LOCATION CALNAT CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Xeric Natrargids
TYPICAL PEDON: Calnat sandy loam--on a 1 percent slope under a cover of basin big sagebrush and black greasewood at about 4,005 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted. When described on June 10, 1982, the soil was dry throughout and the soil temperature at a depth of 20 inches was 65 degrees F.)
A1--0 to 3 inches; light gray (2.5Y 7/2) sandy loam, dark grayish brown (2.5Y 4/2) moist; strong thin and medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots, many very fine and fine vesicular pores; 5 percent calcium carbonate equivalent; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary.
A2--3 to 5 inches; pale brown (10YR 6/3) sandy loam, dark brown (10YR 3/3) moist; moderate very thin and thin platy structure; hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine vesicular pores; slightly effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (Combined thickness of the A horizons is 5 or 6 inches.)
Btnk--5 to 13 inches; light olive brown (2.5Y 5/4) sandy clay loam, dark grayish brown (2.5Y 4/2) moist; weak medium prismatic parting to moderate medium and coarse angular blocky structure; very hard, friable, moderately sticky and moderately plastic; few very fine, fine and medium roots; common very fine tubular pores; common faint clay films on faces of peds and bridging mineral grains; SAR is 39; EC is 7 mmhos; 6 percent calcium carbonate equivalent; violently effervescent; secondary carbonates segregated in few fine and medium masses; strongly alkaline (pH 8.5); clear wavy boundary. (7 or 8 inches thick)
2Cnz--13 to 17 inches; pale yellow (2.5Y 8/2) loam, light yellowish brown (2.5Y 6/4) moist; weak medium angular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; no roots; many very fine and few fine interstitial pores; SAR is 85; EC is 24 mmhos; 22 percent calcium carbonate equivalent; common fine filaments of soluble salts; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary.
2C--17 to 28 inches; pale yellow (2.5Y 8/2) loam, olive brown (2.5Y 4/4) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; no roots; many very fine and few fine interstitial pores; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (Combined thickness of the 2C horizons is 7 to 28 inches.)
3Cr--28 to 60 inches; pale yellow (2.5Y 8/2) soft tuffaceous siltstone, olive (5Y 5/4) moist; moderate and strong thin through thick platy rock structure; common very fine roots along faces of plates in upper 10 inches and few very fine roots along faces of plates below; noneffervescent in matrix but violently effervescent on faces of plates; few vertical cracks.
TYPE LOCATION: Lassen County, California; in Honey Lake Valley on The Island; about 0.5 mile east of the intersection of two dirt roads and north of the east-west road on the section line; about 100 feet north and 2,650 feet east of southwest corner of section 18, T. 27 N., R. 16 E.; USGS Herlong 7.5 minute topographic quadrangle; 40 degrees 11 minutes 18 seconds north latitude and 120 degrees 13 minutes 00 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil moisture control section (about 8 to 20 inches) is dry throughout from June 1 to November 15 (167 days). It is moist throughout from December 1 to April 15. The soil temperature exceeds 41 degrees F from March 1 to December 15 (289 days). The soil temperature exceeds 47 degrees F from April 15 to November 15 (215 days); Aridic moisture regime that borders on xeric.
Mean annual soil temperature - 53 to 56 degrees F.
Ochric epipedon thickness - 5 or 6 inches.
Depth to base of natric horizon - 12 or 13 inches.
Depth to bedrock - 20 to 40 inches to a paralithic contact. The paralithic materials below the contact are soft, weathered lacustrine deposits composed of tuffaceous siltstone or fine-grained sandstone.
Reaction - Moderately alkaline or strongly alkaline.
A horizon - Dry color: 10YR 6/2, 6/3; 2.5Y 6/2 or 7/2.
Moist color: 10YR 3/2, 3/3; 2.5Y 3/2 or 4/2.
Texture: Sandy loam or loamy sand.
Btnk horizon - Dry color: 10YR 6/4, 2.5Y 5/4, 6/2 or 7/4.
Moist color: 10YR 4/4; 2.5Y 3/2 or 4/2.
Clay content: 20 to 25 percent.
Sand content: 50 to 80 percent.
Salinity (EC): 8 to 16 mmhos/cm.
Sodicity (SAR): 25 to 50.
Calcium carbonate equivalent: 5 to 10 percent.
2Cnz and 2C horizons - Dry color: 2.5Y 8/2 or 5Y 8/3.
Moist color: 2.5Y 4/4, 6/4 or 5Y 5/3.
Texture: Loam or silt loam.
Salinity (EC): 16 to 32 mmhos/cm.
Sodicity (SAR): 50 to 100.
Calcium carbonate equivalent: 15 to 25 percent.
COMPETING SERIES: These are the Antelope Springs, Mesman, Slipback, Tannawasha (T), and Wespac series.
Antelope Springs, Mesman, Slipback, and Wespac soils are very deep. Tannawasha soils are moderately deep to lithic contacts.
GEOGRAPHIC SETTING: Calnat soils are on lake terraces. These soils formed in Pleistocene lacustrine deposits derived from mixed rock sources. Slopes are 0 to 2 percent. Elevation ranges from 4,000 to 4,010 feet in the Honey Lake valley and 5,330 to 5,350 feet on the Madeline Plains. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 6 to 9 inches in the Honey Lake Valley and 12 to 14 inches on the Madeline Plains. Most areas receive 10 to 20 inches of snow. The mean annual temperature is 44 to 52 degrees F. The mean January temperature is about 30 degrees F.and the mean July temperature is about 72 degrees F. The frost-free period is 60 to 80 days on the Madeline Plains and 100 to 130 days in the Honey Lake Valley.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Biscaro, McDermott, and Stiles soils. Biscaro soils are fine, moderately deep to paralithic contacts, and have argillic horizons. McDermott soils are fine-silty and very deep. Stiles soils have argillic horizons and have a subhorizon of the argillic with clay texture.
DRAINAGE AND PERMEABILITY: Well drained; low surface runoff; moderately slow permeability.
USE AND VEGETATION: Calnat soils are used as rangeland. The vegetation is basin big sagebrush, black greasewood, basin wildrye, and western wheatgrass.
DISTRIBUTION AND EXTENT: Northeastern California. These soils are not extensive with about 2,500 acres of the series mapped to date. The series concept and main acreage is in MLRA 27, while other acreage occurs in MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lassen County (Susanville Area Soil Survey), California, 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 5 inches (A1 and A2 horizons).
Natric horizon - The zone from 5 to 13 inches (Btnk horizon).
Identifiable secondary carbonates - The zone from 5 to 13 inches (Btkn horizon).
Paralithic contact - The boundary at 28 inches to underlying soft bedrock (3Cr layer).
Particle-size control section - The zone from 5 to 13 inches (Btkn horizon).