State of the art : Acacia albida as a complementary permanent intercrop with annual crops

Although the available literature does not allow a completely accurate analysis of its actual and potential capabilities, it is reported that use of A. albida for foliage cover in intercropped systems on infertile soils has nearly doubled yields of millet and peanuts. Such use also reportedly increases the soil"s organic matter and nitrogen content, soil microbiological activity, and water holding capacity beneath the trees. It has also been suggested, though not proven, that A. albida has increased the capacity of the land to support people from about 10-20 to 25-40 persons per square kilometer. By making unnecessary the continual process of letting mineral-depleted land lie fallow and clearing new land, A. albida is also credited with making possible permanent agricultural settlements. These are the major findings of the state-of-the-art review of the A. albida literature presented in this document. The text begins with the extensive literature review itself and then summarizes the effects of A. albida on crop yield and soil properties, the causes for A. albida-induced soil fertility, its pod yields and food values, and its growth cycle characteristics. The paper concludes with a discussion of ten areas in which, in the opinion of the author, research is urgently needed, either to anticipate and solve A. albida problems before they arise in the field, or to develop better agricultural practices and A. albida cultivars. Two appendices containing interviews with Senegalese farmers and with researchers in Paris and in Senegal concerning A. albida are also included. A foreward describes the method in which the documents (copies of which are now all deposited at the University of California, Riverside Library) contained in this literature review were obtained.