Chapter 15 The Geography of Soils

					Chapter 15: The Geography of Soils

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or
answers the question.
1) Which subsurface diagnostic horizon is used as brick because it is so hard?
A) plinthite B) salic C) argillic D) spodic
Answer: A

2) A high CEC means that
A) soil colloids can store and exchange more cations
B) the soil is probably fertile
C) activity between colloids and the soil solution is high
D) all of these are correct
Answer: D

3) Soil consistency refers to
A) the soil's resistance to breaking and manipulation under different moisture conditions
B) the uniformity of particle size
C) the uniformity of ped types
D) the soil's ability to consistently maintain a given level of soil moisture
Answer: A

4) Andisols are ________ soils that are ______ in CEC.
A) floodplain; high B) floodplain; low C) volcanic; high D) volcanic; low
Answer: C

5) Ped formation benefits soils because it enhances
A) soil texture B) porosity C) permeability D) both b and c
Answer: D

6) Broadleaf trees tend to make the soil more ________, whereas conifers tend to make
it more __________.
A) acidic; neutral B) acidic; alkaline C) neutral; acidic D) alkaline; acidic
Answer: D

7) Soil erosion in the United States
A) is highest in the northeastern states
B) has not been adequately mapped by the Soil Conservation Service
C) is virtually under control given all the conservation practices implemented
D) is causing over 30 percent of farmlands in this country to erode faster than the soil can
be replaced
Answer: D

8) Which diagnostic epidpedon is associated with the fertile soils of the central U.S., is
dark in color, humus-rich, and has good structure?
A) histic B) mollic C) ochric D) plaggen
Answer: B

9) A cation has a _______ charge, and an anion has a ________ charge.
A) positive; neutral B) positive; negative C) neutral; positive D) negative; positive
Answer: B

10) A roughly equal mixture of sand, silt, and clay is called
A) regolith B) solum C) humus D) loam
Answer: D

11) Rounded peds have _________ space between them than other peds, and are
therefore __________.
A) more; worse for plant growth B) more; better for plant growth
C) less; better for plant growth D) less; worse for plant growth
Answer: B

12) A soil order characteristic of the Amazon Basin is a/an
A) Spodosol B) Oxisol C) Alfisol D) Aridisol
Answer: B

13) True solum is made up of
A) layers of soil from the surface all the way to bedrock
B) the A horizon only
C) the surface of the soil body
D) a combination of the A, E, and B horizons
Answer: D

14) Because Aridisols form in arid environments, they are likely to
A) contain little organic matter
B) contain calcic and salic horizons
C) be very thin and poorly developed
D) all of the above
E) none of the above
Answer: D

15) The E horizon is dominated by ____________, whereas the B horizon is dominated
by ____________.
A) eluviation; illuviation B) laterization; illuviation
C) illuviation; eluviation D) eluviation; podzolation
Answer: A

16) Which of the following soils would have limited horizon development and would be
destructive of buildings and roads?
A) Inceptisols B) Vertisols C) Alfisols D) Mollisols
Answer: B

17) Which of the following is not true of soils?
A) Soils rich in organic matter are usually dark in color.
B) Their development is affected by climate and organisms.
C) Older soils usually have fewer horizons than younger soils.
D) They usually require centuries or millennia to form.
E) Their properties are affected by the type of rock from which they form.
Answer: C

18) Which type of soil is the least developed?
A) Oxisols B) Inceptisols C) Mollisols D) Entisols
Answer: D

19) Salinization is likely to occur
A) in areas of high potential evapotranspiration and low actual evapotranspiration
B) in humid climate regions
C) in the tropics
D) in areas characterized by sandy soils and coniferous forests
Answer: A

20) Soil separates refer to
A) differing soil colors in a pedon
B) the larger pebbles, gravels, and cobbles
C) the different soil horizons
D) individual mineral particles, such as sand, silt, and clay
Answer: D
21) B horizons tend to
A) accumulate humus B) be dominated by eluviation processes
C) lose materials by leaching D) accumulate clay, iron and aluminum
Answer: D

22) Gelisols are most likely to be found in
A) Arizona B) Greece C) Canada D) Panama
Answer: C

23) A soil horizon that is 20 to 30% or more organic matter is labeled
A) C B) B C) O D) A
Answer: C

