The rice-cum-fish trials in Luapula Province during the rainy season 1992–93 have provided a mixed picture of the actual benefits from this type of integrated farming. As these are the first trials of its kind reported in Zambia, no figures exist to make a direct comparison.
Data from the rice harvest reveals yields from the rice-cum-fish field which on average exceed yields from the rice-only field by 11%. It is likely that the higher productivity in the rice-cum-fish field results from the presence of the fish leading to extra fertilizing, improved weed and insect control as well as mineralization, soil aeration and distribution of nutrients.
Fish yield from the trials (196 kg/ha) is slightly lower than figures from similar farming systems in other parts of the world. These are 200 kg/ha with somewhat more extensive management and about 300 kg/ha with the same level of management. However, rice and fish culture is more widespread in these countries, hence knowledge of practices is better.
Evaluation of the profitability and economic viability of the rice-cum-fish farming system yielded disappointing results.
Under the assumption that household labour has the same value as unskilled agricultural labour, the net return to land as well as to household labour for the rice-cum-fish field is considerably lower than that for the rice-only field. In fact, it is negative, i.e. the trials indicate that the farmers have to pay for this activity.
This picture remains unchanged even when the the second year of production is considered and the initial costs of pond construction are excluded.
If, however, it is assumed that there is no alternative use for household labour, rice-cum-fish production becomes less unfavourable. The net return to land for rice-only farming in this case is only slightly higher than that for the rice-cum-fish farming. After the first year of production, the figures are at the same level.
For the net return to household labour, however, the results indicate that rice-cum-fish farming is far less profitable than the rice-only farming, even in the second year of production.
The overall impression of the trial results is negative. Estimates of the net return to labour show that rice-only farming is economically superior to rice-cum-fish -- mainly because of the time spent on feeding and other management activities in the latter system. Why did fish cultivation entail the extra workload? The intention was that the farmers could look after and manage fish production while already at the field. The high workload attributed to fish production may reflect the true facts; it could also be a consequence of the way questions were put to the farmers.
Nevertheless and somewhat ironically, all the farmers intend to continue with rice-cum-fish farming. Their reason given is that they can discern the potential of this farming system. This suggests that an assessment of future farming practices, and the recommendations that result, should not be built entirely on an economic evaluation. Other factors seems to be important as well -- such as the economic and nutritional security of an extra crop, and the status the farmer gains in his village through this farming system.
