LOCATION BORDA NV+CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Paleargids
TYPICAL PEDON: Borda gravelly sandy loam, rangeland. (Colors are for dry soil unless otherwise noted.)
All--0 to 3 inches; grayish brown (l0YR 5/2) gravelly sandy loam, dark brown (l0YR 4/3) moist; weak medium platy structure; soft, friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; a pavement of pebbles and stones covers 50 percent of the surface; slightly acid (pH 6.3); clear smooth boundary. (2 to 4 inches thick)
Al2--3 to l0 inches; brown (7.5YR 5/2) gravelly loam, dark brown (7.5YR 4/2) moist; weak fine granular structure; hard, friable, nonsticky and slightly plastic; few fine and many very fine roots; many very fine interstitial and tubular pores; slightly acid (pH 6.3); abrupt wavy boundary. (3 to 7 inches thick)
B2t--l0 to 24 inches; brown (7.5YR 5/4) clay, brown (7.5YR 5/4) moist; strong medium prismatic structure; extremely hard, very firm, very sticky and very plastic; few very fine and fine roots; common very fine tubular pores; thick continuous clay films in pores and as bridges; many slickensides; neutral (pH 7.0); clear slightly wavy boundary. (l0 to l7 inches thick)
B3tca--24 to 34 inches; brown (7.5YR 5/4) clay, brown (7.5YR 5/4) moist, few fine and medium distinct reddish brown (7.5YR 6/8) mottles; moderate medium subangular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots in the upper part; common very fine interstitial and tubular pores; many moderately thick clay films on faces of peds and in pores; common fine and medium distinct white (l0YR 8/2) soft masses of lime on faces of peds and undecomposed rock fragments, or as fine concretions; moderately alkaline (pH 8.0); gradual smooth boundary. (l0 to l7 inches thick)
Clca--34 to 50 inches; variegated 40 percent very pale brown (l0YR 7/3), 40 percent light yellowish brown (l0YR 6/4) and 20 percent strong brown (7.5YR 5/8) clay loam, yellowish brown (l0YR 5/4, 5/6, and 7.5YR 5/8) moist; massive; hard, friable, sticky and plastic; few very fine roots; few very fine tubular and many very fine interstitial pores; intermittently effervescent; few fine soft lime nodules in pockets and in cracks; moderately alkaline (pH 8.0); abrupt wavy boundary. (l0 to 20 inches thick)
TYPE LOCATION: Douglas County, Nevada; approximately 2,200 feet south and 200 feet west of the apparent northeast corner of section l5, T. ll N., R. 20 E.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist November through early June.
Soil temperature: 47 to 52 degrees F.
Solum thickness: 30 to 45 inches.
Control section:
Clay content: 45 to 60 percent.
Rock fragments: 0 to l0 percent, mainly strongly weathered pebbles. Depth to bedrock: 40 to 60 inches.
Reaction: Slightly acid or neutral in A horizon and B2 horizon.
A horizon
Hue: l0YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2, 3, or 4.
Rock fragments: l5 to 30 percent, mainly pebbles, when present, 5 to 20 percent cobbles or stones plus pebbles primarily in surface layer.
B2t horizon
Hue: l0YR or 7.5YR
Value: 4 or 5 moist.
Chroma: 3 or 4.
Structure: Medium or coarse prismatic.
B3 horizon
Rock fragments: l0 to 20 percent, mainly weathered pebbles, few cobbles are in some pedons.
Reaction: Slightly acid or neutral upper part, moderately alkaline lower part.
C horizon
Texture: Loam or clay loam.
Rock fragments: 0 to l5 percent, mainly pebbles and cobbles, few stones in some pedons.
COMPETING SERIES: These are the Acoma, Brent, Bowns, Chardoton, Deodar, Gooding, Phing, Reba, Sorf and Verdico series. Acoma soils have l5 to 35 percent pebbles in the argillic horizon. Brent and Chardoton soils have an A2 horizon. Bowns and Gooding soils have bedrock within 40 inches. Deodar soils have an AB horizon and have less than 45 percent clay in the upper part of the argillic horizon. Phing soils have an A2 horizon, Si horizon within 20 to 40 inches and are noncalcareous in the lower solum. Reba soils have less than 45 percent clay in the B2t horizon. Sorf soils have a solum l5 to 30 inches thick, have 5 to 35 percent rock fragments, mostly cobbles and stones in the B2t horizon, and are calcareous at a depth of l0 to to 20 inches. Verdico soils have a paralithic contact within 40 inches.
GEOGRAPHIC SETTING: Borda soils are on foothills at elevations of 5,200 to 7,000 feet. Slopes are 0 to 50 percent. The soils formed in residuum weathered from andesitic tuff and tuff breccia. The annual temperature is 47 1/4 to 50 1/4 F.; mean annual precipitation is l0 to l6 inches; and the frost-free season is l00 to l30 days. GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aldax and Millich soils. Aldax soils lack an argillic horizon and have bedrock within 20 inches. Millich soils have bedrock within 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; slow permeability.
USE AND VEGETATION: Used mainly for livestock grazing and wildlife habitat. The present vegetation is Wyoming big sagebrush, bitterbrush, squirreltail, needlegrass, bluegrass, cheatgrass, and buckwheat, with pinyon pine encroaching in some areas.
DISTRIBUTION AND EXTENT: Western Nevada and east-central California. These soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Douglas County, Area, Nevada, l98l.