24) As with many areas of interest to geographers, soil science is a/n ____________
concerned with __________.
A) multidisciplinary subject; memorization of facts about the Earth
B) sharply limited and defined subject; spatial distributions and processes
C) sharply limited and defined subject; memorization of facts about the Earth
D) multidisciplinary subject; spatial distributions and processes
Answer: D

25) Ultisols experience ________ leaching and therefore have relatively _______ levels
of cations.
A) limited; low B) substantial; high C) limited; high D) substantial; low
Answer: D

26) The great grassland soils of the world are called
A) Spodosols B) Aridisols C) Mollisols D) Ultisols
Answer: C

27) The moist versions of mollisols are the
A) Vertisols B) Ultisols C) Alfisols D) Oxisols
Answer: C

28) Which of the following soil layers would usually contain the greatest amount of clay
in a well-developed soil?
A) B B) A C) C D) R E) E
Answer: A
29) Texture refers to ____________, whereas structure refers to _____________.
A) the aggregation of soil particles into "dirt clods"; soil particle size
B) soil particle size; the aggregation of soil particles into "dirt clods"
C) soil productivity; soil fertility
D) soil fertility; soil productivity
Answer: B

30) The principal natural soil-forming factors
A) are both dynamic and passive in nature
B) include climate, parent material, topography, biotic processes and time
C) include peds, separates, solums, and horizons
D) are all inorganic
E) both a and b are related soil forming factors
Answer: E

31) The basic soil unit used in preparing soils maps, i.e., in identifying a series of soils in
an area, is the
A) profile B) pedon C) A horizon D) polypedon
Answer: D

32) Which pedogenic regime occurs in cool, wet climates in areas of poor drainage, and
results in the accumulation of humus - as well as a water-saturated layer of gray clay?
A) laterization B) gleization C) podzolation D) salinization
Answer: B

33) Which of the following soil horizon designations is in correct sequence from the
surface to bedrock?
A) O, A, E, B, C, R B) O, R, C, B, A C) A, B, C, O, R D) S, O, I, L
Answer: A

34) Important soil components that are involved in the retention of ions formed by clay
and organic particles are called
A) peds B) pH holders C) separates D) colloids
Answer: D

35) The A horizon is usually _________ underlying layers because _________.
A) lighter than; it is made of light-colored, felsic minerals
B) lighter than; it contains little humus, but a considerable amount of mineral particles
C) darker than; it contains humus
D) darker than; it is made of dark-colored, mafic minerals
Answer: C

36) Selenium contamination of western soils is related to
A) the application of chemicals by farmers
B) concentration of a natural element in the soil through irrigation drainage collection
C) reliance of natural precipitation with no irrigation
D) none of the above
Answer: B

37) Which pedogenic regime tends to occur in cool, coniferous forests, and results in
acidification of the soil?
A) laterization B) podzolation C) salinization D) calcification
Answer: B

38) Which of the following does not increase porosity?
A) root growth B) ped formation C) laterization D) worms
Answer: C

39) White to pale hues in soils are generally associated with
A) humus B) plant matter C) iron oxides D) silicates and aluminum oxides
Answer: D

40) B horizons are often _________ in color because of __________.
A) dark; it is made of dark colored, mafic minerals
B) dark; accumulation of humus
C) reddish or yellowish; the minerals they contain are often chemically reduced
D) reddish or yellowish; the minerals they contain are often chemically oxidized
Answer: D

41) Horizons develop in soil because of
A) capillary action
B) leaching
C) eluviation and illuviation
D) all of the above
E) none of the above - the parent material is already layered at the time soil formation
begins and all subsequent development involves only chemical transformation within the
pre-existent horizons
Answer: D
42) Which pedogenic regime is associated with Spodosols?
A) calcification B) podzolization C) laterization D) salinization
Answer: B

43) Recent, undeveloped soils are known as
A) Entisols B) Ultisols C) Spodosols D) Oxisols
Answer: A

44) An individual unit of soil aggregates (a lump of soil) is termed a
A) pedon B) ped C) separate D) solum
Answer: B

45) Which soil order would tend to occur in the southeastern U.S., with its high
temperatures and humid environment?
A) Aridisols B) Mollisols C) Ultisols D) Spodosols
Answer: C

