Question 1

Soils of good tilth and high productivity are usually characterized by stable aggregation and a high percentage of macropores.

Accepted Answer

A) True 
 B)False

Question 2

Dull gray colors are characterized by _____.

Accepted Answer

A) gray hues 
B) low chromas 
C) high color values 
D) low color values 
E) mixed hues

Question 3

The plasticity index is the difference between the plastic limit and the liquid limit.

Accepted Answer

A) True 
 B)False

Question 4

A sticky, putty-like feel indicates a high percentage of which soil separate?

Accepted Answer

A) sand 
B) silt 
C) clay 
D) humus 
E) none of the above

Question 5

Tillage when the soil is too wet is likely to increase the soil bulk density.

Accepted Answer

A) True 
 B)False

Question 6

In many soil profiles, the subsoil is high in clay, but is also quite permeable to percolating water.Why?

Accepted Answer

A) Clay generally promotes free water movement. 
B) The subsoil may have an organic texture. 
C) Prismatic structure may be well developed. 
D) The water table may be present in the subsoil. 
E) All of the above are common reasons.

Question 7

The difference between the liquid and plastic limits of a soil is _______.

Accepted Answer

A) that one is a moisture variable while the other is a density variable 
B) that one is applicable to natural soils the other to artificial growth media 
C) greater than the difference between the solid and liquid limits 
D) the plasticity index 
E) none of the above

Question 8

Which color would be typical of a well drained, low-organic matter sandy surface soil?

Accepted Answer

A) 10YR5/8 
B) 7.5YR6/2 
C) 2.5YR6/1 
D) 7.5YR2/2 
E) 10YR8/4

Question 9

For which substance would the particle density equal the bulk density?

Accepted Answer

A) an organic soil 
B) a wet soil 
C) a quartz pebble 
D) a soil clod 
E) a well-aggregated surface soil

Question 10

Practices that add organic matter and reduce tillage can be expected to most significantly increase the _____ in a soil.

Accepted Answer

A) macropores 
B) total porosity 
C) bulk density 
D) fineness of texture

Question 11

Which of the following practices is(are) useful in stabilizing surface soil structure?

Accepted Answer

A) use of organic mulches 
B) use of green manure crops 
C) growing grass sod 
D) minimizing tillage 
E) all of the above

Question 12

When preparing a surface soil seedbed, the soil should generally be in the loosest, least dense soil condition in the row where the seed is placed.

Accepted Answer

A) True 
 B)False

Question 13

The percentages of which soil components represent the minimum information necessary in order to determine the textural class of a soil?

Accepted Answer

A) gravel and sand 
B) silt and sand 
C) clay and organic matter 
D) clay, water and air 
E) sand, silt and clay

Question 14

Proper timing of tillage is generally more difficult for a clayey than for a sandy soil.

Accepted Answer

A) True 
 B)False

Question 15

For any soil, the bulk density is always lower than the particle density.

Accepted Answer

A) True 
 B)False

Question 16

A landscaping contractor wants to change the texture of a silt loam soil to meet the specifications for a loam.S/he would most likely do so by adding ______ to the soil and mixing it well.

Accepted Answer

A) humus 
B) compost 
C) clay 
D) sand 
E) either A or B

Question 17

Because of their greater surface area per unit of soil mass, silt loams soils generally have a greater capacity than loamy sand soils to ___.

Accepted Answer

A) adsorb water 
B) adsorb gases 
C) release nutrients by mineral weathering 
D) support bacterial growth 
E) all of the above

Question 18

A chroma greater than 4 generally indicates a soil in good tilth.

Accepted Answer

A) True 
 B)False

Question 19

Soil consistence changes with changes in soil water content.

Accepted Answer

A) True 
 B)False

Question 20

Texture describes the ____ of particles in a soil.

Accepted Answer

A) sizes 
B) colors 
C) arrangement 
D) mineralogical makeup 
E) roughness

Exam 4: Soil Architecture and Physical Properties

Soils of good tilth and high productivity are usually characterized by stable aggregation and a high percentage of macropores.

Dull gray colors are characterized by _____.

The plasticity index is the difference between the plastic limit and the liquid limit.

A sticky, putty-like feel indicates a high percentage of which soil separate?

Tillage when the soil is too wet is likely to increase the soil bulk density.

In many soil profiles, the subsoil is high in clay, but is also quite permeable to percolating water.Why?

The difference between the liquid and plastic limits of a soil is _______.

Which color would be typical of a well drained, low-organic matter sandy surface soil?

For which substance would the particle density equal the bulk density?

Practices that add organic matter and reduce tillage can be expected to most significantly increase the _____ in a soil.

Which of the following practices is(are) useful in stabilizing surface soil structure?

When preparing a surface soil seedbed, the soil should generally be in the loosest, least dense soil condition in the row where the seed is placed.

The percentages of which soil components represent the minimum information necessary in order to determine the textural class of a soil?

Proper timing of tillage is generally more difficult for a clayey than for a sandy soil.

For any soil, the bulk density is always lower than the particle density.

A landscaping contractor wants to change the texture of a silt loam soil to meet the specifications for a loam.S/he would most likely do so by adding ______ to the soil and mixing it well.

Because of their greater surface area per unit of soil mass, silt loams soils generally have a greater capacity than loamy sand soils to ___.

A chroma greater than 4 generally indicates a soil in good tilth.

Soil consistence changes with changes in soil water content.

Texture describes the ____ of particles in a soil.