Biosphere- Soils Flashcards Preview

GEO1213: Our Changing Planet > Biosphere- Soils > Flashcards

Flashcards in Biosphere- Soils Deck (18)
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1
Q

Soil is a dynamic three phase system: solid, liquid and gas. What percentage of the soils do each of these make up

A

25% air
25% water
45% mineral
5% organic matter

2
Q

Soil functions -3 examples

A

Support plant life
Habitat
Storage
filtration

3
Q

How much more carbon do soils store than the atmosphere and vegetation respectively

A

Twice more than the atmosphere

3X more than vegetation

4
Q

What is pedogenesis

A

Soil formation

5
Q

Is soil renewable

A

No, it takes thousands of years so can be seen as non renewable

6
Q

What is soil leaching

A

The movement of water down the soil profile to the lower soil horizons

7
Q

What are the O,A,B and C soil horizons

A
O= organic
A= subsurface 
B= subsoil 
C= parent material
8
Q

What do soils form on

A

Rock surfaces and unconsolidated materials

9
Q

Parent material controls:

A
Weathering rates
Soil chemistry (inc pH)
10
Q

How does climate affect soils

A

Affects rate of weathering and decomposition
Rainfall redistributes materials
Affects vegetation and organic matter inputs

11
Q

How does landscape position and hydrology affect soils

A

Landscape position alters soil hydrology with implications for soil processes
Water logging alters the chemistry of soil minerals and affects decomposition

12
Q

What is soil fertility

A

The soils ability to support the desired crop

13
Q

Soil must provide adequate amounts of…

A

Water
Air (porosity and humidity)
Nutrients (cation exchange capacity and nutrient availability)

14
Q

Factors that affect soil fertility

A

Soil texture
Soil fertility
Porosity

15
Q

Density =

A

Mass divided by volume

16
Q

3 things necessary for soil fertility

A

Water availability
Air
Nutrients

17
Q

Give 3 examples of human impact on soils

A

Acidification
Compaction
Loss of organic matter

18
Q

Why is organic matter important

A

Improves water holding capacity
Improves aeration
Binds mineral particles together