Soil

Question 1

What does soil include?

Answer 1

Broken rocks, minerals, living organisms and decaying organic matter

Question 2

Humus=

Answer 2

Decaying organic matter

Question 3

3 UK soil types

Answer 3

Brown earth, podzol and gley

Question 4

What are soil layers called ?

Answer 4

Horizon’s (O,A,B,C)

Question 5

Stage 1 formation: weathering

Answer 5

Breaks apart parent rock to form regolith, clay particles join together

Question 6

Stage 2 formation: humification

Answer 6

Organisms eg algae/ lichens colonise which add organic matter when they die (Humus)

Question 7

Stage 3 formation: translocation

Answer 7

Movement in any form in any direction, has greatest effect with very high/ low rainfall

Question 8

Leaching

Answer 8

Washing down of soluble minerals

Question 9

Eluviation

Answer 9

Washing down of small suspended insoluble minerals to lower horizons

Question 10

Illuviation

Answer 10

Where minerals are moved to horizon C

Question 11

3 types of soil

Answer 11

Brown earth
Podzol
Gley

Question 12

Soil properties
(5)

Answer 12

Aeration
Temperature
Texture/ structure
Water availability
pH

Question 13

O horizon

Answer 13

Surface litter, partly decomposed organic matter

Question 14

A horizon

Answer 14

Topsoil with humus, living organisms and inorganic minerals

Question 15

B horizon

Answer 15

Subsoil with clay, iron, aluminium compounds accumulated from leaching

Question 16

C horizon

Answer 16

Weathered parent material and partially broken down inorganic mineralz

Question 17

Bedrock

Answer 17

Parent material - the crust limestone bedrock, alkaline/ neutral granite bedrock: acidic

Question 18

Factors that affect soil formation

Answer 18

Time
Human activity
Vegetation/ animals

Question 19

Rate of soil formation and rate of natural soil erosion makes…

Answer 19

Soils natural equilibrium

Question 20

2 main processes leading to soil deterioration

Answer 20

Erosion (e.g wind and water)
Degradation (e.g leaching and pollution)

Question 21

Major causes of soil degradation

Answer 21

Water and wind erosion,
Chemical and physical degradation

Question 22

Underlying causes of soil degradation

Answer 22

Overgrazing
Deforestation
Agricultural activity
Overuse of vegetation
Industrial activity

Question 23

Human causes leading to soil degradation

Answer 23

Overgrazing
Over cropping
Deforestation
Urbanisation
Unsustainable agriculture inc. cultivation methods

Question 24

Soil erosion: water

Answer 24

Leaves deflect heavy rain, roots hold soil together and humus absorbs large quantities of water BUT unprotected surface soil washed away during heavy rain (sheet wash) or channels develop on hillside (gullying)

Question 25

Sheet wash

Answer 25

Heavy rain washing away unprotected surface soil

Question 26

Gullying

Answer 26

Heavy rainfall can develop channels on hillsides

Question 27

Soil erosion: wind

Answer 27

Unprotected soils at higher risk of wind erosion, more if they are dry as top layer consistently removed through saltation, creep and suspension

Question 28

The three major types of soil erosion

Answer 28

Wind Water Human interaction

Question 29

Rain splash erosion

Answer 29

Rain hits soil, becomes water saturated and displaces soil which creates gully’s and washes it away through surface runoff, bare and dry ground most effected

Question 30

How can vegetation reduce wind erosion?

Answer 30

Protects soil from winds by creating a blanket of friction

Question 31

Creep

Answer 31

Movement of particles rolling along the ground

Question 32

Saltation

Answer 32

Sediment being taken into the air quickly and dropped quickly

Question 33

Sorting

Answer 33

Worms and invertebrates blurring horizon lines

Question 34

Human activities that increase soil erosion rates

Answer 34

Vegetation removal Ploughing vulnerable soils Overgrazing Reduced soil biota Cultivating steep slopes Soil compaction

Question 35

Farming methods that reduce soil loss

Answer 35

Strip cropping Windbreaks Terracing Contour cropping No till planting Cover crops

Question 36

Strip cropping

Answer 36

Groundwater plants e.g grasses planted in strips between field/ crops Stops of groundwater soak up rain and slow runoff

Question 37

Windbreaks

Answer 37

Rows of trees planted between fields Trees slow down wind and reduce wind erosion

Question 38

Terracing

Answer 38

Steps built on slopes to prevent runoff downhill and carrying away soil

Question 39

Contour cropping

Answer 39

Crops planted in curving rows to follow contour of hills Slows runoff and reduces erosion

Question 40

No till planting

Answer 40

Seeds planted in ground without tilling (plowing) soil first Dead plants/ humus from previous crop remain to hold soil in place with roots

Question 41

Cover crops

Answer 41

Plants cover soil to hold in place year round, even in seasons when crops don’t grow

Question 42

The Universal Soil Loss Equation (USLE)

Answer 42

A= R*K*L*S*C*P

Question 43

A

Answer 43

Average annual soil loss

Question 44

R

Answer 44

Rainfall erosivity

Question 45

K

Answer 45

Kind of soil

Question 46

L

Answer 46

Length of slope

Question 47

S

Answer 47

Slope gradient

Question 48

C

Answer 48

Crop management

Question 49

P

Answer 49

Prevention of soil loss

Question 50

Limitations of USLE

Answer 50

- averages must be taken - time consuming - expensive - mostly based on winter (e.g K) - no account of previous land uses - most measurements made in North America