LOCATION SCOSSA                  NV

Established Series
Rev. EWB-TM-JVC-JBF
06/2017

SCOSSA SERIES

The Scossa series consists of very deep, very poorly drained soils that formed in alluvium derived from granitic rocks. Scossa soils are on alluvial fans. Slopes are 2 to 8 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, acid, mesic Histic Humaquepts

TYPICAL PEDON: Scossa mucky peat--pasture. (Colors are for moist soil unless otherwise noted.)

Oi1--0 to 8 cm; very dark brown (10YR 2/2) mucky peat, very dark grayish brown (10YR 3/2) dry; 68 percent herbaceous fiber material unrubbed, 44 percent rubbed; massive, slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; extremely acid (pH 3.9); clear wavy boundary. (5 to 25 cm thick)

Oi2--8 to 20 cm; black (10YR 2/1) mucky peat, very dark gray (10YR 3/1) dry, massive; 76 percent herbaceous fiber material unrubbed, 48 percent rubbed; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; extremely acid (pH 4.2); clear wavy boundary. (8 to 23 cm thick)

A1--20 to 25 cm; black (N 2.5/) mucky clay loam, dark gray (10YR 4/1) dry; massive; slightly hard, very friable, slightly sticky and nonplastic; many very fine and fine roots; many fine interstitial pores and common very fine tubular pores; extremely acid (pH 4.2); abrupt wavy boundary. (0 to 10 cm thick)

A2--25 to 30 cm; black (N 2.5/) mucky sandy clay loam, dark gray (10YR 4/1) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores and few fine interstitial pores; few (1 percent) fine distinct dark brown (10YR 3/3) pore linings of iron and manganese accumulation; extremely acid (pH 4.2); abrupt wavy boundary. (5 to 25 cm thick)

A3--30 to 43 cm; very dark gray (10YR 3/1) coarse sandy loam, dark gray (10YR 4/1) dry, massive; slightly hard, friable, slightly sticky and nonplastic; common very fine roots; common very fine and few fine tubular pores; common (15 percent) fine and medium distinct dark yellowish brown (10YR 4/4) masses of iron accumulation and common (20 percent) fine and medium prominent dark brown (7.5YR 3/4) pore linings of iron and manganese accumulation; 5 percent gravel; strongly acid (pH 5.1); abrupt wavy boundary. (10 to 25 cm thick)

A4--43 to 51 cm; black (10YR 2/1) fine sandy loam, dark gray (10YR 4/1) dry; massive; hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and few fine tubular pores; common (20 percent) fine and medium distinct dark yellowish brown (10YR 3/4) irregular masses and pore linings of iron accumulation; strongly acid (pH 5.3); abrupt wavy boundary. (8 to 25 cm thick)

A5--51 to 76 cm; very dark gray (10YR 3/1) coarse sandy loam, dark gray (10YR 4/1) dry; massive; hard, friable, moderately sticky and slightly plastic; common very fine roots; common very fine tubular pores; many (30 percent) fine and medium prominent brown (7.5YR 4/4) pore linings and irregular masses of iron accumulation; strongly acid (pH 5.3); clear wavy boundary. (8 to 25 cm thick)

A6--76 to 102 cm; very dark gray (10YR 3/1) loamy coarse sand, dark gray (10YR 4/1) dry; massive; hard, firm, nonsticky and nonplastic; few very fine interstitial pores; few (1 percent) fine and medium distinct brown (10YR 4/3) irregular masses of iron accumulation in the matrix; strongly acid (pH 5.5); clear wavy boundary. (0 to 30 cm thick)

Cg--102 to 152 cm; dark gray (N 4/) loamy coarse sand, dark gray (5Y 4/1) dry; massive; hard, firm, nonsticky and nonplastic; few very fine roots; few very fine interstitial pores; very strongly acid (pH 4.6).

TYPE LOCATION: Douglas County, Nevada; about 1.5 miles south-southeast of Mottsville and adjacent to NV state highway 206 (Foothill Road); about 650 feet north and 1,850 feet east of the southwest corner of section 23, T. 12 N., R. 19 E.; USGS Minden 7.5 minute topographic quadrangle; latitude 38 degrees 52 minutes 58.9 seconds N and longitude 119 degrees 49 minutes 8.7 seconds W; WGS84 Decimal Degrees 38.8830278 latitude, -119.8190833 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Saturated to the surface throughout most of the year in normal years; peraquic soil moisture regime.
Mean annual soil temperature: 8 to 12 degrees C.
Histic epipedon thickness: 20 to 40 cm.
Depth to base of umbric epipedon: 60 to 150 cm.

