Exam 2

Question 1

Types of water erosion

Answer 1

1. sheet
2. Rill
3. Gully
4. Stream bank

Question 2

Sheet Erosion

Answer 2

uniform removal of thin layers of soils over the whole soil surface.

Question 3

Rill Erosion

Answer 3

small visible erosion channels that can be erased by normal tillage operations

Question 4

Gully Erosion

Answer 4

Erosion channels to large to be erased by normal tillage operations.
-Ephemeral Gullies

Question 5

Ephemeral Gullies

Answer 5

Natural water courses that can persist even after large scale mechanical fillings

Question 6

Active Gully

Answer 6

Bare vertical walls
little vegetation
active head cutting

Question 7

Inactive gully

Answer 7

Vegetated, somewhat rounded walls, no head cutting.

Question 8

Stream bank Erosion

Answer 8

Usually around outside bends, moves material a long distance from origin

Question 9

Water Erosion Damage

Answer 9

1. Soil loss
2. Nutrient loss
3. Texture change
4. Soil Structure Damage
5. Productive capacity is reduced
6. Field Dissection
7. Engineering Structure damage
8. Water Pollution
9. Siltation of lakes and stream channels.

Question 10

Terminal velocity

Answer 10

1. maximum speed of falling against air resistance

Question 11

Energy of water

Answer 11

-Falling raindrops have more energy than running water

Question 12

Principles of water erosion control

Answer 12

1. reduce raindrop impact on the soil
2. reduce runoff volume and velocity
3. increase the soils resistance to erosion

Question 13

Types of soil movement

Answer 13

1. Suspension
2. Saltation
3. Surface creep

Question 14

damages of wind erosion

Answer 14

1. loss of soil
2. Textural changes
3. Nutrient loss
4. Abrasion
5. Air Pollution
6. Deposition

Question 15

factors effecting wind

Answer 15

1. Soil resistance
2. surface ridges
3. climate
4. topography
5. length of exposed area
6. vegetative cover

Question 16

principles of wind erosion control

Answer 16

1. reduce wind velocity at ground level

2. remove abrasive material from s

Question 17

universal soil loss equation

Answer 17

A=RKLSCP

Question 18

A

Answer 18

estimated average annual soil loss

Question 19

R

Answer 19

Rainfall and runoff factor (rt snowmelt runoff)

Question 20

K

Answer 20

Soil erodibility factor

Question 21

LS

Answer 21

slope length factor

Question 22

Wind erosion equation

Answer 22

E=f(I’,k’,c’,l’,v)

Question 23

I’

Answer 23

Potention soil loss in T/ac/yr from isolated field with bare smooth non crusting surface.

Question 24

row crops

Answer 24

open bare areas between rows

Question 25

small grain

Answer 25

between plantings

Question 26

companion/nurse crop

Answer 26

Erosion control or soil crustin

Question 27

cover crops

Answer 27

for protecting the soil by filling in the gaps in time or space when other crops are not there

Question 28

Green manure

Answer 28

tilling in of live crops for the benefits of increasing soil organic matter content. Green! not dead! Soil structure, soil permeability, soil fertility

Question 29

multiple croping

Answer 29

two or more crops in a single year

• small grains then corn or hay
• corn or potatoes-fall peas forrage

Question 30

Soil structure

Answer 30

as soil structure gets weaker soil tilth goes down (harder to till) soil permeability is lower (more ponding and soil runoff) soil watering holding capacity is lower, CEC is lower ( holds less nutrients) .

Question 31

surface residue

Answer 31

helps for water erosion control. organic matter works like glue to reduce it.

Question 32

companion/nurse crop

Answer 32

Erosion control or soil crusting

Question 33

multiple cropping

Answer 33

two or more crops in a single year

• small grains then corn or hay
• corn or potatoes-fall peas forage

Question 34

surface residue

Answer 34

helps for water erosion control. organic matter works like glue to reduce it.

Question 35

What does tillage do?

Answer 35

• it breaks down the soil structure

- it decreases the organic matter

Question 36

soil conditioning rating indices

Answer 36

numbers system that accounts for conservation effort that sees if there is a positive or negative affect on the soil.

Question 37

Threshold Velocity

Answer 37

the minimum velocity of the wind to cause soil movement

Question 38

Avalanching

Answer 38

Increasing rate of wind erosion as the wind moves farther across the field. More material is added as it blows across the field

Question 39

Rating indices

Answer 39

to mesure if something is improving, maintaining or deteriorating a soil.