Deck 18: The Geography of Soils

Question 1

A vertical section of soil is generally organized into distinct horizontal layers called

A) soil profiles.
B) pedons.
C) soil horizons.
D) polypedons.

Answer 1

C

Question 2

The branch of soil science that studies soil as a medium for sustaining the growth of higher plants is known as

A) pedology.
B) edaphology.
C) geology.
D) geomorphology.

Answer 2

B

Question 3

The horizon identified as regolith is the ________ horizon.

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

Answer 3

E

Question 4

Which of the following soil horizon designations is i the correct sequence from the surface to the bedrock?

A) O, E, C, B, A
B) A, B, C, O, R
C) S, O, I, L
D) O, A, E, B, C

Question 5

In regards to soil-formation, which of the following best describes the role of climate?

A) Because all soils are ancient, they show the climatic conditions of the period in which they formed.
B) Of the five principle soil-forming factors, climate is the least significant with little correlation between soil and climates worldwide.
C) Temperature and moisture determine the chemical reactions, organic activity, and water movement within soils.
D) Relative humidity and atmospheric pressure are the dormant climatic factors that influence soil development.

Question 6

Where would one likely find the deepest soil development?

A) on steep slopes
B) level or nearly level grounds
C) moderately sloping, south facing hills
D) over the oldest geological formations in an area, regardless of slope

Question 7

Which of the following best describes the composition of soil?

A) Soil is primarily mineral matter (approximately 72%), but also consists of organic matter (10%), and water (18%).
B) Soil consists of approximately 45% organic matter, 50% mineral matter, and 5% water and/or air.
C) Soil is composed of about 45% mineral matter, 5% organic matter, and 50% pore space containing air and water.
D) Soil includes pebbles, gravel, cobbles, and a varying combination of sands, silts, and clays.

Question 8

Which of the following best describes the role of biological activity in soils development?

A) Broadleaf trees tend to increase the alkalinity of soil, whereas needleleaf trees increase the acidity.
B) Earthworms increase soil porosity and contribute to soil movement and organic content.
C) Plant roots provide channels for air and water movement in soils.
D) All organisms living in, on, and over the soil, influence soil development and characteristics: they can influence the pH, the organic matter, chemical content, and biological content of soils.

Question 9

The horizon that is commonly called topsoil is the ________ horizon.

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

Question 10

The horizon in which leached materials from other horizons is accumulated is the ________ horizon.

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

Question 11

Which of the following is correct regarding the soil physical property of soil?

A) Dark soils always indicate high organic content.
B) Despite the imporantance of color in describing soils, there is no standard methods for standardized descriptions.
C) Soil color is used solely to determine the moisture content of soil-darker soils have a higher moisture content, whereas lighter soils have less water content.
D) Color reflects composition and chemical makeup of a soil.

Question 12

Which of the following is not a physical property used to distinguish soils?

A) color
B) texture
C) porosity
D) moisture
E) temperature

Question 13

A vertical cross section of soil extending from the surface to the deepest extent of plant root activity or to the regolith and bedrock is known as a

A) pedon.
B) soil profile.
C) soil horizon.
D) polypedon.

Question 14

The horizon in which water moves fine particles downward in a process called eluviation is the ________ horizon.

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

Question 15

The basic sampling unit, in soil surveys representing all the characteristics and variability used for classification, is

A) soil profile.
B) pedon.
C) soil horizon.
D) polypedon.

Question 16

Soils will develop at faster rates in which of the following environments?

A) hot and dry
B) cold and dry
C) warm and humid
D) in areas where they can develop directly from bedrock, regardless of climate conditions

Question 17

The organic rich horizon found at the top of the soil profile is the ________ horizon.

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

Question 18

Which of the following best describes soil?

A) Soil is composed of solely mineral fragments less than 2 mm in size.
B) Soil lacks biological material.
C) Soil is a renewable resource.
D) Soil is a dynamic natural material composed of water, air, mineral fragments, and organic matter.

Question 19

The branch of soil science that deals with the origin, classification, distribution, and description of soils is known as

A) pedology.
B) edaphology.
C) geology.
D) geomorphology.

Question 20

Which of the following is not one of the five primary soil-forming factors?

A) topography
B) climate
C) human activity
D) biological activity
E) parent material

Question 21

A soil that is 40% sand, 40% silt, and 20% clay is classified as

A) loam.
B) silty clay.
C) silt loam.
D) clay loam.

Question 22

The practice of leaving crop residue on the field between plantings to help prevent soil erosion is known as

A) slash and burn agriculture.
B) swidden.
C) shifting cultivation.
D) no-till agriculture.

Question 23

A plant that is unable to extract needed water from soil has reached its

A) field capacity.
B) permeability.
C) wilting point.
D) porosity.

Question 24

Why is cation-exchange capacity (CEC) an important soil characteristic?

A) CEC is an indication of the soil permeability; the lower the CEC the higher the permeability.
B) CEC is a measure of soil fertility; the higher the CEC the higher the soil fertility.
C) CEC is an indirect way to measure soil pH; it indicates whether the soil is neutral, alkaline, or acidic.
D) CEC is used to infer soil texture without having to use a soil texture triangle.

