LOCATION SHROYTON OR

Established Series
Rev: WMF/TDT
11/2010

SHROYTON SERIES

The Shroyton series consists of deep, well drained soils on volcanic uplands. They formed in ash. Slopes are 30 to 50 percent. The mean annual precipitation is about 40 inches and the mean annual temperature is about 42 degrees F.

TAXONOMIC CLASS: Ashy, glassy Humic Xeric Vitricryands

TYPICAL PEDON: Shroyton ashy loamy sand - woodland, on a 30 percent northeast-facing slope at 4860 feet elevation. (When described (8/7/86), the soil was dry throughout. Colors are for moist soil unless otherwise noted.)

Oi--0 to 2 inches; slightly decomposed needles and twigs of ponderosa pine and white fir.

A1--2 to 4 inches; dark brown (7.5YR 3/2) ashy loamy sand, brown (7.5YR 5/4) dry; weak fine granular structure; loose, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine irregular pores; 2 percent gravel; 35 percent sand-size pumice (0.5-2.0 millimeters); neutral (pH 7.0); gradual wavy boundary.

A2--4 to 17 inches; dark brown (7.5YR 3/2) ashy loamy sand, brown (7.5YR 5/4) dry; weak fine granular structure; loose, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine irregular pores; 2 percent gravel; 35 percent sand-size pumice (0.5-2.0 millimeters); neutral (pH 7.0); clear irregular boundary. (Combined thickness of the A horizon is 10 to 20 inches)

2Bw1--17 to 33 inches; strong brown (7.5YR 4/6) gravelly ashy coarse sandy loam, brown (7.5YR 5/4) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium and coarse roots; common very fine and fine irregular and common fine vesicular pores; 30 percent gravel; 30 percent sand-size pumice (0.5-2.0 millimeters); neutral (pH 7.0); clear wavy boundary. (10 to 20 inches thick)

3Bw2--33 to 57 inches; dark brown (10YR 3/3) gravelly ashy sandy loam, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine and medium roots; common very fine and fine irregular and common fine vesicular pores; 30 percent gravel; 40 percent sand-size pumice (0.5-2.0 millimeters); neutral (pH 7.0); abrupt irregular boundary. (20 to 30 inches thick)

4R--57 inches; andesite.

TYPE LOCATION: Deschutes County, Oregon; southwest corner of the southeast quarter of section 6, T. 17 S., R. 10 E. (Latitude 44 degrees, 7 minutes, 42 seconds N, Longitude 121 degrees, 34 minutes, 18 seconds W)

RANGE IN CHARACTERISTICS: These soils are usually moist but are dry in all parts of the moisture control section for 45 to 60 consecutive days after the summer solstice. The mean annual soil temperature is 41 to 45 degrees F. The mean summer soil temperature is 43 to 47 degrees F. The mollic epipedon is 10 to 20 inches thick. The solum contains 50 to 80 percent volcanic glass and glass-coated aggregates, phosphate retention is 40 to 70 percent, acid oxalate aluminum plus one half the iron is 0.40 to 0.80 percent and 15-bar water content on dried and undried samples is 5 to 12 percent. Depth to bedrock is 40 to 60 inches. Reaction is neutral throughout.

The Oi horizon is 1 to 3 inches thick except where disturbed.

The A horizon has value of 2 or 3 moist and 4 or 5 dry and chroma of 2 or 3 moist and 3 or 4 dry. It contains 0 to 10 percent gravel and 25 to 40 percent sand-size pumice (0.5-2.0 millimeters). Base saturation is assumed to be 50 to 80 percent. Organic matter content is 1 to 4 percent. Field estimated clay content is 2 to 6 percent.

The Bw horizon has value of 3 or 4 moist and 5 or 6 dry and chroma of 3, 4 or 6 moist and 3 or 4 dry. It is gravelly ashy sandy loam or gravelly ashy coarse sandy loam. It contains 15 to 30 percent gravels and 0 to 10 percent cobbles. Total rock fragment content is 15 to 35 percent. It contains 30 to 60 percent sand-size pumice (0.5-2.0 millimeters). Field estimated clay content is 5 to 10 percent.

A gravelly ashy loamy sand or ashy sandy loam C horizon may be present in some pedons.

COMPETING SERIES: These are the Kittleson, Steiger, and Sycan series. Kittleson soils have an ochric epipedon, field estimated clay content of 10 to 18 percent clay, and a paralithic contact at 40 to 60 inches. Steiger soils have an ochric epipedon, are very deep, and field estimated clay content is less than 5 percent. Sycan soils have an ochric epipedon.

GEOGRAPHIC SETTING: The Shroyton soils are on volcanic uplands at elevations of 4500 to 6400 feet. The soils formed in ash over bedrock. The climate is characterized by cold, wet winters and cool, dry summers. The mean annual precipitation is 30 to 50 inches, falling mostly as snow. The mean annual temperature is 40 to 44 degrees F. The frost-free period is 10 to 50 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sisters and Yapoah soils. They are on volcanic uplands and are frigid.

DRAINAGE AND PERMEABILITY: Well drained; rapid permeability.

USE AND VEGETATION: These soils are used for timber production, wildlife habitat and recreation. Potential native vegetation is ponderosa pine, white fir, Douglas fir, snowberry, and pinegrass.

DISTRIBUTION AND EXTENT: Footslopes of the eastern high Cascade Mountains in central Oregon; MLRA 6. The series is not extensive.

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

SERIES ESTABLISHED: Deschutes County (Upper Deschutes River Area), Oregon, 1992.

REMARKS: Diagnostic horizons and features in this pedon are:

mollic epipedon - from 2 to 17 inches (A1, A2 horizons); assume base saturation is over 50 percent by ammonium acetate.

cambic horizon - from 17 to 57 inches (2Bw, 3Bw horizons).

andic soil properties - 0 to 55 inches; based on laboratory data from the Wanoga Series. The Wanoga series is in a lower precipitation zone, but the ash material is from the same volcanic event.

National Cooperative Soil Survey
U.S.A.