LOCATION NORTH POWDER       OR
Established Series
Rev. AON/TDT
10/2002

NORTH POWDER SERIES


The North Powder series consists of moderately deep, well drained soils that formed in colluvium from quartz diorite, granite, or meta gabbro. North Powder soils are on hills and have slopes of 2 to 35 percent. The mean annual precipitation is 13 inches, and the mean annual temperature is 48 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Xeric Haplocambids

TYPICAL PEDON: North Powder loam, range. (Colors are for dry soil unless otherwise noted.)

A1--0 to 4 inches; light brownish gray (10YR 6/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots;many very fine pores; slightly acid (pH 6.2); clear smooth boundary. (2 to 8 inches thick)

A2--4 to 8 inches; light brownish gray (10YR 6/2) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (3 to 6 inches thick)

BA--8 to 12 inches; pale brown (10YR 6/3) loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular pores; neutral (pH 6.6); clear smooth boundary. (0 to 6 inches thick)

2Bw1--12 to 18 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, sticky and plastic; few roots; few fine pores; neutral (pH 7.0); gradual smooth boundary. (4 to 8 inches thick)

2Bw2--18 to 22 inches; brown (10YR 5/3) clay loam, dark brown (10YR 4/3) moist; weak, medium subangular blocky structure; hard, firm, sticky and plastic; few fine roots; few fine tubular pores; mildly alkaline (pH 7.4); gradual smooth boundary. (0 to 8 inches thick)

2Bk--22 to 28 inches; pale brown (10YR 6/3) loam, dark brown (10YR 4/3) moist; massive; hard, firm, slightly sticky and slightly plastic; few fine roots; few fine tubular pores; fine mycellia of lime, strong effervescence; moderately alkaline (pH 8.4); abrupt wavy boundary. (4 to 10 inches thick)

3Cr--28 inches; unconsolidated quartz diorite.

TYPE LOCATION: Baker County, Oregon; 40 feet south, 70 feet east of the northwest corner of sec. 21, T. 7 S., R. 39 E.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 52 degrees F. The soils are usually dry but are dry in all parts between depths of 4 and 12 inches for less than 75 percent of the time (cumulative) during the period that the soil temperature exceeds 41 degrees F, and the soils are continuously moist in all parts between depths of 4 and 12 inches for at least the 3 months period following the winter solstice. Depth to a paralithic contact is 20 to 40 inches.

The A horizon has value of 3 or 4 moist. It is slightly acid to neutral.

The Bw horizon has value of 3 or 4 moist, 4 through 6 dry and chroma of 3 or 4 moist and dry. It is clay loam, loam, or sandy clay loam with 18 to 35 percent clay and more than 15 percent particles coarser than very fine sand. Some pedons have few thin clay films in pores and very few on faces of peds.

The 2Bk horizon has value of 5 through 7 dry and 4 or 5 moist and chroma of 2 or 3 moist and dry. This horizon is mildly alkaline or moderately alkaline and is calcareous in some or all parts. It is loam, clay loam, gravelly loam, gravelly clay loam or sandy loam. It has 0 to 30 percent gravel.

COMPETING SERIES: These are the Agency, Defenbaugh(T), Ferdelford, Legler, Oxman, Pocan, Potratz and Redmond series. Agency soils have a lithic contact at a depth of 20 to 40 inches. Ferdelford soils are calcareous throughout except for the thin A1 horizon and have weathered tuff at a depth of less than 20 inches. Legler, Defenbaugh, and Pocan soils are more than 40 inches deep. Oxman soils are calcareous throughout. Potratz soils have a lithic contact at a depth of 20 to 40 inches. Redmond soils have 20 to 60 percent ash in the particle-size control section and have a lithic contact at a depth of 20 to 40 inches.

GEOGRAPHIC SETTING: The North Powder soils are on hills and have slopes of 2 to 35 percent. Elevations of 2,200 to 3,800 feet. The soils formed in colluvium from quartz diorite or granite with an influence of volcanic ash and loess in the A horizon. The climate is semiarid with warm dry summers and cool moist winters. The mean annual precipitation is 9 to 14 inches. The mean annual temperature is 45 to 50 degrees F. The mean January temperature is about 27 degrees F, and the mean July temperature is about 68 degrees F. The frost-free period is 110 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Keating, Ruckles, Ruclick, Virtue and the competing Legler series. Keating soils are fine textured and have an argillic horizon. Ruckles and Ruclick soils are clayey-skeletal. Virtue soils are fine-silty and 20 to 40 inches to a duripan.

DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderate permeability.

USE AND VEGETATION: Cropland and range. Dryland grain and irrigated hay and pasture are the principal crops. Native vegetation is bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, big sagebrush and rabbitbrush.

DISTRIBUTION AND EXTENT: Northeastern Oregon. The series is inextensive.

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

SERIES ESTABLISHED: Baker Area, Baker County, Oregon; 1942.

NSTH 17, RECLASSIFICATION ONLY, 3/95


National Cooperative Soil Survey
U.S.A.