Test #4 Ch. 18

the science that deals with the origin, classification, and distribution of soils is known as _____
the basic sampling unit in soil surveys is called
a pedon
the basic soil unit used in preparing soils maps; i.e., in identifying a series of soils in an area, is the
the general name for any distinct layer in a pedon is
which of the following soil horizons designations is in the correct sequences from the surface to bedrock?
O, A, E, B, C, R
the movement of material out of a layer is called _____, whereas the deposition of materials in a layer is called______.
eluviation; illuviation
true solum is made up of
a combination of the A, E, and B horizons
The R horizons refers to
unweathered sediment of consolidated bedrock
soil color does not reflect composition or chemical makeup of soils. T/F
White to pale color in soils are generally associated with
silicates and aluminum oxides
soils associated with iron oxides generally show ____ color.
soil texture describes the size of ____
soil particles
a roughly equal mixture of sand, silt, and clay is called
the arrangement of soil particles is called soil _______
terms used to describe soils structure include ______, _______, and _______
fine, medium, and coarse
a soil rich in hydrogen ions is a(n) _____ soil, and high in base cations is a(n) ______ soil.
the principle natural soil-forming factors
include climate, vegetation, topography
which of the following lists of soil categories gives the proper hierarchy for soil Taxonomy
soil orders, suborders, great groups, subgroups, families, series
a soil order characteristic of the Amazon Basin is a(n)
Salinization is likely to occur
in areas of high potential evapotranspiration and low actual evapotranspiration
at present, which of the soils orders of soil taxonomy occupy the most land area in the United States?
At present, which of the following soil orders occupies the most land area worldwide?
Mollisols are associated with
the greatest grain harvests in the world
which soil order would tend to occur in the southeastern U.S. with its high temperature and humid environment?
heavy, expandable clay soils are classified as
which of the following soils would have limited horizon development and would be destructive of buildings and roads?
Swelling clays can damage foundation because they swell when moisten and shrink when dried. T/F
Gelisols are most likely to be found in