LOCATION ARTA WA
Established Series
Rev. SBC/RFP/RJE
05/2012
ARTA SERIES
The Arta series consists of very deep, moderately well drained soils that formed in old alluvium. Arta soils are on terraces and have 0 to 30 percent slopes. The mean annual temperature is about 49 degrees F. and the mean annual precipitation is about 90 inches.
TAXONOMIC CLASS: Medial, ferrihydritic, mesic Aquic Fulvudands
TYPICAL PEDON: Arta medial silt loam-on southwest-facing 3 percent slope under grass pasture of 60 foot elevation. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures. When described the soil was nearly dry to 26 inches and moist below.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) medial silt loam, dark grayish brown (10YR 4/2) dry; strong fine and very fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; many fine and very fine roots; common very fine interstitial pores; strongly acid (pH 5.2); clear smooth boundary. (5 to 7 inches thick)
A1--6 to 18 inches; very dark grayish brown (10YR 3/2) medial silt loam, grayish brown (10YR 5/2) dry; strong very fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; many fine and very fine roots; common very fine interstitial pores; strongly acid (pH 5.2); clear wavy boundary. (5 to 13 inches thick)
BA--18 to 26 inches; brown (10YR 4/3) medial silty clay loam, brown (10YR 5/3) dry; strong very fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine and very fine roots; many fine and very fine tubular pores; very strongly acid (pH 5.0); gradual wavy boundary. (0 to 13 inches thick)
Bw1--26 to 39 inches; dark yellowish brown (10YR 4/4) medial silty clay loam, yellowish brown (10YR 5/4) dry; few fine distinct strong brown (7.5YR 5/6) mottles, reddish yellow (7.5YR 6/8) dry; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; few fine and very fine roots; common fine tubular pores; 10 percent rounded paragravel sandstone fragments; very strongly acid (pH 4.8); clear smooth boundary. (9 to 14 inches thick)
Bw2--39 to 60 inches; dark yellowish brown (10YR 4/4) medial silty clay loam, light yellowish brown (2.5Y 6/4) dry; common fine distinct strong brown (7.5YR 5/6) mottles, reddish yellow (7.5YR 6/8) dry, and common fine distinct gray (10YR 5/1) mottles, light gray (10YR 7/1) dry; weak fine subangular blocky structure; hard, friable, sticky and slightly plastic; few very fine roots; common fine tubular pores; 5 percent rounded paragravel sandstone fragments; very strongly acid (pH 4.8).
TYPE LOCATION: Pacific County, Washington; 2 miles south of Menlo on State Highway 6, then east on private road that splits hayfields; 40 feet south of road, 150 feet west of railroad tracks; NE1/4 NE1/4 SW1/4 sec. 24, T. 13 N., R. 8 W.
RANGE IN CHARACTERISTICS: The solum is 40 to more than 60 inches thick. Depth to redox features, with chroma of 2 or less, is 25 to 40 inches. The particle-size control section is 27 to 35 percent clay and 10 to 15 percent sandstone paragravel fragments. Mean annual soil temperature is 47 to 50 degrees F. The umbric epipedon is 10 to 20 inches thick. Organic carbon is less than 4 percent in the upper two-thirds of the control section.
The A horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 1 through 3. It has moderate or strong granular or subangular blocky structure. It is strongly acid or very strongly acid.
The B horizon has hue of 7.5YR, 10YR or 2.5Y, value of 3 through 5 moist, 5 or 6 dry and chroma of 3 through 6. It is dominantly medial silty clay loam but ranges to silty clay below a depth of 40 inches. This horizon has 0 to 15 percent sedimentary paragravel rock fragments. It has weak to strong subangular blocky structure. It is extremely acid to strongly acid.
COMPETING SERIES: These are the
Astoria,
Boistfort,
Bunker,
Copalis,
Elochoman,
Hoquiam,
Ilwaco,
Kinney,
Knappton,
Lebam,
Lytell,
Makah,
Mopang,
Narel, Hewskah,
Oyhut,
Palix,
Papac,
Silcox,
Skamo,
Vesta, Wallville,
Willapa,
Zenker and
Zyzyl series. Astoria and Boistfort soils are more than 35 percent apparent clay and lack mottles. Bunker and Hoquiam soils have 15 to 35 percent and 5 to 35 percent, respectively, hard rock fragments in the control section and lack mottles. Copalis soils have 35 or more percent soft rock fragments in the control section, lack mottles and have a paralithic contact within 40 inches. Elochoman soils have 20 to 27 percent apparent clay and lack mottles. Ilwaco and
Newskah soils have less than 27 percent apparent clay, 4 to 7 percent organic carbon in the upper two-thirds of the control section and lack mottles. Kinney soils have 25 to 35 percent hard rock fragments in the control section and lack mottles. Knappton and Papac soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section, 15 to 35 percent hard rock fragments in the control section and lack mottles. Also Papac soils have a paralithic contact within 40 inches. Lebam and Vesta soils have 35 or more percent apparent clay in the control section, 4 to 7 percent organic carbon in the upper two-thirds of the control section and lack mottles. Lytell, Zenker and Zyzyl soils have 35 to 80 percent soft rock fragments in the control section and lack mottles. Makah soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section, 15 to 30 percent hard and 15 to 40 percent soft rock fragments in the control section, 5 to 15 percent hard rock fragments in the control section and lack mottles. Narel soils have apparent texture of loam or silt loam, 4 to 7 percent organic carbon in the upper two-thirds of the control section and lack mottles. Oyhut soils have 10 to 35 percent hard rock fragments in the control section and a petroferric contact at a depth of 24 to 40 inches. Palix soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section, 20 to 80 percent soft rock fragments in the control section and lack mottles. Silcox soils have apparent texture of sandy loam or fine sandy loam, 10 to 35 percent hard rock fragments in the control section and lack mottles. Skamo soils have apparent texture of silty clay or silty clay loam with more than 35 percent clay.
Walville soils have 35 to 60 percent soft weathered breccia fragments and lack mottles. Willapa soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section.
GEOGRAPHIC SETTING: Arta soils are on terraces ranging in elevation from 50 to 500 feet. Slopes are 0 to 30 percent. These soils formed in alluvium. They are in a humid marine climate with cool wet winters and cool dry summers. The mean annual precipitation is 70 to 110 inches. The mean January temperature is 38 degrees F., mean July temperature is 59 degrees F.; and the mean annual temperature is 49 degrees F. The growing season (28 degrees F.) is 150 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Grehalem,
Nemah and the competing
Astoria,
Elochoman,
Lytell and
Sylvia soils. Grehalem soils lack grayish mottles in the control section and have an irregular decrease in organic carbon. Nemah soils have an aquic moisture regime.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderate permeability.
USE AND VEGETATION: Timber production, hay crops and pasture are the principal uses. Small areas are cleared for homesites. Native vegetation is western hemlock and Douglas-fir with scattered Sitka spruce, western redcedar and red alder, and an understory of vinemaple, Devil's club, western swordfern, western brackenfern, salal, huckleberry and blackberry.
DISTRIBUTION AND EXTENT: Southwestern Washington; MLRA 1. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 1970.
REMARKS: Classification changed 4/94 because of recent amendments to Soil Taxonomy, and permeability corrected. The particle-size control section is assumed to have 5 to 10 percent volcanic glass and 2.0 to 3.0 percent Al + 1/2 Fe by ammonium oxalate.
National Cooperative Soil Survey
U.S.A.