Deck 16: Soils

Question 1

Acidic soils tend to be

A)agriculturally productive, because the high concentration of cations in them causes them to attract nutrients with positive ions.
B)agriculturally productive, because the low concentration of cations in them causes them to attract nutrients with positive ions.
C)agriculturally unproductive, because the high concentration of cations in them causes them to leach away nutrients with positive ions.
D)agriculturally unproductive, because the low concentration of cations in them causes them to leach away nutrients with positive ions.

Answer 1

C

Question 2

In the diagram below, the yellow area represents

A)primary silicate minerals.
B)secondary silicate minerals.

Answer 2

B

Question 3

If a soil is too sandy, it will usually

A)lose its water and nutrients too easily.
B)be too compacted for most engineering applications.
C)have a high cation exchange capacity.
D)form steep bluffs and encourage contact metamorphism.

Answer 3

A

Question 4

Which of the following is not true of soil texture?

A)It can be modified substantially by humans.
B)It exerts a major control on the soil's fertility, stability, and other properties.
C)It describes the size distribution of the particles in a soil.
D)It can be described using a triangular plot of the percentage of sand, silt, and clay.

Question 5

Which of the following soils would probably have the lowest permeability?

A)loosely cemented sandy soils
B)clay-rich soil in an uninhabited area
C)clay-rich soil being used as cattle pasture
D)loam

Question 6

Which of the following is not a common cation that acts as a nutrient for plants?

A)sodium
B)magnesium
C)potassium
D)nitrogen

Question 7

Which of the following is not a function that humus and other organic matter serve in making a soil healthy?

A)improving infiltration
B)retaining water
C)increasing evaporation rates
D)retaining and cycling nutrients
E)reducing erosion

Question 8

Soils composed mostly of primary minerals will tend to have a higher percentage of _____ and a lower percentage of _____ than soils composed mostly of secondary minerals.

A)sand; clay
B)clay; silt
C)silt; sand
D)clay; sand

Question 9

The pore space, or porosity, of soils composed mainly of clays is generally

A)less than that in soils composed mainly of sands, because the grains in clays fit together very well compared to sands.
B)less than that in soils composed mainly of sands, because clay soils usually have more abundant organic matter than sandy soils.
C)greater than that in soils composed mainly of sands, because the grains in clays do not fit together very well compared to sands.
D)greater than that in soils composed mainly of sands, because clay soils usually have less organic matter than sandy soils.

Question 10

Which of the following is not a component of soil?

A)minerals
B)dead organic material
C)living organic material
D)water
E)All are components of soil

Question 11

The soil with the highest cation exchange capacity will have

A)abundant organic matter and acidic conditions.
B)abundant organic matter and alkaline conditions.
C)little organic matter and acidic conditions.
D)little organic matter and alkaline conditions.

Question 12

The soil shown in the photograph below has a reddish tint, which may mean that

A)it has abundant aluminum and/or iron oxides.
B)it contains abundant organic matter.
C)it has been waterlogged at some point.
D)there are salts or other minerals that have been deposited by the evaporation of water.

Question 13

The most direct impact of the process of capillary action is to

A)contribute to overland flow.
B)decrease the water available for transpiration.
C)increase the infiltration rate.
D)move water to the surface.

Question 14

The soil shown in the photograph below has a greenish or grayish tint, which may mean that

A)it has abundant aluminum and/or iron oxides.
B)it contains abundant organic matter.
C)it has been waterlogged at some point.
D)there are salts or other minerals that have been deposited by the evaporation of water.

Question 15

Clay soils will usually have a higher cation exchange capacity than sandy soils because

A)clay particles have round surfaces that reduce surface area where positively charged particles can accumulate.
B)clay particles have round surfaces that reduce surface area where negatively charged particles can accumulate.
C)clay particles have elongated surfaces that support negative charges.
D)clay particles have elongated surfaces that support positive charges.

Question 16

In general, the healthiest soil texture for plants is one in which

A)sand dominates, clays are next highest in concentration, and silt has the smallest concentration.
B)clay dominates, sands are next highest in concentration, and silt has the smallest concentration.
C)sand dominates, silts are next highest in concentration, and clay has the smallest concentration.
D)there is a relatively even percentage of sand, silt, and clay.

