(a) Draw a labelled diagram of a… | Geography

Question 1 Report

(a) Draw a labelled diagram of a simple soil profile

(b) Describe the characteristics of any two of the zones in the soil profile drawn in (a) above. Give reasons for each characteristic

Answer

Answer Details

(a) Labelled diagram of a simple soil profile

(b) Characteristics of two zones in the soil profile

A horizon (topsoil or zone of eluviation)
- It is dark brown or black in colour and contains much humus. This is because dead leaves, plants and animals decay at or near the surface to form organic matter.
- It contains many plant roots, earthworms and micro-organisms and has high biological activity. This is because it is close to the surface, where air, moisture and decaying organic materials are readily available.
- It is often leached of clay and soluble minerals. This is because percolating rainwater washes fine particles and dissolved minerals downward into the B horizon.
B horizon (subsoil or zone of illuviation)
- It is usually lighter in colour than the topsoil and contains little humus. This is because most organic matter is concentrated and decomposes in the A horizon.
- It is richer in clay, iron compounds and other minerals. This is because materials washed down from the A horizon accumulate in this layer.
- It is more compact and contains fewer roots and soil organisms. This is because it has less humus, less aeration and fewer nutrients than the topsoil.

(a) Draw a labelled diagram of a simple soil profile (b) Describe the characteristics of any two of the zones in the soil profile drawn in (a) above. Give r...