Soils Exam One
Which of the following parent material originates from weathering of underlying rock?
Residuum
The lithosphere is made up of _________.
Rock
Complexation, a chemical weathering reaction, is best described as _________.
The solubilizing and binding of organic acids with inorganic minerals
Most of the water flowing in rivers passed through a soil profile or over soil surfaces before reaching the river.
True
Most of the water in our rivers and lakes has come in contact with and has been affected by soils.
True
Practices that tend to increase the amount of organic matter in soils would be expected to reduce the global greenhouse effect.
True
The water in the soil typically differs from pure water because the soil water ________.
All of the above
Which of the following is considered to be a plant macronutrient?
All of the above
A(n) _______ develops at the mouth of narrow canyons in upland areas.
Alluvial Fan
Which of the following is (are) essential plant nutrients?
Cu
______ is a method of physical weathering that results from the expansion and contraction of rocks due to differences in daytime and nighttime temperature.
Exfoliation
Soil air usually has a higher carbon dioxide content than the air in the atmosphere.
True
The principal climatic variables that influence soil formation are...
Wind duration and velocity
"Topsoil" is generally equivalent to which soil horizon?
A
Which of the following pH values represents the most acid condition?
1.0
In a typical mineral soil in optimal condition for plant growth, approximately what percentage of the soil would be filled with water and what percentage filled with air?
25% water, 25% air
In a load of 10 cubic meters of topsoil, approximately how many cubic meters of the volume would be solid material?
5
Which of the following pH values represents a neutral condition?
7.0
Organic matter accumulation is most pronounced in the ____.
A horizon
Hydrolysis, a chemical weathering reaction, is best described as _________.
A water molecule splitting into H+ and OH- ions, and H+ replacing a cation in the mineral structure
What is the soil formation process that involves the movement of inorganic and organic materials laterally within a horizon or vertically from one horizon up or down to another?
Additions
Hydration, a chemical weathering reaction, is best described as _________.
An intact water molecule that binds with a mineral and becomes part of the mineral crystal structure
Oxidation reduction, a chemical weathering reaction, is best described as _________.
An intact water molecule that binds with a mineral and becomes part of the mineral crystal structure
The topographical feature that describes the direction that a slope faces with respect to the sun is called:
Aspect
Subsoil" is generally equivalent to which soil horizon?
B
Silicate clay accumulation is most common in the ____.
B horizon
_______ weathering is involved in the synthesis of secondary minerals.
Chemical
Soils that form from the eroded and deposited underwater sediments that build up over a long period of time that become exposed due to sea level changes or geological uplift are most appropriately called:
Coastal Sediments
An alluvial deposit formed where a stream or river drops its sediment load upon entering a quieter body of water is most appropriately referred to as:
Delta
In which of the following horizons has the process of illuviation most likely occurred?
E horizon
Although subsoil is more difficult to obtain, it is generally equally as good as topsoil for landscaping purposes.
False
Soil, like concrete and steel, is a standard construction material. Its properties are well characterized and predictable so that standard building foundation designs can be used uniformly at all building sites of a given topography.
False
Subsoil is typically equivalent to the O horizon.
False
Where organic matter constitutes only 1 or 2 percent of the soil by weight, it has only negligible influence on soil properties.
False
While many organisms depend on the soil for nutrients and water, only a few very specialized organisms live in the soil itself.
False
The land bordering a stream, built up of sediment from overflow of the stream and subject to inundation when the stream is at flood stage is most appropriately referred to
Floodplain
Plants contribute organic matter when they die and decompose, which of the following vegetative types would contribute a lot of organic matter to the soil surface but not into the soil itself?
Forest
Dissolution, a chemical weathering reaction, is best described as _________.
Hydration and disassociation of minerals into individual ions surrounded by water
The reaction: mica + H2O K++ OH-+ acid clay is an example of ________.
Hydrolysis
Silt-size particles deposited by wind are called _____.
Loess
What is the soil formation process where materials leach from the soil profile to groundwater or volatilize as a gas into the atmosphere?
Losses
Sediment carried by water flowing from under a glacier form a(n) ______.
Moraine
In the temperate regions of the northern hemisphere, which slope aspect would have soils with the highest soil organic matter?
North
Which of the following soil descriptions would be the most mature and possibly the oldest?
O and C horizons only
Peat and muck soils develop from _____ that decomposed incompletely after being deposited in water.
Organic Matter
______ refers to the activity of animals on the soil development process.
Pedoturbation
_______ weathering is the process of breaking big rocks into smaller pieces.
Physical
________ rocks were formed from weathering products of other rocks.
Sedimentary
The degree of deviation of a surface from horizontal, measured in numerical ratio, percent, or degrees is called:
Slope
Most of the different nutrients essential for growth are supplied to plants directly from the ______.
Soil solution
As temperature increases and abundant water is available soil formation will:
Stay the same
Acid Reactions, a chemical weathering reaction, is best described as _________.
The dissolution of minerals by acids formed in the soil solution such as carbonic acid
Eolian parent materials are transported by ______.
Wind
Which of the following relates to the configuration of land surfaces?
Topography
What is the soil formation process when soil constituents are chemically and physically modified or destroyed and others are synthesized?
Transformation
What is the soil formation process where materials are input into the developing soil profile from outside sources?
Translocation
The mineral particles in soil consist of sand, silt, and clay.
True
Soil occupies the ______part of the regolith.
Upper
Which of the following is not considered one of the five major factors influencing soil formation?
Valence state
If you wanted to find a soil where physical weathering dominated over chemical breakdown you would be most apt to find it in ______.
a desert region of Arizona
The mixed angular gravel, rock, and soil found at the foot of a slope is typical of what type of parent material?
colluvial
Glacial till is a term used to describe parent materials that:
contain a heterogeneous mixture of mineral debris dropped by receding glaciers.
The element most often involved in oxidation reactions as minerals weather is _____.
iron
Residual parent materials are best described as
materials formed by weathering of rocks and minerals in place
Which of the following is not a secondary mineral?
microcline
Igneous rocks can best be characterized as:
rocks formed when molten magma solidifies
Exfoliation is caused by changes in _________.
temperature
The amount of different sizes of mineral particles in a soil defines the soil ________.
texture
Mechanical or physical weathering processes result in:
the disintegration of rocks due to differential expansion of minerals
A soil profile consists of _________.
the set of layers seen in a vertical cross section of a soil
Igneous, sedimentary, and metamorphic are three _________.
types of rocks