Small-scale rural aquaculture is an activity that relies almost entirely on resources and inputs that are available on-farm, or at the most in the immediate vicinity (neighbours and friends). Very rarely are inputs purchased. In this and other aspects, it resembles the farming of ordinary food crops.
Within the framework of the farming system, fish culture is one of several complementary activities that serve to spread the risks of subsistence farming. The general low returns from fish farming correspond with the limited inputs in kind and labour. The inputs also seem to be in balance with what the households can afford without risking other complementary activities.
Labour is the most crucial ingredient; at certain times of the year its scarcity prevents substantial increases in agricultural production. Labour constraints in fish farming are connected to the number of people in the extended family households. This is because fish ponds are managed exclusively with household labour. Access to such labour is a paramount condition to fully utilize other resources that are made available for fish farming. Seen against the scarce labour situation in the rainy season, there is little scope for increased labour input in fish farming.
During the dry season more labour is available. However, only a small part of surplus labour during this time appears to be spent on fish culture. Male labour is diverted towards already established off-farm economic activities. The dry season is also the period when family members spend time to socialize, travel to see relatives, arrange marriages and other social activities.
Ponds are inadequately fertilized, if at all. There is limited scope to increase fertilization of fish ponds with manure from farm animals, because the latter are very few. Composting has some potential but the practice is little known.
Farmers are aware of the precarious situation for feed in the dry season. Apart from the practice of soaking cassava tubes in the ponds and leaving the peels as fish feed, there are few examples of integration of fish farming with other activities, or other methods aimed at increasing the availability of feed.
There are no crucial differences between subsistence farmers and semi-commercial farmers in the way they operate their fish ponds. In both groups, fish farming works according to the principles of complementarity outlined above. Small-scale rural fish farmers integrate into their ponds surplus resources generated out of the annual cycle of the farming systems. They do so without giving up other activities.
Semi-commercial farmers have an advantage over subsistence farmers. They achieve a slightly higher production from their ponds and, as a result, are more motivated to dig additional ponds using their own means. At least one reason is obvious: semi-commercial farmers have access to, and integrate more resources and inputs such as fertilizers, tools and, possibly, fish feed. This, however, is a difference of degree, not of kind, between the two types of farmers.
In spite of the constraints mentioned, fish ponds are assets that give their owners additional relish, and the means to hire agricultural labour. Fish from the ponds serves as gifts on social occasions; to a limited extent it is sold for cash.
Fish is the most important animal relish and is eaten all year round. To have fish readily available for consumption whenever needed is perhaps the most important reason why farmers grow fish in ponds. This is most clearly indicated by of intermittent harvesting, a practice aimed exclusively at securing fish for family consumption and which involves virtually every household.