This is a system which involves the growing of food crops in spaces between hedge-rows of trees or shrubs, which must undergo regular pruning every five or six weeks. The species of plants that can be used for alley cropping include: nitrogen fixing Gliricidia and Leucaena. The spacing of these plants is put at 4 metres between rows, to allow enough space for the growing of food crops. The soil nutrients are recycled through the decomposition of the organic residue.
Advantages of alley cropping
- The pruned leaves help in the feeding of ruminants in the dry season as fodder.
- The branches or stems are cut and used as yam stake and firewood.
- The shades provided by the plants help to suppress weed growth.
- The pruned leaves also serve as mulching materials.
- The shrubs serve as a barrier when planted across the slope in the control of erosion.
- Alley cropping serves as an alternative to bush fallowing.
- The nitrogen fixing plants fix nitrogen for the food crops.
Disadvantages of alley cropping
- The plants used can easily smother the growing food crops, if they are not pruned in time.
- Nitrogen supply may be in short fall to the crops, if non-nitrogen fixing plants are used.
- The system may be difficult to practise on a large scale.