Notes to broadcasters
Farmers in your listening audience have probably practised agroforestry — growing trees with crops — for generations. For example, they may use trees as windbreaks, and to mark boundaries. Or they may have a home garden made up of trees and crops that grow at different levels, or maintain some forest on the land they farm. When discussing agroforestry with your listeners, keep in mind that this practice is probably not new to them. Use familiar words to describe agroforestry systems.
FADE IN MUSIC UNDER INTRODUCTION.
Agroforestry is a new word for something you may have been doing for years.
It means growing farm crops with trees.
Today we’re going to discuss trees and crops, including what kinds of trees grow well with crops.
FADE OUT MUSIC.
In years gone by, we used to leave a piece of land to rest for a number of years.
This practice of not cultivating land for a few years is called fallow.
The resting land would grow grass, bushes and trees and after many years, perhaps 20 years, it would be a natural forest.
Our ancestors knew that the leaves, twigs, animal droppings and the bodies of all the insects and dead animals would restore the fertility of that piece of land.
After some years they would clear the land and grow crops again.
Today, this practice is often not possible.
The land is needed for growing crops to feed people.
But farmers need to grow wood as well as food.
They need firewood, building wood and fence posts.
Agroforestry is a system in which crops and wood can be grown together.
If you want to use this system you will have to grow trees which do well together with crops.
The crops need moisture, air and light.
So you need trees which do not shade the crops too much and which do not take too much moisture from the soil.
Trees such as eucalyptus, also known as gum trees, make good building-wood and firewood, but most trees of this species take a lot of moisture from the soil.
So they are not good for agroforestry and should be grown away from the crops.
For agroforestry we need trees that do not interfere with crops
We need trees with deep roots that can take moisture from deep down in the soil so the crops do not suffer from lack of moisture.
Good trees for agroforestry are often the leguminous trees.
You can recognize leguminous trees because they grow seed pods.
Most of these trees have deep roots.
They also take nitrogen from the air and store it in their surface roots.
This is important for the crops because they need this nitrogen very much.
Most leguminous trees also have small leaves which don’t shade the crops too much.
Often, their leaves are good food for livestock.
These kinds of trees also make good firewood and good building wood which makes them economical for farmers.
Many leguminous trees are also good for honey production.
Leguminous trees are good to grow with farm crops because:
- They add nitrogen to the soil.
- Their leaves are good fodder for livestock.
- They provide good firewood.
- They provide building wood.
To know which trees to plant, you need to consider your soil and your climate.
Cooler climates will need trees that are different from hot climates.
In dry areas where you need every drop of rain to grow food, you can create a more humid environment by growing trees around the boundaries of the fields, along the walls of terraces and particularly on steep hillsides.
I urge you to learn more about which trees will grow well on your farm.
Learn where to plant them, how much firewood they will provide, and how they can contribute to your farm income.
Learn how trees can improve your life.
Contributed by: John Njoroge, Director, Kenya Institute of Organic Farming, PO Box 34972, Nairobi.
Reviewed by: Dr. Helen Hambly, Associate Officer, International Service for National Agricultural Research (ISNAR), The Hague, The Netherlands.