LOCATION HARSTON IDEstablished Series
The Harston series consists of deep, well drained soils that formed in
moderately coarse textured alluvium. Harston soils are on alluvial
fans and low terraces and have slopes of 0 to 4 percent. The mean
annual precipitation is about 10 inches and the mean annual temperature
is about 45 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, frigid Xeric Torrifluvents
Torrifluvents.
TYPICAL PEDON: Harston fine sandy loam - rangeland. (Colors are for
dry soil unless otherwise noted.)
A1--0 to 10 inches; light brownish gray (10YR 6/2) fine sandy loam,
dark grayish brown (10YR 4/2) moist; weak fine granular structure;
soft, very friable; many very fine and fine roots; mildly alkaline (pH
7.4); clear smooth boundary. (0 to 11 inches thick)
C1--10 to 20 inches; pale brown (10YR 6/3) fine sandy loam, dark
brown (10YR 4/3) moist; weak coarse subangular blocky structure;
slightly hard, very friable; common very fine and many fine roots;
moderately calcareous; moderately alkaline (pH 8.0); clear smooth
boundary. (10 to 30 inches thick)
C2--20 to 25 inches; light gray (10YR 7/2) fine sandy loam, brown
(10YR 5/3) moist; weak medium and coarse subangular blocky structure;
slightly hard, very friable; common very fine and fine roots;
moderately calcareous; moderately alkaline (pH 8.0); clear smooth
boundary. (0 to 10 inches thick)
IIC3--25 to 60 inches; very gravelly coarse sand; lime coatings on
lower surface of pebbles; mildly alkaline (pH 7.6).
TYPE LOCATION: Bonneville County, Idaho; 2,560 feet west and 150 feet
south of the NE corner of sec. 35, T.2 N., R. 36 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 41
degrees to 47 degrees F., and the mean summer temperature at depth of
20 inches is 59 degrees to 66 degrees F. The 10- to 40-inch control
section averages moderately coarse texture and has less than 18 percent
clay (mostly less than 12) and less than 35 percent rock fragments.
Below a depth of 10 inches and to a depth of 25 inches or more, the
dominant texture is sandy loam, fine sandy loam, coarse sandy loam or
gravelly sandy loam containing more than 50 percent fine sand or
coarser. A layer of loose sand and gravel or very gravelly loamy sand
has its upper boundary between depths of 24 and 40 inches. The organic
matter content decreases irregularly with increasing depth and reaches
levels 0.2 to 0.35 percent within a depth of 50 inches. Reaction is
mildly alkaline or moderately alkaline.
The Ap horizon has hue of 10YR or 2.5Y, value of 5 through 7 dry, 3
through 5 moist and chroma of 2 or 3. It is too thin or has too little
organic matter to be a mollic epipedon.
The C horizon has color like the A horizon and also includes higher
value and chroma.
COMPETING SERIES: This is the Hayeston series. Hayeston soils have a
regular decrease in organic matter with increasing depth.
GEOGRAPHIC SETTING: Harston soils are on bottomlands, alluvial fans,
and low terraces at elevations of 4,200 to 6,100 feet. Slopes are
dominantly less than 2 percent and range from 0 to 4 percent. The
soils formed in moderately coarse textured alluvium over stream
deposited gravel and sand and lake shore sediments. The alluvium is
dominantly from quartzite and sedimentary rock sources with lesser
influence from rhyolite, basaltic, and granitic materials. The climate
is semiarid with dry summers and has a mean annual precipitation of 8
to 13 inches, and the mean annual temperature is about 39 degrees to 45
degrees F. The frost-free period is 70 to 126 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bannock, Blackfoot,
Heiseton and Wardboro soils. Bannock and Blackfoot soils have a mollic
epipedon. Heiseton soils have fluctuating water table at depths of 4
to 6 feet. Wardboro soils have loose sand and gravel within 20 inches
of the surface.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderately
rapid permeability in the C1 horizon and very rapid in the sand and
gravel. These soils are subject to occasional or frequent flooding.
USE AND VEGETATION: Mostly cultivated under irrigation for hay,
pasture, potatoes, and small grains. The natural vegetation is mainly
big sagebrush, cheatgrass, rabbitbrush, needleandthread, streambank
wheatgrass, Indian ricegrass, Great Basin wildrye and Nevada bluegrass.
DISTRIBUTION AND EXTENT: The series is moderately extensive in the
bottomlands and low terraces of the upper Snake River Valley and the
tributary valleys in eastern Idaho.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Bonneville County Area, Idaho, 1978.
REMARKS: Soils correlated as Hayeston in Bingham Area and Jefferson
County, Idaho are Xeric Torrifluvents and are now included in the
Harston series.
National Cooperative Soil Survey