Mono- and polyculture of silver barb (Puntius gonionotus) in deepwater rice systems in Bangladesh

Experiments with fish enclosures were conducted at the Deepwater Rice Farming Systems Research Site at Shuvullah, Mirzapur, Bangladesh. The objective was to study the performance of silver barb (Puntius gonionotus) called Thai sharputi or rajputi in Bangladesh in mono-and-polyculture with grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), catla (Catla catla) and rohu (Labeo rohita). Each enclosure measured 21 m x 21 m with an approximate net height of 3.5 m. The stocking densities per cubic meter were 1 fingerling for Thai sharputi monoculture (enclosure 1), and 2 fingerlings for the polyculture systems (enclosure 2 and 3). The species ratio for enclosure 2 was 0.37:0.27:0.02:0.34 (grass carp:Thai sharputi:common carp:catla) and for enclosure 3, 0.4:0.4:0.2 (catla:rohu:Thai sharputi). In monoculture (enclosure 1), Thai sharputi performed well. This relatively good production was mainly attributed to the use of appropriately sized fingerlings and rapid growth from consumption of an abundant supply of azolla in addition to feed given. For the polyculture in enclosure 2, the average weight gain of common carp was the highest (673 g) followed by grass carp (475 g) and Thai sharputi (286 g). For the polyculture in enclosure 3, the length and weight gains for Thai sharputi were almost the same as for the monoculture.

Integrated aquaculture-agriculture adoption and impact in rainfed farming systems in Sakata, Malawi

ICLARM introduced integrated aquaculture-agriculture (IAA) in Sakata, Malawi three years ago. Since that time, and without extension support, the number of farmers with ponds increased from 4 in 1993/94 to 12 in 1995/96. To learn why and how IAA is spreading, a study of impact and adoption was conducted in the 1995/96 production season. Interviews were conducted with farmers to discuss lAA and collect data on farm function through the use of bioresource flow diagrams. Motivations given by farmers as to why they adopted IAA were to improve household nutrition and income. Constraints to adoption identified by farmers were availability of labor and capital to purchase inputs

Community water access, availability and management in the Tonle Sap region, Cambodia.

During the rollout of CGIAR Research Program on Aquatic Agricultural Systems (AAS) in Tonle Sap in 2013, water management was highlighted as one of the key development challenges. With limited capacity to regulate water, the situation oscillates between too much water in the wet season and too little water in the dry season. Access to and availability of water were seen by local communities as major limitations for aquatic and agricultural production, impacting on functions that include the lake fishery, intensive (dry season) rice crops, recession rice, rainfed rice and floating rice by the lakeside. For both fish and rice production, water and water management are determined principally by the natural flooding of the Tonle Sap Lake. This study is based on a community survey on water access, availability and management and was conceived out of the AAS consultation process and was developed to help identify existing practices in water use and management, as well as best practices where lessons can be learned and promising activities scaled out to other communities. The community survey also aims to understand, identify and analyze constraints and opportunities related to water, and includes a gender perspective to better understand the role of women in water management and use.

Inland fisheries resources and the current status of aquaculture in Sri Lanka

The aim of this working paper was to evaluate the potential of different fisheries enhancement and aquacultural systems to benefit marginal farmers who manage small rainfed irrigation systems in the lowland Dry zone of Sri Lanka. Analysis was based on secondary data and key informant interviews with professional fishermen and marginal farmers in N.W Province. [PDF contains 57 pages]

Integrated rice-prawn farming in the Mekong Delta, Vietnam: a route towards sustainable and profitable farming systems?

Economic analysis and performance of the integrated rice-prawn farming systems in the Mekong Delta (Vietnam) are reviewed, including the problems and constraints of this integrated system technology.

Suitability of rich-fish culture under mono and polyculture systems in the boro rice ecosystem

An experiment was conducted in farmers’ fields under Paikgacha thana, Khulna to study the suitability of integrated rice-cum-fish culture. Three treatments namely T1 (Puntius gonionotus), T2 (Puntius gonionotus and Cyprinus carpio) and T3 ( Cyprinus carpio) were included for the study each having three replicates. The fish were stocked at a density of 3750/ha in all the rice plots. The physicochemical parameters of water viz., water depth, temperature, dissolved oxygen, pH, salinity, nitrate and phosphate etc. recorded during the study period were found within optimum range. Of the two cultured species C. carpio attained the highest average individual weight (160g) and survival (81.06%). With respect to biomass and income, highest average fish production and net profit per hectare (306.74kg and Tk. 8177.91) were obtained in T2 and the lowest (184.17kg and Tk. 2049.41) obtained in T1 and a significant variation (p<0.05) in fish production was observed among the treatments while for rice production, it was insignificant. The cost benefit ratio of fish production found were 1:1.29, 1:2.14 and 1:1.90 for T1, T2 and T3, respectively.

