Water management of integrated rice-fish farming in inundated floodplains of Balajtala Kalmadanga subproject

Abstract

The burning Issues that currently surround the countries in South Asia arc food security and ecosystem security. While food security is of paramount importance, protein requirement is also an important issue, since many of the rum! children and older people suffer from severe protein malnutrition. In Bangladesh, fish is the only source of free animal protein for the poorer section of the community. One of the potential scopes for improving fish production in Bangladesh is to integrate aquaculture with rice farming, and considerable scopes arc there to exercise such practice in inundated rice fields during the monsoon season through local community based water management. In this study, the potential of integrated rice-fish farming was explored in inundated areas of a small water management project, namely, Balajtala.Kalmadanga Subproject in Gopalganj district of the Southwest region of Bangladesh. The study followed an interdisciplinary approach through tcclmical assessments a;, well as application of participatory tools to address different dimensions of integrated rice-fish farming in the study area, including physical, socio.economie, institutional and environmental aspects. Using a set of criteria and indicators, the system was evaluated from a sustainabllity point of view; for example, whether the existing physical systems are suitable for integrated farming prdctice, whether the new system Is able or have the potential to have a positive impact on the socio.economic condition, whether the system will be environmentaliy sound, and what kind of management infrastructure and water management system arc required for the integrated farming system to be sustainable over long periods. The water management Infrastructures In the project area were found to be c\mducive to the adoption of the new farming system. Desired water levels required for minimization of rice yield reduction and in~-reasing favorable condition for fish culture were analyzed, which can be met from the available water in the study arca. Results indicate that standing water depth up to 50% of plant height is recommended during the different growing slages ofrice that maximizes yield and increases the favorable condition for fish culture. Benefits obtained by the community were more than that they obtained in • previous years from riee monoculture. Howcver, potential of further enhancement of benefits are there in the study area. Since introduction of ]ish culture is still in an experiment stage in the study area, the existing fish yield is relatively on the lower side at 0.10 tonlha. However, there are immense potentials to increase the yield many folds by increasing the stockIng of fish fingerlings feasible for the study area. With increased stocking of ]ish fingerlings, the simulated fish yield was 6.20 tonlha, which is much higher than the present yield. Full implementation of the project by Local Government Engineering Department (LGED) will allow more area to be brought under cultivation during Kharif-lJ season. The existing benefit-cost ratio (BCR) for rice-only is 1.61 compared to 1.78 in the projected post~projcct condition. Integration offish with rice will increase the HCR manifolds; the simulated BCR for rice plus fish cultivation system is 5.11 compared to the existing ratio of2.18. The integrated farming system was found to be socially acceptable. The quality of soils was enhanced with the introduction offish in inundated rice field, which is favorable for 8oro crops to be followed in the field in the dry season. Organic carbon, organic matter and nitrogen content in soil after !ish cultivation in rice field recorded about 2, 3 and 19 time.> higher, respectively than that of only ricc cultivation system. However, no remarkable impacts on soil quaJitywere found in pll, phosphorous and potassium content between with and without rice-fish cultivation system. The integrated farming system improved pest management and weed control, and did not negatively impact water quality, indigenous capture fisheries and biodiversity. There are some shortcomings in the management process with the integrated system, including community-based fish fanning through Water Management Co-operative Association with fair distribution of shares and benefits among landowner, landless, traditional fisher men and women. The sludy suggests some management processes, and anticipates that these will pave the way for more motivation and social acceptability among the community members with disparate socio--economic >;latus,which in tum will help sustain the system. The results conclude that community-based fish culture app",ach in the sludy area has the potential of being technically feasible, economically profitable, environmentally sound, and socially acceptable.