Question 17

Soils that are most likely to be compacted have

A)high porosity.
B)high permeability.
C)low porosity.
D)low permeability.

Question 18

Hygroscopic water

A)is generally unavailable to plants because its high surface tension causes it to adhere so tightly to the soil particles.
B)allows water to flow downward into the subsurface because it is often found in permeable soils.
C)generally enhances transpiration rates by allowing plants to be more active.
D)is water that runs off the surface after the soil reaches field capacity.

Question 19

In terms of particle sizes, secondary minerals are usually

A)smaller than primary minerals, because they have undergone fairly intense chemical weathering processes compared to primary minerals.
B)smaller than primary minerals, because they have undergone fairly intense physical weathering processes compared to primary minerals.
C)larger than primary minerals, because they are fairly resistant to chemical weathering processes compared to primary minerals.
D)larger than primary minerals, because they are fairly resistant to physical weathering processes compared to primary minerals.

Question 20

Soils that have a blocky structure

A)are usually difficult to plow.
B)come apart in fragments that are taller than they are wide.
C)do not break apart into peds.
D)consist of grains that do not stick together.

Question 21

Which of the following is not a function that organic matter serves in soil?

A)separates soil particles
B)bonds nutrients
C)cycles nutrients vital for health
D)serves as an energy source for organisms

Question 22

Loess is transported by _____ and is important because _______.

A)flowing streams; it tends to braid streams and dam the water
B)mass wasting processes down slopes; it can cause debris avalanches
C)wind around glaciers; it is fertile
D)flowing streams; erodes very quickly

Question 23

In the soil profile below, iron is present in both the top and bottom later, as labeled, but why is only the second layer a reddish color?

A)The iron oxide was leached from the top layer in what was most likely a wet environment.
B)The iron oxide was leached from the top layer in what was most likely an arid environment.
C)When exposed to air, the iron oxide loses its reddish tint in what was most likely a wet environment.
D)When exposed to air, the iron oxide loses its reddish tint in what was most likely an arid environment.

Question 24

In the figure below, the zone of accumulation occurs where?

A)1
B)2
C)3
D)4

Question 25

The primary difference between the O and A horizons is that the O horizon usually has

A)more leaching than the A horizon.
B)less leaching than the A horizon.
C)more plant litter than the A horizon.
D)less plant litter than the A horizon.

Question 26

Podzolization is most likely to occur in the ___ horizon.

A)A
B)B
C)C
D)E

Question 27

Which of these features is typical of soils in temperate environments?

A)excessive eluviation
B)relatively immobile nutrients
C)retention of nutrients within the crop root zone
D)excessive splash erosion

Question 28

The primary source of nutrients for plants is found in the ___ horizon.

A)O
B)A
C)E
D)B

Question 29

In general, warm, wet climates allow for fast formation of soils primarily because

A)chemical weathering proceeds at rapid rates.
B)parent material found in warm, wet climates tends to allow it to break down faster than the types of parent material found in colder climates.
C)physical weathering proceeds at rapid rates.
D)there is less biological activity in warm, wet climates than elsewhere.

Question 30

In the diagram below, eluviation has begun to create a distinct horizon in which image?

A)1
B)2
C)3
D)4

Question 31

Typically when a glacier recedes, the deposited material leaves behind

A)material of a wide range of sizes, until streams moving around the area begin to sort the material by size.
B)material of a wide range of sizes only after streams moving around the area begin to mix together the particles of different sizes.
C)primarily clay-sized material, because material bigger than clay cannot be picked up by ice easily.
D)primarily sand-sized materials and larger because the ice tends to crush the finer materials into a powder.

Question 32

Soils with shale-derived parent material usually differ from those from sandstone-derived parent material in that they tend to

A)be more drought-prone than the sandstone-derived soils.
B)break down organic matter slower than sandstone-derived soils.
C)resist weathering more than sandstone-derived soils.
D)form clays with more soluble cations than the sandstone-derived soils.

Question 33

In general, compared with soils on gentle slopes, soils on steep slopes will tend to be

A)better developed.
B)more clayey.
C)more easily eroded.
D)more acidic.

