Tools & tillage: a journal on the history of the implements of cultivation and other agricultural processes (6.1988/1991)

THE GRASSLAND MOUND-SYSTEM OF
THE AISA-MAMBWE OF ZAMBIA

By
Peter Str0mgaard'’'

The Mambwe tribe of Northern Zambia has
developed a compost-mound based agricultu-
ral system, where the cultivation strategy is
adapted to the diminishing vegetation cover
and incipient soil degradation under the
breakdown of the local traditional system of
shifting cultivation. This shifting cultivation
system, the chitemene, of the Bemba tribe, de-
pends on the miobo woodland as an agricul-
tural fallow crop; the branches of a larger area
- the outfield - are chopped and burned on a
smaller area - the infield (Stromgaard 1985a,
1985b,; Kakeya and Sugiyama 1985). Al-
though in their lopping of the trees the
Bemba ensure a faster regrowth than under
clear-cutting, future deforestation under the
increasing population pressure is a possible
risk. It is therefore of interest to study the
cultivation strategies which have developed
up to the marginal areas of the chitemene
shifting cultivation area (Stromgaard 1989a).
Adaptations'here to the less vigorous forest
cover might be a possible solution for future
shifting cultivators, and some of the systems
can be described as natural successors to the
chitemene system.
The Mambwe
Towards the northern boundary of the
Bemba territory, Fig. 1, the Mambwe (Alder
1960; Watson 1958, 1970; Jones 1977; Pottier
1983), have developed strategies against the
diminishing forest resources: a type of hoe-
based grassland compost system (Trapnell
1953; Watson 1958).

The Mambwe, who practise this system
and live in the grassland area, are Aisa
Mambwe, whereas the forest-dwellers, who
practise both the tree lopping chitemene
method of the Bemba and the mound system
of the Aisa Mambwe are Maswepa Mambwe.
The latter have now more or less taken over
the mound system of the Aisa Mambwe due
to deforestation.
Most probably the adaptation of the
mound system originates from the early in-
trusion of Bemba raids into Mambwe terri-
tory (Roberts 1973), forcing the Mambwe to-
wards the border of the plateau into less
wooded areas, marginal for shifting cultiva-
tion. The transition of the chitemene system
into a system incorporating bean mounds,
followed by millet and re-cultivation after a
grass fallow, has developed also among the
Fipa of southern Tanzania (Willis 1966; Mo-
hamed 1988). Although the systems thus
might have been enforced by tribes north of
the Mambwe, also occupying a treeless envi-
ronment, the developement of the grass sys-
tem as an adaptation to the breakdown of the
chitemene system is proved, for example, by
the retention of the chikuka, the small
patches within the main gardens where small
branches, excess grass and trash, are stacked,
burned and later planted with finger millet.
Whether the change in cultivation system, i.e.
'•'Institute of Geography, University of Copen-
hagen, 0ster Voldgade 10, DK-1350 Copenhagen
K, Denmark.