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Aquaculture Technology Research For Smallholder Farmers In Rural Malawi

R.P. Noble And B.A. Costa-Pierce

International Center for Living Aquatic Resources

Management (ICLARM)-GTZ Africa Project

Zomba, Malawi

Abstract

In order to develop aquaculture systems and technologies relevant to the maize-based farming system in rural Africa, the International Center for Living Aquatic Resources Management (ICLARM) is conducting farmer-participatory research in Malawi. This involves farmer-researcher interaction throughout the aquaculture program, thus enabling researchers to: (1) assess farmers' agroecological resources and the extent of their traditional agricultural knowledge to provide information on the constraints to adoption of aquaculture; (2) develop on-station research to test technologies relevant to rural farmers and their farming systems; and (3) monitor and evaluate, in collaboration with farmers, the performance and impact of new technologies and integrated agriculture-aquaculture models on farming systems.

The research process involves a continuing transfer of information and ideas between farmers and researchers so that research agendas can be adjusted to meet changing needs as indigenous aquaculture systems evolve.

Malawian aquaculturalists generally have one pond of approximately 300-400 m² in which they polyculture Oreochromis shiranus and Tilapia rendalli, sometimes with Cyprinus carpio. Yields from fish ponds are low (1 t/ha/yr). The major pond input is maize bran, which is used for human and animal food and is scarce during the rainy season.

On-farm bioresource assessments have shown that there are agricultural residues such as maize stover (2.5 t/ha/yr), grasses (>4 t/ha measured at the end of the wet season) and wood ash (400 kg/farm/yr), which could be used as pond inputs. Experiments have demonstrated that application of napier grass and maize bran together can improve fish yields up to 3 t/ha/yr. Wood ash from household cooking fires can improve water fertility and raise pH.

Low-cost technology transfer is accomplished by showing farmers a "basket" of technologies at the research station where they are encouraged to critically assess the available technologies. Farmers who have seen and critically evaluated these technologies are more likely to adopt them. In a farmer survey, 76% of those who had visited the research station were using more than one technology compared with only 32% of a control group. Using the "shopping basket" approach to technology transfer has resulted in rapid adoption of rice-fish culture. This has never been practiced in Malawi before. Farmers achieved rice yields of 2-2.4 t/ha/yr and fish yields of 1.5-2.4 t/ha/yr from rice-fish ponds. Farmers who usually grow only one crop of rice per year are now starting second crops during the dry season.

Introduction

Aquaculture has not been adopted widely in rural Africa, primarily because the technology has no traditional base in smallholder agriculture. Most rural households operate outside the cash economy, and thus have little expendable income to purchase the feeds and fertilizer that make aquaculture economically viable.

Malawi's population is 8.2 million (NSO 1987), of which 80% are directly involved in agricultural production. The International Service for National Agricultural Research (ISNAR 1982) stated that smallholder farming accounted for 84% of the agricultural GDP. However, only 25% of that contribution entered the cash economy in the early 1980s. Current figures are not available, but demographic and economic indicators suggest there has been little change since ISNAR's report.

Malawi government policy has favored estate development rather than smallholder agriculture, resulting in further limitations on participation in the cash economy (Kydd and Christiansen 1982, Peters and Herrera 1989). Malawi's high population growth (3.7% per annum, NSO 1987) further exacerbates this situation and is leading to a shortfall in food supply among rural communities.

Production of smallholder food crops has been falling since the mid-1970s. This reduction has been due to increasing shortage of arable land. Average per capita landholdings are expected to decline to 0.26 ha by the year 2000 in Malawi (World Bank 1989). With such severe land constraints it will be necessary to use marginal lands and improve the utilization of existing land.

Fish is the major source of animal protein for human consumption (60-70%, Satia 1989) but is quickly becoming a scarce and expensive food commodity in Malawi. Msiska (1985) noted that between 1972 and 1984, per capita consumption of fish fell by 53 %, from 17.9 kg to 9.5 kg per year. Malawi's lake fisheries have reached their productive limit in terms of fish supply (60,000-70,000 t/yr) and cannot meet the demands of a rapidly growing population (Msiska 1985). The Malawi government is now attempting to expand smallholder aquaculture to help relieve the shortfall in fish supplies and raise rural incomes.

