LOCATION SAWABE NVEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, frigid, shallow Abruptic Xeric Argidurids
TYPICAL PEDON: Sawabe very gravelly loam - rangeland (Color is for dry soil unless otherwise stated).
A1--0 to 2 inches; dark grayish-brown (10YR 4/2) very gravelly loam, very dark brown (10YR 2/2) moist; moderate very fine granular stucture; soft, very friable, slightly sticky, slightly plastic; many micro, and common fine roots; many very fine interstitial pores; contains 65 to 85 percent gravel; slightly acid (pH 6.6); clear smooth boundary. (1 to 3 inches thick.)
A2--2 to 5 inches; light brownish-gray (10YR 6/2) loam, very dark grayish-brown (10YR 3/2) moist; massive soft, very friable, slightly sticky, slightly plastic; many micro and very fine, and common fine roots; common fine, and few medium tubular pores; many clean sand grains; neutral (pH 6.8); clear wavy boundary. (2 to 4 inches thick.)
A2--5 to 8 inches; light gray (10YR 7/1) gravelly silt loam, dark grayish-brown (10YR 4/2) moist; massive; soft, very friable, slightly sticky, slightly plastic; common very fine, and few fine roots; many very fine interstitial pores; many clean sand grains; neutral (pH 6.8); abrupt wavy boundary. (2 to 4 4 inches thick.)
Bt1--8 to-12 inches; brown (7.5YR 5/4) clay, with cautinuous brown (7.5YR 4/4) pressure cutans on ped faces, brown (7.5YR 4/4) moist; strong medium prismatic structure; very hard, very firm, very sticky, very plastic; few very fine and fine exped roots; few very fine tubular pores; few slickensides; neutral (pH 6.8); abrupt wavy boundary. (3 to 7 inches thick.)
Bt2k--15 to 22 inches; pink (7.5YR 7/4) clay loam, brown (7.5YR 4/4) moist; moderately fine and medium platy stricture; slightly hard, friable, sticky, plastic; no roots observed; few very fine interstitial and tubular pores; common moderately thick brown (7.5YR 4/4) clay films on ped faces; slightly effervescent; mildly alkaline (pH 7.8); abrupt wavy boundary. (2 to 4 inches thick.)
Bqkm--15 to 22 inches; brownish-yellow (10YR 6/6) indurated gravelly duripan with many continuous very thin very pale brown and white (10YR 7/3 and 8/1) silica and lime laminae, yellowish-brown (10YR 5/4) moist; massive; extremely hard, extremely firm, few very fine interstitial pores; many silica ridges between sand grains and all gravel are silica and lime coated; strongly effervescent in matrix but violently effervescent in limy part of laminae; moderatly alkaline (pH 8.2).
TYPE LOCATION: Washoe County, Nevada. The site is located approximately 25 feet east of the livestock exclosure on the Sheldon Game Range near the center of section 6, T. 46 N., R. 23 E., Mount Diablo base line and meridian.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the duripan ranges from 10 to 19 inches. The mean annual soil temperature ranges from 42 to 45 F., and mean summer soil temperature from 59 to 62 F. These soils are usually dry but are moist 1/4 of the time the soil temperature is 41 F. Mineralogy is montmorillonitic. They have nonclcareous upper sola that range in pH from 6.2 to 7.2. Their lower sola and duripan are weakly calcareous and range in pH from 7.6 to 8.6. Color of the A1 horizons includes hues of 10YR, values of 4 or 5 dry and 2 or 3 moist, and chromas of 2. Color values are 5.5 dry after the surface 7 inches are mixed. Structure of the A1 horizons ranges from weak or moderate, very fine to medium granular or subangular blocky, or is massive. Consistence ranges from soft or slightly hard. Thickness of the A2 horizons ranges from 5 to 8 inches. Colors include hues of 10YR, values of 6 or 7 dry and 3 or 4 moist, and chromas of 1 or 2. Common to many clean sand grains are present. Color of the B2t horizons includes hues of 7.5YR or 10YR, values of 5 or 4 dry or moist and chromas of 3 to 5. Structure ranges from strong, fine or medium, prismatic or colmnar. If two parts of the B2t horizons are present, the structure of the lower part ranges from weak, fine or medium prismatic or moderate or strong, medium or coarse angular blocky. Texture is predominantly heavy clay, but clay may also occur. When the argillic horizon is mixed the weighted average clay content is 60 percent. Few to many, fine or medium lime segregations and laminae also occur. Structure of the lower B horizons. Color of the duripan ranges widely and includes hues of 10YR or 7.5YR, values of 5 or 7 dry and 5 or 6 moist, and chromas of 3 to 6. White lime segregations and laminae also occur.Structure of the upper 4 to 8 inches of the duripan ranges from moderate or strong, medium or thick platy, or is massive.
COMPETING SERIES: The Fertaline series is the only other series classified in the same family at the present time. Fertaline soils differ by having 18 to 30 inch thick sola and depth to duripans. Catnip Millerlux soils are also similar but differ mainly in lacking indurated duripans but are underlain by hard bedrock. In addition Catnip soils have argillic horizons containing 60 percent clay.
GEOGRAPHICAL SETTING: Sawabe soils are on smooth to gently rolling, nearly level to moderately sloping plateaus having slope gradients of 0 to 9 percent. They have developed in loamy alluvium derived mainly from siliceous tuff with minor admixtures of basalt, andesite, rhyolite and volcanic ash.They occur at elevations of 6,000 to 7,000 feet in a cold continental climate having an average precipitation of 10 to 14 inches. The mean annual air temperature ranges from 41 to 44 F.
GEOGRAPHICALLY ASSOCIATED SOILS: Sawabe soils occur in the same general area as Espil and Powley in addition to the aforementioned Fertaline soils. Both the Espil and Powley soils not only have clay B2t horizons and duripans, but also have mollic epipedons.
DRAINAGE PERMEABILITY: Well drained. Surface runoff is medium. Permeability is very slow.
USE AND VEGETATION: Used to provide grazing for livestock and wildlife. The dominant vegetation consists of low sagebrush, Sandberg bluegrass, Thurber needlegrass, Webbers ricegrass, squirreltail, and miscellaneous annual and perennial forbs.
DISTRIBUTION AND EXTENT: Sawabe soils occur in northwestern Nevada and southeastern Oregon, where known areas are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Massacre Area, Washoe County, Nevada, 1968. Sawabe is the Indian name for big sagebrush.
REMARKS: Sawabe soils were formerly classified as Brown soils. This classification is tentatlve pending determination of sodium status of the B horizons in several more pedons.
OSED scanned by NSSQA. Last revised by state on 10/68.