LOCATION HEIDTMAN NVEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Cumulic Haploxerolls
TYPICAL PEDON: Heidtman loam--hayland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 7 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and interstitial pores; neutral (pH 7.3); clear smooth boundary. (5 to 11 inches thick)
A1--7 to l6 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine tubular pores; neutral (pH 7.3); clear smooth boundary. (6 to l2 inches thick)
ABk--l6 to 22 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine tubular and interstitial pores; secondary carbonates segregated in few fine masses and coats on faces of peds; strongly effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (6 to l0 inches thick)
A2--22 to 30 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and few fine roots; common very fine tubular and interstitial pores; slightly effervescent; moderately alkaline (pH 8.4); clear smooth boundary.
A3--30 to 40 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; common medium distinct dark yellowish brown (10YR 3/4) moist, masses of iron accumulation; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary.
A4--40 to 47 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; massive, slightly hard, very friable, slightly sticky and nonplastic; few very fine roots; common very fine tubular pores; common medium faint dark yellowish brown (10YR 3/4) moist, masses of iron accumulation; slightly alkaline (pH 7.8); clear smooth boundary. (Combined thickness of the A horizons is more than 40 inches)
Ag--47 to 53 inches; dark gray (10YR 4/1) clay loam, black (10YR 2/1) moist; massive, hard, very friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; common medium distinct dark brown (10YR 3/3) moist, masses of iron accumulation; slightly alkaline (pH 7.6); clear smooth boundary. (0 to 12 inches thick)
Ccg--53 to 60 inches; gray (10YR 6/1) sandy loam, dark gray (5Y 4/1) moist; massive; hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular and interstitial pores; 25 percent 1 to 3 millimeter diameter nodules of iron; common medium prominent dark yellowish brown (10YR 3/4) moist, masses of iron accumulation; slightly alkaline (pH 7.6).
TYPE LOCATION: Douglas County, Nevada; along the West Fork of the Carson River about 0.75 mile northwest of Centerville; 2,300 feet north and 950 feet west of the southeast corner of section 12, T. l2 N., R. l9 E.; USGS Minden 7.5 minute topographic quadrangle; 38 degrees 55 minutes 02 seconds north latitude and 119 degrees 47 minutes 27 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry in the moisture control section, moist in winter and spring, dry in summer and fall unless irrigated; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 48 to 53 degrees F.
Mollic epipedon thickness - 40 to 60 inches.
Depth to horizons with secondary carbonates - 10 to 30 inches.
Depth to aquic conditions - 36 to 60 inches.
Control section - Clay content: 18 to 25 percent; Rock fragments: 5 to 15 percent. Lithology of fragments are mixed.
Other features - Organic carbon content decreases irregularly with depth.
Ap horizon - Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.
Reaction: Neutral to moderately alkaline.
Salinity (EC): 2 to 4 mmhos/cm.
Sodicity (SAR): 0 to 5.
ABk horizon - Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Stratified sandy loam to clay loam, averaging loam.
Organic matter content: 1 or 2 percent.
Salinity (EC): 4 to 8 mmhos/cm.
Sodicity (SAR): 13 to 30.
Identifiable secondary carbonates: Occurs as few or common masses or filaments.
Calcium carbonate equivalent: 1 to 5 percent.
A1 through A4 horizons - Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist; some pedons have thin subhorizons with chroma of 0 (when neutral hue), or 1.
Texture: Stratified sandy loam to clay loam, averaging loam.
Organic matter content: 1 or 2 percent.
Reaction: Neutral to moderately alkaline.
Redoximorphic features: Redox concentrations occur in the lower subhorizons as masses of iron accumulation.
Ag horizon (when present) - Hue: 10YR, 2.5Y, or neutral (N).
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 0 (when neutral hue) or 1, dry or moist.
Texture: Stratified sandy loam to clay loam, averaging loam.
Organic matter content: 1 or 2 percent.
Reaction: Neutral to moderately alkaline.