The introduction of aquaculture to farmers in Malawi started in the early 1950s but has not been particularly successful. This is reflected in the low production figures for the 1980s of approximately 100 t/yr for the whole country, just 0.1% of capture fisheries production (Balarin 1987).

Kalinga (1991) suggests that lack of capital, suitable fish species and feeds, appropriate management techniques, and extension capacity all contribute to Malawi's poor performance in aquaculture. Balarin (1987) suggests that the lack of an integrated development approach is also a major problem.

Aquaculture projects often fail to address the problems and needs of smallholder and subsistence farmers and too often treat aquaculture as a stand-alone enterprise in the farming system. For example, many aquaculture projects in Malawi have presented farmers with technological packages designed to operate only as an independent commercial operation (GOPA 1987).

With farm sizes of usually less than 1 hectare, many Malawian farmers are operating at, or close to, subsistence and have very low cash incomes. Under these circumstances, they cannot afford

to purchase the formulated feeds and chemical fertilizers that are demanded by commercial aquaculture. Therefore, such technology packages will only be appropriate for a very small, restricted group of households with relatively high incomes.

If aquaculture is to have a wide impact on nutrition, farm incomes, and rehabilitation of resource systems in rural Malawi, it is necessary to have flexible aquaculture technologies that fit into a wide range of traditional farming practices and farm resources.

Aquaculture Research

In 1987, ICLARM, funded by Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ), initiated a farmer-participatory research project with the Malawi Department of Fisheries (FD), the objective being to develop aquaculture technology appropriate for rural Africa (ICLARM and GTZ 1991). The target group of research efforts are rural smallholder farmers with access to, or tenure rights over, water resources.

Studies are directed toward integrating aquaculture technologies into the smallholder maize-based farming systems. This is achieved by continual farmer-researcher interaction throughout the research program, thus enabling researchers to:

- Assess the agroecological resources of farmers and the extent of their traditional agricultural knowledge, thus providing information on the constraints to adoption of aquaculture;

- Develop on-station research to test technologies relevant to rural farmers and their farming systems; and

- Monitor and evaluate, in collaboration with farmers, the performance and impact of new technologies and integrated agriculture-aquaculture models on farming systems.

A report of the ICLARM-GTZ/FD collaborative research program is presented in Costa-Pierce et al. (1991).

On-Farm Bioresources Assessments and Current Status of Aquaculture

A large survey of farmers practicing aquaculture in Zomba District, Southern Malawi, was conducted to establish baseline data on pond sizes, number of ponds per farm, species of fish reared, etc. Table I summarizes this information.

A smaller survey of farmers was carried out to establish cropping and land use patterns. Biomass and production of crop and weed residues were measured wherever possible. Livestock wastes were estimated for some farms, as well as inputs of agricultural residues into fish ponds. Tables 2, 3, and 4 show land use patterns and availability of crop residues.

Data from bioresource assessments established that certain materials were often underutilized and had the potential for use in ponds. These were maize stovers, fallow land grasses, and wood ash from household cooking fires.

TABLE 1 Vital Statistics of 209 Smallholder Fish Ponds on 128 Farms in Zomba District, Malawi

 

Quartiles

 

Mean

Median

25 %

75 %

Pond area (m²)

338 (SE=34)

196

105

400

Total area of land under ponds on each farm (m²)

537 (SE=80)

205

96

558

Pond number/farm

1.8 (SE=O. 1)

1

-

-

 

Total number of hatchery ponds: 36 (17%)

Total number of production ponds: 173 (83%)

For example, maize stover production was 2.5 t/ha/yr, all of which was composted directly into the ground. There were enough stovers on farms for a proportion to be converted to high-quality compost as a pond input. Therefore, one potential research study was to look at the suitability of converting maize stover into a high-quality compost for use as a pond input.

Fallow land grasses and weeds were in relative abundance. The values in Table 4 are end-ofseason biomass, so turnover rates and grass production could be increased by cropping grass regularly for use as a pond input. Edwards et al. (1988) has shown that fish yields can reach as high as 5-6 t/ha/yr with vegetation as a sole pond input.

