LOCATION TULANA OR+CAEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Aquandic Humaquepts
TYPICAL PEDON: Tulana silt loam, cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 8 inches; black (10YR 2/1) silt loam, gray (10YR 5/1) dry; weak very fine granular structure; soft, friable, slightly sticky and nonplastic; many very fine roots; many very fine pores; neutral (pH 7.3); abrupt smooth boundary. (8 to 20 inches thick)
A--8 to 23 inches; black (N 2/ ) silt loam, gray (N 5/ ) and flecks of light gray (N 7/ ) dry; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular pores; neutral (pH 7.3); abrupt smooth boundary. (2 to 18 inches thick)
C--23 to 37 inches; grayish brown (2.5Y 5/2) silt, light gray (10YR 7/1) dry; common faint dark grayish brown (2.5Y 4/2) mottles; and common yellowish brown (10YR 5/6) mottles in root channels and pores; moderate very thin platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular pores; neutral (pH 7.3); abrupt smooth boundary. (6 to 27 inches thick)
2Ab--37 to 46 inches; dark brown (7.5YR 3/2) mucky silt, gray (10YR 6/1) dry; common fine distinct dark gray (10YR 4/1) and strong brown (7.5YR 5/6) mottles; weak thin platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular pores; neutral (pH 6.6); abrupt smooth boundary. (0 to 10 inches thick)
2C1--46 to 57 inches; grayish brown (10YR 5/2) silt, light gray (10YR 7/2) dry; common strong brown (7.5YR 5/6) mottles; weak very thin platy structure; hard, friable, slightly sticky and nonplastic; few roots; few very fine tubular pores; slightly acid (pH 6.3); abrupt smooth boundary. (0 to 15 inches thick)
3C2--57 to 64 inches; grayish brown (10YR 5/2) very fine sandy loam, light gray (10YR 7/2) dry; common fine strong brown mottles and black streaks and spots; massive; soft, very friable; slightly sticky and nonplastic; few roots; many very fine pores; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 10 inches thick)
4C3--64 to 82 inches; grayish brown (2.5Y 5/2) silt loam, light gray (10YR 7/2) dry; common strong brown (7.5YR 5/6) mottles; common black flecks and patches; weak very thin platy structure (bedding planes); slightly hard, friable, slightly sticky and slightly plastic; few roots; few very fine tubular pores; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 20 inches thick)
5C4--82 to 86 inches; dark grayish brown (2.5Y 4/2) fine sand, gray (10YR 6/1) dry; common fine strong brown (7.5YR 5/6) mottles; massive; soft, very friable, nonsticky and nonplastic; few roots; many very fine pores; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 30 inches thick)
6C5--86 to 92 inches; olive gray (5Y 4/2) silt loam, light gray (10YR 7/1) dry; common fine strong brown (7.5YR 5/6) mottles; massive; slightly hard, friable, slightly sticky and slightly plastic; many very fine pores; moderately acid (pH 6.0)
TYPE LOCATION: Klamath County, Oregon; about 500 feet south of the intersection of Center Canal and Klamath Straight Drain; 2,800 feet south and 200 feet west of the northeast corner section 31, T. 40 S., R. 9 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 to 49 degrees F.; and the mean January soil temperature is about 28 degrees F. The soils are ponded under natural conditions. The upper part of the soil is slightly acid to mildly alkaline and the lower part is mildly alkaline to extremely acid. Ranges in soil reaction are reflective of drained and undrained conditions. The mollic epipedon is 10 to 23 inches thick. Bulk density at 1/3 bar water retention ranges from about 0.40 to 0.85 grams per cubic centimeter throughout the soil. The soils have high amounts of diatoms, sponge spicules, and amorphous materials. Mucky layers 4 to 10 inches thick are common at depths below 20 inches. Pumiceous ash layers 1 to 6 inches thick are common at depths below 35 inches. The organic matter decreases irregularly with depth. A silty light gray volcanic ash layer 6 to 27 inches thick is immediately under the mollic epipedon, but is less than 14 inches cumulative inches thick within 24 inches of the surface. The particle-size control section has less than 15 percent fine sand or coarser material and 10 to 30 percent clay with the weighted average being over 18 percent clay.
The A horizon has value of 4 or 5 dry, and chroma of 0 or 1 moist and 0 to 2 dry. The 15 bar water is about 45 to 65 percent. Organic matter is 10 to 20 percent. Base saturation (sum of cations) is 50 to 85 percent.
The C horizon has hue of 10YR to 5Y, value of 2 to 7 moist, 5 to 8 dry, and chroma of 0 to 2 moist and dry. It is silt, silt loam, or silty clay loam. The C horizon below depth of 35 inches is stratified silt loam to fine sand. Base saturation (sum of cations) is 30 to 45 percent.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Tulana soils are on lake bottoms at elevations of 4,084 to 4,140 feet. The soils formed in lacustrine sediments consisting mainly of diatoms, ash, and similar materials. The climate is semiarid with cool moist winters and hot dry summers. The mean annual precipitation is 8 to 14 inches. The mean January temperature is 27 to 29 degrees F., the mean July temperature is 65 to 69 degrees F., and the mean annual temperature is 45 to 49 degrees F. The frost-free period is 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Algoma, Henley, Laki and Teeters soils. Algoma and Teeters soils have an SAR of over 13 in the surface. Henley and Laki soils are calcareous, strongly to very strongly alkaline, and have more than 15 percent coarser than very fine sand. Henley soils also have a duripan at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Poorly drained; ponded or very slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for irrigated pasture and small grains and for wildlife habitat. Vegetation on undrained areas consists mainly of cattails and bulrushes.
DISTRIBUTION AND EXTENT: Lake basins in south-central Oregon and northeastern California. The soils are extensive.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Modoc County, California, 1974.
REMARKS: Diagnostic horizons and other features:
-Mollic epipedon - 0 to 23 inches (Ap, A horizons)
-Andic feature - 23 to 37 inches (C horizon)
The soils in their natural condition have an aquic soil moisture regime.
Base saturation is less than 50 percent by sum of cations and by ammonium acetate in the lower part of the profile.
The particle size control section averages over 18 percent clay, the 13 to 23 inch layer averages about 27 percent clay and the 23 to 40 inch layer averages about 10 percent clay.
The soil was formerly classified as medial, nonacid, mesic Mollic Andaquepts. Classification changed in May 1990.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
ADDITIONAL DATA: Characterization data on 2 Oregon profiles (S67 Oreg. 18-11 and 18-12) reported in Riverside Soil Survey Laboratory report for Tulana soils sample in Klamath County, Oregon, 1967 and 1 California profile (S72 Cal. 25-23). Unpublished.
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.