LOCATION MILKIWAY NVTentative Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Haplargids
TYPICAL PEDON: Milkiway clay loam--hayland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 6 inches; brown (10YR 5/3) clay loam, dark brown (10YR 3/3) moist; moderate medium angular blocky structure; very hard, firm, very sticky and very plastic; common very fine and common fine roots; common very fine tubular pores; neutral (pH 6.8); clear smooth boundary. (4 to 9 inches thick)
Bt1--6 to 20 inches; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; strong medium prismatic parting to moderate medium angular blocky structure; very hard, firm, very sticky and very plastic; common very fine, fine and medium and few coarse roots; common very fine tubular pores; common pressure faces; neutral (pH 6.9); clear smooth boundary. (8 to 16 inches thick)
Bt2--20 to 30 inches; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; moderate medium prismatic parting to moderate medium angular blocky structure; very hard, firm, very sticky and very plastic; few very fine, common fine, and common medium roots; common very fine tubular pores; common pressure faces; neutral (pH 7.0); clear smooth boundary. (4 to 12 inches thick)
Btk1--30 to 40 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; weak medium prismatic parting to moderate medium angular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine, few fine, and few medium roots; common very fine tubular pores; common distinct clay films on faces of peds and lining pores; secondary carbonates segregated as few fine masses; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (4 to 12 inches thick)
Btk2--40 to 46 inches; pale brown (10YR 6/3) sandy clay loam, moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine, common fine, and common medium roots; common very fine tubular pores; few distinct clay films on faces of peds and lining pores; secondary carbonates segregated as few fine masses; slightly effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (5 to 10 inches thick)
Bqk--46 to 51 inches; light brownish gray (10YR 6/2) coarse sandy loam, dark grayish brown (10YR 4/2) moist; massive; hard, friable, nonsticky and nonplastic; few very fine, fine and medium roots; common very fine tubular pores; 20 percent weakly cemented planar durinodes; secondary carbonates segregated as few fine masses; slightly effervescent; moderately alkaline (pH 8.3); clear wavy boundary. (0 to 20 inches thick)
C--51 to 60 inches; light brownish gray (10YR 6/2) loamy sand, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine and few fine roots; common very fine tubular and interstitial pores; common medium prominent dark yellowish brown (10YR 4/6) moist masses of iron accumulation and common coarse faint black (10YR 2/1) moist masses of manganese accumulation; slightly effervescent; moderately alkaline (pH 8.3)
TYPE LOCATION: Douglas County, Nevada; in Carson Valley about 0.25 mile west of the county airport; about 2,100 feet north and 1,450 feet east of the southwest corner of section 8, T. 13 N., R. 20 E.; USGS Genoa 7.5 minute topographic quadrangle; 39 degrees 0 minutes 12.8 seconds north latitude and 119 degrees 45 minutes 49.3 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry in the moisture control section; moist in some part during winter and spring; dry in all parts summer through early fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 48 to 53 degrees F.
Depth to base of argillic horizon - 25 to 50 inches.
Depth to identifiable secondary carbonates - 20 to 40 inches.
Control section - Clay content: Averages 35 to 45 percent; Rock fragments: 0 to 5 percent, mainly pebbles. Lithology of fragments are mainly igneous rocks.
A horizon - Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Neutral or slightly alkaline.
Bt horizons - Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay or clay loam.
Clay content: 35 to 50 percent.
Rock fragments: 0 to 5 percent.
Consistence: Moderately hard to very hard dry, firm moist.
Reaction: Neutral or slightly alkaline.
Btk horizons - Hue 7.5YR or 10YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay loam or sandy clay loam.
Clay content: 25 to 35 percent.
Rock fragments: 0 to 5 percent.
Consistence: Moderately hard to very hard dry, firm moist.
Reaction: Slightly alkaline or moderately alkaline.
Identifiable secondary carbonates: Occurs as few or common masses, filaments, or coats on peds.
Calcium carbonate equivalent: 1 to 3 percent.
Bqk horizon (when present) - Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Stratified loamy coarse sand through loam, averages coarse sandy loam or sandy loam.
Clay content: 8 to 15 percent.
Rock fragments: 0 to 5 percent.
Durinodes: 20 to 80 percent 0.5 to 2.0 inch diameter planar durinodes.
Identifiable secondary carbonates: Occurs as few or common masses, filaments, or coats on peds.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 1 to 3 percent.
C horizon - Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4, dry or moist.
Texture: Stratified coarse sand through sandy loam, averages coarse sandy loam, sandy loam, or loamy sand.
Clay content: 5 to 12 percent.
Sand content: Greater than 45 percent.
Rock fragments: 0 to 5 percent.
Reaction: Slightly alkaline or moderately alkaline.
Redoximorphic features: Redox concentrations occurring as masses of iron and manganese accumulation are present within a depth of 40 to 60 inches in most pedons.
COMPETING SERIES: These are the Buncelvoir, Diaz, Farmell, Glasgow, Lanktree, Oppio, Risley, Schamp, and Trunk series.
Buncelvoir, Farmell, Lanktree, and Schamp soils do not have redox concentrations or endosaturation within 60 inches of the soil surface. Diaz, Glasgow, Oppio, and Trunk soils are moderately deep to lithic contacts. Risley soils are moderately deep to paralithic contacts.
GEOGRAPHIC SETTING: Milkiway soils are on stream terraces. They formed in alluvium derived from mixed sources but with a strong influence from granitic rocks. Slopes are 0 to 2 percent. Elevations range from 4,600 to 4,800 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 8 to 10 inches, mean annual temperature is 46 to 51 degrees F, and the frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dangberg, Gardnerville, Godecke, Ormsby, and Turria soils. Dangberg soils have natric horizons and are moderately deep to duripans. Gardnerville soils have albic horizons, natric horizons, and horizons with durinodes within 40 inches of the soil surface. Godecke soils are fine-loamy and have natric horizons. Ormsby soils are sandy, have horizons with a firm and brittle matrix, and do not have argillic horizons. Turria soils are fine-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; high surface runoff; slow permeability in the subsoil and rapid permeability in the lower substratum. Endosaturation is present with a seasonal high water table between 48 and 60 inches (deep internal free water occurrence class) from December through May. Cumulative annual duration classes are Common or Persistent.
USE AND VEGETATION: Milkiway soils are used for irrigated cropland. Common crops are alfalfa hay, small grains, and grass-legume hay.
DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 26.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES PROPOSED: Douglas County, Nevada, 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 6 inches (Ap horizon).
Argillic horizon - The zone from 6 to 46 inches (Bt1, Bt2, Btk1, and Btk2 horizons).
Identifiable secondary carbonates - The zone from 30 to 51 inches (Btk1, Btk2, and Bqk horizons).
Endosaturation feature - The condition of ground water with an upper boundary between 48 and 60 inches at certain times during normal years (parts of the Bqk and C horizons).
Particle size control section - The zone from 6 to 26 inches (Bt1 horizon and part of the Bt2 horizon).