46) Oxisols are ________ and _________.
A) poorly leached; nutrient-poor B) poorly leached; nutrient-rich
C) highly leached; nutrient-rich D) highly leached; nutrient-poor
Answer: D

47) Farmers are concerned with soil from the standpoint of
A) geomorphology B) edaphology C) pedology D) plantology
Answer: B

48) Accumulations of thick organic matter, such as in the beds of former lakes or bogs,
are classified as
A) Mollisols B) Entisols C) Vertisols D) Histosols
Answer: D

49) Which of the following is not true?
A) Fertilizers can maintain soil fertility and productivity into the distant future - even if
the soil is eroding.
B) Soil erosion is occurring throughout most of the densely inhabited regions of the
C) Both the direct and indirect costs of soil erosion is estimated at hundreds of billions of
dollars worldwide.
D) Loss of soil, combined with exponential population growth, could lead to serious food
E) Soil that has eroded could take centuries to be replaced.
Answer: A

50) Which of the following lists of soil categories gives the proper hierarchy for the Soil
Taxonomy system - from the largest grouping to the smallest unit (i.e., from least to most
in terms of the number of soils included)?
A) epipedon, subsurface diagnostic horizon
B) pedon, polypedon, horizons, profiles
C) soil orders, suborders, great groups, subgroups, families, series
D) orders, suborders, soil series, small groups
Answer: C

51) In a transect across the 98th meridian, from west to east, which of the following
gives the correct sequence of soil orders?
A) Alfisols, Aridisols, Ultisols
B) Aridisols, Oxisols, Mollisols
C) Alfisols, Mollisols, Aridisols
D) Aridisols, Spodosols, Ultisols
E) Aridisols, Mollisols, Alfisols
Answer: E

52) Soils characteristic of the northern coniferous forests are the
A) Aridisols B) Spodosols C) Mollisols D) Alfisols
Answer: B

53) At present, which of the soil orders of Soil Taxonomy occupy the most land area in
the United States?
A) Oxisols B) Spodosols C) Mollisols D) Aridisols
Answer: C

54) The ability of certain soil particles to transfer mineral ions between their surfaces
and the soil solution is referred to as
A) soil acidity B) cation-exchange capacity C) colloidal action D) soil alkalinity
Answer: B
55) The science that deals with the origin, classification, and distribution of soils is
known as _________, whereas the science that deals with soil as a medium for plant
growth is called ___________.
A) pedology; geomorphology B) pedology; edaphology
C) edaphology; pedology D) geomorphology; edaphology
Answer: B

56) Prairie soil can contain evidence of processes that date back
A) no more than 500 years B) no more than 50 years
C) no more than 1000 years D) at least 15,000 years
Answer: D

57) Which of the following is not true of the C horizon?
A) Although it may be deep, it lies within the realm of significant biological influences.
B) It lacks clay concentrations.
C) Roots rarely reach this layer.
D) It is generally made up of carbonates, gypsum, or soluble salts.
E) It is equivalent to regolith.
Answer: A

58) At present, which of the soil orders of Soil Taxonomy occupy the most land area
A) Alfisols B) Aridisols C) Ultisols D) Oxisols
Answer: B

59) The soil at the base of a hillslope is likely to be __________ compared to the soil on
the slope.
A) thicker
B) nutrient-rich
C) wetter
D) all of these
E) none of these
Answer: D

60) Acidic soils
A) cause more rapid weathering and leaching of nutrients
B) are generally defined as soils with a pH of about 6 or less
C) are generally very fertile
D) all of the above
E) only a and b are true
Answer: E
61) Mollisols are associated with
A) the greatest timber harvests in the world
B) intense leaching
C) floodplains
D) the greatest grain harvests in the world
Answer: D

62) Weathered bedrock or weathered parent material (regolith), excluding the
unweathered bedrock itself, is designated the ____ horizon.
A) R B) C C) B D) A
Answer: B

63) Which of the following sets of descriptors is correctly matched with the soil moisture
condition indicated?
A) wet - little adherence of particles; capable of being rolled into a thin strand
B) dry - loose; soft; hard; extremely hard
C) moist - friable; firm
D) all of the above are correctly matched
Answer: D

