Soil

Question 1

What is a soil?

Answer 1

Soil is a naturally occurring thin layer of material on the earth’s surface, that is a medium in which vegetation grows

Question 2

What are the six factors that affect soil formation?

Answer 2

Parent material
Climate
Relief
Drainage
Vegetation cover
Passage of time

Question 3

What is parent material? How does it contribute to soil?

Answer 3

Parent material is the material the soil is formed from. It controls the depth, texture, drainage and quality of the soil

Question 4

Describe three ways that climate can influence soil formation

Answer 4

• Climate influences the rate of weathering of the parent rock
• It affects the type of vegetation that grows in an area
• If rainfall is light or evapotranspiration is greater than precipitation, capillary action begins and water and minerals are drawn to the surface

Question 5

What is a soil profile?

Answer 5

The complete set of vertical sequence of layers of the soil

Question 6

What is a horizon?

Answer 6

A layer of soil

Question 7

What order are the horizons in?

Answer 7

O
A
E
B
C
R
(Only An Elephant Baby Can Rest)

Question 8

What is the O horizon?

Answer 8

It’s the organic horizon and has loose and partly decayed organic matter (humus)

Question 9

What is the A horizon?

Answer 9

Mineral matter mixed with some humus

Question 10

What is the E horizon?

Answer 10

Has light coloured mineral particles and is a zone of eluviasion and leaching

Question 11

What is the B horizon?

Answer 11

Accumulation of clay, transported from above

Question 12

What is the C horizon?

Answer 12

Partially altered parent material

Question 13

What is the R horizon?

Answer 13

Unweathered parent material

Question 14

What are the characteristics of ferrasols?

Answer 14

• Red/yellow due to metal oxides (iron and aluminium)
• Geologically old parent material
• Found in humid/tropical climates
• Have rainforests on them
• Only the top few cm are fertile due to metals and rainfall leaching minerals

Question 15

What are the characteristics of cambisols?

Answer 15

• Brown earth soils
• Not particularly fertile
• Little humus
• Clay layer/salts/oxides

Question 16

What are the characteristics of fluvisols?

Answer 16

• Very fertile
• Deposition of alluvium of the flood plain
• Humus and minerals
• Layers of deposition

Question 17

What are the characteristics of vertisols?

Answer 17

• Dark brown/black heavy clay
• Not much humus
• Dry and crack during any season
• Low permeability
• Seasonal (sticky when wet, hard when dry)

Question 18

What are the characteristics of leptosols?

Answer 18

• Desert soils
• Shallow
• Lack organic material
• Soluble soils
• Not fertile
• Little evidence of soil forming (no layers)

Question 19

What are the characteristics of andosols (volcanic soils)?

Answer 19

• Very porous (lots of holes) and dark
• Volcanic parent material
• Rich in nutrients and minerals
• Good ability to hold water
• High aluminium content making phosphates unavailable

Question 20

What does the soil type in the RNDB depend on?

Answer 20

The climate and parent material/rock that is under the ground and the vegetation that grows on it

Question 21

Where are ferrasols found?

Answer 21

Uganda (mainly)

Question 22

Where are cambisols found?

Answer 22

Sudan
South Sudan
Egypt

Question 23

Where are fluvisols found?

Answer 23

North Egypt

River Nile

Question 24

Where are vertisols found?

Answer 24

Sudan
South Sudan
West Ethiopia

Question 25

Where are leptosols found?

Answer 25

Egypt

Question 26

Where are andosols/volcanic soils found?

Answer 26

Ethiopia

Blue Nile Valley