LOCATION LAIDLAW OR
Established Series
Rev. WMF/TDT
03/2011
LAIDLAW SERIES
The Laidlaw series consists of very deep, well drained soils in swales on volcanic uplands. They formed in ash over alluvium. Slopes are 0 to 40 percent. The mean annual precipitation is about 15 inches and the mean annual temperature is about 45 degrees F.
TAXONOMIC CLASS: Ashy, glassy, frigid Humic Vitrixerands
TYPICAL PEDON: Laidlaw ashy sandy loam - rangeland, on a 3 percent east facing slope at 3100 feet elevation. (When described (8/19/85), the soil was dry throughout. Colors are for moist soil unless otherwise noted)
Oi--0 to 1 inch; slightly decomposed litter of ponderosa pine, twigs and needles. (0 to 1 inch thick)
A1--1 to 6 inches; dark brown (10YR 3/3) ashy sandy loam, brown (10YR 4/3) dry; weak very fine granular structure; slightly hard, friable, nonsticky and nonplastic; many very fine, and common fine roots; many very fine irregular pores; 2 percent gravel; neutral (pH 7.0); clear wavy boundary.
A2--6 to 16 inches; dark brown (10YR 3/3) ashy sandy loam, brown (10YR 4/3) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 2 percent gravel; neutral (pH 7.0); gradual wavy boundary. (Combined thickness of the A horizon is 10 to 19 inches) thick).
Bw--16 to 27 inches; dark yellowish brown (10YR 3/4) ashy sandy loam, dark yellowish brown (10YR 4/4) dry; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few fine, medium and coarse roots; many very fine irregular pores; 2 percent gravel; neutral (pH 7.0); clear wavy boundary. (5 to 12 inches thick).
Bq1--27 to 39 inches; dark brown (10YR 3/3) ashy sandy loam, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few fine and medium roots; few medium tubular and many fine vesicular pores; 10 percent silica nodules which are hard and very hard dry and firm moist, and have iron and manganese stains; 2 percent gravel; neutral (pH 7.2); clear wavy boundary. (10 to 20 inches thick).
2Bq2--39 to 46 inches; dark brown (10YR 3/3) ashy fine sandy loam, brown (10YR 4/3) dry; weak medium subangular blocky structure; loose, nonsticky and nonplastic; few fine, medium and coarse roots; few medium tubular and many fine irregular pores; 30 percent silica nodules, which are hard and very hard dry and firm moist; neutral (pH 7.2); gradual wavy boundary. (5 to 12 inches thick).
2Bq3--46 to 61 inches; dark brown (10YR 3/3) ashy loamy fine sand, dark grayish brown (2.5Y 4/2) dry; weak medium subangular blocky structure; loose, nonsticky and nonplastic; few fine, medium and coarse roots; few medium tubular and many fine irregular pores; 10 percent silica nodules, which are hard and very hard dry, firm moist; neutral (pH 7.2).
TYPE LOCATION: Deschutes County, Oregon; 200 feet south and 200 feet east of the northwest corner of section 24, T.14 S, R.10 E (Latitude 44 degrees, 20 minutes, 55 seconds N, 121 degrees, 28 minutes, 48 seconds W)
RANGE IN CHARACTERISTICS: These soils are intermittently moist and are dry in all parts of the soil moisture control section for 90 to 110 consecutive days. The mean annual soil temperature is 44 to 47 degrees F. Depth of the solum is greater than 20 inches. Depth to bedrock is over 60 inches. The upper part of the solum contains 50 to 80 percent volcanic glass and glass-coated aggregates. Phosphate retention is 40 to 70 percent. The acid oxalate extractable aluminum plus one-half the acid oxalate extractable iron is 0.40 to 1.0 percent. The 15-bar water content on both dried and undried samples is 5 to 12 percent. Field estimated clay content is 5 to 15 percent clay. The mollic epipedon is 10 to 19 inches thick. Base saturation is 80 to 100 percent by ammonium acetate.
