LOCATION TOANO NVEstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, calcareous, mesic Typic Torriorthents
TYPICAL PEDON: Toano silt loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; light gray (10YR 7/2) silt loam, grayish brown (10YR 5/2) moist; moderate thick platy structure; hard, very friable, slightly sticky and slightly plastic; common very fine, fine and few medium roots; many very fine, fine interstitial and common very fine vesicular pores; 2 percent pebbles; strongly effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 4 inches thick)
A2--3 to 5 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; weak coarse subangular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine, fine and few medium roots; many very fine interstitial and common very fine, fine tubular pores; 2 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 6 inches thick)
Bk--5 to 21 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine and common medium roots; many very fine interstitial and common very fine and fine tubular pores; 2 percent pebbles; secondary carbonates segregated as few coats on bottoms of rock fragments; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (6 to 20 inches thick)
C1--21 to 31 inches; light gray (2.5Y 7/2) silt loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine interstitial pores; violently effervescent; strongly alkaline (pH 9.0); clear wavy boundary. (7 to 27 inches thick)
C2--31 to 39 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine interstitial pores; 3 percent pebbles; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 24 inches thick)
C3--39 to 60 inches; light gray (2.5Y 7/2) very fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial and few very fine and fine tubular pores; 3 percent pebbles; violently effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Elko County, Nevada; about 9 miles northeast of Montello in Tecoma Valley and 0.25 mile west of the Utah-Nevada line; about 4,500 feet east and 2,000 feet north of the southwest corner of section 21, T. 40 N., R. 70 E.; USGS Tecoma 7.5 minute topographic quadrangle; 41 degrees 20 minutes 03 seconds north latitude and 114 degrees 02 minutes 41 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry; moist for short periods in winter and spring, dry late May through November; typic aridic (torric) moisture regime.
Mean annual soil temperature - 53 to 59 degrees F.
Depth to horizon with identifiable secondary carbonates - 3 to 9 inches.
Control section - Clay content: 8 to 15 percent; Rock fragments: 0 to 5 percent pebbles in any subhorizon.
Reaction - Moderately alkaline or strongly alkaline.
A horizons - Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist.
Effervescence: Strongly effervescent or violently effervescent.
Calcium carbonate equivalent: 10 to 20 percent.
Bk horizon - Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 4 through 6 moist.
Chroma: 2 through 4, dry or moist.
Texture: Silt loam or very fine sandy loam.
Structure: Fine to coarse subangular blocky.
Consistence: Soft or slightly hard dry.
Salinity (EC): 0 to 16 mmhos/cm.
Sodicity (SAR): 0 to 5.
Identifiable secondary carbonates: Occurs as masses on the bottom of rock fragments in amounts less than 5 percent by volume.
Calcium carbonate equivalent: 15 to 30 percent.
C horizons - Hue: 10YR or 2.5Y.
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 2 or 3, dry or moist.
Texture: Silt loam or very fine sandy loam.
Structure: Massive or platy.
Consistence: Soft or slightly hard dry, nonsticky or slightly sticky and nonplastic or slightly plastic wet.
Salinity (EC): 4 to 16 mmhos/cm.
Sodicity (SAR): 1 to 12.
Calcium carbonate equivalent: 15 to 30 percent.
Other features: Some pedons have stratified extremely gravelly sandy loam to extremely gravelly sand below 40 inches; Some pedons have relict redoximorphic features in the lower C horizons.
COMPETING SERIES: These are the Garbutt, Penoyer, Smaug, and Yipor series.
Garbutt soils do not have horizons with secondary carbonates, have 3 to 15 percent calcium carbonate equivalent, and have subhorizons within 40 inches that have 20 to 50 percent volcanic glass. Penoyer soils do not have horizons with secondary carbonates, average less than 15 percent calcium carbonate equivalent, and are intermittently moist in some part for 10 to 20 days cumulative in summer months. Smaug soils do not have horizons with secondary carbonates and formed in lacustrine deposits with platy structure. Yipor soils have mean annual soil temperature of 47 to 52 degrees F. and average less than 10 percent calcium carbonate equivalent.
GEOGRAPHIC SETTING: Toano soils are on alluvial flats, fan skirts, inset fans, lagoons, and stream terraces. These soils formed in alluvium derived from sedimentary rocks, loess, and volcanic ash. Slopes are 0 to 8 percent. Elevations range from 4,400 to 6,500 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 5 to 8 inches, mean annual temperature is 48 to 55 degrees F., and the frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ixian, Ocala, Sondoa, and Tulase soils.
DRAINAGE AND PERMEABILITY: Well drained; low or medium surface runoff; moderate permeability. These soils are usually not susceptible to flooding. Some phases are susceptible to occasional flooding for very brief periods between February and May or rare flooding for very brief periods year-round.
USE AND VEGETATION: Toano soils are used for rangeland and wildlife habitat. The present vegetation is mainly sickle saltbush, bud sagebrush, and mustard. Areas that are subject to thin sheet flooding have mainly winterfat, Indian ricegrass, and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Eastern and central Nevada. These soils are moderately extensive. The series concept and main acreage occurs in MLRA 28A. Other acres of this series are mapped in MLRAs 25 and 28B.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Elko County (Northeast Part), Nevada, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 5 inches (A1 and A2 horizons).
Identifiable secondary carbonates - The zone from 5 to 21 inches (Bk horizon).
Particle size control section - The zone from 10 to 40 inches (C1 and C2 horizons and parts of the Bk and C3 horizons).