1. SOIL A thin layer of loose material
Most important natural resource because it grows food

2. SOIL COMPOSITION What is soil composed of
Provides Oxygen and nitrogen
Eroded particles of rock
Binds soil & allows plants to soak up nutrients
Remains of dead plants and animals = Humus

3. Soil Profile

5. LEACHING
This is where the rain washes away the minerals in the top soil.
The minerals are washed downwards into the bottom layers.
HOW DO FARMERS DEAL WITH THE PROBLEM OF LEACHING

6. SOIL TYPES Ireland has two types of soil BROWN SOILS
Found in places which had Deciduous forests
Found in places with less rainfall
They are very fertile because:
* Less leaching
* Contain lots of humus
* Dark brown colour
Best for tillage and dairy farming.
South, East and Midlands of Ireland
PODZOLS
Found in places which had Coniferous forest or bogland
Found in places with more rainfall
They are less fertile because:
* More leaching
* Contain less of humus
* Lighter in colour
Used for rough grazing or forestry.
EXTENSION Draw map of world and mark in Tropical Soil areas Diagram 7 p133

7. Tropical Climates: Central America

9. WHY IS IT BAD TO CLEAR A TROPICAL FOREST?
Tropical Soils
Tropical soil is… (Brown, Yellow, Red)
Tropical forests and plants decaying on the ground cause a lot of __________________weathering.
This ________________weathering gives rise to DEEP / SHALLOW soils.
The ________________weathering also causes iron in the soil to change to ________________
This is why the soil looks ___________________________.
WHY IS IT BAD TO CLEAR A TROPICAL FOREST?

10. SOIL AND VEGATATION
Plant litter forms humus which helps form soil and bind soil
Vegetation
grows and drop leaves and litter
Vegetation
Helps also bind soil and stops it blowing away
Fertile soil encourages more plants and vegetation to grow
Soil gathers nutrients and minerals from humus and parent rocks