UNESCO Ancient Civilizations of Africa (Editor G. Mokhtar)

Ancient Civilizations of Africa
characteristics by selective breeding, while losing some old character traits.
Plant cultivation here refers to the deliberate planting of tubers or seeds
and the protection of fruit trees, vines, etc., with a view to obtaining for
human use an appreciable quantity of these tubers, seeds and fruits.
Terms such as 'vegeculture and arboriculture, common in the literature,
are avoided here because they carry connotations of evolutionary sealing
of cultural superiority. So also is the definition (e.g. Spencer, 1968) 1 of
agriculture in the technological sense as 'systems of food production that
involve advanced tools, draught animals or mechanical power, developed
cropping systems and mature technologies of production'. Certain words
are italicized in order to emphasize the subjective nature of such a
definition.
Ecological studies indicate, first,that animal domestication if feasible
in the semi-arid tropical and subtropical savannah areas (Bonsma, 1970) 2
because the soil PH is fairly high (±7-0), and consequently the macroelements
(nitrogen and phosphorus) are relatively readily assimilable and
pastures have a relatively high protein content. Secondly, and in contrast,
such studies indicate that domesticated animals are not an important feature
of food production in the humid tropical regions partly because the soil
PH and the assimilability of the macro-elements nitrogen, phosphorus and
calcium are generally low; hence the pasturage is high in cellulose and
crude fibre, and has a high heat increment value. Heat production and
dissipation by the animals are thus real problems for livestock in the humid
tropics. To maintain thermal equilibrium in such regions cattle are usually
small, giving them a large surface area per unit weight and facilitating
heat dissipation. Where some domesticated animals were in fact kept, the
problem of high temperatures appears to have been overcome by the
selection of small livestock which could adapt to tropical conditions.
Thirdly, ecological studies show that the annual plants cultivated in most
of West Africa, in complete contrast to those of the Middle East, were
and still are adapted to growth in a season of high temperature and high
humidity. Except in the cool and relatively dry highlands, Middle Eastern
cereals fail completely because of their inability to withstand pathogens
that flourishat high temperatures. Botanical investigations (Portères, 1950,
1951,1962; Doggett, 1965; Havinden, 1970) 3 indicate that cereal crops such
as millet (Pennisetum typhoideum), fonio (Digitaria exilis) and rice {Oryza
glaberrima), vegetable crops like cow pea (Vigna Sinensis) and earth pea
( Vcandzeia subterránea), tubers such as Guinea yams (Dioscorea cayenensis
and D. Rotundata) and the oil palm (Elaies guinensis) and the ground
nut (Kerstingiella geocarpa) are indigenous and probably have a long history
of cultivation in various parts of West Africa. 4
1. J. E. Spencer, pp. 501-2.
2. J. C. Bonsma, pp. 169-72.
3. A. Portères, 1950, pp. 489-507; 1951a, pp. 16-21; 1951b, pp. 38-42; 1962, pp. 195-
210; H. Doggett, pp. 50-69; M. A. Havinden, pp. 532-55.
4. See Volume I, Chapter 25.
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