LOCATION CEDARGROVE OR
Established Series
Rev. SLR/DRJ/TDT
01/2023
CEDARGROVE SERIES
The Cedargrove series consists of very deep, well drained soils formed in residuum and colluvium derived from granodiorite. Cedargrove soils are on foot slopes and hill sideslopes Slopes are 3 to 60 percent. The mean annual precipitation is about 35 inches, and the mean annual temperature is about 52 degrees F.
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Ultic Haploxeralfs
TYPICAL PEDON: Cedargrove silt loam-forested, on a north-facing slope of 55 percent at an elevation of 1200 feet. (Colors are for moist soil unless otherwise noted.)
Oi--1 inch to 0; slightly decomposed grasses, twigs, bark, and leaves.
A1--0 to 7 inches; dark brown (7.5YR 3/2) silt loam, brown (7.5YR 5/4) dry; moderate very fine subangular blocky structure parting to moderate very fine and fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; many fine and common medium pores; strongly acid (pH 5.5); clear smooth boundary. (5 to 9 inches thick)
A2--7 to 14 inches; dark brown (7.5YR 3/4) silt loam, light brown (7.5YR 6/4) dry; moderate very fine and fine subangular blocky structure parting to moderate very fine and fine granular; slightly hard, friable, slightly sticky and slightly plastic; few very fine, common fine and medium, and few coarse roots; many very fine, fine and medium irregular pores; moderately acid (pH 5.8); clear smooth boundary. (6 to 9 inches thick)
Bt1--14 to 18 inches; dark brown (7.5YR 3/4) silty clay loam, yellowish brown (10YR 5/4) dry; moderate fine and medium subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; few very fine, common fine and medium, and few coarse roots; many very fine and fine, common medium, and few coarse irregular pores; very few faint clay films on faces of peds and in pores; moderately acid (pH 5.8); clear smooth boundary.
Bt2--18 to 30 inches; dark brown (7.5YR 3/4) silty clay loam, yellowish brown (10YR 5/4) dry; few medium faint strong brown (7.5YR 4/6) variegations; strong medium and coarse subangular blocky structure; extremely hard, firm, sticky and plastic; few fine roots; common very fine and fine irregular pores; common prominent clay films on faces of peds and in pores; moderately acid (pH 5.8); gradual smooth boundary.
Bt3--30 to 46 inches; brown (10YR 4/3) clay, light olive brown (2.5Y 5/4) dry; few medium faint strong brown (7.5YR 4/6) variegations; strong medium and coarse subangular blocky structure; extremely hard, firm, sticky and plastic; few fine and medium roots; common very fine irregular pores; common prominent clay films on faces of peds and in pores; moderately acid (pH 5.9); gradual smooth boundary.
Bt4--46 to 60 inches; brown (10YR 4/3) clay, light olive brown (2.5Y 5/4) dry; few medium faint brown (7.5YR 5/4) variegations; moderate fine, medium, and coarse subangular blocky structure; extremely hard, firm, sticky and plastic; few fine roots; common very fine irregular pores; few faint clay films on faces of peds and in pores; slightly acid (pH 6.2). (Combined thickness of the Bt horizon is 45 or more inches thick)
TYPE LOCATION: Douglas County, Oregon, 5 miles east of the town of Myrtle Creek, 2100 feet south and 650 feet west of the northeast corner of section 29, T. 29 S., R. 4 W., W.M. (Latitude 43 degrees, 1 minute, 16 seconds N, Longitude 123 degrees, 11 minutes, 28 seconds W)
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock is 60 inches or more. The mean annual soil temperature is 50 to 56 degrees F. The soil is usually moist but is dry within all parts of the moisture control section for 60 to 90 consecutive days following the summer solstice. It has 0 to 15 percent gravel throughout the solum. The particle-size control section averages 35 to 45 percent clay.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 5 to 7 dry, and chroma of 2 to 4 moist, 3 or 4 dry. It is strongly acid or slighty acid. It has 3 to 6 percent organic matter.
