LOCATION QUATAMA OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aquultic Haploxeralfs
TYPICAL PEDON: Quatama loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 9 inches; dark brown (10YR 3/3) loam, brown (10YR 5/3) dry; moderate fine and very fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine roots; many fine and very fine tubular pores; moderately acid (pH 5.6); abrupt smooth boundary. (7 to 9 inches thick)
Bt1--9 to 15 inches; dark yellowish brown (10YR 3/4) loam, pale brown (10YR 6/3) dry; weak coarse subangular blocky structure; hard, firm, slightly sticky and moderately plastic; few very fine roots; many medium to very fine tubular pores; continuous faint clay films in pores and few faint and moderately thick clay films on peds; moderately acid (pH 5.8); clear smooth boundary. (5 to 7 inches thick)
Bt2--15 to 21 inches; dark yellowish brown (10YR 3/4) clay loam, pale brown (10YR 6/3) dry; moderate fine subangular blocky structure; hard, firm, slightly sticky and moderately plastic; few very fine roots; many very fine tubular pores; continuous faint clay films in pores and few faint and distinct clay films on peds; moderately acid (pH 5.8); clear smooth boundary. (5 to 7 inches thick)
Bt3--21 to 30 inches; dark yellowish brown (10YR 3/4) clay loam, pale brown (10YR 6/3) dry; few fine distinct light brownish gray (10YR 6/2) redox depletions and reddish brown (5YR 4/3) redox concentrations; weak medium subangular blocky structure; hard, firm, slightly sticky and moderately plastic; few roots; many medium to very fine tubular pores; continuous faint clay films in pores and few faint and distinct clay films on peds; common manganese stains; moderately acid (pH 5.9); gradual wavy boundary. (6 to 12 inches thick)
BCt--30 to 43 inches; dark yellowish brown (10YR 3/4) loam, pale brown (10YR 6/3) dry; common fine dark grayish brown (10YR 4/2) redox depletions; weak coarse subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common medium to very fine tubular pores; many faint clay films; moderately acid (pH 6.0); gradual wavy boundary. (10 to 15 inches thick)
C--43 to 62 inches; dark yellowish brown (10YR 3/4) loam, yellowish brown (10YR 5/4) dry; common grayish brown (10YR 6/2 and 5/2) redox depletions and yellowish red (5YR 4/6 and 5/8) redox concentrations; massive; hard, firm, slightly sticky and slightly plastic; common very fine tubular pores.
TYPE LOCATION: Washington County, Oregon; about 100 feet east of the road in the SE corner of the SW1/4NW1/4NE1/4 sec. 9, T. 2 S., R. 2 W., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 54 to 56 degrees F. The soils are usually moist but are dry between depths of 4 and 12 inches each year during the summer for 45 to 60 consecutive days. Depth to bedrock is 60 inches or more and the thickness of the solum ranges from 40 to 60 inches. Depth to redox depletions with chroma of 2 or less ranges from 15 to 30 inches.
The A horizon has chroma of 2 or 3.
The B2t horizon has value of 3 or 4 moist and 4, 5 or 6 dry and chroma of 3 or 4 moist and dry. It is clay loam or silty clay loam and averages 27 to 35 percent clay and more than 15 percent coarser than very fine sand. This horizon has moderate coarse to fine subangular blocky structure in the upper part, to weak coarse or medium subangular blocky structure in the lower part. Clay films are faint to distinct and are in channels, pores, and on some vertical and horizontal faces of peds.
Stratified layers of sandy loam to loamy sand are below depths of 40 inches in some pedons.
COMPETING SERIES: This is the Stockel series. Stockel soils are somewhat poorly drained and have mottles throughout the profile. They are dry for 60 to 90 consecutive days during the summer. A similar soil with active mineralogy is the Wellsdale (T) series. Wellsdate soils have up to 50 percent sand coats on faces of peds and lack stratified lo9amy sand to sandy loam materials at depths of 40 inches or more.
GEOGRAPHIC SETTING: Quatama soils are on nearly level to gently sloping, low terraces with short, steep escarpment fronts at elevations of 95 to 400 feet. The soils formed in loamy, old alluvium of mixed origin. The climate is temperate with warm, dry summers and cool, moist winters. Annual precipitation is 40 to 50 inches. The mean January temperature is 36 to 38 degrees F, the mean July temperature is 65 to 67 degrees F, and the mean annual temperature is 52 to 54 degrees F. The frost-free period is 165 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aloha, Hillsboro, Huberly, and Woodburn soils. Aloha soils lack Bt horizons. Hillsboro soils are well drained, have a mollic epipedon, lack mottles, and are fine-silty. Huberly soils are poorly drained and have a fragipan. Woodburn soils have mollic epipedons and are fine-silty.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for production of berries, vegetables, orchards, nursery stock, grains, seed crops, hay and pasture. The native vegetation is Douglas fir, some western red cedar, oak, ash, Oregon grape, grasses and weeds.
DISTRIBUTION AND EXTENT: Tualatin Valley and the northern Willamette Valley, Oregon; MLRA 2. The soils are inextensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Washington County, Oregon, 1975.
REMARKS:
Ochric epipefdon
Argillic horizon - the zone from 9 to 43 inches (Bt1, Bt2, Bt3, and BCt horizons)
ADDITIONAL DATA: Characterization data on 1 profile reported in Riverside Soil Survey Laboratory report for Quatama soils (S68 Oreg 34- 1), unpublished, and sample # S99OR-067-001, NSSL, Lincoln, NE 5/01.