LOCATION FITZWATER OR+CA NV

Established Series
Rev. JVC-JBF
12/2022

FITZWATER SERIES

The Fitzwater series consists of deep and very deep, well drained soils that formed in colluvium and residuum derived from basalt or tuff. Fitzwater soils are on plateaus, canyons, hills and mountains. Slopes are 0 to 70 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Haploxerolls

TYPICAL PEDON: Fitzwater loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure breaking to moderate very fine granular; soft, very friable, slightly sticky and nonplastic; many very fine and fine roots; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (3 to 23 cm thick)

A2--10 to 25 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium and fine subangular blocky structure; soft, friable, slightly sticky and nonplastic; many very fine and fine roots; 10 percent gravel; neutral (pH 6.6); clear smooth boundary. (0 to 25 cm thick)

2Bw--25 to 48 cm; brown (7.5YR 5/4) extremely cobbly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; common fine roots; 5 percent stones, 45 percent cobbles, and 25 percent gravel; neutral (pH 7.0); diffuse irregular boundary. (18 to 66 cm thick)

2C--48 to 152 cm; pale brown (10YR 6/3) extremely cobbly loam, brown (10YR 4/3) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few fine roots; 20 percent stones, 45 percent cobbles, and 25 percent gravel; neutral (pH 7.0).

TYPE LOCATION: Lake County, Oregon; about 0.75 miles west of Paiute Creek on the Hart Mountain National Antelope Refuge; in the SE 1/4 of the SW 1/4 of the NE 1/4 of section 21, T. 35 S., R. 26 E.; USGS Campbell Lake 7.5 minute topographic quadrangle; approximately latitude 42 degrees 31 minutes 30 seconds N and longitude 119 degrees 39 minutes 55 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry in summer and fall; these soils are dry for more than half the time when soil temperature is greater than 5 degrees C; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 30 cm.
Depth to base of cambic horizon: 25 to 100 cm.
Depth to bedrock: 100 to more than 150 cm to a lithic contact.
Reaction: Neutral or slightly alkaline.

Particle-size control section - Clay content: Averages 18 to 27 percent.
Sand content: 30 to 50 percent.
Rock fragments: Averages 50 to 90 percent, mainly cobbles. Lithology of fragments is volcanic rocks such as basalt and tuff.

A horizons
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Rock fragments: 0 to 40 percent stones, 0 to 40 percent cobbles, and 5 to 50 percent gravel. Loam surface texture with less than 15 percent total rock fragments is typically on slopes of 5 percent or less.
Organic matter content: 1 to 3 percent.

2Bw horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Extremely cobbly loam, extremely cobbly clay loam, very cobbly loam, very cobbly clay loam, very gravelly loam, extremely gravelly loam, or extremely gravelly sandy loam.
Clay content: 16 to 30 percent.
Rock fragments: 0 to 15 percent stones, 5 to 50 percent cobbles, 15 to 65 percent gravel.
2C horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry.
Chroma: 3 or 4 dry.
Texture: Extremely cobbly loam, extremely cobbly sandy loam, extremely stony loam, or extremely stony sandy loam; some pedons have extremely gravelly sandy loam.
Clay content: 15 to 25 percent.
Rock fragments: 0 to 40 percent stones, 15 to 50 percent cobbles, 10 to 60 percent gravel.

COMPETING SERIES: These are the Hartig, Loncan, Riddleranch, Snapeed, and Swahlen series.

Hartig soils average 12 to 18 percent clay in the particle-size control section. Loncan, Riddleranch, and Snapeed soils are moderately deep to lithic contacts. Swahlen soils have mollic epipedons that are 30 to 46 cm thick and have texture of extremely gravelly sandy loam or coarse sandy loam in the substratum.

GEOGRAPHIC SETTING: Fitzwater soils are on plateaus, canyons, hills and mountains. They typically occur on backslope positions. These soils formed in colluvium and residuum derived from basalt or tuff. Slopes are 0 to 70 percent. Elevations range from 1,250 to 2,290 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 250 to 400 mm, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 50 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lonegrave, Hapgood, Harcany, and Westbutte soils. Lonegrave soils have ochric epipedons and are moderately deep to lithic contacts. Hapgood and Harcany soils have thick mollic epipedons and a cryic temperature regime. Westbutte soils have thick mollic epipedons and are moderately deep to lithic contacts.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very low through medium surface runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Fitzwater soils are used for livestock grazing and wildlife habitat. Native vegetation is Wyoming big sagebrush, bluebunch wheatgrass, and Idaho fescue. Areas that have thin A horizons (5 inches or less thick) have low sagebrush, bluebunch wheatgrass, Thurber's needlegrass, and Sandberg's bluegrass.

DISTRIBUTION AND EXTENT: South-central Oregon, northeastern California, and northwestern Nevada. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Lake County (Southern Part), Oregon, 1991.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 25 cm (A1 and A2 horizons).
Cambic horizon - The zone from 25 to 48 cm (2Bw horizon).
Particle-size control section - The zone from 25 to 100 cm (2Bw and part of the 2C horizons).

ADDITIONAL DATA: Previous authors and editors include: AJM-RJK-TDT.

National Cooperative Soil Survey
U.S.A.