LOCATION MADRAS OR+IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argixerolls
TYPICAL PEDON: Madras loam - cropland, on nearly level irrigated field at 2400 feet elevation. (When described (10/18/89), the soil was dry throughout. Colors are for dry soil unless otherwise noted.)
Ap1--0 to 4 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine interstitial pores; neutral (pH 6.8); abrupt smooth boundary.
Ap2--4 to 10 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate coarse platy structure; hard, friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; neutral (pH 6.8); abrupt smooth boundary. (Combined thickness of the Ap horizon is 7 to 14 inches)
Bt1--10 to 16 inches; yellowish brown (10YR 5/4) loam, dark brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, friable, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; few faint clay films lining pores and on faces of peds; 25 percent clay (estimated); neutral (pH 7.2); clear smooth boundary.
Bt2--16 to 23 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 4/3) moist; weak coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine tubular pores; common prominent clay films lining pores and on faces of peds; 35 percent clay (estimated); mildly alkaline (pH 7.6); clear wavy boundary. (Combined thickness of the Bt horizon is 8 to 20 inches)
2Crk--23 to 27 inches; consolidated gravel, cobble, and sand sediments of the Deschutes Formation, moderately effervescent with carbonates along fractures. (2 to 6 inches thick) (See Remarks)
2R--27 inches; basalt.
TYPE LOCATION: Jefferson County, Oregon; 100 feet east and 50 south of the northwest corner of the southwest quarter of the southwest quarter of section 23, T. 10 S., R. 13 E. (Latitude 44 degrees, 40 minutes, 57 seconds N, Longitude 121 degrees, 8 minutes, 31 seconds W)
RANGE IN CHARACTERISTICS: The depth to basalt or tuff bedrock (lithic) is 22 to 40 inches. The soil moisture control section is usually dry and 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 mollic epipedon is 7 to 14 inches thick. The particle-size control section averages 25 to 35 percent clay.
The A horizon has hue of 10YR, value of 5 dry and 3 moist, and chroma of 3 dry and 2 or 3 moist. It is sandy loam and loam. It is neutral or mildly alkaline. It contains 10 to 30 percent glass and glass-coated aggregate and has an acid oxalate extractable aluminum plus one-half the acid oxalate iron of less than 0.4 percent.
The Bt horizon has hue of 10YR, value of 5 dry and 3 moist, and chroma of 4 dry and moist. It is loam, clay loam, or cobbly loam or clay loam. Rock fragment content ranges from 0 to 20 percent gravel and 0 to 25 percent cobbles. Total rock fragments range from 5 to 30 percent. It is neutral to moderately alkaline.
COMPETING SERIES: These are the Bissell, Bjork, Cowiche, Dodes, Indiano, Margerum, Noslo, Orr, Pahrange, Simcoe, Springmeyer, Truax(T), Uhaldi, and Wenatchee series. Bissell, Cowiche, Margerum, Orr, Springmeyer, Truax, and Wenatchee soils are greater than 40 inches to bedrock. Bjork, Noslo, Pahrange, and Uhaldi soils lack the lithic contact below the paralithic layer. Indiano soils are slightly acid or neutral, typically have a stony or very stony surface and have formed in colluvium from rhyolitic rocks. Simcoe soils lack the thin paralithic layer above the lithic rock.
GEOGRAPHIC SETTING: Madras soils are on nearly level to hilly uplands, terraces, and plateaus. Slopes are 0 to 40 percent but are typically less than 15 percent. These soils formed in medium textured eolian materials and are underlain by gravels and basalt of the Deschutes Formation. The climate is characterized by cool, moist winters and hot, dry summers. Elevations range from 2000 to 3,200 feet. The mean annual precipitation is 8 to 12 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 Agency, Cullius, and Era soils. Agency soils are on terraces and plateaus and do not have an argillic horizon. Cullius soils are on terraces and plateaus and are shallow, fine textured soils with an argillic horizon. Era soils are in swales on uplands and are deep and coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: These soils are used for irrigated cropland, pasture, and livestock grazing. Potential native vegetation is western juniper, mountain and 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: Deschutes Irrigation Project, 1946.
REMARKS: Diagnostic horizons and features in this pedon:
mollic epipedon - from the soil surface to 10 inches. (Ap1 and Ap2 horizons)
argillic horizon - from 10 to 23 inches. (Bt1 and Bt2 horizons)
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.
This draft (2/92) reflects a change in classification from fine-loamy, mixed, mesic Xerollic Durargids based on the presence of a mollic epipedon from 0 to 10 inches and review of the duripan. The pan is considered to be geologic Deschutes Formation material.
ADDITIONAL DATA: Partial laboratory data are available for this soil. Reference sample S89OR-031-014 from Jefferson County, Oregon, NSSL, Lincoln, NE, 5/30/90.