LOCATION POORMA NVInactive Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Durinodic Xeric Haplocambids
TYPICAL PEDON: Poorma very fine sandy loam - rangeland (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; weak thin and medium platy structure; soft, very friable, nonsticky, nonplastic; few fine roots; many very fine interstitial pores; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (2 to 5 inches thick)
Bw--3 to 17 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; weak medium subanglar blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common fine and medium roots; many very fine and fine interstitial, and many fine, and few medium tubular pores; violently effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (10 to 18 inches thick)
Bq1--17 to 54 inches; pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; massive; hard, friable, slightly sticky, slightly plastic; few fine and medium roots; many very fine and fine interstitial, and common fine tubular pores; few very large cicada channels; 60 percent 1/2 x 2 inch, hard, firm, brittle durinodes; violently effervescent; strongly alkaline (pH 8.6); gradual smooth boundary. (30 to 48 inches thick)
Bq2--54 to 72 inches;pale brown (10YR 6/3) very fine sandy loam, brown (10YR 4/3) moist; weak medium angular and subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic; few fine and medium roots; few fine tubular, and many fine interstitial pores; 10 percent 1/2 x 2 inch, hard, firm, brittle durinodes; violently effervescent, strongly alkaline (pH 8.6).
TYPE LOCATION: Lincoln County, Nevada; approximately 75 feet west of the southeast corner of sec. 9, T.3N., R.70E.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the winter and early spring.
Soil temperature - 45 to 47 F.
Summer soil temperature - 62 to 64 F.
Control section 10 to 40-inch control section is dominantly silt loam or very fine sandy loam but includes strata of loam, fine sandy loam or sandy loam in some pedons.
Soil reaction: Slightly to violently
The A horizons has value of 3 or 4 moist.
Chroma: 2 through 4.
Organic matter: 0.6 to 1.2 percent.
The Bw and Bq horizons have hue of 10YR or 7.5YR,
Value of 4 or 5 moist,
Chroma: 2 through 4.
Structure: Bw horizon has weak or moderate, fine to coarse subangular blocky or prismatic structure.
Bq horizon: 30 to 70 percent durinodes.
Consistence: Slightly hard or hard matrix that is very friable or friable when moist.
Durinodes: Hard or very hard and firm or very firm.
COMPETING SERIES: These are the Fort Rock, Humdun, and Silverado series. Fort Rock soils have mildly or moderately alkaline A1 horizons and have less than 20 percent durinodes. Humdun soils have noncalcareous sola 24 to 33 inches thick. Silverado soils have noncalcareous sola and weakly cemented Bqk horizons.
GEOGRAPHIC SETTING: Poorma soils are on smooth, nearly level and gently sloping alluvial fans at elevations of 5,800 to 6,600 feet. Slopes are O to 4 percent. The soils formed in silty alluvium primarily from ignimbrites, limestone, and Miocene lacustrine sediments. The climate is cool, semiarid. The mean annual temperature is 43 to 45 F., mean summer temperature is 60 to 62 F., and the frost-free season is approximately 100 days. The mean annual precipitation is 8 to 10 inches, with most of it coming as snow.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buster, Fanu, Holsine, Holtle, and Usine soils. Buster soils have argillic horizons and weakly cemented Csica horizons. Fanu and Holtle soils have mollic epipedons. Fanu soils also lack durinodes. Holsine soils have calcic horizons and lack durinodes, Usine soils have very gravelly sandy control sections.
DRAINAGE AND PERMIABILITY: Well-drained; slow or medium runoff; moderate permeability.
USE AND VEGETATION: Used for grazing. The principal vegetation is big sagebrush, cheatgrass, squirreltail, Indian ricegrass and needle grass.
DISTRIBUTION AND EXTENT: East-central Nevada. Poorma soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lincoln County (Meadow Valley Area), Nevada, 1971.
REMARKS: Poorma soils were formerly classified as Alluvial soils.
OSED scanned by NSSQA. Last update by state 1/74.