Soils

Question 1

What is soil

Answer 1

The top layer of earths surface
Made of: Rock, mineral particles and decaying plants and animals
It provides nutrients

Question 2

What is soil composed of

Answer 2

Mineral particles : underlying rock broken down by weathering and erosion forming loose rock (regolith)
Air
Water
Humus - plant decay
Living organisms e.g. Bacteria to break down plant remains

Question 3

How is it formed

Answer 3

1) climate - weathering, erosions, bedrock into mineral particles, coarse to very fine, growth of vegetation
2) time - 1000s of years for suitable agricultural soil
3) people - fertilise and drain soil, overgrazing and over cultivation

Question 4

What is a soil profile

Answer 4

Cross section of the soil
Different horizons
Plant litter - decaying leaves and vegetation
A horizon - dark brown , humus, top soil
B horizon - subsoil, lighter, stones included
C horizon - bedrock

Question 5

What is leaching and hard pan

Answer 5

Leaching - rain washes minerals from A-B horizon, soil is fertile
Hardpan - heavy rainfall, minerals form a crust (hardpan) prevents water sinking (impermeable) water logging soil -> wet and soggy

Question 6

What are the soil types

Answer 6

Brown soils - lowland, deciduous forest, plant litter, rich in humus, principle soil type in Ireland. Arable and pastoral farming, south, east and Midlands of Ireland
Podzols- grey, upland, coniferous, pine needles, less litter, less fertile, heavy forestry, leaching and hardpan develops, areas such as cork and Tyrone

Peaty and gley soils

Question 7

What are tropical red soils

Answer 7

Tropical red soil - close to equator, hot and wet, Equatorial climates,formed by chemical weathering strong tree growth
Heavy plant litter = acidic, breaks down parent rock
The break down of iron oxide through weathering gives it the reddish colour
Very fertile

Question 8

How do natural vegetation and soil influence each other

Answer 8

Soil influences vegetation- provide nutrients for growth, deep soil needed for deciduous trees and shallow soils for coniferous trees
Vegetation influences soil - plant litter - humus, fertile, cover for the soil, but can be destroyed by deforestation and overgrazing the soil is blown away or washed away - soil erosion