Salinity (EC): 2 to 4 mmhos/cm.
Sodicity (SAR): 0 to 5.
Redoximorphic features: Redox depletion of iron is present as the gleyed, low chroma matrix. Redox concentrations occur as masses of iron accumulation.
Ccg or Cg horizon - Hue: 10YR through 5Y or neutral (N).
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 0 (when neutral hue), 1 or 2, dry or moist.
Texture: Stratified very gravelly loamy coarse sand to clay loam.
Clay content: averages 18 to 25 percent.
Rock fragments: averages less than 15 percent, but individual subhorizons have up to 50 percent pebbles.
Reaction: Neutral to moderately alkaline.
Salinity (EC): 2 to 4 mmhos/cm.
Sodicity (SAR): 0 to 5.
Redoximorphic features: Redox depletion of iron is present as the gleyed, low chroma matrix. Redox concentrations occur as masses of iron accumulation. Most pedons have 1 to 5 millimeter diameter nodules of iron.
COMPETING SERIES: These are the Birdow, Blackrock, Coit, Collister (T), Dagor, Eastcan, Goose Creek, Goosenawt, Gosinta, Lakeview, Monroe, Oxy (T), Shoepeg, Soquel, Willowdale, and Winn series.
Birdow, Blackrock, Dagor, Goosenawt, Monroe, and Willowdale soils do not have endosaturation or aquic conditions within the series control section. Coit and Eastcan soils are effervescent throughout and do not have horizons with identifiable secondary carbonates. Collister, Goose Creek, Gosinta, Shoepeg, and Winn soils do not have horizons with identifiable secondary carbonates. Lakeview soils do not have horizons with identifiable secondary carbonates between 10 and 30 inches. Oxy soils are moderately deep to lithic contacts and do not have endosaturation or aquic conditions. Soquel soils have xeric moisture regime and mean annual soil temperature of 56 to 58 degrees F.
GEOGRAPHIC SETTING: Heidtman soils are on flood plains and low stream terraces. These soils formed in alluvium derived mainly from granitic rocks. Slopes are 0 to 2 percent. Elevations range from 4,630 to 4,750 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation 8 to 10 inches, mean annual temperature is 46 to 51 degrees F., and the frost-free period is 90 to l10 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mindlebaugh, Fettic, Job, and Voltaire soils. Mindlebaugh soils have aquic conditions between 20 and 30 inches and mollic epipedons less than 20 inches thick. Fettic soils have natric horizons and mollic epipedons less than 20 inches thick. Job soils are coarse-loamy and have ochric epipedons. Voltaire soils have aquic conditions high in the profile and have mollic epipedons less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium surface runoff; moderately slow permeability. Endosaturation is present with an apparent seasonal high water table between 3 and 5 feet (moderately deep and deep free water occurrence classes) from December through May. Cumulative annual duration classes are Common or Persistent. The water table drops to 5 or 6 feet in the fall. These soils are susceptible to occasional flooding for brief periods between December and May.
USE AND VEGETATION: Heidtman soils are used for irrigated cropland, pasture, and hayland. The principal crops are alfalfa hay and small grains.
DISTRIBUTION AND EXTENT: Western Nevada. These soils are not extensive. MLRA 26.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Douglas County (Carson Valley Area), Nevada l975.
REMARKS: This revision moves the type location to a more representative area. It also changes the series concept by increasing the thickness of the mollic epipedon and updating the taxonomic subgroup from Fluvaquentic to Cumulic.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 53 inches (Ap, A1, ABk, A2, A3, A4, and Ag horizons).
Identifiable secondary carbonates - The zone from 16 to 22 inches (ABk horizon).
Aquic conditions - The conditions and endosaturation, reduction, and redoximorphic features from 47 to 60 inches at some time in normal years (Ag and Ccg horizons).
Particle size control section - The zone from 10 to 40 inches (ABk, A2, and A3 horizons and part of the A1 horizon).