Growth performance, recovery rate and fish yield of GIFT strain at various water depths under rice-fish culture systems

Effect of water depth on recovery rate, growth performance and fish yield of GIFT in the rice-fish production systems was studies in experimental plots of 123 m2 with a pond refuge of I meter deep which covered 10% of the total land area. Mortality rate of fish was very low ranging from 0.81-1.63%. However, at harvest, recovery rate ranged from 76.69-82.93% with the highest recovery at 11-15 em of water depth. Significantly the highest absolute growth (99.97) and specific growth rate (2.42%) were found at 21-25 cm water depth. The same treatment also produced significantly higher fish yield (909.76 kg/ha) although statistically similar to the fish yield (862.60 kg/ha) obtained at ll-15 em of water depth. Results also suggested that higher water depth can produce bigger fish but no significant effects of water depth was found on fish yield in the treatments 11-15 cm and 21-25 cm water depths of this experiment.

Integrating fish and azolla into rice-duck farming in Asia

Several countries in Asia practice integrated rice-duck farming. On-farm resources such as duck manure and feed waste are not adequately used and recycled in the system. This indicates the potential for research to increase the productivity of the rice-duck system. The integration of fish and the nitrogen-fixing aquatic fern azolla show promise for increasing the production potential of the system. Fish, azolla and ducks integrated with rice farming can result in nutrient enhancement, pest control, feed supplementation and biological control. Some of the results of a case study on integrated rice-fish-azolla-duck farming systems conducted in the Philippines are presented in this paper.

Stocking of eggs versus hatchlings in rice fields: a comparison of survival and growth of common carp (Cyprinus carpio) fingerlings

The study assesses the relative profitability of stocking eggs versus hatchlings of common carp (Cyprinus carpio) in the rice-fish systems in Bangladesh. Results showed that although stocking eggs-covered water hyacinths directly into rice fields is a simple low cost option, the yields and profits are much higher from incubating eggs in cloth hapas and nursing hatchlings before stocking them into rice fields.

Production-related risk in rice-fish culture: a target MOTAD analysis

The article is a summary of the preliminary results of an AFSSRN-funded study on Risk Programming of Rice-Fish Production Systems in the Philippines conducted early 1993 by the AFSSRN-CLSU team. The results show that rice-fish culture leads to a higher rice production compared to rice monoculture.

Integration of freshwater prawn culture with rice farming in Kuttanad, India

The integration of paddy cultivation with prawn/fish culture can become a viable alternative to effectively utilize the vast area of derelict polders (embanked coastal flood plains) in Kuttanad, India. Nearly 55 000 ha of wetlands in Kuttanad are available for paddy cultivation year-round. Around 5 000 ha of the polders are utilized for Macrobrachium rosenbergii culture as a follow-up crop. Of the total area, about 250 ha of fallow polders are utilized for monoculture of M. rosenbergii from March to October, while in 4 750 ha polyculture with Indian and exotic carps is practiced from November to June. Stocking density is 15 000 to 60 000/ha for monoculture of M. rosenbergii, while in polyculture with carps, it is 5 000 to 20 000/ha of prawn and 5 000 to 10 000/ha of fish. Production from monoculture varies from 95 to 1 297 kg/ha whereas production from polyculture systems it is 70 to 500 kg/ha of prawn and 200 - 1 200 kg/ha of fish. Profits range from Rs. 5 000 to 20 000/ha. An evaluation is made of how the present polders of Kuttanad are best utilized for culture of M. rosenbergii following different systems of integrated farming and how the integration is useful in the aquaculture sustainability of Kuttanad, a tropical wetland ecosystem.

Rice-freshwater prawn (Macrobrachium rosenbergii) farms in the Mekong Delta, Vietnam

Aquaculture in riceland has been practiced in Mekong Delta, Vietnam for a long time and integrated rice-freshwater prawn (Macrobrachium rosenbergii) farming has become more and more popular. The integrated farming systems developed and practiced by farmers in the area to produce more food and more cash crops are presented and discussed.

Effect of different rice brans on the growth of Thai silver barb (Puntius gonionotus Bleeker) in seasonal ponds

An experiment was conducted for a period of 110 days to study the effect of different rice brans on the growth of Thai silver barb (Puntius gonionotus, Bleeker) in rainfed seasonal ponds (30 m² each). Each of the ponds was stocked with 150 fish with the mean initial body weight of 2.03 ± 0.03 g. There were three treatments namely R1, R2 and R3 each having four replicates. Three types of rice bran namely coarse, auto (fine) and red were applied to the treatments R1, R2 and R3 respectively. Fish received different types of rice bran at a rate of 5% of body weight daily. The water quality parameters were found within the productive range. The results showed that treatment R1 produced significantly (p<0.05) highest growth and treatment R2 produced the lowest growth. The survival rates varied between 77 and 84% with treatment R3 producing the highest survival. However, the overall best production (1530 kg/ha) and economic return for the culture period was obtained in treatment R1 receiving coarse rice bran. The results of the present study demonstrated that the coarse rice bran resulted in better growth and production of P. gonionotus.