|Better Farming Series 04 - The Soil: How the Soil is Made up (FAO - INADES, 1976, 37 p.)|
|What is soil made of ?|
· Brush fires
In traditional farming; leaves and branches are burned.
The fire destroys the organic matter, so that no organic matter is left to make humus.
The brush fire destroys the organic matter and changes the soil structure.
Modern farmers do not make brush fires.
Cassava gives an example.
When cassava is harvested, the whole plant is lifted: the root for eating and the stems for replanting.
Almost nothing is left either on the soil or in the soil.
The cassava has taken humus from the soil, but the organic matter of the cassava is not returned to the soil. So the soil is less rich.
After growing, cassava farmers let the soil rest. They let it lie fallow.
During the fallow, the soil gets all the dead plants; it gets the organic matter from the dead plants, and the soil improves.
Soil must be given organic matter. The remains of the crop, grass, manure, provide organic matter.
· Some crops improve the soil.
When you harvest a bean plant, you take only the fruits.
The stems, roots and leaves are left to rot on the soil.
They decompose and give humus.
Beans are a crop that leaves organic matter in the soil.
The beans take humus from the soil but return organic matter to it.
Modern farmers use animal manure.
Manure returns to the soil the organic matter taken out by the crop.
· Do not mix the soil and the subsoil.
The soil is rich in humus.
The subsoil has no humus.
In tilling, the farmer should never mix the soil and the subsoil, so as to keep his soil rich.
In planting a tree, do not mix the layers of soil.
Do not mix the layers of soil