Theory question 206
Soils(a) With the aid of a well-labelled diagram, describe a typical soil profile (b) Highlight the importance of soil
Show the model answer
Model answer
(a) Diagram of horizons: O (organic litter); A horizon (topsoil: dark, rich in humus, much life, leached); B horizon (subsoil: lighter, where leached minerals such as iron and clay accumulate); C horizon (weathered parent material); D/R (bedrock).
(b) Medium for plant growth and food; supplies nutrients and water; habitat for organisms; raw materials (clay for bricks and pottery, laterite for roads); foundation for buildings; filters and stores water; supports grazing and forests.
Explanation
Label each horizon and say what it contains.