5.1 soil systems

Question 1

what is soil?

Answer 1

mixture of four basic parts – minerals, organic matter, air and water

serves three primary functions:
- supplies plants with nutrients and water for growth
- major water storage and purification system
- provides habitat for 1/4 of all living species (bacteria, insects and mammals)

Question 2

soil horizons

Answer 2

organic layer (humus)
topsoil (humus + minerals)
eluviation layer (leached minerals + organic matter)
subsoil (deposited minerals + metal salts)
parent rock (partly weathered rock)
bedrock (unweathered parent rock)