LOCATION ALVOR WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Cumulic Endoaquolls
TYPICAL PEDON: Alvor silty clay loam, alfalfa, clover hay. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) silty clay loam, brown (10YR 4/3) dry; strong coarse subangular blocky structure that parts to strong fine subangular blocky; hard, friable, sticky and plastic; common roots; many very fine interstitial pores; medium acid (pH 6.0); clear smooth boundary. (6 to 8 inches thick)
A12--7 to 14 inches; very dark brown (10YR 2/2) silty clay loam, brown (10YR 4/3) dry; strong medium subangular blocky structure that parts to strong fine and very fine subangular blocky; hard, friable, sticky and plastic; common roots; many very fine interstitial pores; medium acid (pH 6.0); gradual smooth boundary. (6 to 9 inches thick)
A3--14 to 25 inches; dark brown (7.5YR 3/2) silty clay, brown (7.5YR 4/2) dry; common medium distinct dark gray (5YR 4/1) and few fine prominent yellowish red (5YR 4/8) mottles, strong brown (7.5YR 5/8) dry; strong medium subangular blocky structure parting to strong fine subangular blocky; very hard, firm, very sticky and plastic; few roots; many very fine interstitial pores; medium acid (pH 6.0); gradual smooth boundary. (9 to 15 inches thick)
B21g--25 to 37 inches; dark gray (10YR 4/1) silty clay, brown (10YR 5/3) dry; many fine prominent yellowish red (5YR 4/8) mottles, reddish yellow (5YR 6/8) dry; strong medium subangular blocky structure parting to strong fine and very fine subangular blocky; hard, firm, very sticky and plastic; few roots; few very fine and fine tubular and many very fine interstitial pores; slightly acid (pH 6.4); gradual smooth boundary. (11 to 14 inches thick)
B22g--37 to 47 inches; grayish brown (10YR 5/2) silty clay, light gray (10YR 6/1) dry; common medium prominent yellowish red (5YR 4/8) mottles, reddish yellow (5YR 6/8) dry; strong medium subangular blocky structure parting to strong fine subangular blocky; very hard, firm, very sticky and plastic; few fine and very fine tubular and many very fine interstitial pores; slightly acid (pH 6.2); clear smooth boundary. (8 to 10 inches thick)
B23g--47 to 60 inches; grayish brown (10YR 5/2) clay, light gray (N 7/) dry; common medium prominent yellowish red (5YR 4/8) mottles, reddish yellow (5YR 6/8) dry; strong medium subangular blocky structure; extremely hard, firm, very sticky and very plastic; common fine tubular and many very fine interstitial pores; medium acid (pH 6.0).
TYPE LOCATION: Lewis County, Washington; two miles north of Chehalis; 100 feet east, 200 feet north of center sec. 18, T.14N., R.2W.
RANGE IN CHARACTERISTICS: The solum thickness ranges from 48 to more than 60 inches. Alvor soils are usually moist. The mean annual soil temperature at depth of 20 inches ranges from 47 degrees to 52 degrees F. The control section is silty clay or clay and has 40 to 55 percent clay. Rock fragments in the solum range from 0 to 10 percent. The mollic epipedon is 24 to more than 30 inches thick. Soil reaction is medium to slightly acid and hue is 10YR or 7.5YR.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist or dry.
The B horizon has value of 3 through 5 moist, 4 through 6 dry and chroma of neutral through 3 dry. It is silty clay or clay.
COMPETING SERIES: This is the Chehalem series. Chehalem soils are somewhat poorly drained, lack mottles to a depth of about 23 inches and in the B horizon lack chroma of neutral or 1.
GEOGRAPHIC SETTING: Alvor soils are on low terraces adjacent to perennial streams at elevations of 100 to 350 feet. These soils formed in alluvium weathered from shale, sandstone and basic igneous rocks. They are in a marine climate with 40 to 60 inches annual precipitation occurring mostly as rain in the winter. Mean January temperature is 38 degrees F., mean July temperature is 65 degrees F., and mean annual temperature is 52 degrees F. The frost-free season is 150 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chehalis, Clato, Galvin, Newruss, and Reed soils. Chehalis and Clato soils are well drained. Newruss soils are somewhat excessively drained. Reed soils have argillic horizons. Galvin soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; moderate permeability in the A horizon and moderately slow in the B horizon; water table within .5 to 1.5 feet of the soil surface during the winter. Alvor soils are subject to frequent overflow.
USE AND VEGETATION: Hay, pasture, small grain, and cultivated crops. The native vegetation is Douglas-fir, red alder, vinemaple, and brush.
DISTRIBUTION AND EXTENT: Located along the Chehalis River and its tributaries. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1976.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.