LOCATION MACNOT                  NV+CA

Established Series
Rev. SES-JBF-TM-JVC
01/2023

MACNOT SERIES

The Macnot series consists of very deep, somewhat excessively drained soils that formed in volcanic ash and alluvium derived from volcanic rocks. Macnot soils are on beach terraces, inset fans, and alluvial fans. Slopes are 0 to 8 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, mesic Vitrixerandic Haplocalcids

TYPICAL PEDON: Macnot very gravelly ashy sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 3 cm; light brownish gray (2.5Y 6/2) very gravelly ashy sandy loam, dark grayish brown (2.5Y 4/2) moist; moderate thick and very thick platy structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine vesicular pores; 50 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (3 to 13 cm thick)

A2--3 to 15 cm; light brownish gray (2.5Y 6/2) gravelly ashy sandy loam, light olive brown (2.5Y 5/3) moist; strong medium and thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; many very fine vesicular pores; 25 percent gravel; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 25 cm thick)

Bk1--15 to 41 cm; light gray (10YR 7/2) very gravelly ashy sandy loam, brown (10YR 5/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; 50 percent gravel; 5 percent 2 to 5 mm carbonate coats on faces of peds and 20 percent 0.5 to 1 mm thick coats on bottoms of rock fragments; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (15 to 38 cm thick)

2Bk--41 to 61 cm; very pale brown (10YR 8/2) very gravelly ashy loamy sand, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial pores; 55 percent gravel; common medium and coarse masses of secondary carbonate; 10 percent 0.5 to 1 mm thick carbonate coats on bottoms of rock fragments; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (10 to 25 cm thick)

2Bkq1--61 to 91 cm; very pale brown (10YR 8/2) extremely gravelly ashy sand, brown (10YR 5/3) moist; massive; soft, very friable; nonsticky and nonplastic; common very fine and few fine roots; many very fine interstitial pores; nearly continuous 0.5 to 1 mm thick carbonate and silica coats on rock fragments; 60 percent gravel; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (10 to 48 cm thick)

2Bkq2--91 to 157 cm; light gray (10YR 7/2) stratified extremely gravelly ashy coarse sand and very gravelly ashy sand, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine interstitial pores; averages 65 percent gravel and 5 percent cobbles; 5 percent discontinuous lenses of weak silica cementation; violently effervescent; strongly alkaline (pH 8.8).

TYPE LOCATION: Washoe County, Nevada; on the east side of Duck Flat; approximately 1,000 feet east and 1,400 feet north of the southwest corner of section 26, T. 36 N., R. 20 E.; USGS Hillside Spring 7.5 minute topographic quadrangle; latitude 40 degrees 58 minutes 1.8 seconds N and longitude 119 degrees 42 minutes 31.8 seconds W; WGS84 Decimal Degrees 40.9671667 latitude, -119.7088333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in late winter and early spring; dry in late spring through early winter; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 10 degrees C.
Depth to calcic horizon: 15 to 30 cm.
Volcanic glass content: 60 to 80 percent in coarse silt through very coarse sand fractions.

Particle-size control section - Clay content: Averages 1 to 6 percent,
Rock fragments: Averages 50 to 70 percent, mainly gravel. Lithology of fragments is volcanic rocks such as andesite and basalt.

A horizon
Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 1 through 3, dry or moist.
Reaction: Slightly alkaline through strongly alkaline.
Effervescence: Noneffervescent to violently effervescent.
Calcium carbonate equivalent: 1 to 5 percent.

Bk1 horizon
Hue: 10YR or 2.5Y.
Value: 6 through 8 dry, 4 or 5 moist.
Texture: Ashy sandy loam or ashy loamy sand.
Clay content: 4 to 10 percent.
Rock fragments: 35 to 60 percent, mainly gravel.
Structure: Fine through coarse subangular blocky or is massive.
Salinity (EC): 0 to 8 mmhos/cm.
Calcium carbonate equivalent: 10 to 15 percent.
Identifiable secondary carbonates: 10 to 90 percent coats on bottoms of rock fragments and 5 to 15 percent masses and threads (filaments).

2Bk2 and 2Bkq horizons
Hue: 10YR or 2.5Y.
Value: 6 through 8 dry, 4 through 6 moist.
Texture: Very gravelly ashy loamy sand in the 2Bk2 horizon; Stratified extremely gravelly ashy coarse sand to very gravelly ashy sand in the 2Bkq horizons.
Clay content: 0 to 5 percent.
Rock fragments: 35 to 80 percent, mainly gravel.
Reaction: Moderately alkaline or strongly alkaline.
Salinity (EC): 0 to 4 mmhos/cm.
Calcium carbonate equivalent: 3 to 8 percent.
Identifiable secondary carbonates and silica: 0 to 10 percent silica-carbonate cemented nodules and 0 to 10 percent silica-carbonate coats on rock fragments.

COMPETING SERIES: This is the Udaho series. Udaho soils are moderately deep to paralithic contacts.

GEOGRAPHIC SETTING: Macnot soils are on beach terraces, inset fans, and alluvial fans. These soils formed in volcanic ash and alluvium derived from volcanic rocks. Slopes are 0 to 8 percent. Elevations range from 1,260 to 1,920 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 cm, the mean annual temperature is 7 to 8 degrees C, and the frost-free period is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the McWatt and Nomazu soils. McWatt soils have bedrock at 100 to 150 cm and are on upper beach terraces. Nomazu soils lack rock fragments and are on lake plains and fan skirts.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; low or very low surface runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Macnot soils are used for rangeland. The native vegetation is mainly big sagebrush, spiny hopsage, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: Northwestern Nevada and northeastern California. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Surprise Valley-Home Camp Area, California and Nevada, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1, A2 and part of the Bk1 horizons).
Calcic horizon - The zone from 15 to 61 cm (Bk1 and 2Bk2 horizons).
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from 25 to 100 cm (2Bk2, 2Bkq1, parts of the Bk1 and 2Bkq2 horizons).

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National Cooperative Soil Survey
U.S.A.