LOCATION SEZNA                   NV

Established Series
Rev. RWW/RLB/WED
12/2015

SEZNA SERIES

The Sezna series consists of shallow over an indurated petrocalcic, well drained soils that formed in mixed alluvium mainly from limestone, with some calcareous shale and quartzite. The Sezna soils are on ballenas. Slopes are 2 to 15 percent. The mean annual precipitation is about 6 inches and the mean annual temperature is about 60 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic, shallow Argic Petrocalcids

TYPICAL PEDON: Sezna gravelly sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.) About 70 percent of the soil surface is covered with pebbles, 5 percent with cobbles and 1 percent with stones.

A--0 to 3 inches; pale brown (10YR 6/3) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine and fine interstitial pores; 25 percent pebbles and 2 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (2 to 4 inches thick)

Btk--3 to 18 inches; light yellowish brown (10YR 6/4) very cobbly clay loam, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine and few medium roots; many very fine and fine interstitial and few very fine tubular pores; few faint clay films bridging and coating sand grains; 25 percent pebbles and 20 percent cobbles; common thick lime coats on undersides of rock fragments; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (8 to 17 inches thick)

Bkm--18 to 60 inches; white (10YR 8/2) very gravelly indurated petrocalcic horizon, very pale brown (10YR 7/3) moist; massive; violently effervescent.

TYPE LOCATION: Nye County, Nevada; approximately 3 miles southwest of Johnnie and about 1,700 feet west and 1,450 feet south of the northeast corner of Section 34, T. 18 S., R. 52 E., 36 degrees, 21 minutes, 6 seconds north latitude and 116 degrees, 5 minutes, 44 seconds west longitude.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist for short periods of time in the late winter.

Soil temperature - 62 to 67 degrees F.

Depth to petrocalcic horizon - 10 to 20 inches.

Reaction - Moderately alkaline or strongly alkaline.


Control section - Clay content : 25 to 35 percent.

Rock fragment - 35 to 60 percent pebbles and cobbles sizes fragments.


A horizon - Value: 5 through 7 dry, 3 or 4 moist.

Chroma: 3 or 4.


Btk horizon - Value: 5 through 7 dry, 3 through 5 moist.

Texture: Very cobbly sandy clay loam, very cobbly clay loam or very cobbly loam.

Clay content: 25 to 35 percent.

Rock fragments: 35 to 60 percent, mainly cobbles.


Bkm horizon - 3 to 15 feet thick.

COMPETING SERIES: This is the Colorock (NV) and Hachita (T NM) series. Colorock soils have 15 to 20 percent clay in the particle-size control section and the hues of 7.5YR or 5YR. Hachita soils receive significant moisture during July through September, and have hue of 5YR or 7.5YR in the Bt horizon.

GEOGRAPHIC SETTING: Sezna soils are on the crests and upper slopes of gently convex ballenas that are dissected by deep intermittent stream channels. The exposed petrocalcic horizon is as thick as 15 feet in some pedons. These soils formed in mixed alluvium, dominantly from limestone, calcareous shale, and quartzite. Elevations are 3,400 to 4,200 feet. Slopes are 2 to 15 percent. The climate is arid with cool moist winters and hot, dry summers. The mean annual precipitation is 5 to 8 inches; with relatively even distribution of precipitation with slight peaks in January and August. Mean annual temperature is 58 to 62 degrees F., and the frost-free season is about 200 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo and Yermo soils. Both lack an argillic horizon and a petrocalcic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability above the indurated petrocalcic horizon.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly creosotebush, white bursage, shadscale, Anderson wolfberry, bladdersage and Indian ricegrass.

DISTRIBUTION AND EXTENT: Southwestern Nevada. These soils are not extensive. MLRA 30.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES PROPOSED: Nye County, Nevada, Southwest Part, 1983. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Argillic horizon - The zone from about 3 to 18 inches (Btk horizon).

Petrocalcic horizon - The zone from 18 to 60 inches (Bkm horizon).

Particle-size control section - The zone from about 3 to 18 inches (Btk horizon).

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 11/2001. ET

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National Cooperative Soil Survey
U.S.A.