LOCATION MCCULLY OR

Established Series
Rev. RHM-TDT
06/2011

MCCULLY SERIES

The McCully series consists of deep, well drained soils that formed in fine textured colluvium and residuum from basic igneous rock. These soils are on saddles, sideslopes, and broad ridgetops. Slopes are 2 to 70 percent. The mean annual precipitation is 75 inches, and the mean annual temperature is 48 degrees F.

TAXONOMIC CLASS: Fine, isotic, mesic Typic Humudepts

TYPICAL PEDON: McCully clay loam, forested. (Colors are for moist soil unless otherwise noted.)

Oi--0 to 1 inch; slightly decomposed fern, fir needles, leaves, twigs, etc.

A--1 to 7 inches; dark reddish brown (5YR 3/2) clay loam, brown (7.5YR 4/4) dry; strong medium and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine irregular pores; many medium reddish brown concretions; many coarse sand-size rock fragments; strongly acid (pH 5.4); abrupt smooth boundary. (6 to 10 inches thick)

AB--7 to 11 inches; dark reddish brown (5YR 3/2) clay loam, brown (7.5YR 4/4) dry; strong medium and fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; many roots; many very fine irregular pores; common medium reddish brown concretions; common coarse sand-size light colored rock fragments; strongly acid (pH 5.2); clear wavy boundary. (0 to 10 inches thick)

Bw1--11 to 25 inches; dark reddish brown (5YR 3/4) clay, yellowish red (5YR 4/6) dry; weak medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many roots; many very fine tubular pores; few small reddish brown concretions; few coarse sand-size light colored rock fragments; very strongly acid (pH 4.6); clear smooth boundary. (0 to 12 inches thick)

Bw2--25 to 50 inches; dark reddish brown (5YR 3/4) clay, yellowish red (5YR 4/6) dry; thin slightly darker coatings; weak medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common roots; many very fine tubular pores; few reddish brown concretions; few light colored coarse sand and gravel-size rock fragments; very strongly acid (pH 4.6); gradual smooth boundary. (15 to 30 inches thick)

Bw3--50 to 58 inches; dark reddish brown (5YR 3/4) clay, reddish brown (5YR 4/4) dry; weak medium and fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few roots; many very fine tubular pores; few small concretions, common light colored coarse sand particles and 5 percent gravel; very strongly acid (pH 4.6); clear wavy boundary. (0 to 10 inches thick)

2Cr--58 inches; variegated brown (10YR 4/3); dark yellowish brown (10YR 4/4), brown (7.5YR 4/4), and dusky red (2.5YR 3/2) massive, weathered rock; very strongly acid (pH 4.6).

TYPE LOCATION: Marion County, Oregon; 0.2 mile southeast of South Burn Guard Station; 100 feet east of South Burn Road in southwest 1/4 southeast 1/4 southwest 1/4, sec. 26, T. 8 S., R. 1 E.

RANGE IN CHARACTERISTICS: The soil is usually moist and is dry between depths of 4 and 11 inches for less than 45 consecutive days during the summer. The mean annual soil temperature is 48 to 53 degrees F. Depth to a paralithic contact ranges from 40 to 60 inches or more. The solum ranges from 40 to 60 inches or more thick. The solum is strongly acid or very strongly acid. The umbric epipedon is from 10 to 20 inches thick. The particle-size control section is silty clay or clay with 45 to 55 percent clay.

The A horizon has hue of 7.5YR or 5YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is silt loam, clay loam, silty clay loam, or gravelly loam. It has moderate or strong granular or very fine subangular blocky structure. It has 0 to 25 percent gravel. Some pedons have stones on the surface.

The Bw horizon has hue of 5YR or 2.5YR, value of 3 or 4 moist, 4 or 5 dry, and chroma of 4 to 6 dry. It is clay or silty clay. It has weak fine or medium subangular blocky structure.

COMPETING SERIES: These are the Astoria, Blachly, Ead, Fendall, and Gleneden series. Astoria soils have amorphous materials in the exchange complex and have hue yellower than 5YR throughout. Blachly soils have an ochric epipedon. Ead and Fendall soils have bedrock at depths of less than 40 inches and lack hue as red as 5YR. Ead soils also have an epipedon thicker than 20 inches. Gleneden soils are somewhat poorly drained and have matrix colors of 10YR or yellower.

GEOGRAPHIC SETTING: McCully soils are on uplands at elevations between 800 to 3,000 feet. Slopes are dominantly 4 to 30 percent but range from 2 to 70 percent. The soils formed in fine textured colluvium over fine and coarse grained, basic igneous, tuffaceous agglomerate. The climate is humid with a mean annual precipitation of 60 to 90 inches. The mean January temperature is 36 degrees F, the mean July temperature is 62 degrees F, and the mean annual temperature is 45 to 51 degrees F. The frost-free period is 145 to 200 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cumley, Honeygrove, and Kinney soils. Cumley and Honeygrove soils have an argillic horizon. Cumley soils also are mottled in the lower part of the B horizon. Kinney soils are moderately fine textured and have amorphous materials in the exchange complex.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderately slow permeability.

USE AND VEGETATION: Primarily forest, but some areas are cropped to small grains, grass seed, and pasture. Native vegetation is Douglas-fir, western hemlock, cascara, salal, western swordfern, and brackenfern.

DISTRIBUTION AND EXTENT: Foothills of the western Cascade Mountains in Oregon. The series is extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Marion County, Oregon, 1973.

REMARKS: Diagnostic horizons and features recognized in this pedon include:

Umbric epipedon - from 1 to 11 inches (A and AB horizons)
Cambic horizon - from 11 to 58 inches (Bw1, Bw2, and BC horizons)

ADDITIONAL DATA: Characterization data on 2 profiles (S60-OR-24-3 and 4) reported in Riverside Soil Survey Lab report for soils sampled in Marion County, Oregon, 1960.

National Cooperative Soil Survey
U.S.A.