LOCATION SURGEM NVEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Xeric Haplargids
TYPICAL PEDON: Surgem stony sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A1-0 to 2 inches; grayish brown (10YR 5/2) stony sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; 2 percent stones, 60 percent pebbles; slightly acid (pH 6.4); abrupt wavy boundary. (1to 3 inches thick)
A2--2 to 4 inches; pale brown (10YR 6/3) very gravelly loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine vesicular pores; 35 percent pebbles; slightly acid (pH 6.4); abrupt wavy boundary. (2 to 4 inches thick)
Bt1--4 to 10 inches; brown (10YR 5/3) very cobbly clay loam, dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky structure; hard, friable, sticky and plastic; common very fine and fine roots; few very fine tubular pores; few thin clay films on peds and in pores; 25 percent pebbles, 25 percent cobbles; neutral (pH 6.6); clear irregular boundary. (2 to 8 inches thick)
Bt2--10 to 24 inches; brown (7.5YR 5/4) very cobbly clay, dark brown (7.5YR 5/4) moist; strong medium angular and subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; 60 percent cobbles; neutral (pH 6.8); abrupt irregular boundary. (10 to 18 inches thick)
R--24 inches; fractured granodiorite with clay in the fractures.
TYPE LOCATION: Washoe County, Nevada; approximately 5 1/2 miles north of Sparks; about 1,000 feet west and 1,700 feet south of the northeast corner of section 8, T. 20 N., R. 20 E.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, June thru October.
Soil temperature: 49 to 52 degrees F.
Solum thickness: 20 to 30 inches.
Depth to bedrock: 20 to 30 inches.
Control section: Rock fragments: 50 to 80 percent
A horizon Value: 5 or 6 dry; 3 or 4 moist.
Chroma: 2 or 3.
Reaction: Neutral to medium acid.
Bt1 and Bt2 horizon - Hue: 7.5YR, 10YR.
Value: 4 through 6 dry; 2 through 4 moist.
Chroma: 2 through 4.
Texture: Clay, sandy clay, with subhorizon of sandy clay loam and loam.
Rock fragments: 50 to 80 percent.
Structure: Blocky with prismatic in some pedons.
Reaction: Slightly acid to slightly alkaline.
COMPETING SERIES: These are the Berning, Havingdon, Tenmile and Zephan series. Berning and Tenmile soils have 24 to 60 inch thick sola and lack bedrock within 40 inches. Havingdon soils have coarse fragments consisting of angular chert in the control section and are underlain by chert bedrock with visible secondary lime masses. Zephan soils lack a lithic contact within 40 inches.
GEOGRAPHIC SETTING: Surgem soils are on convex uplands at elevations of 4,500 to 6,000 feet. Slopes are 8 to 50 percent. They have formed in residuum weathered from granodiorite. Few to many rock outcrop are present. The climate is semiarid. The mean annual precipitation is 10 to 12 inches; mean annual temperature is 47 to 50 degrees F.; mean January temperature is 30 to 32 F.; mean July temperature is 68 to 70 degrees F.; and the frost-free season is 100 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Oppio, Risley, Wedekind, and Yuko series. All of these soils have less than 35 percent coarse fragments in their control section.
DRAINAGE AND PERMEABILITY: Well drained; rapid or very rapid runoff; slow permeability.
USE AND VEGETATION: Surgem soils are used principally for rangeland, recreation, and wildlife habitat. The native vegetation is low sagebrush, low rabbitbrush, and squirreltail.
DISTRIBUTION AND EXTENT: Reno area of southwestern Washoe County, Nevada. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Washoe County (South Part), Nevada 1980.
Diagnostic horizon and features recognized in this pedon are:
Ochric epipedon -The zone from 0 to 4 inches (A1 and A2 horizon).
Argillic horizon - The zone from 4 to 24 inches (Bt1 and Bt2 horizon).
Particle size control section - The zone from 4 to 24 inches (Bt1 and Bt2 horizon)
Lithic contact _ The zone at 24 inches (R horizon)