LOCATION DONNA                   NV

Established Series
Rev. RAF/PWB/RLB/JBF
01/2019

DONNA SERIES

The Donna series consists of well drained soils that are moderately deep to a duripan that formed in alluvium derived from mixed rocks with a component of loess high in volcanic ash. Donna soils are on fan piedmont remnants. Slopes are 2 to 15 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Very-fine, smectitic, frigid Abruptic Argiduridic Durixerolls

TYPICAL PEDON: Donna gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) About 30 percent of the surface is covered by a gravel pavement.

A1--0 to 5 cm; light brownish gray (10YR 6/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate coarse platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine vesicular and tubular pores; 25 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (1 to 8 cm thick)

A2--5 to 10 cm; grayish brown (10YR 5/2) gravelly loam, dark brown (10YR 3/3) moist; weak coarse platy structure parting to moderate very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular and vesicular pores; 15 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (3 to 13 cm thick)

A3--10 to 20 cm; grayish brown (10YR 5/2) gravelly loam, dark brown (10YR 3/3) moist; moderate medium and fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and few fine roots; many very fine and few fine tubular, common very fine interstitial pores; 15 percent gravel; neutral (pH 7.0); abrupt smooth boundary. (0 to 13 cm thick)

EB--20 to 33 cm; light brownish gray (10YR 6/2) gravelly clay loam with many uncoated sand grains, dark brown (10YR 3/3) moist; strong very fine granular structure; hard, friable, very sticky and very plastic; many very fine, common fine, few medium roots; many very fine interstitial and tubular pores; 15 percent gravel; few distinct clay films on faces of peds; neutral (pH 7.0); very abrupt wavy boundary. (0 to 13 cm thick)

Bt1--33 to 46 cm; brown (10YR 5/3) clay, yellowish brown (10YR 5/4) moist; strong medium and fine prismatic structure; very hard, very firm, very sticky and very plastic; many very fine and few fine exped roots mostly in the upper 5 cm, few exped roots below; few very fine and fine tubular pores in upper 2 cm and very few very fine tubular pores below; many distinct clay films in pores, many slickensides and pressure cutans; neutral (pH 7.0); clear wavy boundary. (8 to 33 cm thick)

Bt2--46 to 56 cm; light yellowish brown (10YR 6/4) sandy clay, yellowish brown (10YR 5/4) moist; massive; hard, firm, moderately sticky and very plastic; few fine and very fine roots; common fine tubular pores; many distinct clay bridges between sand grains, common slickensides; neutral (pH 7.2); abrupt wavy boundary. (3 to 36 cm thick)

Bqm--56 to 69 cm; light yellowish brown (10YR 6/4) indurated duripan with continuous 2 to 5 mm thick, white (10YR 8/1) silica laminae, brown (10YR 4/3) moist; massive; extremely hard, extremely firm; common very fine roots matting the laminar surface and along some fracture planes only; common very fine tubular pores; slightly alkaline (pH 7.4); abrupt wavy boundary. (0 to 15 cm thick)

Bqkm--69 to 97 cm; very pale brown (10YR 7/3) indurated duripan, with very thin (1 to 2 mm) continuous and discontinuous, randomly oriented, white (10YR 8/1) silica-carbonate laminae, grayish brown (10YR 5/2) moist; massive; extremely hard, extremely firm; few very fine tubular pores; strongly effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (25 to 50 cm thick)

2Btkb--97 to 129 cm; light gray (10YR 7/2), and very pale brown (10YR 7/3) extremely gravelly loam, brown (10YR 5/3) moist; massive; hard, firm, slightly sticky and slightly plastic; few very fine tubular pores; common distinct clay films and silica coats in pores; few very fine tubular pores; 60 percent gravel, 15 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 38 cm thick)

2Btb--129 to 147 cm; light yellowish brown (10YR 6/4) extremely gravelly sandy clay loam, yellowish brown (10YR 5/4) moist; massive; hard, firm, very sticky and moderately plastic; few very fine tubular and many very fine interstitial pores; few medium soft carbonate segregations; 40 percent gravel, 20 percent cobbles; common distinct clay films in tubular pores and common distinct clay bridges between sand grains; few very fine tubular and interstitial pores; noneffervescent matrix but violently effervescent in spots; moderately alkaline (pH 8.2); clear wavy boundary. (0 to 25 cm thick)

2Bk--147 to 173 cm; pale brown (10YR 6/3) extremely gravelly sandy clay loam, brown (10YR 5/3) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; many very fine, common fine and few medium interstitial pores; 45 percent gravel, 30 percent cobbles; common medium soft seams of carbonates; very few distinct clay bridges between sand grains; noneffervescent matrix but violently effervescent in seams; slightly alkaline (pH 7.8).

