Soils Flashcards
(27 cards)
Soils
What does soil composition depend on? (5)
Parent material
Climate
Other organisms
Topography
Age
Soils
4 Soil horizons?
O horizon
A horizon
B horizon
C horizon
Soils
O horizon (2) =
Leaf litter
Very little mineral
Soils
A horizon (3) =
High organic content
Some mineral
“Top soil”
Soils
B horizon (2) =
Subsoil
Less organics, more minerals
Soils
C horizon (2)
Parent material, rock
Maybe stored water in an aquifer
Soils
Parent material =
example?
Minerals
Serpentine
Soils
Serpentine =
High in heavy metals
Climate
Some rain =
Well developed soil
Climate
A lot or too much rain =
Minerals wash away
Climate
Frost wedging =
Frozen water (ice) breaks apart rocks
Living Organisms
1/1000 of soil is ___
Alive - bacteria
Living Organisms
Decomposers purpose
Make organic molecules available to plants
Living Organisms
Decomposers provide ___ (molecule)
CO2
Topography =
The lay of the land
Topography
Steep slope causes…
Small particles to wash away
Topography
Standing water prevents… (2)
Gas exchange
Limits bacterial activity
Soil Structure
Sand size
0.05mm-2mm
Soil Structure
Sand characteristics (2)
Drains quickly
Holds air
Soil Structure
Sand benefit
Gas exchange
Soil Structure
Sand disadvantage
Nitrogen might be depleted
Soil Structure
Silt size
0.002mm - 0.05mm
Soil Structure
Clay size
Less than 0.002mm
Soil Structure
Clay characteristics (2)
Drains slowly
More empty space
