|Better Farming Series 06 - The Soil: How to Improve the Soil (FAO - INADES, 1976, 29 p.)|
|How to improve the soil for many years|
In Booklet No. 4, page 29, we saw how important water is in the soil.
When land does not have enough water, you can bring water to a field. This is called irrigation.
When land has too much water, you can take water away from a field. This is called drainage.
· Before you dig and plant a field, you must clean it.
You have to take away the grass and plants and trees. This is
clearing the land.
You also have to take away the stumps of trees. This is called grubbing.
When you have water, in a stream, a pool, a well or a dam, use
it as much as possible.
Putting water on crops is irrigation.
With irrigation you can get better harvests, and you can even grow crops when it does not rain.
Build a little wall across a stream to hold back the water.
Look for a place where it is easy to hold back the water, where the banks of the stream are high and where the stream is not wide.
In the dry season, get stones, branches, earth and pebbles.
Drive wooden posts into the bed of the stream. Build up the dam with branches,
earth and pebbles.
In many villages the farmers get together to build little dams.
The dam stores up water. With this water you can
· give the animals water to
· water the crops,
· even raise fish.
Before making a dam, ask for advice from the extension service.
· With a calabash or gourd. This takes a long time and is very tiring. Only small fields can be watered.
· With a counterpoise lift (shadoof).
Counterpoise lift (shadoof)
· With a rope and bucket lift
(noria). This uses animal power.
· With a hand pump or motor-driven pump.
Ditches must be made so as to bring water to the edge of the
The ditches must be kept well cleaned out, so that the water flows easily and is not wasted.
Ditch bringing water
The field to be irrigated is surrounded with a ridge or
Thus the whole field forms a basin.
To fill the field with water, make a hole in the ridge of the ditch.
The water flows into the field.
The water flows over the field
When the field is flooded, close the ditch, and let the water
into another field.
For salad plants, for tomatoes, the whole field is not flooded.
The field is not covered with water.
The water is made to flow between the rows of the crop, between the crop ridges.
Water flows between ridges
Sometimes clay soils and the soil beside rivers and streams are
covered with water. The land cannot be farmed.
The surplus water must be made to run away, the soil must be drained.
Dig a ditch at the lowest place. The water flows into this ditch. Bit by bit the land beside the ditch becomes dry and can be farmed.
Ditch Water has gone; land can be farmed
When the land is very wet, a number of ditches must be made.
Drainage of very wet land
Clearing the land means removing weeds and grasses and cutting down small trees.
But not all plants are removed.
Trees are left standing if they:
· are too big.
You cannot easily cut down and remove big trees such as the baobab, or the kapok tree.
· are useful.
For instance, if they provide food for people or animals, such
as the oil palm.
If they protect and enrich the soil, especially in savanna country.
If they give shade: cocoa, coffee and pepper grow better if they are In shade.
· can be sold.
There are trees that can be sold for firewood, or for making
furniture, or for export.
If the land is not well cleared, if too many trees are left, the harvests are less good, because the crop plants have to share food with the trees left in the field.
If the land is well cleared, if only a few plants are left, the harvests are better.
The crop plants can use all the food in the soil.
Cut the grass and weeds and the small trees.
Put them in a heap to make them rot.
This organic matter (see Booklet No. 2, page 23) will give humus to the soil.
Do not make a brush fire (see Booklet No. 5, page 21).
The bigger trees too must be cut. The wood is taken to the village for fuel.
Often farmers cut the trunk of a tree, and leave in the ground the base of the tree and its roots. This is the stump. New shoots may grow on the stump.
When the stump is left in the ground the tree often remains alive.
When the field is left fallow, the tree grows again and the shoots get bigger.
After the fallow, all the work has to be done again.
Stumps prevent farming with animal power.
Tools such as hoes and ploughs are often damaged and bent by big roots.
· You cannot sow in rows, the stumps get in the way.
· The stumps go on taking food from the soil. Around stumps the crops are less good, the plants are not so tall, and rice, for example, turns yellow.
· The tree stumps must be taken out.
The trees must be grubbed.
Grubbing takes a lot of work. Grubbing is hard. Grubbing is necessary to improve your farming and earn more.
If a farmer has cleared the land, if he has grubbed all the trees, he can farm with animal power, he can farm his field for a longer time.
After a fallow, the next clearing will be much easier, the trees will not have grown again. There will be no more grubbing to do.
Grubbing takes a lot of work.
When you grub trees, ask the authorities for permission to farm the field for a long time.
· First way Cut the trees with a machete or axe. Then take out the stump.
Make a hole round the stump so that you can clearly see the
Cut the roots with an axe or a special grubbing tool.
This tool can be made by the village blacksmith from a leaf of a lorry spring.
The blacksmith flattens one end in his forge and sharpens it on a stone.
He turns over the other end to make it hold in a long wooden handle. This is 1.50 metres long.
This tool is used for taking out earth from around roots, and also for cutting roots.
The tool cuts better if the handle is heavy.
Pull out the tree with its stump. Do not cut the tree
Tie a thick, very strong rope to the tree trunk, about half way up.
The rope should be longer than the height of the tree.
Make a hole around the tree.
Cut the roots.
Then several men pull on the rope till the tree falls and pulls out its stump.
The work is easier if the rope is pulled by oxen, by an actor, or with a winch.
The winch is tied to a big tree so it will not move
Tackle reduces the amount of effort needed
HOW TO PULL OUT A TREE WITH A WINCH
The winch is tied to the base of a big tree.
Take the cable of the winch (a cable is an iron rope) and fix it to the middle of the tree that is to be pulled down.
With the winch handle or lever, wind the cable round the winch.
The cable pulIs the tree.
The tree falls, pulling out its root.
Several farmers in a village can get together to buy or hire a winch.
Ask the extension service for advice.