Soil Flashcards
What is soil
The layer of loose materials on the earths surface. It is a very important resource
What is soil made up of
Air 25% Water 25% Mineral matter 43% Living organisms 2% Humus 5%
Air
Bug ingredient in soil. Made up of small pieces of rocks (sand silt and clay) broken down by weathering and erosion
Water
Water contains dissolved minerals and plants to absorb minerals through their roots
Living organisms
Earth worms, slugs, wood lice and insects break down dead plants and help to create humus
What is soil made from
Humus
What is humus
Dark, decaying organic matter. It is the remains of dead creatures, plants, grass and leaves, provides nutrients in the soil
Name the 6 ways soils are formed
Climate Parent material Vegetation Living organisms Landscapes Time
What does hot climates influence in rocks
Chemical weathering
What does cold climate influence in rocks
Freeze thaw
What is the type of rock that effects soil formation
Parent rock
Soil profile
Soils number of different layers
Each layer is called a horizon
A horizon
Upper layer of soil. Dark in colour because posts of hums and organisms live here
B horizon
Beneath the topsoil. Lighter in colour because it has less humus. Contains more rocks than A horizon
C horizon
This is the parent rock. Made from bedrock and pieces of rock
Leaching
Occurs when heavy rainfalls washes the mineral, nutrients and humus down into the B horizon.
Hard pan
A hard impermeable crust formed when leaching occurs. It causes water logging in the soil.
Name 2 soils
Brown soils
Podzol soils
Where are Brown soils formed
Formed in areas covered by deciduous forests high provided a large amount of plant litter, which rapidly decays into humus
About Brown soils
Rainfall is limited so leaching and hard pan do not develop
The land is fertile, suitable for farming.
Found in dryer lowland areas of the south Midlands + east
Where are podzol soils formed
Areas covered by coniferous forest.. Pine needles provide limited plant litter. The plant litter decays slowly providing limited amounts of humus
About podzol soils
Greater rainfall causes leaching and hard pan and the A horizon becomes grey in colour
Podzol soils are fertile and slightly acidic
Where are podzol soils found
In wetter upland areas of Cork, Galway and Wexford
