Deck 21: Formation of Soils

Question 1

Soil is a(n) ____ resource.

A) nonrenewable
B) renewable
C) endangered
D) enormous

Answer 1

B

Question 2

Which of the following is NOT a component of soil?

A) organic matter
B) inorganic matter
C) gases
D) rocks

Answer 2

D

Question 3

The soil resides at the intersection of which spheres?

A) atmosphere, lithosphere
B) lithosphere, hydrosphere
C) biosphere, lithosphere
D) all of these

Answer 3

D

Question 4

Which best describes the relationship between rocks and minerals?

A) minerals are composed of rocks
B) minerals can be broken down into rocks
C) rocks are composed of minerals
D) rocks and minerals do not exist at the same place

Question 5

Parent material of soil is generally:

A) decomposed plant litter
B) weathered bedrock
C) clay
D) dirt

Question 6

The process of illuviation adds particles in the ____ layer.

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

Question 7

Which layer best represents the weathered bedrock layer?

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

Question 8

Which of the following soil horizons when reading from left to right indicate the correct order from top to bottom?

A) A, B, C, E, O, R
B) A, B, C, E, R, O
C) O, A, E, B, C, R
D) A, B, E, C, O, R

Question 9

The process of transporting particles from a higher layer to a lower layer is called ____.

A) eluviation
B) illuviation
C) transmigration
D) illumination

Question 10

Decomposed organic matter form a dark, top layer of soil is called:

A) fertilizer
B) organic rock
C) humus
D) mud
E) hummus

Question 11

Steep-sided mountainous soils tend to be ____ in depth.

A) thin
B) very deep
C) average
D) highly variable, but usually deep

Question 12

A soil profile shows a sequence of layers called ___.

A) plates
B) horizons
C) verticals
D) steps
E) stairs

Question 13

Where would soil formation be relatively rapid?

A) in a dry desert
B) in polar tundra
C) on a tropical volcanic island
D) the high Arctic

Question 14

The soil formation process involving the introduction of dissolved and suspended particles from upper layers into lower ones is called:

A) illuviation
B) transformation
C) propagation
D) translocation
E) sedimentation

Question 15

Loess is:

A) loose mixtures of minerals and organic clumps
B) loose layers of fine volcanic ash
C) deposits of windblown dust, often several feet thick
D) deposits of river sediments settling on banks

Question 16

Soil air contains more ____ and less ____ and nitrogen than atmospheric air does.

A) oxygen; carbon monoxide
B) carbon dioxide; oxygen
C) oxygen; argon
D) oxygen; dust

Question 17

The R soil horizon stands for ____.

A) rock
B) residuals
C) regolith
D) rock hard

Question 18

In the tropics, what causes organic matter to be quickly destroyed?

A) rapid bacterial action
B) rapid heating of the soil
C) poor farming practices
D) all of these

Question 19

The reddish-brown color in the B horizon of eastern U.S. forest soils are caused by:

A) the accumulation of red decomposed leafs
B) the addition of aluminum and iron oxides from above
C) the removal of grayish salts by ground water
D) the decomposition of reddish organisms in the soil

Question 20

All soils have distinct horizons that are used in classifying them.

Question 21

Most tropical soils are rich in nutrients and make very productive agricultural lands.

Question 22

The process of translocation occurs only in the lowest layer.