64) If humus were lost from the soil due to excessive farming or soil erosion, which of
the following could occur?
A) loss of soil structure
B) loss of water holding capacity
C) loss of fertility
D) all of the above
E) a and b only
Answer: D

65) The basic sampling unit in soil surveys is called
A) a horizon B) the A horizon C) a polypedon D) a pedon
Answer: D

66) Irrigation of Aridisols tends to promote
A) gleization B) salinization C) laterization D) podzolation
Answer: B

67) The R horizon refers to
A) the basic mapping unit of soils in an area
B) a zone of eluviation in the soil horizon
C) soils redeveloped through reclamation
D) unweathered sediment or consolidated bedrock
Answer: D

68) Which pedogenic regime is associated with tropical soils?
A) podzolization B) salinization C) calcification D) laterization
Answer: D

69) Soil is
A) ground-up rock B) composed only of mineral particles
C) a dynamic, natural body D) a physical, geological product
Answer: C

TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false.
70) Over 15,000 soil series have been classified up to this time in the United States and
Answer: TRUE

71) Mollisols are the most predominant soil order in the United States.
Answer: TRUE

72) Entisols are the least developed soils in the world.
Answer: TRUE

73) Irrigation of arid lands can destroy the soil.
Answer: TRUE

74) Since 1950, as much as 38% of the world's farmable land has been lost to soil
Answer: TRUE

75) Irrigated land accounts for only about 4% of the world's food harvests.
Answer: FALSE

76) Plowing the land could alter the structure of a soil, but not the texture.
Answer: FALSE

77) A pedon is the basic soil mapping unit, and a polypedon is the basic soil sampling
Answer: TRUE

78) The C horizon lies within the zone of significant biological activity.
Answer: FALSE

79) Irrigation runoff can sometimes kill wildlife.
Answer: TRUE

80) Histosols develop in cold, arid climates.
Answer: FALSE

81) The Soil Taxonomy is based on observable soil properties, rather than the former
system, which used dynamic natural processes and soil genesis as the basis of
Answer: TRUE

82) Gelisols are most common in the middle latitudes.
Answer: FALSE

83) Oxisols are not very fertile.
Answer: TRUE

84) Soil scientists no longer consider climate a relevant factor in determining soil
Answer: FALSE

85) A dark colored soil is usually rich in organic matter.
Answer: TRUE

86) 2.5 cm (1 in) of prime farmland soil can take 500 years to form.
Answer: TRUE
87) Pedology is concerned with the practical use of a soil as a medium for plant growth.
Answer: FALSE

88) Soil is a dynamic natural body comprising fine materials in which plants grow, and
which is composed of both mineral and organic matter.
Answer: TRUE

89) Generally speaking, a high cation exchange capacity indicates good soil fertility.
Answer: TRUE

90) Peds increase the porosity and permeability of a soil, and therefore benefit the soil.
Answer: TRUE

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or
answers the question.
1) A

                                                  10) D
2) D

                                                  11) B
3) A

                                                  12) B
4) C

                                                  13) D
5) D

                                                  14) D
6) D

                                                  15) A
7) D

                                                  16) B
8) B

                                                  17) C
9) B
        33) A
18) D

        34) D
19) A

        35) C
20) D

        36) B
21) D

        37) B
22) C

        38) C
23) C

        39) D
24) D

        40) D
25) D

        41) D
26) C

        42) B
27) C

        43) A
28) A

        44) B
29) B

        45) C
30) E

        46) D
31) D

        47) B
32) B

        48) D
        64) D
49) A

        65) D
50) C

        66) B
51) E

        67) D
52) B

        68) D
53) C

        69) C
54) B

        TRUE/FALSE. Write 'T' if the
55) B   statement is true and 'F' if the statement
        is false.
        70) TRUE
56) D

        71) TRUE
57) A

        72) TRUE
58) B

        73) TRUE
59) D

        74) TRUE
60) E

        75) FALSE
61) D

        76) FALSE
62) B

        77) TRUE
63) D

            85) TRUE
79) TRUE

            86) TRUE

            87) FALSE
81) TRUE

            88) TRUE

            89) TRUE
83) TRUE

            90) TRUE

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