Soils Flashcards
What are the five components of soil
Water Air Mineral matter Humus Living organisms
Explain mineral matter in terms of it being a component of soil.
Mineral matter makes up most of the soil. This consists of broken down material ex. Rocks that have been broken down by weathering and erosion. Mineral matter in soil is made up of stones, sand, silt and clay
Explain water in terms of it being a component of soil.
Water binds the soil together and contains minerals which plants absorb through their roots.
Explain air in terms of it being a component of soil.
Air fills the spaces between the minerals in the soil. Air contains nitrogen and oxygen which plants and animals in the soil need to live
Explain humus in terms of it being a component of soil.
Humus is dark partly decayed mineral matter in soil. Made up of remains of organisms and the soil itself it keeps the soil fertile.
Name three factors which form soil
The climate
People
Time
Give a positive effect that people can have on soil
We can increase soil fertility and health by draining irrigation and fertilising the soil
Give in percentages the composition of soil
45%- Mineral matter
25%- air
25%- water
5% - living organisms and plant remains
Give one Negetive effect people can have on soil
People can reduce the fertility of soil by overworking the land
Explain how climate allows soil to form
Climate influences vegetation growth which when it decays forms humus.
Climate provides water in soil from precipitation
Climate also provides frost and water which erodes rock by weathering to form mineral particles
Minerals+water+humus = soil
Explain what is needed for humus to form
Micro organisms oxygen and warm conditions lead to the humification of plant litter
Explain leaching
Leaching is when water soaks down through the soil carrying nutrients down past the level of the plant roots
Explain the negetive effect leaching can have
Too much leaching can lead to plants being deprived of their nutrients, minerals can build up in the soil forming a hard layer called hard pan
What sort of material is found in first layer or horizon A of soil
Humus dark horizon, living organisms
What sort of material is found in second layer or horizon B of soil
This is lighter in colour contains small stones
What sort of material is found in third layer or horizon C of soil
Bedrock or the parent rock ex. Limestone
Name four types of soil in Ireland
Podzol soils
Brown earth soils
Peaty soils
Gley soils
What is the most common soil in Ireland
Brown earth soils
Where and how do brown earth soils form
They develop on areas previously covered in deciduous forest but now develop under grassland or crops.
Because of the large amount of plant litter in a forest this soil has lots of humus forming making it fertile.
Rainfall does not tend to seep into the soil because of vegetation so little leaching occurs
Where can he be found in Ireland
Across the Midlands, east and in the lowlands of the south
Why is brown earth soil popular for farmers
It is very fertile and is suitable for almost every type of farming
Where and how to podzol soils form
They form on floors on coniferous forests in cold wet areas. There is little plant litter in these forests so little humus. There is little earthworm activity because of conditions
Heavy rainfall causes leaching creating a hard pan. The A horizon gives off a grey colour.
Infertile and acidic
Where are podzol soils found in Ireland
Poorly drained areas of Galway and Cork
Give characteristics of podzol soil
Very wet, contains hardpan due to leaching, grey
Where are podzol soils found?
Coniferous forests (parts of cork, Wexford, galway)
Characteristics of tropical red soils
-Rusty red in colour because acids in humus speed up chemical weathering
-humus is created rapidly due to large amount of plant litter
Hot climate causes bedrock to decompose quickly
Where are tropical red soils found
Near the equator in hot/wet places
How does soil influence vegetation?
- Rich/weak in nutrients
- Well drained/waterlogged
- Deep/shallow
How does vegetation influence soil?
Deciduous- lots of humus (rich in nutrients)
Coniferous- less humus (less fertile)
Vegetation absorbs water and protects soil
