LOCATION CULLIUS OR

Established Series
REV: RPM/TDT
11/2010

CULLIUS SERIES

The Cullius series consists of shallow, well drained soils on terraces and plateaus. They formed in fine-textured colluvium over semiconsolidated sediments and welded tuff from the Deschutes Formation. Slopes are 0 to 15 percent. The mean annual precipitation is about 10 inches and the mean annual temperature is about 48 degrees F.

TAXONOMIC CLASS: Clayey, smectitic, mesic Aridic Lithic Argixerolls

TYPICAL PEDON: Cullius loam - cropland, on a 3 percent west-facing slope at 2700 feet elevation. (When described (10/10/89), the soil was dry throughout. Colors are for dry soil unless otherwise noted.)

Ap--0 to 3 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; neutral (pH 7.2); abrupt smooth boundary.

A--3 to 6 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; neutral (pH 7.3); clear wavy boundary. (Combined thickness of the A horizon is 3 to 11 inches)

2Bt1--6 to 9 inches; grayish brown (10YR 5/2) clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, firm, nonsticky and slightly plastic; few fine roots; many very fine tubular pores; few faint clay films in pores and ped faces; 30 percent clay (estimated); 10 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary.

2Bt2--9 to 17 inches; grayish brown (10YR 5/2) clay, dark yellowish brown (10YR 3/4) moist; moderate coarse prismatic structure; hard, firm, sticky and plastic; few very fine tubular pores; many prominent clay films in pores and ped faces; 60 percent clay (estimated); 10 percent cobbles; slightly alkaline (pH 7.8); abrupt smooth boundary. (Combined thickness of the 2Bt is 7 to 13)

2Crkq--17 to 18 inches; fractured tuff; common medium discontinuous veins of silica and calcium carbonate; effervescent. (0 to 4 inches thick)

2R--18 inches: welded tuff of the Deschutes Formation (see Remarks)

TYPE LOCATION: Jefferson County, Oregon; 500 feet north and 500 feet west of the southeast corner of the southwest quarter of section 17, T.12 S., R.13 E.(Latitude 44 degrees, 31 minutes, 21 seconds N, Longitude 121 degrees, 10 minutes, 9 seconds W)

RANGE IN CHARACTERISTICS: The solum thickness and depth to bedrock is 10 to 20 inches. The soil moisture control section is usually dry, it is dry in all parts for 120 to 150 days (cumulative) in the 4 months that follow the summer solstice. The mean annual soil temperature is 48 to 54 degrees F. The particle-size control section averages 35 to 50 percent clay.

The A horizon has hue of 10YR, value of 5 dry and 2 or 3 moist, and chroma of 2 or 3 moist and dry. It contains 10 to 30 percent volcanic glass and glass-coated aggregates. It is neutral to slightly alkaline.

The 2Bt horizon has hue of 10YR, value of 5 dry and 3 moist, and chroma of or 3 dry and 3 or 4 moist. It contains 0 to 10 percent gravel and 0 to 10 percent cobbles. It contains 0 to 10 percent total rock fragments. The lower part of the 2Bt has medium to coarse prismatic structure.

The 2Crkq horizon has discontinuous silica cementation and secondary carbonates in the form of soft powdery lime and coatings on the fractured tuff fragments.

COMPETING SERIES: These are the Devada, Deven, Devnot (T), Dunnlake (T), and Wylo soils. Devada soils lack the 2Crkq horizon above the lithic contact, have an abrupt A/B boundary and lack the pumice ash in the surface layers. Devnot soils contain 15 to 35 percent rock fragments, have a xeric moisture regime and lack the pumice ash in the surface. Deven soils have a xeric soil moisture regime. Dunnlake soils lack the pumice ash in the surface. Wylo soils have a mean annual soil temperature of 54 to 59 degrees F. and have 15 to 35 percent rock fragments in the particle-size control section.

GEOGRAPHIC SETTING: Cullius soils are on nearly level to gently sloping terraces and plateaus. They formed in fine textured colluvium over sediments from the Deschutes Formation. The climate is characterized by cool, moist winters and hot, dry summers. Elevations range from 2500 to 3000 feet. The mean annual precipitation is 8 to 11 inches. The mean annual temperature is 47 to 52 degrees F. The frost-free period is 110 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Madras, Agency, Era, Caphealy, and Reuter soils. Madras soils are moderately deep to bedrock. Agency soils are fine-loamy and moderately deep to bedrock. Era soils are in swales and are deep. Caphealy soils are on uplands and are moderately deep to semiconsolidated sediments. Reuter soils are on uplands and are shallow to semiconsolidated sediments.

DRAINAGE AND PERMEABILITY: Well drained; permeability is slow.

USE AND VEGETATION: These soils are used for irrigated cropland and livestock grazing. Potential native vegetation is western juniper, basin big sagebrush, antelope bitterbrush, bluebunch wheatgrass, and Idaho fescue.

DISTRIBUTION AND EXTENT: Terraces and plateaus of central Oregon; MLRA 10. The series is moderately extensive.

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

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

REMARKS: Diagnostic horizons and features recognized in this pedon:

mollic epipedon - the zone from the surface to 9 inches. (A and 2Bt1 horizons)

argillic horizon - the zone from 6 to 17 inches. (2Bt1 and 2Bt2 horizons)

aridic soil moisture regime

Deschutes Formation - semiconsolidated water-laid sediments composed of sands, gravels, and silts of volcanic origin, and reworked volcanic materials. Interbedded basalts and ash-flow tuffs are included in this formation.

National Cooperative Soil Survey
U.S.A.