crease complementarity between trees and crops
(Kang and Wilson, 1987). During the cropping period
the hedgerows are periodically pruned to minimise
shading of the companion crops. When there
are no crops in the field, the hedgerows are allowed
to grow freely to cover the land.
The technique is scale neutral. Although originally
developed for smallholder family farms, it can
also be mechanised for large-scale farming. The
concept of alley cropping, which is sometimes also
called ‘improved bush fallow system’, is based on
. the following principles:
1. trees grown in managed hedgerows still perform
the same functions as in the traditional b&h
fallow system for nutrient recycling and soil fertility
regeneration;
2. hedgerow prunings supply in-situ mulch and green
manure;
3. partial shading by the hedgerows during off-season
helps in weed suppression;
4. inclusion of N-fixing legumes add N to the system;
5. presence of woody species aids in soil and water
conservation;
6. hedgerows also serve as a source of browse and
other auxiliary products, such as staking material
and firewood.
Biologically, the success of the alley cropping
system depends on: (1) correct choice of woody
species; (2) successful hedgerow establishment; (3)
efficient hedgerow and crop management.
Although a large number of MPTS are p.otentially
suitable for use in alley cropping, only a small