Lesson 2

Question 1

What is the size range of soil particles?

Answer 1

Boulders in diameter meters to clay partials less then .002 in diameter.

Question 2

What is the size range of Sand

Answer 2

.2mm to .05mm

Question 3

What is the size range of Silt?

Answer 3

.05mm to .002mm

Question 4

What is the size range of Clay?

Answer 4

Less then .002mm

Question 5

What are fine earth particle fraction size

Answer 5

Less then 2mm in size

Question 6

What are 4 f characteristics of Fine Earth Fractions

Answer 6

1. They are less then 2mm in size
2. They are sand, silt, and clay
3. They have the greatest surface area
4. They are the most chemically and biologically active

Question 7

What is the size range of Colloidal particles?

Answer 7

Less then .005 in diameter

Question 8

What are Colloidal Particals

Answer 8

small solid particles that are suspended in a fluid phase

Question 9

What are the effects of Colloidal particles

Answer 9

They are physically and chemically reactive

Question 10

What is an example of Colloidal Particles

Answer 10

Clay

Question 11

How soil texture described

Answer 11

1. Size of particle
2. Proportion of Sand, Silt, Clay
3. USDA Soil Texture Triangle

Question 12

How is soil Particle size measured

Answer 12

1. Feel Method
2. Ribbon Test
3. Soil buoyancy test

Question 13

What is used for a soil buoyancy test

Answer 13

Hydrometer

Question 14

What is another name for aggregate

Answer 14

Peds

Question 15

What are aggregates

Answer 15

Soil particles held together by stabilizing agents

Question 16

How are aggregates described

Answer 16

By there shape size and stability

Question 17

When does soil have structure

Answer 17

When soil particles are aggregated

Question 18

How is soil structure characterized

Answer 18

By each horizons aggregated particles and the effort to be broken apart when handled.

Question 19

What are 5 aggregate shapes

Answer 19

1. Granular
2. Blocky
3. Prismatic
4. Columnar
5. Platy

Question 20

Describe Granular Structure shape and where they can be found.

Answer 20

Horizon A, they are Spherical shaped

Question 21

Describe Blocky Structure and where its found

Answer 21

Horizon B, Cube shaped

Question 22

What is sub-angular blocky

Answer 22

Rounded corners

Question 23

What is angular blocky

Answer 23

Not rounded corners

Question 24

Describe Prismatic Structure and where it can be found

Answer 24

B horizon, longer then wide, angular edges and tops

Question 25

Describe Columnar Structure and where it can be found

Answer 25

B horizon, In columns, tops and sides are rounded

Question 26

Describe Platy Structure and where it can be found

Answer 26

Horizon E, thin and flat

Question 27

What are the 2 types of Structure-less Soil

Answer 27

1. Massive 2. Single Grain

Question 28

What is Massive structure

Answer 28

All particles are stuck together, no individual aggregates

Question 29

What is single Grain Structure

Answer 29

Each particle acts individually

Question 30

What are 7 causes for aggregate stay together in a structure

Answer 30

The pushing together and pulling apart due to; 1. Water 2. Shrinking 3. Swelling 4. Freezing 5.Thawing 6. Roots 7. Animals

Question 31

What is weak aggregate structure

Answer 31

Aggregate braces apart with little handling

Question 32

What is moderate aggregate structure

Answer 32

Soil can be removed from horizon in an aggregate structure

Question 33

What is strong aggregate structure

Answer 33

Aggregates no not readily fall apart when handled

Question 34

When is structure strength used

Answer 34

When describing each structure

Question 35

When is a structure a structure

Answer 35

Once particles are stuck together

Question 36

How is aggregate stability characterized

Answer 36

1. It is the resistance of destruction by water 2. Stabilizing agents

Question 37

What are 3 ways minerals influence soil

Answer 37

1. The rate of soil formation 2. The amounts and types of soil nutrients available to plants 3. The bonding ability and cation exchange capacity

Question 38

That is definition of Cations

Answer 38

An Ion that is positively charged

Question 39

What is an ion

Answer 39

A charged atom or molecule

Question 40

What is organic matter and what 5 elements does it contain

Answer 40

1. Any carbon based compound 2. Contains hydrogen, oxygen, phosphorus nitrogen and sulfur

Question 41

What are 4 characteristics of Humus

Answer 41

1. Highly decomposed organic matter 2. Organic glue 3. Highly charged 4. Has large surface area per unit mass

Question 42

What is consistence

Answer 42

1. The measurement of soils cohesion and adhesion 2. The measured resistance to deformation and rupture

Question 43

Name 3 types of consistence

Answer 43

1. Dry Sandy loam: individual grains do not stick together 2. Moist Loose or extremely firm depending on soil 3. Wet Sticky

Question 44

Why does Clay influence the three consistence measurements of wet moist dry

Answer 44

1. Increases the hardness of dry soil 2. Increases firmness of moist soil 3. Increases stickiness and plasticity of wet soil

Question 45

Describe Pores in soil

Answer 45

1. Air and water flow within 2. Comes in all sizes and shapes

Question 46

What is the difference between Intra and Inter aggregate pores

Answer 46

1. Intra- larger pores around aggregate, carry more water 2. Inter- pores inside of aggregate

Question 47

What is Vesicular when associated with pores

Answer 47

Do not transmit water or air

Question 48

What are macropores

Answer 48

Large pores that drain quicker

Question 49

What are Micropores

Answer 49

Smaller pores