Question 25

Carbon dioxide concentrations in soil are ________ than in the atmosphere because ________.

A) lower; transpiration
B) lower; plant photosynthesis
C) higher; ongoing respiration in the ground
D) higher; decay of dead plants and animals

Question 26

Between 1982 and 2007, soil erosion on U.S. cropland

A) decreased by 43%.
B) increased by 25%
C) increased by 13%.
D) decreased by 21%.

Question 27

Acidic soils

A) are exceptionally rare.
B) cause more rapid weathering and leaching of nutrients.
C) tend to be very fertile and excellent for agriculture purposes.
D) are high in calcium, magnesium, potassium, and sodium ions.

Question 28

The term used to denote the part of a volume of soil that is filled with air, gases, or water is

A) soil texture.
B) porosity.
C) permeability.
D) soil structure.

Question 29

A few centimeters' thickness of prime farmland soil may require ________ years to form.

A) 10
B) 50
C) 100
D) 500

Question 30

A roughly equal mix of sand, silt, and clay is called

A) humus.
B) regolith.
C) solum.
D) loam.

Question 31

________ refers to the size and shape of the aggregates of particles of soil.

A) Soil texture
B) Soil consistence
C) Soil structure
D) Soil plasticity

Question 32

The multiyear period of severe wind erosion and soil loss occurred in the Great Plains during the 1930s is known as

A) desertification.
B) the Grapes of Wrath.
C) the Black Blizzard.
D) the Dust Bowl.

Question 33

Rounded peds have ________ space between them than other peds, and are therefore ________ for plant growth.

A) less; better
B) less; worse
C) more; worse
D) more; better

Question 34

Which of the following human activities may make soils more prone to erosion?

A) overcultivation
B) overgrazing
C) forest clearance
D) overcultivation, overgrazing,and forest clearance may all make soils more prone to erosion

Question 35

A soil that is 20% sand, 60% silt, and 20% clay is classified as

A) sandy clay.
B) sandy clay loam.
C) silt loam.
D) clay loam.

Question 36

The smallest natural lump or cluster of soil particles is known as a

A) horizon.
B) ped.
C) profile.
D) separate.

Question 37

Soil separates refers to

A) differing soil colors in a pedon.
B) individual mineral particles, such as sand, silt, and clay.
C) the different soil horizons.
D) pebbles, gravel, cobble, and other materials greater than 2 mm in diameter found in soils.

Question 38

Soil structure can be defined as which of the following?

A) crumb or granular
B) platy
C) blocky
D) prismatic
E) crumb or granular, platy, blocky, or prismatic are all type of soil structure

Question 39

In soil science, the term to describe the cohesion of soil particles is

A) soil texture.
B) permeability.
C) consistence.
D) soil structure.

Question 40

Ped formation enhances

A) soil texture.
B) permeability.
C) soil horizons.
D) plasticity.

Question 41

In terms of pedogenic regimes, the leaching process in humid and warm climates is known as

A) laterization
B) salinization.
C) calcification.
D) podzolization.
E) gleization.

Question 42

Worldwide, desertification is affecting an estimated ________ people.

A) 100,000
B) 1,000,000
C) 5,000,000
D) 1,000,000,000

Question 43

Calcification is likely to occur

A) in areas with Vertisols.
B) in areas with Mollisols and Aridisols.
C) in tropical climate regions.
D) in areas characterized by coniferous forests.

Question 44

The phenomenon of desert expansion along the margins of semiarid and arid lands is known as

A) deflation.
B) desertification.
C) erosion.
D) permeability.

Question 45

Oxisols have a ________ cation-exchange and, therefore, ________ fertility.

A) high; high
B) low; high
C) low; low
D) high; low

Question 46

Salinization is likely to occur

A) in the tropics.
B) in areas of high potential evapotranspiration rates.
C) in humid climate regions.
D) in areas characterized by coniferous forests.

Question 47

In terms of pedogenic regimes, the process that produces an illuviated accumulation of calcium carbonate in continental climates is

A) laterization
B) salinization.
C) calcification.
D) podzolization.
E) gleization.

Question 48

The lowest and most precise level of the U.S. soil classification system is

A) soil family.
B) soil order.
C) soil series.
D) soil group.

Question 49

In terms of pedogenic regimes, the process that concentrates salts in soils in climates with high evapotranspiration is

A) laterization.
B) salinization.
C) calcification.
D) podzolization.
E) gleization.

Question 50

These mature soils are found in the tropics.

A) Oxisols
B) Mollisols
C) Aridisols
D) Andisols

Question 51

Podzolization is likely to occur

A) in the tropics.
B) in areas with broadleaf forests.
C) in humid climate regions.
D) in areas characterized coniferous forests.

Question 52

In terms of pedogenic regimes, the process that results in an accumulation of humus overlaying a thick, water saturated layer of clay in cold, wet climates with poor drainage conditions is

A) laterization
B) salinization.
C) calcification.
D) podzolization.
E) gleization.

Question 53

In terms of pedogenic regimes, soil acidification associated with forest soils in cool climates is

A) laterization.
B) salinization.
C) calcification.
D) podzolization.
E) gleization.

