Agroforestry
Agroforestry
Agroforestry tests the deliberate integration of trees with crops or livestock, the classification of systems, tree–crop interactions and the role of nitrogen-fixing trees.
Core rules
- Agroforestry is the deliberate growing of woody perennials with crops and/or animals on the same land unit.
- Agrisilviculture combines crops and trees; silvopasture combines trees with pasture or livestock; agrisilvopasture combines all three.
- Alley cropping grows crops between rows of trees; shelterbelts and windbreaks protect fields from wind.
- Multipurpose trees provide fuel, fodder, timber and shade; nitrogen-fixing species include Leucaena, Gliricidia, Sesbania and Acacia.
- Trees compete with crops for light, water and nutrients, so spacing and root pruning matter.
Worked example
A field has poplar rows with wheat grown between them. Because crops and trees share the unit, the system is agrisilviculture. If grass and cattle were added between the same tree rows, it would become agrisilvopasture. The reasoning is to identify the components present, not the tree species alone.
Mark-losing traps
- Calling any tree planting agroforestry; there must be a deliberate crop or livestock component.
- Confusing a windbreak with a shelterbelt; both protect from wind but differ in layout and scale.
- Ignoring below-ground competition when recommending close tree spacing.
- Treating all nitrogen-fixing trees as suitable for all rainfall zones.