LOCATION ADAMSON ID+WYEstablished Series
The Adamson series consists of very deep, well drained soils that
formed in alluvium from mixed sources. Adamson soils are on stream
terraces and have slopes of 0 to 4 percent. Permeability is moderate
to 28 inches and very rapid below. The average annual precipitation is
about 14 inches, and the average annual air temperature is about 42
degrees F.
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Calcic Pachic Haploxerolls
frigid Calcic Pachic Haploxerolls.
TYPICAL PEDON: Adamson loam - on a 1 percent slope at an elevation of
5,020 feet in rangeland. When described on August 17, 1971, the soil
was dry to 28 inches and moist below. (Colors are for dry soil unless
otherwise noted.)
A--0 to 5 inches; grayish brown (10YR 5/2) loam, very dark grayish
brown (10YR 3/2) moist; moderate fine and medium granular structure;
slightly hard, friable, slightly sticky and slightly plastic; many fine
roots; many very fine interstitial pores; neutral (pH 6.6); clear
smooth boundary. (5 to 10 inches thick)
BA--5 to 19 inches; grayish brown (2.5Y 5/2) loam, very dark
grayish brown (2.5Y 3/2) moist; weak medium subangular blocky
structure; slightly hard, friable; many fine roots; common very fine
interstitial pores; neutral (pH 6.6); clear smooth boundary. (6 to 14
inches thick)
Bw--19 to 28 inches; grayish brown (10YR 5/2) fine sandy loam, very
dark grayish brown (10YR 3/2) moist; massive; soft, very friable; many
fine and medium roots; about 5 percent pebbles; mildly alkaline (pH
7.6); clear wavy boundary. (4 to 12 inches thick)
2Bk--28 to 61 inches; light grayish brown (10YR 6/2) very gravelly
coarse sand, dark grayish brown (10YR 4/2) moist; single grain; loose,
few fine roots; about 40 percent pebbles and 20 percent cobbles; slight
effervescence (calcium carbonate accumulation on underside of rock
fragments) mildly alkaline (pH 7.8).
TYPE LOCATION: Blaine County, Idaho; about 3 miles south and 1 mile
west of Bellevue; 800 feet west and 125 feet south of the northeast
corner of sec. 23, T. 1 N., R. 18 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 42 to 47 degrees F
Thickness of mollic epipedon - 20 to 36 inches
Depth to sandy skeletal layer - 23 to 36 inches
A horizon
Color value, dry - 3 through 5
Value, moist - 2 or 3
Chroma, moist or dry - 1 or 3
Reaction - neutral to mildly alkaline
BA and Bw horizon
Color, hue - 10YR or 2.5Y
Value, dry - 4 or 5
Value, moist - 2 or 3
Chroma, moist or dry - 2 or 3
Texture- L, FSL, VFSL
Clay content - 8 to 18 percent
Coarse fragments - 0 to 15 percent
Reaction - slightly acid through mildly alkaline
2Bk horizon
Texture- GRV-COS, GRV-S, GRX-COS, CBX-LCOS, CBX-COS, STX-COS
Clay content - 0 to 5 percent
Rock fragments - 35 to 85 percent
Reaction - neutral to mildly alkaline
COMPETING SERIES: There are no other soils recognized in this family.
The Balaam series are in a similar family. The Balaam soils have
thinner mollic epipedons and are in a sandy-skeletal family.
GEOGRAPHIC SETTING: Adamson soils are on stream terraces. Slopes
range from 0 to 4 percent. Elevation ranges from 4,700 to 6,000 feet.
The soil formed in recent alluvium. The annual precipitation is 14 to
18 inches, most of which falls as snow and early spring rain. The
average annual air temperature is about 40 degrees to 45 degrees F.
The frost-free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Balaam, Bruneel, Carey
Lake, Hutton, and Little Wood soils. Little Wood soils have more than
35 percent rock fragments in the control section. Bruneel and Hutton
soils have Aquic moisture regimes. Carey Lake soils have argillic
horizons. Carey Lake and Little Wood soils occur on older alluvial
fans and fan terraces. Bruneel and Hutton soils occur on recent
floodplains. Balaam soils occur on the same landscape position.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
Subject to rare or occasional flooding in the spring.
USE AND VEGETATION: Mainly used for irrigated pasture, hay and small
grain and some rangeland. Vegetation is basin big sagebrush, bluebunch
wheatgrass, mountain big sagebrush, Idaho fescue, slender wheatgrass,
and Sandberg bluegrass.
DISTRIBUTION AND EXTENT: Adamson soils are inextensive in southcentral
Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Diagnostic horizons and features recognized in this series
are:
Mollic epipedon - occurs from the soil surface to approximately 28
inches (A, BA, and Bw horizons)
Secondary calcium carbonate accumulations - occur in the zone from 28
to 61 inches (Bk horizon)
National Cooperative Soil Survey