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Book (stand-alone)International Conference on Domestication and Commercialization of Non-Timber Forest Products in Agroforestry Systems 1996
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No results found.The International Conference on Domestication and Commercialization of Non-Timber Forest Products in Agroforestry Systems, hosted by ICRAF, was held in Nairobi, Kenya, from 19 to 23 February 1996. This was the first world-level meeting to be held exclusively to draw attention to issues dealing with domestication and commercialization of non-timber forest products in agroforestry systems. -
Book (series)A strategic reassessment of fish farming potential in Africa 1998
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No results found.The present study is an update of an earlier assessment of warm-water fish farming potential in Africa, by Kapetsky (1994). The objective of this study was to assess locations and areal expanses that have potential for warm-water and temperate-water fish farming in continental Africa. The study was based on previous estimates for Africa by the above author, and on estimates of potential for warm-water and temperate-water fish farming in Latin America by Kapetsky and Nath (1997). However, a nu mber of refinements have been made. The most important refinement was that new data allowed a sevenfold increase in resolution over that used in the previous Africa study, and a twofold increase over that of Latin America (i.e. to 3 arc minutes, equivalent to 5 km x 5 km grids at the equator), making the present results more usable in order to assess fish farming potential at the national level. A geographical information system (GIS) was used to evaluate each grid cell on the basis of severa l land-quality factors important for fish-farm development and operation regardless of the fish species used. Protected areas, large inland water bodies and major cities were identified as constraint areas, and were excluded from any fish farming development altogether. Small-scale fish farming potential was assessed on the basis of four factors: water requirement from ponds due to evaporation and seepage, soil and terrain suitability for pond construction based on a variety of soil attributes a nd slopes, availability of livestock wastes and agricultural by-products as feed inputs based on manure and crop potential, and farm-gate sales as a function of population density. For commercial farming, an urban market potential criterion was added based on population size of urban centres and travel time proximity. Both small-scale and commercial models were developed by weighting the above factors using a multi-criteria decision-making procedure. A bioenergetics model was incorporated int o the GIS to predict, for the first time, fish yields across Africa. A gridded water temperature data set was used as input to a bioenergetics model to predict number of crops per year for the following three species: Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus) and Common carp (Cyprinus carpio). Similar analytical approaches to those by Kapetsky and Nath (1997) were followed in the yield estimation. However, different specifications were used for small-scale and co mmercial farming scenarios in order to reflect the types of culture practices found in Africa. Moreover, the fish growth simulation model, documented in Kapetsky and Nath (1997), was refined to enable consideration of feed quality and high fish biomass in ponds. The small-scale and commercial models derived from the land-quality evaluation were combined with the yield potential of each grid cell for each of the three fish species to show the coincidence of each land-quality suitability class with a range of yield potentials. Finally, the land quality-fish yield potential combinations were put together to show where the fish farming potential coincided for the three fish species. The results are generally positive. Estimates of the quality of land show that about 23% of continental Africa scored very suitable for both small-scale and commercial fish farming. For the three fish species, 50-76% of Africa's land has the highest yield range potential, and the spatial distribution of th is yield is quite similar among the species and farming systems. However, the spatial distribution of carp culture potential was greater than for Nile tilapia and African catfish. Combining the two farming system models with the favourable yields of the three fish species suggest that over 15% of the continent has land areas with high suitability for pond aquaculture. -
Book (stand-alone)Guidelines: land evaluation for extensive grazing
FAO Soils Bulletin No. 58
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No results found.Extensive grazing is the predominant form of land use on at least a quarter of the world’s land surface, in which livestock are raised on food that comes mainly from rangelands. Extensive grazing differs from crop or forestry production, in which the produce remains in situ whilst growing. Evaluation for extensive grazing, unlike that for cropping or forestry, must take into account the production of both grazing forage, termed primary production, and the livestock that feed on this forage, term ed secondary production. Extensive grazing also differs from intensive grazing, in which the animal feed comes mainly from artificial, seeded pastures and not from unimproved rangeland. This relationship between livestock and arable farming must be considered when evaluating land for improved uses in which livestock play a major part. If one component of the overall land use is developed in isolation from the others, the balance between extensive grazing and arable farming may easily be distur bed. Land evaluation is used to identify alternative land uses or changes in management that will better meet national or local needs, and to estimate the consequences of each feasible change. In terms of extensive grazing, it encourages the promotion of sustainable land uses that integrate land, livestock and people for their mutual benefit.
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