Question 34

Which of the following is not true about the spatial scales at which soil scientists study soils?

A)The smallest individual unit with which soils are described is called a soil pedon.
B)A pedon can be about 1 to 10 m² and deep enough (about 2 m deep)to distinguish soil horizons.
C)A pedon must be significantly different in properties from the pedons adjacent to it.
D)Boundaries between different soil types on the landscape can be gradational or fairly abrupt.

Question 35

In the diagram below, horizonation has begun in which image?

A)1
B)2
C)3
D)4

Question 36

The diagram below is most likely from

A)humid environment because of the abundant organic matter and evidence of oxidation.
B)dry environment because of the visible lack of soil erosion.
C)a waterlogged environment because there is strong evidence of anaerobic conditions.
D)a temperate environment because of the well-developed horizons.

Question 37

In the diagram below, regolith forms in which area?

A)a
B)b
C)c
D)d

Question 38

Which nutrient is most directly responsible for efficient water uptake and conservation?

A)nitrogen
B)potassium
C)phosphorus
D)titanium

Question 39

All of the following are in the topsoil layer and contribute directly to processes occurring there except

A)earthworms.
B)plant litter.
C)humus.
D)bacteria.

Question 40

Which of the following is not true about the C horizon?

A)It has no organic matter.
B)It accumulates iron, aluminum, clay, and other materials leached down from layers above it.
C)It is little affected by the processes that impact the layers above it.
D)It is also known as the regolith.

Question 41

The thick __ horizon in the soil profile shown in the diagram below is one of the distinguishing features of the _______ soil type.

A)B; Ultisol
B)O; Ultisol
C)B; Oxisol
D)O; Oxisol

Question 42

The bleached, grayish E horizon shown in the diagram here is characteristic of

A)Spodosols.
B)Alfisols.
C)Gelisols.
D)Andisols.

Question 43

The climatic features that tend to be most important in forming Aridisols include

A)nearby warm ocean currents on the air masses in the area.
B)descending air and high pressure.
C)the intertropical convergence zone for at least part of the year.
D)monsoon circulation.

Question 44

In the world map below, the color that represents the soil type with the most ideal balance between leaching and retention of nutrients is

A)dark green.
B)pink.
C)medium blue.
D)purple.

Question 45

The limited horizonation in the soil type pictured below occurs because

A)the subsurface is covered by permafrost.
B)precipitation is limited.
C)volcanic ash has penetrated very deeply beneath the surface in this soil type.
D)leaf litter is so abundant that it tends to leach downward across all of the layers.

Question 46

Compared with Mollisols, Alfisols tend to be somewhat

A)more fertile and agriculturally productive.
B)more likely to become acidic.
C)more narrowly distributed around the world.
D)more prone to calcification.

Question 47

Which of the following soil types is most likely to be found in mountainous or sandy regions?

A)Mollisols
B)Histosols
C)Entisols
D)Inceptisols

Question 48

Gelisols generally are most closely associated with

A)lack of organic matter.
B)fast rates of chemical weathering.
C)salinization.
D)permafrost.

Question 49

Which of the following types of soil is most strongly influenced by its climate?

A)Andisol
B)Histosol
C)Inceptisol
D)Gelisol

Question 50

Which of the following is true of Mollisols?

A)They are commonly found in tropical conditions.
B)Leaching is excessive in most of these soil types.
C)They are found in places with seasonal moisture deficits.
D)Gleization is an important process contributing to their formation.

Question 51

The most common soil type on Earth is

A)Entisols.
B)Andisols.
C)Ultisols.
D)Mollisols.

Question 52

In the world map below, the purple color represents

A)Gelisols.
B)Histosols.
C)Entisols.
D)Ultisols.

Question 53

Vertisols, Aridisols, Oxisols, and Ultisols all have in common that they

A)lack a well-developed A horizon.
B)resist formation into polypedons.
C)form in warm climates.
D)are deeply weathered soils.

Question 54

The absence of a layered structure in the soil pictured below occurs because

A)leaching is so strong that it removes the distinguishing features of each layer.
B)swelling as the soil absorbs water and shrinking as it dries out removes the horizonation.
C)calcification has caused caliche to be left behind in all of the horizons.
D)volcanic ash has penetrated very deeply beneath the surface in this soil type.

