Enhancing benefits from polycultures including tilapia (Oreochromis niloticus) within integrated pond-dike systems: A participatory trial with households of varying socio-economic level in rural and peri-urban areas of Bangladesh
Karim, M. ; Little, D.C. ; Verdegem, M.C.J. ; Telfer, T. ; Wahab, M.A. - \ 2011
Aquaculture 314 (2011)1-4. - ISSN 0044-8486 - p. 225 - 235.
resource-poor farmers - farming systems - aquaculture - fertilization - diversity - thailand - issues - nile
Linkages between the fish ponds and surrounding land for horticulture are a distinctive feature of farming households in Bangladesh. It was hypothesised that integration of fish ponds in integrated farming system enhances livelihoods and reduces poverty. The effects of introducing tilapia into existing integrated farming systems on the broader pond-dike system and associated livelihoods in rural and peri-urban settlements in central north (Mymensingh District) of Bangladesh were evaluated. Farmer participatory research carried out during June 2004 to March 2005 showed that production of fish could be substantially increased by increasing nutrient inputs rather than by stocking tilapia as an additional species. However, the ‘improved’ nutrient input applied by farmers was still well below the level required for optimal tilapia performance. Rural households benefited more than peri-urban households through enhanced direct consumption of fish and vegetables. In contrast, peri-urban households benefited more through cash sales of both fish and vegetables than rural households. Households with access to ponds, identified as relatively better-off and worse-off in the researched communities benefited equally selling and consuming fish and vegetable. Similar production levels of vegetable production between groups applying different fish culture practises suggesting that increased investment in fish production is complementary rather than competitive to vegetable production in integrated pond-dike farming systems. It was concluded that considerable potential exists to further develop pond-dike systems, which would improve livelihoods of both better-off and worse-off producers. Reference is made to the potential impacts of such changes in integrated pond-dike management if promoted more widely in Bangladesh.
Does the Limpopo River Basin have sufficient water for massive irrigation development in the plains of Mozambique?
Zaag, P. van der; Juizo, D. ; Vilanculos, A. ; Bolding, J.A. ; Post Uiterweer, N.C. - \ 2010
Physics and Chemistry of the Earth 35 (2010)13-14. - ISSN 1474-7065 - p. 832 - 837.
southern africa - management - nile
This paper verifies whether the water resources of the transboundary Limpopo River Basin are sufficient for the planned massive irrigation developments in the Mozambique part of this basin, namely 73,000 ha, in addition to existing irrigation (estimated at 9400 ha), and natural growth of common use irrigation (4000 ha). This development includes the expansion of sugar cane production for the production of ethanol as a biofuel. Total additional water requirements may amount to 1.3 × 109 m3/a or more. A simple river basin simulation model was constructed in order to assess different irrigation development scenarios, and at two storage capacities of the existing Massingir dam. Many uncertainties surround current and future water availability in the Lower Limpopo River Basin. Discharge measurements are incomplete and sometimes inconsistent, while upstream developments during the last 25 years have been dramatic and future trends are unknown. In Mozambique it is not precisely known how much water is currently consumed, especially by the many small-scale users of surface and shallow alluvial groundwater. Future impacts of climate change increase existing uncertainties. Model simulations indicate that the Limpopo River does not carry sufficient water for all planned irrigation. A maximum of approx. 58,000 ha of irrigated agriculture can be sustained in the Mozambican part of the basin. This figure assumes that Massingir will be operated at increased reservoir capacity, and implies that only about 44,000 ha of new irrigation can be developed, which is 60% of the envisaged developments. Any additional water use would certainly impact downstream users and thus create tensions. Some time will elapse before 44,000 ha of new irrigated land will have been developed. This time could be used to improve monitoring networks to decrease current uncertainties. Meanwhile the four riparian Limpopo States are preparing a joint river basin study. In this study a methodology could be developed to estimate and safeguard water availability for those users who under the law do not need registration – but who do need water