The A horizon has hue of 10YR, value of 2 or 3 moist and 4 or 5 dry and chroma of 2 or 3 moist and 2 through 4 dry. It contains 0 to 30 percent gravel. It is ashy loamy sand or ashy sandy loam.
The 2Bq or 2Bw horizon has hue of 10YR or 2.5Y value of 3 moist, 4 or 5 dry and chroma of 2 through 4 moist and dry. It is ashy fine sandy loam, ashy sandy loam, or ashy loamy fine sand. It contains 0 to 15 percent gravel, 0 to 30 percent cobbles, and 0 to 30 percent hard firm silica nodules. The pumiceous ash content is 20 to 50 percent.
A 2C horizon may be present in some pedons. When present, it has hue of 10YR, value of 4 or 5 dry, 2 or 3 moist, chroma of 2 or 3 moist and dry. It is ashy sandy loam, ashy loamy sand, ashy fine sandy loam, ashy loamy fine sand or cobbly ashy loamy sand and contains 0 to 10 percent gravel and 0 to 30 percent cobbles. The pumiceous ash content is 10 to 30 percent. It is neutral or slightly acid.
COMPETING SERIES: These are the
Cobey,
Drypok (T),
Ermabell,
Lundgren,
Pilotbutte,
Retep,
Suttle,
Trailcreek and
Wanoga series. Ermabell soils have skeletal glacial outwash material at 40 to 60 inches. Lundgren soils have skeletal glacial outwash material at 20 to 40 inches. Wanoga soils have a lithic contact at 20 to 40 inches. Cobey soils are dry for 60 to 75 consecutive days and have a 20 to 30 inch thick mollic epipedon. Suttle soils have an umbric epipedon and are somewhat poorly drained. Trailcreek soils are moderately deep to a paralithic contact. Drypok soils are dry for 60 to 90 consecutive days, have a 20 to 30 inch thick mollic epipedon and are 20 to 40 inches deep to a paralithic contact. Pilotbutte soils are dry for 60 to 90 consecutive days, have a 20 to 40 inche thick mollic epipedon and have 2 to 5 percent clay in the particle-size control section. Retep soils are dry for 60 to 75 consecutive days and are 20 to 40 inches deep to a paralithic contact.
GEOGRAPHIC SETTING: The Laidlaw soils are in swales and depressions on volcanic uplands at elevations of 2,800 to 5,270 feet. These soils formed in ash and alluvium. The climate is characterized by cold, wet winters and hot, dry summers. The mean annual precipitation is 12 to 18 inches. The mean annual temperature is 42 to 47 degrees F. The frost-free period is 20 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Fremkle,
Fryrear,
Henkle and
Wanoga soils. Fremkle, and Henkle soils have bedrock within 20 inches of the surface. Fryrear and Wanoga soils have bedrock at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: These soils are used for livestock grazing, wildlife habitat, and recreation. Potential native vegetation is ponderosa pine, western juniper, antelope bitterbrush, mountain big sagebrush, and Idaho fescue.
DISTRIBUTION AND EXTENT: Footslopes and plateaus of the eastern Cascades of central Oregon; MLRA 6. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Deschutes County, Oregon, 1939.
REMARKS: Diagnostic horizons and features in this pedon are:
mollic epipedon - from 1 to 16 inches (A1, A2 horizons)
cambic horizon - from 16 to 46 inches (Bq, 2Bq horizons)
Andic soil properties: for the zone from 1 to 39 inches based on laboratory data from the associated Wanoga series, S860R-017-001. P-retention is about 60 percent. The amount of glass and glass-coated aggregates in the very fine sand fraction is about 70 percent. The acid oxalate aluminum plus one-half the iron is about 0.45 percent. The 15-bar water content on both dried and undried samples is less than 10 percent.
The ash deposit is from Mt. Mazama.
National Cooperative Soil Survey
U.S.A.