Population escalation in the developing world has been associated with increased poverty, food
insecurity and environmental degradation. The situation in Rwanda, with 2.82% annual
population increase is no exception. The objective of the present study was to investigate an
innovative integrated system of sustainable production suitable for resource-poor rural farmers,
the Integrated Rabbit–Fish–Rice (IRFR) system. The study was targeted towards contributing to
Rwanda government’s goals of eradicating extreme poverty and hunger, enhancing food security
as well as abating environmental degradation.
Three experiments, were carried out between 2008 and 2010, and designed to fertilise pond water
with rabbit droppings and boost phytoplankton production. We also used results from our
previous study, conducted in 2005 in the same ponds and under similar experimental conditions,
especially rabbit and fish species and age, fishpond dimensions, as well as the fertilisation mode.
The fishpond effluent was re-used to irrigate rice fields rather than being discharged into the
environment.
This study advocated the potential adaptation of rabbits to wetland conditions and the role of
rabbit droppings as organic fertilisers in providing a better environment for fish production.
On-farm resources, including rabbit droppings, were the main source of nutrients in the system.
The analysis of nutrient flow revealed that 27% N and 79% P of the total nitrogen and
phosphorus in fertilizing input in fishponds were supplied by rabbit droppings only. Nile tilapia
Oreochromis niloticus were able to recover 18.5–37.6% N and 16.9–34.3% P of the total nitrogen
and phosphorus inputs, the rest being accumulated in the pond water and the sediment, making
them useful for soil fertilisation.
The re-use of nutrient-rich effluent in rice irrigation increased rice production, allowing a
successful complete substitution of inorganic fertilisers. The irrigation also reduced
environmental pollution as the water seeping through rice field was 31.8 and 83.3% less
concentrated in total phosphorus and nitrite pollutants, respectively, than was the pond water.
Economically, the IRFR generated up to 597% net return over that of the rice inorganically
fertilised, thereby substantiating the sustainability of the system.
Overall, it is concluded that the IRFR system works well, is readily applicable, and capable of
high, diversified, and sustainable production on limited land. As such, the study demonstrates the
potentialities of the IRFR system to contribute successfully to poverty reduction, and the
enhancement of food security in rural areas. The system promises economic returns and is
environmental friendly.
The research recommends the optimal range of rabbit density, that is, 800–1200 rabbits per
hectare of pond, and the best fish stocking density, that is, 3 fish.mˉ², for a sustainable IRFR
culture system. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/8590 |
| Date | January 2011 |
| Creators | Tabaro, Simon Rukera. |
| Contributors | Mutanga, Onisimo., Micha, Jean Claude. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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