Growing the same crops in the same site year after year reduces soil fertility
and can encourage a build up of pests, diseases and weeds in the soil. Organic Crops
should be moved to a different area of land each year, and not returned to the
original site for several years. For vegetables a 3 to 4 year rotation is usually
recommended as a minimum.
Crop rotation means having times where the fertility of the soil is being built up
and times where crops are grown which remove nutrients.
Crop rotation also helps a variety of natural predators to survive on the farm by
providing diverse habitats and sources of food for them.
A typical 4 year rotation would include a cycle with maize and beans, a root
crop and cereals with either of the following;
- Grass or bush fallow (a fallow period where no crops are grown).
- A legume crop where a green manure, which is a plant grown mainly for
the benefit of the soil, is grown.