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.
Give in percentages the composition of soil
45%- Mineral matter
25%- air
25%- water
5% - living organisms and plant remains
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 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
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
Why is brown earth soil popular for farmers
It is very fertile and is suitable for almost every type of farming
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