TYPE LOCATION: Elko County, Nevada; approximately 24 miles north of Carlin; 4.5 miles northwest of the confluence of Beaver and Maggie Creeks; about 2,500 feet west and 525 feet north of the southeast corner of section 8, T. 37 N., R. 52 E.; USGS Beaver Creek 7.5 minute topographic quadrangle; latitude 41 degrees 6 minutes 27 seconds N and longitude 116 degrees 9 minutes 14 seconds W; WGS84 Decimal Degrees 41.1075000 latitude, -116.1538889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist in winter and spring, dry mid June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 30 cm.
Depth to duripan: 50 to 90 cm.
Thickness of duripan: 25 to 50 cm.
Other features: There is an increase of 15 to 30 percent clay at the upper boundary of the Bt horizon.

Particle-size control section - Clay content: 60 to 70 percent.
Rock fragments: 0 to 15 percent, mainly gravel.

A horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 2 or 4 moist; 6 dry and 4 moist only in the surface 2 to 8 cm. After mixing the top 18 cm the soil meets the 5.5 dry and 3.5 moist color requirement for mollic.
Chroma: 2 or 3.
Reaction: Slightly acid or neutral.

Bt horizon
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 4 or 5 moist.
Chroma: 3 through 6.
Structure: Weak to strong medium or coarse prismatic, parting to angular blocky, massive in the lower part.
Consistence: Hard or very hard dry, firm or very firm moist, sticky or very sticky and plastic or very plastic wet.
Reaction: Slightly acid or neutral; some pedons are mildly alkaline immediately above the duripan.

Bqm, Bqkm horizons
Reaction: Neutral to slightly alkaline where the upper subhorizons lack carbonates; moderately alkaline to strongly alkaline in the calcareous portions.
Other features: Commonly noncalcareous in the upper part but few or common fine soft carbonate seams are along fracture planes in some pedons.

2Bk and 2Bqk horizons
Texture: Commonly stratified, ranges from extremely gravelly sandy loam to gravelly sandy clay loam.
Rock fragments: Averages 35 to 65 percent, mainly gravel.
Reaction: Slightly alkaline or moderately alkaline.

COMPETING SERIES: This is the Charwell soils. Charwell soils are moderately deep to a duripan over bedrock.

GEOGRAPHIC SETTING: Donna soils are on fan piedmont remnants. These soils formed in alluvium derived from dominantly mixed rocks with a component of loess high in volcanic ash. Slopes are 2 to 15 percent. Elevations are 1,585 to 2,255 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm; mean annual temperature is 6 to 7 degrees C, and the frost-free season is 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Short Creek soils and the similar Stampede soils. Short Creek soils lack a duripan.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, Sandberg bluegrass, Thurber needlegrass, bottlebrush squirreltail, cheatgrass, Indian ricegrass, Webber ricegrass, phlox, arrowleaf balsamroot, and Eriogonum.

DISTRIBUTION AND EXTENT: Northeastern Nevada. MLRA 25. These soils are moderately extensive.

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

SERIES ESTABLISHED: Elko County, Nevada, 1975.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to about 28 cm (the A1, A2 and A3 horizons).
Argillic horizon - the zone from about 33 to 56 cm (the Bt1 and Bt2 horizons).
Indurated duripan - the zone from about 56 to 97 cm (the Bqm and Bqkm horizons).
Aridic feature - Aridic soil moisture regime bordering on xeric.
Abrupt textural change - the boundary at about 33 cm (between EB and Bt1 horizons).
Particle-size control section - the zone from about 33 to 56 cm (the Bt1 and Bt2 horizons).

---

National Cooperative Soil Survey
U.S.A.