LOCATION YACHATS                 OR

Established Series
Rev. JAS/TDT/RWL
06/2011

YACHATS SERIES

The Yachats series consists of very deep, well drained soils that formed in recent alluvium. Yachats soils are on flood plains and have slopes of 0 to 3 percent. The mean annual precipitation is about 80 inches and the mean annual temperature is about 51 degrees F.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, isomesic Fluventic Humudepts

TYPICAL PEDON: Yachats very fine sandy loam, pasture. (Color are for moist soil unless otherwise noted.)

Ap-- 0 to 7 inches; dark brown (10YR 3/3) very fine sandy loam, brown (10YR 5/3) dry; weak fine subangular blocky structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; strongly acid (pH 5.5); abrupt smooth boundary. (6 to 9 inches thick)

A--7 to 14 inches; dark brown (10YR 3/3) fine sandy loam, brown (10YR 5/3) dry; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular pores; strongly acid (pH 5.5); abrupt smooth boundary. (4 to 11 inches thick)

Bw--14 to 22 inches; brown (10YR 4/3) loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine irregular parting to many fine continuous tubular pores; strongly acid (pH 5.5); gradual smooth boundary. (0 to 15 inches thick)

C1--22 to 31 inches; brown (10YR 4/3) fine sandy loam, yellowish brown (10YR 5/4) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine continuous tubular pores; strongly acid (pH 5.4); gradual smooth boundary. (8 to 25 inches thick)

C2--31 to 60 inches; brown (10YR 4/3) loamy fine sand, light yellowish brown (10YR 6/4) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine foots; many very fine continuous tubular pores; strongly acid (5.4).

TYPE LOCATION: Lincoln County, Oregon; about 50 feet northeast of Yachats River on the lower surface of the flood plain in the SW1/4 NW1/4 NE1/4 section 36, T. 14 S., R. 12 W.

RANGE IN CHARACTERISTICS: The soils are dry less than 45 consecutive days between the depths of 4 and 12 inches following the summer solstice. The mean annual soil temperature is 50 to 54 degrees F. Under native vegetation the difference between the mean summer and mean winter soil temperature is 5 to 9 degrees F. It is extremely acid to strongly acid throughout. The umbric epipedon is from 10 to 20 inches thick. The particl-size control section averages 5 to 15 percent clay and more than 15 percent sand that is coarser than very fine sand. Organic carbon decreases irregularly throughout the profile.

The Ap and A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It is loam, very fine sandy loam or fine sandy loam and has 5 to 18 percent clay. It has 4 to 8 percent organic matter.

The Bw horizon, when present, has value of 3 to 5 moist, 5 or 6 dry and chroma of 3 or 4 moist and dry. It is loam, silt loam, very fine sandy loam, or fine sandy loam.

The C horizon has value of 3 to 5 moist, 5 or 6 dry and chroma of 2 to 4 moist and dry. I tis very fine sandy loam, fine sandy loam, or loamy fine sand. It has 5 to 10 percent clay. Stratified sandy or gravelly layers may occur in some pedons.

COMPETING SERIES: There are no competing series in this family.

GEOGRAPHIC SETTING: Yachats soils are on lower surfaces of the flood plain at elevations of 10 to 100 feet. Slopes are 0 to 3 percent. The soils formed in recent alluvium. The climate is characterized by warm, wet winters and warm, moist summers with fog. The mean annual precipitation is 70 to 90 inches. The amean annual temperature is 49 to 53 degrees F. The frost-free period is about 160 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brenner, Nehalem and Nestucca soils. All of these soils occur on flood plains. Brenner, Nehalem and Nestucca soils are fine-silty. Brenner soils are poorly drained and Nestucca soils are somewhat poorly drained.

DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability. The soils are subject to brief periods of frequent flooding during the months of November through April. An apparent water table is at its highest limit during this same period.

USE AND VEGETATION: Most areas of this soil have been cleared and seeded to pasture. Native vegetation includes red alder, salmonberry, willow, western swordfern, grasses and forbs. A few young Sitka spruce are present in some areas.

DISTRIBUTION AND EXTENT: Flood plain of the Ingram geomorphic surface along coastal rivers in western Oregon; MLRA 4A. The series is of small extent.

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

SERIES ESTABLISHED: Lincoln County, Oregon, 1990.

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

Umbric epipedon - from soil surface to a depth of 14 inches. (Ap and A horizon)
Cambic horizon - from 14 to 22 inches. (Bw horizon)
Organic carbon decreases irregularly throughout the profile.

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National Cooperative Soil Survey
U.S.A.