|Better Farming Series 04 - The Soil: How the Soil is Made up (FAO - INADES, 1976, 37 p.)|
|Different kinds of land|
· Savanna soils
The depth of soil varies a great deal.
Often the soil is missing.
You can see the pebbles.
Bad savanna soil
The subsoil is very unstable.
It may become very hard.
Then a hardpan forms.
Roots cannot penetrate it.
Nothing can be grown on it.
· Mountain soils
In the mountains there is often neither soil nor subsoil.
You can see the parent rock and nothing grows.
If there is a little soil on the parent rock, a few small trees and some grass grow among the stones.
· Forest soils
The soil is rich.
The subsoil is always very poor; it contains no mineral salts; it does not become hard and does not form a hardpan.
· Soils of the same village
In various fields of the same village the layers of soil can be
very different. On the slopes, for example, the soil may have been carried away
by the rain.
That is why the soil is deeper in the valleys.
Soil is deeper in the valleys