Tropicultura (Jan 2005)
Commercialisation des chenilles comestibles en République Centrafricaine
Abstract
Commercialization of Edible Caterpillars in Central African Republic. Clay particle distribution of an oxisol was measured along a chronosequence of shifting cultivation systems in Southern Cameroon. The influence of clay content variation on other soil characteristics was also evaluated. The chronosequence was made up of two treatments derived from mixed cropping system, three from fallows of different durations, one old cocoa plantation, and virgin forest used as control. A synchronic approach that analyses simultaneously in space crop fields and fallow of various durations was combined to diachronic observations on food crop plots. Three soil depths (0-0.1, 0.1-0.2, 0.3-0.5 m) were used for the study. The analysis of variance and mean separation (Tukey's HSD) were used to evaluate changes in clay content. Multilinear regression analyses allowed to evaluate relationships between clay content and other soil properties. Compared to virgin forest, clay content decreased considerably by 40%, 20% and 12% respectively in the three layers after three to four cycles of cropping and fallowing, and by 20%, 10% and 4% in the cropping period when compared to the preceding fallow. During the fallow period, clay content tended to increase, but remained lower than the value obtained under the virgin forest, even with longer fallow duration. Leaching and sheet erosion due to heavy rainfall on bare soil at the beginning of the cropping season may be responsible for this situation, and need future investigation. This process itself is probably facilitated by a solubilisation of clay silicate and oxyhydroxide particles due to pH increase by burned vegetation biomass. The consequences of the losses of soil fine particles as deducted from highly significant correlations (p= 0.000) with other soil properties, are: the irreversible increase in bulk density, the degradation of the structural stability of soil aggregates, the decrease of soil porosity, and the loss of soil absorption power. The edible caterpillars are an unconventional food resource of great economic and social importance in Central African Republic. It is a source of proteins and food diversification for the population. The analysis of caterpillar commercialization, from a sample of 120 actors, shows that collection and sale are profitable activities. The main actors are pupils or students during holidays. These activities help the students to prepare school opening and for those who get bad school results to insert themselves in active life as fruit and vegetable salers.
