15 degrees C. Minniecreek soils are dry in all parts from about June to October (about 120 days) and have a mean annual soil temperature of 13 to 14 degrees C. Willakenzie soils formed in tuffaceous sandstone and are dry for 45 to 60 days following the summer solstice.
GEOGRAPHIC SETTING: Speaker soils are on hillslopes and mountain slopes with gradients of 2 to 75 percent. These soils are at elevations of 400 to 4,800 feet (120 to 1455 m). The soils formed in moderately fine textured colluvium weathered from sedimentary and volcanic sandstone, conglomerate sandstone and metavolcanic rocks. Summers are warm and dry and winters are cool and moist with an average annual precipitation of 30 to 60 inches. The mean annual temperature is 45 to 56 degrees F (7 to 13 degrees C). The frost-free period is 100 to 235 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Beekman,
Colestine,
Josephine and
Vermisa soils. Josephine soils are more than 40 inches deep to bedrock. Beekman, Colestine, and Vermisa soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber production, water supply, recreation, and wildlife habitat.Natural vegetation is mainly Douglas fir, Pacific madrone, ponderosa pine, California black oak, cascade Oregongrape, common snowberry and whipplevine.
DISTRIBUTION AND EXTENT: Southwestern and west-central Oregon and coastal mountains of northern California, MLRA 5. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Josephine County, Oregon, 1979.
REMARKS:
09/2025--Competing series checked and updated. -JBB
National Cooperative Soil Survey
U.S.A.