Rapidly increasing population trends in developing countries generally require a rapid increase in agricultural production and, as the majority of the population of developing countries are small-scale farmers, the major development challenge is to increase the production of food by this particular group. Experience in Asia in particular and more recently in Africa indicates that farming systems based on the integration of crops, livestock and fish production can make a significant contribution to this required increase in food supplies.
More specifically, development potential has been clearly demonstrated to exist for this form of production in the rural areas of Zambia and local technologies have been tested and successfully applied.
The basic advantage of integrated systems is that; through the application of the waste products from one system as fertilizer or supplementary feed to boost the production in another system (as in the application of vegetable waste as compost or feed in a fish pond), the total output of the farm is increased beyond that which would be possible if the different production systems were operated independently. A major socio-economic benefit of integrated fish-farming is that inputs to the various subsystems which comprise the farming system tend to come from within the farm. Moreover, fish efficiently convert low grade feeds into high quality animal protein and can be kept alive on maintenance diets without loss of condition, thereby allowing a greater degree of flexibility in harvesting strategies. In this way a high-value and nutritious source of food can be obtained with a minimum of effort and external inputs.
Integrated crop-livestock-fish systems are also highly flexible in that a wide range of fertilizing and supplementary feed substances can be utilized and a similarly wide range of levels of management, from extensive to highly intensive, can be successfully applied. Obviously, the higher the grades of fertilizer and feeds and the more intensive the level of management applied, the higher the yield of fish is likely to be. However, the important consideration for the small-scale farmer and in the context of global food shortage, is that increases in yield can be achieved without recourse to costly manufactured inputs and by applying management strategies which are within the capacities of existing small-scale farming systems. These features of low external input and flexibility in the level of management which can be applied make integrated crop-livestock-fish systems highly attractive solutions, especially for those small-scale farmers who are experiencing undernourishment and lack of income.
The theoretical yields (Figure 1) indicate that substantial returns, in the form of extra food and income, can be obtained for relatively little cost in the form of labour and investments. The main impediments to achieving increased production of fish from integrated farming in Africa are not likely to be biotechnical in nature (although there may be biotechnical barriers to achieving the highest possible yields). Rather, the real constraints are more likely to be found in human and social factors, such as the levels of awareness of farmers or the social, cultural and management aspects of their farming systems.
These factors have to be understood and appropriate approaches to development within the particular context of the small-scale agriculture sector must be devised and applied.
In integrated crop-livestock-fish production systems, since the key integrating elements are the wastes produced by crop and livestock production, it is especially important that the crop and livestock farming systems are fully understood. The constraints and potentials within these systems will determine whether and to what extent the integration of fish production will be possible. From this, it clearly follows that the economic development of crop-livestock-fish farming requires a broad, multi-disciplinary and holistic approach. All elements of the integrated system need to be developed in concert. Approaches which are based on a concentration on one subsystem, such as fish production, will eventually fail to identify potentials and constraints arising in the other subsystems.
In Zambia, small-scale agriculture is crop-dominated, dependent more on inputs and resources from within integrated and diverse production systems than on external inputs, has only minimal financial resources available and is driven more by the need for basic food security than by the profit motive. The main implication of this for the development of fish-farming in the small-scale sector is that it will have to follow similar patterns and be adapted to similar conditions.