Question 55

What is a major difference between Inceptisols and Entisols?

A)Inceptisols have a weak B horizon while Entisols have no B horizon.
B)Inceptisols are more common in areas where weathering and leaching occur while Entisols are more common where new landscapes have formed.
C)Inceptisols are usually found in wetter areas while Entisols tend to occur in drier areas.
D)All of these are major differences between Inceptisols and Entisols.

Question 56

The soil pictured below is

A)Vertisols.
B)Oxisols.
C)Gelisols.
D)Spodosols.

Question 57

Which of the following types of soil is least strongly influenced by its climate?

A)Entisol
B)Aridisol
C)Mollisol
D)Spodosol

Question 58

Extremely fertile soils that have been formed out of volcanic material are

A)Andisols.
B)Histosols.
C)Entisols.
D)Inceptisols.

Question 59

Soils that were covered by continental ice sheets and have not developed since the last glacial advance are classified as

A)Andisols.
B)Histosols.
C)Entisols.
D)Inceptisols.

Question 60

Areas that experience frequent water budget surpluses are most likely to experience which of these pedogenic regimes?

A)salinization
B)calcification
C)gleization
D)podzolization

Question 61

In the world map below, the color that represents soils that are least mature is

A)pink.
B)light green.
C)dark green.
D)yellow.

Question 62

"No-till" agriculture reduces soil erosion by

A)increasing sheetwash.
B)causing soils to dry out faster.
C)reducing rainsplash.
D)All of the above.

Question 63

The ideal texture for a soil to minimize the risk of pollution is one that

A)is very coarse, so that it drains efficiently.
B)is very fine, so that it minimizes the contamination to groundwater.
C)is very fine, so that it improves the ability to dissolve hazardous materials.
D)is of moderate sized particles, to reduce ponding while still having some filtering capabilities.

Question 64

The red areas in the map below are places where

A)soil erosion due to wind is a major problem.
B)soil erosion due to water is a major problem.
C)soil is being formed faster than it is being eroded away.
D)salinization is leaving the soil ineffective for agriculture.

Question 65

Compared with soils beneath built-up areas, soils beneath a for?ested watershed will generally

A)reduce surface runoff.
B)become compacted more quickly.
C)be more likely to flood.
D)be more likely to shrink and swell.

Question 66

The wind erosion processes shown at A and B in the diagram below are

A)suspension and saltation.
B)saltation and creep.
C)drifting and abrasion.
D)ablation and plucking.

Question 67

Liquefaction will generally be most problematic in

A)places with Aridisols that lie along hillslopes.
B)places with Inceptisols that get about the same amount of precipitation throughout the year.
C)waterlogged, earthquake-prone locations.
D)places in which vegetation leaves behind an acidic residue.

Question 68

In which colored area in the world map below has slash and burn agriculture been most prominent in leaving relatively infertile soils beneath the forest exposed?

A)dark green
B)light blue
C)pink
D)purple

Question 69

The use of strip cropping helps to control soil erosion by

A)increasing the cation exchange capacity.
B)increasing saltation.
C)reducing leaching.
D)reducing runoff.

Question 70

A major danger of soils that become too acidic is that

A)solifluction becomes a bigger danger.
B)soils can become calcified more easily, especially in coastal environments.
C)the harmful effects of heavy metal pollutants become magnified.
D)crops that grow on them become more sensitive to cold temperatures.

Question 71

A forensic application of soil science might involve

A)finding the appropriate mixture of soil textures for a tennis court's surface.
B)linking the soil type on a shoe to the soil type where a crime took place.
C)identifying the type of clays in soil that accelerate healing processes.
D)classifying the soil type by its acidity.

Question 72

In the world map below the color that represents soils that swell and shrink excessively is

A)pink.
B)light green.
C)medium blue.
D)purple.

Question 73

The most direct and fundamental relationship between overgrazing and soil erosion is that

A)overgrazing leads to soil compaction.
B)overgrazing increases that amount of suspended particles in the air.
C)overgrazing causes eutrophication.
D)overgrazing leads to the loss of vegetation.