LOCATION TOPPER             OR
Established Series
Rev. MGL/AON/RWL
03/2001

TOPPER SERIES


The Topper series consists of very deep, well drained soils that formed in loess with an influence of volcanic ash in the surface. Topper soils are on hills. Slopes are 2 to 30 percent. The mean annual precipitation is about 16 inches and the mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Vitrandic Haploxerolls

TYPICAL PEDON: Topper ashy silt loam, cultivated, at an elevation of 4,160 feet. (Colors are for moist soil unless otherwise noted.)

Ap--0 to 6 inches; very dark brown (10YR 2/2) ashy silt loam grayish brown (10YR 5/2) dry; weak fine platy structure; soft, friable, slightly sticky and slightly plastic; many very fine roots; few very fine tubular pores; neutral (pH 6.8); abrupt smooth boundary.

A--6 to 11 inches; dark brown (10YR 3/3) ashy silt loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common fine roots; common fine tubular pores; neutral (pH 6.8); abrupt irregular boundary. (Combined thickness of the A horizon is 10 to 16 inches)

C--11 to 15 inches; brown (10YR 4/3) silt loam, light gray (10YR 7/2) dry; massive; soft, very friable, nonsticky and nonplastic; few fine roots; common very fine tubular pores; slightly alkaline (pH 7.4); abrupt irregular boundary. (0 to 8 inches thick)

2Bwb--15 to 25 inches; dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; weak coarse prismatic structure; slightly hard, friable, sticky and plastic; few fine roots; many fine tubular pores; neutral (pH 7.2); clear smooth boundary. (0 to 12 inches thick)

2Bkb1--25 to 35 inches; dark yellowish brown (10YR 4/4) silty clay loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; hard, friable, sticky and plastic; few fine roots; many fine tubular pores; strongly effervescent; mycelium lime; strongly alkaline (pH 8.6); gradual boundary. (6 to 12 inches thick)

2Bkb2--35 to 60 inches; brown (10YR 5/3) silt loam, light gray (10YR 7/2) dry; massive; soft, friable, slightly sticky and slightly plastic; few fine roots; many fine tubular pores; strongly effervescent; soft segregated lime throughout; strongly alkaline (pH 8.6).

TYPE LOCATION: Wallowa County, Oregon; located about 6 miles north of Joseph; center of section 29, T. 1 S., R. 45 E. (Latitude 45 degrees, 26 minutes, 56 seconds N.; Longitude 117 degrees, 13 minutes, 04 seconds W.)

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 44 to 47 degrees F. In most years the soils are usually moist but dry between 4 and 12 inches for 60 to 90 consecutive days within the 3-month period following the summer solstice. The mollic epipedon is 10 to 16 inches thick. Depth to secondary lime ranges from 20 to 40 inches with the calcic horizon having a calcium carbonate equivalent of 15 to 20 percent. The particle-size control section is 18 to 30 percent clay and less than 15 percent coarser than very fine sand. Depth to bedrock is greater than 60 inches.

The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It has 30 to 60 percent volcanic glass and glass coated aggregate and less than 0.1 percent acid oxalate extractable aluminum plus one-half iron. It is ashy silt loam with 18 to 27 percent clay.

The C horizon, when present, has value of 3 or 4 moist, 5 to 7 dry and chroma of 2 to 4 moist and dry. It is neutral or slightly alkaline. It is silt loam with 18 to 27 percent clay.

The 2Bwb horizon has value of 3 or 4 moist, 5 or 6 dry and chroma of 3 or 4 moist and dry. It is silt loam with 18 to 27 percent clay.

The 2Bkb1 horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 or 4 moist and dry. It is silt loam or silty clay loam with 18 to 30 percent clay. It is moderately to strongly calcareous with segregated or mycelium lime in the lower part.

The 2Bk2 horizon has value of 4 or 5 moist, 6 or 7 dry and chroma of 2 to 4 moist and dry. It is silt loam or loam with 18 to 27 percent clay. It has 0 to 10 percent gravel and 0 to 5 percent cobbles.

COMPETING SERIES: This is the Hadencreek series. The Hadencreek soils are moderately well drained, have 5 to 20 percent volcanic glass in the upper 7 to 14 inches, and have 5 to 20 percent calcium carbonate equivalent in the Bk horizon.

GEOGRAPHIC SETTING: The Topper soils are on hills and have slopes of 2 to 30 percent. The soils formed in loess and mixed loess and volcanic ash . Elevations of 3,400 to 4,500 feet. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation of 13 to 17 inches. The mean annual temperature is 42 to 45 degrees F. The frost-free period season is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hurwal, Parsnip, Powwatka, and Snell series. Hurwal soils are on north-facing slopes, have argillic horizons, and lack secondary lime. Parsnip soils are on broad plateaus, have argillic horizons, and are 10 to 20 inches to bedrock. Powwatka soils are on adjacent hills, have argillic horizons, lack secondary lime, and are 20 to 40 inches to bedrock. Snell soils are on north-facing slopes, are clayey-skeletal, and lack secondary lime.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.

USE AND VEGETATION: The soils are used mainly for small grain, alfalfa and pasture. Native vegetation is Idaho fescue with small amounts of associated forbs.

DISTRIBUTION AND EXTENT: Valleys of northeastern Oregon; MLRA 9. The series is inextensive.

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

SERIES ESTABLISHED: Wallowa County, Oregon, 1998. The source of name is Topper lookout.

REMARKS: This series has been reclassified from a Calcic Haploxerolls to a Vitrandic Haploxerolls.

Diagnostic horizons and features recognized in this pedon include:

Mollic epipedon - the zone from 0 to 11 inches (Ap and A horizons)

Calcic horizon - the zone from 25 to 60 inches (2Bkb1 and 2Bkb2 horizons) with an assumed calcium carbonate equivalent of 15 to 20 percent.

Calcic subgroup feature - presence of calcic horizon beginning at 25 inches.

Vitrandic subgroup feature - the zone from 0 to 11 inches (Ap and A horizons) based on laboratory data from the associated Parsnip soil.

Particle-size control section - the zone from 10 to 40 inches.


National Cooperative Soil Survey
U.S.A.