Question 54

Which of the following areas has the highest rick of desertification?

A) the Sahel (Sub-Saharan Africa)
B) northeastern Australia
C) central Asia
D) Venezuela

Question 55

Which of the following is not a factor contributing to desertification?

A) overgrazing
B) no-till agriculture
C) salinization
D) climate change

Question 56

Which soil order occupies the most land area worldwide?

A) Oxisols
B) Mollisols
C) Aridisols
D) Andisols

Question 57

Which of the following is correct about the U.S. soil classification system?

A) Soil variation is too complex for a single classification system, so many regional classification systems are used within the U.S.
B) The Soil Taxonomy is hierarchical, consisting of six categories from soil series to soil order.
C) The soil classification system was finalized in 1975 and no additional changes to it will be made.
D) It is primarily based on pedogenic regimes in which each soil-forming process is attached to a climatic region.

Question 58

Which of the following is among the most mature soils on Earth?

A) Andisols
B) Inceptisols
C) Entisols
D) Oxisols

Question 59

In which of the following areas would one likely find Oxisols?

A) higher latitudes, especially areas dominated by permafrost
B) tropical regions
C) in mountainous areas with steep slopes
D) primarily in grasslands

Question 60

Laterization is likely to occur

A) in the tropics.
B) in areas of high potential evapotranspiration rates.
C) in humid climate regions.
D) in areas characterized by sandy soils and coniferous forests.

Question 61

________ are high latitude soils containing permafrost and large amounts of organic matter.

A) Alfisols
B) Ultisols
C) Inceptisols
D) Gelisols

Question 62

These soils are the most spatially widespread, extending from the equator to high latitudes.

A) Vertisols
B) Alfisols
C) Entisols
D) Gelisols

Question 63

________ are recently developed soils lacking vertical horizon development.

A) Spodosols
B) Entisols
C) Oxisols
D) Mollisols

Question 64

Expandable clay soils, such as montmorillonite, characterize this soil order.

A) Oxisols
B) Mollisols
C) Vertisols
D) Aridisols

Question 65

Most of the glacially derived till and outwash materials from New York through the Appalachians are

A) Spodosols.
B) Histosols.
C) Inceptisols.
D) Gelisols.

Question 66

________ are hydric soils, forming in beds of former lakes and small, poorly drained depressions.

A) Histosols
B) Andisols
C) Vertisols
D) Aridisols

Question 67

________ are among the Earth's most agriculturally significant soils.

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

Question 68

In which of the following areas would one likely find Aridisols?

A) northern Europe
B) the selva in Brazil
C) the U.S. southwest
D) marine west coast climates

Question 69

The southeast United States is dominated by which soil order?

A) Ultisols
B) Alfisols
C) Oxisols
D) Mollisols

Question 70

These soils primarily occur in the northern coniferous forests, but may also occur with more moderate properties under mixed or deciduous forests.

A) Ultisols
B) Inceptisols
C) Entisols
D) Spodosols

Question 71

Which soil order is the most spatially widespread?

A) Vertisols
B) Alfisols
C) Entisols
D) Gelisols

Question 72

Soils with volcanic parent material belong to which soil order?

A) Andisols
B) Histosols
C) Vertisols
D) Gelisols

Question 73

In a west to east transect across the 98th meridian in the United States, which of the following is the correct sequence of soil orders?

A) Alfisols, Aridisols, Ultisols
B) Aridisols, Oxisols, Mollisols
C) Aridisols, Mollisols, Alfisols
D) Alfisols, Mollisols, Utilsols

Question 74

These high latitude, periglacial soils contain about half of the pool of global carbon.

A) Oxisols
B) Spodosols
C) Gelisols
D) Mollisols

Question 75

These grassland soils are some of the Earth's most significant agricultural soils.

A) Gelisols
B) Molliso1s
C) Aridisols
D) Inceptisols

Question 76

In which of the following areas would one likely find Mollisols?

A) Sub-Saharan Africa
B) the U.S. Great Plains
C) central Africa
D) southeast United States

Question 77

Warming temperatures have accelerated the thawing of Gelisols. This is of particular concern because

A) Gelisols contain about half of the pool of global carbon and this release of carbon dioxide and methane into the atmosphere could further affect warming climate.
B) as the permafrost metals, the meltwater will runoff, further contributing to global sea-level rise.
C) Gelisols are an important soils for growing specialty cold weather crops. The thawing of the Gelisols will adversely impact this lucrative market.
D) Gelisols are the youngest, least developed soils on the planet. Warming will further stifle the horizontal development of these soils.

Question 78

This is the world's largest soil order, occurring on 19% of the Earth's land surface in the world's dry regions.

A) Oxisols
B) Mollisols
C) Aridisols
D) Andisols

Question 79

In which of the following regions would one likely find Spodosols?

A) savannas and grasslands
B) tropical rainforests
C) northern coniferous forests
D) deserts and semiarid areas

Question 80

Relatively high precipitation in the regions in which these soils are found cause greater mineral alterations and more alluvial leaching than in other soils.

A) Oxisols
B) Andisols
C) Gelisols
D) Ultisols