LOCATION RUMPAH                  NV

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

RUMPAH SERIES

The Rumpah series consists of very deep, well drained soils that formed in alluvium from mixed sources. The Rumpah soils are on old lake plains. Slopes are 0 to 2 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 63 degrees F.

TAXONOMIC CLASS: Fine, smectitic, thermic Sodic Haplotorrerts

TYPICAL PEDON: Rumpah clay, 0 to 2 percent slopes, (Colors are for dry soil unless otherwise noted.)

A--0 to 3 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong very fine and fine granular structure; hard, firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (2 to 3 inches thick)

Bw--3 to 10 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong coarse prismatic structure; hard, very firm, very sticky and very plastic; few very fine and fine tubular pores; few fine lime and gypsum flecks; violently effervescent; 3 percent gypsum; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 8 inches thick)

Bss1--10 to 22 inches; pale brown (10YR 6/3) clay, brown (10YR 5/3) moist; strong coarse prismatic structure; very hard, very firm, very sticky and very plastic; few fine tubular pores; few intersecting slickensides, few fine lime and gypsum flecks; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (10 to 15 inches thick)

Bss2--22 to 32 inches; pale brown (10YR 6/3) clay, pale brown (10YR 6/3) moist; strong coarse prismatic structure; very hard, very firm, very sticky and very plastic; few fine tubular pores; few intersecting slickensides, few fine lime and gypsum flecks; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (10 to 12 inches thick)

Bss3--32 to 54 inches; pale brown (10YR 6/3) clay, pale brown (10YR 6/3) moist; strong coarse prismatic structure parting to moderate medium angular blocky; very hard, very firm, very sticky and very plastic; few fine tubular pores; few fine lime flecks; violently effervescent; strongly alkaline (pH 8.9); clear smooth boundary. (20 to 30 inches thick)

2Bk--54 to 74 inches; white (N 8/0) clay, white (10YR 8/2) moist; moderate coarse prismatic structure parting to strong fine and medium subangular blocky; very hard, very firm, very sticky and very plastic; few fine tubular pores, mostly filled with lime; violently effervescent; strongly alkaline (pH 8.5)

TYPE LOCATION: Nye County, Nevada; in Pahrump Valley about 2375 feet south and 1580 feet west of the northeast corner of section 19 T. 20 S., R. 52 E.; 36 degrees, 11 minutes, 54 seconds north latitude and 116 degrees, 2 minutes, 40 seconds west longitude.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in the winter and early spring and for 10 to 20 days during the summer following summer convection storms from July through October.

Soil temperature - 62 to 66 degrees F.

Depth to 2Bk horizon - 40 to 65 inches.



Control section - Clay content: Averages 45 to 60 percent.

Calcium carbonates equivalent: 20 to 40 percent, mainly disseminated lime.

Other features: 1-to-5 centimeter wide vertical cracks, 8 to 18 inches apart, extending from the surface to a depth of 36 to 50 inches when the soil is dry.

Gilgi feature: Cracks are closed 5 to 30 days in most years.

SAR- 13 to 30 percent.



A horizon - Value: 5 or 6 dry, 4 or 5 moist.

Chroma: 2 or 3.

Consistence: Slightly hard or hard, firm or very firm, sticky or very sticky.

Reaction- Moderately alkaline or strongly alkaline.



Bw and Bss horizons - Value: 5 through 7 dry, 4 through 6 moist.

Texture: Clay or silty clay.

Structure: Prismatic or angular blocky.

Clay content: 45 to 60 percent, weighted average.

Consistence: Hard or very hard, very firm or extremely firm, sticky or very sticky.

Reaction- Moderately alkaline or strongly alkaline.



2Bk horizon - Hue: 10YR, 2.5Y or N.

Value: 7 or 8 dry or moist.

Chroma: 0 through 2.

Texture: Clay or silty clay.

Structure: Prismatic or subangular blocky.

Clay content: 45 to 60 percent weighted average.

Calcium carbonates equivalent- 40 to 60 percent.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Rumpah soils are on old lake plains. These soils formed in alluvium from mixed sources mainly limestone, quartzite and reworked lacustrine sediments. Slopes are 0 to 2 percent. Elevations are 2400 to 2700 feet. The climate is arid with hot summers and mild winters. The mean annual precipitation is 3 to 5 inches with relatively even monthly distribution with slight peaks in January and August; mean annual temperature is 60 to 64 degrees F., and the frost-free season is 200 to 220 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Besherm and Nopah. Besherm is carbonatic. Nopah is fine loamy and carbonatic.

DRAINAGE AND PERMEABILITY: Well drained, slow runoff; very slow permeability.

USE AND VEGETATION: Wildlife habitat. The present vegetation is mainly fourwing saltbush and shadscale.

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

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

SERIES PROPOSED: Nye County, Nevada, Southwest Part, 1985. The name is coined.

REMARKS: The classification was changed from Typic Torrerts to Sodic Haplotorrerts in 7/94.

Diagnostic horizons and features recognized in this pedon are:

Vertic subgroup features - Cracks in the zone from the soil surface to a depth of 36 inches and slickensides.

Sodic feature - SAR of 13 or more in the control section.

Particle-size control section - The zone from 10 to 40 inches.

ADDITIONAL DATA: Partial characterization data S84-NV-023-001.

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 5/1997. ET

---

National Cooperative Soil Survey
U.S.A.