Unit 2 Knowledge Organiser: 2.4

Unit 2 Knowledge Organiser:

2.4 Why are soils the root of life?

2.4 Why are soils the root of life?

Soil is a thin layer on the Earth’s surface between the lithosphere and biosphere. It is a layer of minerals, water and organic matter that forms from the weathered rock below, and decaying vegetation above. 

Soil

Soil is very precious. Plants root in it, and take up minerals and water to grow. 

Soil types

It is usually 1–3 metres deep. It can take between 100 and 1,000 years for just one centimetre of soil to build up. 

Multiple Select

What lives in soil? Select all correct answers

• fungi

• bacteria

• insects

• earthworms

• animals

Soil is alive!

Soil is alive with organisms, like fungi, bacteria, insects, earthworms and burrowing animals, that all have a role to play in developing the soil. Scientists believe that there are probably more individual species living below ground than above the surface.