Particle-size control section - Clay content: Averages 10 to 18 percent.
Rock fragments: 0 to 15 percent. Lithology of fragments is granitic rocks such as granodiorite.

Oe1 and Oe2 horizons
Hue: 10YR or neutral (N).
Value: 2 or 3 moist, 3 or 4 dry.
Chroma: 0 (if Hue is neutral) 1 or 2.
Reaction: Extremely acid through strongly acid.
Organic matter content: 30 to 50 percent.

A1 and A2 horizons
Hue: 10YR or neutral (N).
Value: 2 or 3 moist, 3 or 4 dry.
Chroma: Dominantly 0 (if Hue is neutral) or 1, but may be 2 in some subhorizon.
Texture: Mucky sandy clay loam, mucky loam, or mucky clay loam.
Clay content: 20 to 35 percent.
Rock fragments: 0 to 15 percent, dominantly fine (2 to 5 mm diameter) gravel.
Structure: Massive or subangular blocky.
Consistence: Slightly hard or hard dry, very friable to firm moist.
Reaction: Extremely acid through strongly acid.
Organic matter content: 10 to 25 percent.
Base saturation: Less than 50 percent by ammonium acetate.
Redoximorphic features: Few through many redox concentrations or depletions are typically present, but may be absent in some subhorizons.

Lower A horizons
Hue: 10YR or neutral (N).
Value: 2 or 3 moist, 3 or 4 dry.
Chroma: Dominantly 0 (if Hue is neutral) or 1, but may be 2 in some subhorizon.
Texture: Dominantly stratified coarse sandy loam to loam. Subhorizons of coarse sand or loamy coarse sand are present below 75 cm in some pedons.
Clay content: 10 to 18 percent.
Rock fragments: 0 to 15 percent, dominantly fine (2 to 5 mm diameter) gravel.
Structure: Massive or subangular blocky.
Consistence: Slightly hard or hard dry, very friable to firm moist.
Reaction: Extremely acid through strongly acid.
Organic matter content: 1 to 5 percent.
Redoximorphic features: Few through many redox concentrations or depletions are typically present, but may be absent in some subhorizons.

Cg horizon
Hue: 2.5Y, 5Y, or neutral (N).
Value: 4 or 5 moist, 4 through 6 dry.
Chroma: 0 (if hue is neutral) or 1.
Texture: Dominantly stratified coarse sandy loam to loam. Subhorizons of coarse sand or loamy coarse sand are present in some pedons.
Clay content: 10 to 18 percent.
Rock fragments: 0 to 15 percent, dominantly fine (2 to 5 mm diameter) gravel.
Reaction: Very strongly acid or strongly acid.
Redoximorphic features: Few through many redox concentrations or depletions may be present in some pedons.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Scossa soils are on alluvial fans adjacent to seeps. These soils formed in alluvium derived mainly from granitic rocks. Slopes are 2 to 8 percent. Elevations range from 1,435 to 1,590 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 8 to 11 degrees C, and the frost-free period is 90 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mottsville and Ophir soils. These soils are sandy, do not have Histic epipedons, and have mollic epipedons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Very poorly drained; low surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Scossa soils are used for pasture and wildlife habitat. The present vegetation is mainly sedges and rushes.

DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 26.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Douglas County, Nevada, 2012.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Histic epipedon - The zone from the soil surface to 20 cm (Oe1 and Oe2 horizons).
Umbric epipedon - The zone from 20 to 41 cm (A1, A2, A3, A4, A5, and A6 horizons).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between 25 and 152 cm at certain times during normal years (parts of the A1, A2, A3, A4, A5, A6, and Cg horizons).
Particle-size control section - The zone from 50 to 125 cm (A4, A5, A6 and part of the A3 and Cq horizons).

ADDITIONAL DATA: The typical pedon at the series type location is reference sampled for the Soil Survey Laboratory (SSL), Lincoln, NE, as soil survey sample number S01NV-005-003 (pedon # 02N0632). Selected data are available.

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National Cooperative Soil Survey
U.S.A.