LOCATION LAWARD ID
Tentative Series
Ird. BAG/GAH/EMM
06/2014
LAWARD SERIES
The Laward series consists of very deep, very poorly drained soils that formed in alluvium. Laward soils are on valley floors. Slopes range from 0 to 2 percent. Mean annual precipitation is about 500 millimeters and mean annual air temperature is about 2.2 degrees C.
TAXONOMIC CLASS: Fine, smectitic Argic Cryaquolls
TYPICAL PEDON: Laward silty clay loam, on a level 0 percent slope in pasture at an elevation of 1946 meters. (Colors are for dry soil unless otherwise noted).
Oe--0 to 6 cm; black (10YR 2/1) mucky peat, very dark brown (10YR 2/2) moist; rubbed and pressed hemic material; about 85 percent unrubbed fibers; 50 percent rubbed; many very fine and fine, and common medium roots; very slightly effervescent; slightly alkaline (pH 7.4); clear smooth boundary. (1 to 8 cm thick)
A--6 to 17 cm; very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; strong fine subangular structure; soft, very friable, moderately sticky and moderately plastic; many very fine and few fine and medium roots; many fine irregular and tubular pores; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 35 cm thick)
ABt--17 to 35 cm; dark gray (10YR 4/1) silty clay, very dark gray (10YR 3/1) moist; common course prismatic structure parting to strong medium angular blocky; hard, firm, very sticky and very plastic; few fine roots; common fine tubular pores; 5 percent faint clay films on faces of peds; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (15 to 35 cm thick)
Bkg1--35 to 89 cm; white (10YR 8/1) silty clay loam, pale brown (10YR 6/3) moist; strong coarse subangular blocky structure; moderately hard, firm, very sticky and very plastic; few medium roots; common fine tubular pores; 40 percent fine irregular masses of secondary calcium carbonate; violently effervescent; 10 percent fine faint yellowish brown (10YR 5/6) oxidized iron masses; moderately alkaline (pH 8.4); gradual smooth boundary.
Bkg2--89 to 120 cm; very pale brown (10YR 7/3) silty clay loam, pale brown (10YR 6/3) moist; strong medium subangular blocky structure; moderately hard, firm, very sticky and very plastic; many fine tubular pores; 5 percent fine irregular masses of secondary calcium carbonate; violently effervescent; 2 percent fine manganese masses; 10 percent fine faint yellowish brown (10YR 5/6) oxidized iron masses; moderately alkaline (pH 8.4); gradual smooth boundary. (combined thickness of the Bkg horizons is 65 to 100 cm)
Cg--120 to 150 cm; pinkish gray (7.5YR 7/2) clay loam, brown (7.5YR 5/2) moist; massive; hard, firm, moderately sticky and moderately plastic; few very fine and fine tubular pores; violently effervescent; 25 percent medium distinct yellowish brown (10YR 5/6) oxidized iron masses; 30 percent coarse distinct greenish gray (5GY 6/1) iron depletions; strongly alkaline (pH 8.6).
TYPE LOCATION: Caribou County, Idaho; about 700 meters west of the Grays Lake Road and 7.5 kilometers north of State Highway 34. About 710 meters west and 47 meters south of the northeast corner of section 10, T.5 S., R.43 E.; Bear Island, USGS topographic quadrangle; latitude 43 degrees 00 minutes 23.41 seconds north and longitude 111 degrees 24 minutes 6.7 seconds west, NAD 83
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 1.7 to 3.9 degrees C.
Mollic epipedon thickness: 25 to 40 cm
Depth to diagnostic features measured from the soil surface:
Depth to argillic horizon: 10 to 35 cm
Depth to calcic horizon: 25 to 70 cm
Depth to redox concentrations: 25 to 70 cm
Depth to redox depletions: 90 to 130 cm
Depth to apparent water table: 25 to 70 cm, from July to September.
Oe horizon
Value: 2 or 3 moist
Chroma: 2 to 4 moist
Slightly to Moderately decomposed sedges, rushes, and grasses
Reaction: 6.2 to 7.6
A horizon:
Hue: 10YR or 7.5YR
Value: 2 to 4 dry, 2 or 3 moist
Chroma: 1 or 2, dry or moist
Clay content: 28 to 35 percent
Reaction: pH 6.6 to 7.8
ABt horizon:
Hue: 10YR or 7.5YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 1 or 2, dry or moist
Texture: silty clay loam, silty clay, or clay
Clay content: 35 to 50 percent
Reaction: pH 7.2 to 8.0
Bkg horizons
Hue: 10YR or 7.5YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 1 to 3, dry or moist
Texture: silt loam or silty clay loam
Clay content: 24 to 38 percent
Reaction: pH 8.2 to 8.6
Cg horizon:
Hue: 10YR or 7.5YR
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 1 or 2, dry or moist
Texture: loam or clay loam
Clay content: 20 to 35 percent
Reaction: pH 8.2 to 8.6
COMPETING SERIES:
Ute: Do not have a calcic horizon
GEOGRAPHIC SETTING:
Landform: valley floors
Landscape: valleys
Elevation: 1940 to 1950 meters
Slope: 0 to 2 percent
Parent Material: alluvium from loess, metamorphic, and sedimentary rocks
Mean annual air temperature: 0.6 to 3.3 degrees C.
Mean annual precipitation: 450 to 550 millimeters
Frost-free period: 30 to 65 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Chubbflat: Do not have an argillic horizon and are on higher positions of the same landform.
Grayslake: have a histic epipedon greater than 150 cm and are on lower positions of the same landform.
Outlet: do not have clay films and are on higher positions of the same landform.
Sibbett: have less than 35 percent clay in the control section and occupy positions adjacent to Laward.
Tepete: have a histic epipedon greater than 40 cm thick and are on lower positions of the same landform.
DRAINAGE AND PERMEABILITY:
Drainage class: very poorly
Saturated hydraulic conductivity: moderately low
Ponding: 5 to 25 cm April to June
USE AND VEGETATION:
Major uses: watershed, pastureland, and wildlife habitat
Vegetation: herbaceous cinquefoil, horsetail, Baltic rush, other forbs and grasses, and scattered willows.
DISTRIBUTION AND EXTENT: Southeastern Idaho; MLRA 44B. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Caribou County, Idaho, 2014. The series name is from a nearby historical cemetery.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: from 6 to 35 cm
Argillic horizon: from 17 to 35 cm
Calcic horizon: from 35 to 120 cm
Horizon with redox concentrations: from 35 to 150 cm
Horizon with redox depletions: from 120 to 150 cm
Particle-size control section: from 17 to 35 cm
National Cooperative Soil Survey
U.S.A.