The Bt horizon has hue of 7.5YR or 10YR in the upper part and 10YR or 2.5Y in the lower part, value of 3 to 5 moist, 5 to 7 dry, and chroma of 3 to 6 moist and dry. It is silty clay loam, silty clay, or clay with 35 to 50 percent clay; clay content increases with depth. It is strongly acid to slightly acid. Base saturation by sum is 50 to 75 percent.
COMPETING SERIES: These are the,
Cornutt,
Freezener,
Greengulch,
Jumpoff,
Mildred,
Oak Grove,
Oakland,
Rainier,
Sweetbriar, and
Veneta series. Cornutt soils have a Ca/Mg ratio of more than 1, have hue of 5YR or 2.5YR in the subsoil, and depth to bedrock is 40 to 60 inches. Freezener soils have hue of 7.5YR to 2.5YR throughout, and formed over basic igneous rock. Greengulch soils are 20 to 40 inches deep to a paralithic contact, and formed over granodiorite. Jumpoff soils are moderately well drained, and are dry 45 to 60 consecutive days in the moisture control section during the summer. Mildred soils are 20 to 40 inches to soft bedrock and are dry for more than 90 consecutive days in the moisture control section during the summer. Oak Grove soils have an umbric epipedon, and lack hue more yellow than 7.5YR in the subsoil. Oakland soils are 20 to 40 inches deep to a paralithic contact. Rainier soils are moderately well drained, and are 40 to 60 inches to a lithic contact. Sweetbriar soils have a mollic epipedon, and are dry for 45 to 60 consecutive days in the moisture control section during the summer. Veneta soils are moderately well drained, and have 60 percent or more clay in the lower part of the argillic horizon.
GEOGRAPHIC SETTING: Cedargrove soils are on foot slopes and hill sideslopes. They formed in fine textured residuum and colluvium derived from granodiorite. Slopes are 3 to 60 percent. Elevations are 800 to 2200 feet. The climate is characterized by warm, wet winters and hot, dry summers. The mean annual temperature is 49 to 55 degrees F. The mean annual precipitation is 30 to 40 inches. The frost free period is 120 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are
Beekman,
Josephine,
Pollard,
Siskiyou,
Speaker,
Tethrick,
Vermisa,
Wolfpeak,
Zing, and the competing
Greengulch series. Beekman and Vermisa soils are loamy-skeletal. Josephine and Speaker soils are fine-loamy. Wolfpeak soils are fine-loamy and formed in granodiorite. Pollard soils are kaolinitic. Siskiyou and Tethrick series are coarse-loamy and formed in granodiorite. Zing soils are moderately well or somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production, orchards, grazing, wildlife habitat, and watershed. The native vegetation includes Douglas fir, ponderosa pine, incense cedar, Pacific madrone, California black oak, western swordfern, cascade Oregongrape, tall Oregongrape, creambush oceanspray, Pacific poison oak, and California fescue.
DISTRIBUTION AND EXTENT: Southwester Oregon, MLRA 5. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Douglas County, Oregon 1994.
REMARKS: Diagnostic horizons and features in this pedon are:
Ochric epipedon
Argillic horizon - from 14 to 60 inches. (Bt1, Bt2, Bt3, and Bt4 horizons)
Ultic intergrade - base saturation is assumed to be less than 75 percent throughout the argillic horizon.
Mollic intergrade - color value moist of 3 in the A horizon with more than 0.7 percent organic carbon.
Particle-size control section - from 14 to 34 inches. (Bt1, Bt2, and part of the Bt3 horizons); estimated average clay content is about 40 percent.
This does not qualify as a "Pale" because the lower part of the argillic does not have a hue redder than 10YR.
The superactive cation exchange activity class was added to the classification in 10/2005. The competing series section was not updated at that time. Last revision 3/1995.
National Cooperative Soil Survey
U.S.A.