LOCATION LADD OR+CA IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Argixerolls
TYPICAL PEDON: Ladd loam, cultivated. (Colors are for
moist soil unless otherwise noted.)
Ap--0 to 8 inches; very dark brown (10YR 2/2) loam, dark
grayish brown (10YR 4/2) dry; weak fine granular structure;
friable, slightly hard, slightly sticky and slightly
plastic; many roots; many very fine irregular pores; neutral
(pH 6.6); clear smooth boundary. (6 to 10 inches thick)
Bt1--8 to 16 inches; dark brown (10YR 3/3) loam, brown
(10YR 5/3) dry; weak coarse prismatic structure; friable,
hard, slightly sticky and slightly plastic; common roots;
many very fine tubular pores; few thin clay films as
bridges; slightly acid (pH 6.4); clear wavy boundary. (4 to
11 inches thick)
Bt2--16 to 32 inches; brown (10YR 4/3) clay loam, pale
brown (10YR 6/3) dry; weak coarse prismatic structure;
friable, hard, slightly sticky and slightly plastic; common
roots; many very fine and fine pores; common thin clay films
on peds and in tubular pores; few dark brown krotovinas;
slightly acid (pH 6.2); clear wavy boundary. (8 to 22
inches thick)
C1--32 to 46 inches; brown (10YR 4/3) loam, brown (10YR
6/3) dry; massive; firm, hard, slightly sticky and slightly
plastic; few roots; many very fine and fine tubular pores;
slightly acid (pH 6.2); clear smooth boundary. (0 to 16
inches thick)
2C2--46 to 62 inches; dark yellowish brown (10YR 4/4)
clay loam, light yellowish brown (10YR 6/4) dry; massive;
firm, hard, sticky and plastic; many very fine and fine
tubular pores.
TYPE LOCATION: Baker County, Oregon; 200 feet north; 200
feet west of SE corner of sec. 34, T. 7 S., R. 38 E.
RANGE IN CHARACTERISTICS: The depth of bedrock is 60 inches
or more. These soils are usually moist and are moist in
some part above the lower boundary of the moisture control
section for at least one half the time (cumulative) when the
soil temperature at depth of 20 inches exceeds 41 degrees F
in most years. These soils are dry for 80 to 90 consecutive
days. The mean annual soil temperature ranges from 47 to 52
degrees F. There are less than 35 percent rock fragments in
the texture control section. The sola are slightly acid or
neutral, commonly increasing in alkalinity as depth
increases and have 10YR or 7.5YR hue. The mollic epipedon
is 10 to 20 inches thick.
The A horizon has value of 4 or 5 dry, 2 or 3 moist and
chroma of 2 or 3 dry or moist. It is silt loam, sandy loam,
or loam. The upper part of the A horizon has platy
structure in some pedons. The A horizon is high in volcanic
ash.
The Bt horizon has value of 3 through 5 moist, 4 through 6
dry and chroma of 2 through 4 moist and dry. It is sandy
clay loam, clay loam or loam and averages 18 to 35 percent
clay. It has few patchy thin to many continuous thin clay
films on peds and in pores with moderately thick films in
some pedons. It has weak coarse prismatic to moderate
medium prismatic and subangular blocky structure.
The C or 2C horizon has similar range in color as the Bt
horizon and is dominantly moderately fine textured, but
includes sandy loam and loam. In some pedons the lower part
of the 2C horizon is slightly calcareous.
COMPETING SERIES: These are the
Colma,
Dragoon,
Duzel,
Facey,
Farrot,
Foehlin,
Immiant,
Lobitos,
Los Gatos,
Mehlhorn,
Morical,
Taneum,
Tieton,
Tweedy and
Yaxon series.
Dragoon, Duzel, Farrot, Immiant, Lobitos, Los Gatos,
Mehlhorn, Morical and Tweedy soils are 20 to 40 inches deep
to bedrock. Colma soils have black A horizons thicker than
10 inches, have mottled B horizons overlying slowly to very
slowly permeable C horizons. Facey soils lack any quartz
diorite mixed with volcanic ash and have a solum thickness
of more than 40 inches. Foehlin soils have a mean annual
soil temperature of 52 to 56 degrees F. Taneum soils are
dry in the moisture control section for 60 to 80 days.
Tieton soils have a calcareous C horizon with secondary
carbonates and have bedrock within 60 inches. Yaxon soils
are dry for 80 to 105 consecutive days.
Jauriga, Taneum,
and Tieton soils are not clearly differentiated.
GEOGRAPHIC SETTING: Ladd soils are on alluvial fans,
terraces, and colluvial footslopes. Elevations range from
2,700 to 5,050 feet. Slopes range from 0 to 65 percent.
The soils formed in alluvium and colluvium weathered from
basic igneous rocks high in quartz diorite mixed with loess
and volcanic ash. The frost-free period is 80 to 130 days.
The mean annual precipitation is 12 to 18 inches. The mean
annual temperature is 45 to 50 degrees F; the average
January temperature is 27 to 29 degrees F; and the average
July temperature is about 65 to 68 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ager,
Baker,
Barnard,
Bieber, Cause,
Delma,
Hutchinson, and
Goodrich
soils. Ager soils are clayey and have cracks that open and
close once each year and have slickensides. Baker,
Barnard, Bieber and Hutchinson soils have duripans. Cause
soils are less than 20 inches deep to a paralithic contact.
Delma soils are clayey and less than 20 inches deep to a
paralithic contact. Goodrich soils lack Bt horizons, are
medium textured with less than 18 percent clay, and are
usually dry.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid
runoff; moderate slow permeability.
USE AND VEGETATION: Mostly in irrigated crops of alfalfa,
grass and small grain or dryland pasture and hay or range. Vegetation is mainly Idaho fescue, associated forbs, a few
ponderosa pine or western juniper, big sagebrush,
rabbitbrush, bluebunch wheatgrass, and cheatgrass.
DISTRIBUTION AND EXTENT: Eastern Oregon, southwestern Idaho
and northeastern California. The series is moderately
extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Baker County Area, Oregon; 1942.
REMARKS: Diagnostic horizons and features:
Mollic epipedon - 0 to 16 inches.
Argillic horizon - 8 to 32 inches.