Availability of grass and its use by most farmers as a pond input for growing Tilapia rendalli (macrophytic feeder) led to studies of grass as a direct feed (Chikafumbwa 1990). The most common food input for fish ponds is "madeya" (maize bran), which is seasonally scarce. Maize bran is also sometimes used as food for humans in periods when maize meal is scarce. Therefore, grass has the potential to be a cheap substitute and possibly a more suitable food source for a macrophytic feeding fish such as T. rendalli.

TABLE 2 Pattern of Land Use Areas (ha) on 10 Smallholdings with Fish Ponds in Zomba District, Malawi

 

Mean

Standard Deviation

Range

Holding size

1.6

0.

0.5-3.2

Crop land

1.2 (82%)

0.5

0.5-2.5

Fallow land

0.2 (13 %)

0.2

0-0.6

Total pond area

0.07 (5%)

0.07

0.1-0.2

 

TABLE 3 Average Production of Maize Residues on Farms with Fish Ponds, April-May 1989

 

Local Maize

Hybrid Maize²

 

kg/ha/yr

kg/farm

kg/ha/yr

kg/farm

Stovers

2,479

2,552

2,789

3,068

Sheaths

181

172

122

26

Cobs

281

152

485

321

Bran

291

297

660

466

'Sample of 17 farms

²Sample of 3 farms

Farmers' ponds are nutrient poor in the Zomba district of Malawi. The main cause is the low nutrient status of the underlying ferrous soils and the resulting acidic waters, which lead to very low fertility (alkalinities 5-10 mg/1). Wood ash is a resource that is discarded in most households and has been demonstrated to improve the pH of pond waters and act as a phosphorus source (Jamu 1990). More than 400 kg wood ash/farm/yr was produced on the few farms that were sampled, and most was unutilized.

In the examples just noted, it is obvious that there are materials on farms that could be used as potential feeds and fertilizers in ponds. These on-farm assessments provide researchers with information that enables them to rank research objectives and also establish personal contact with farmers. This interaction helps sensitize farmers to the research program and the importance of their role in helping researchers to adjust their study objectives.

Farm Management and Integration

Coupled with the resource assessment above, farmers were asked to explain their calendar of agricultural activities and why these activities were organized in a particular way. Figure 1 shows a seasonal calendar for a farmer with a moderate level of integrated farm enterprises, and Figure 2 shows a calendar for a farmer with a high diversity of integration. These calendars enable researchers to see seasonal changes in bioresource management.

TABLE 4 Average Terrestrial Weed Biomass on Farms with Fish Ponds, June-July 1989

 

Herbaceous Plants

Grasses

 

kg/ha

kg/farm

kg/ha

kg/farm

Maize fields'

1,128

1,236

120

191

Fallow land²

322

41

4,252

2,516

'Sample of 6 farms

²Sample of 5 farms

A further step in this process is for researchers to encourage farmers to draw pictorial models of their farm systems (Lightfoot and Tuan 1990). These models show the bioresource flows between farm enterprises, thus providing a picture of the dynamics of the system and its level of integration. These pictures allow farmers to visualize their whole farm and see where new enterprises and linkages can improve farm integration, efficiency, and productivity. The process of pictorial modeling is described in a booklet and accompanying video by Lightfoot et al. (1991).


FIGURE 1. Farm with high level of crop-pond production


FIGURE 2. Farm with low-level of crop-pond integration

Smallholder Fish Production

Harvest yields of smallholder ponds were assessed to provide baseline data for comparisons with on-station experimental results. Table 5 shows the harvest yields for farmers practicing polyculture, and Table 6 shows the sizes of fish obtained from harvests (Noble and Chimatiro, unpublished). Yields are generally poor and fish small.

Results of On-Station Research

Results of on-station experimentation with on-farm bioresources and other low-cost materials are shown in Table 7. What is clear is that fish yields can be increased significantly using resources already available on most smallholder farms. In addition, farmers could mix resources, depending on their seasonal availability, and raise production well above that of maize bran input alone.

For example, a mix of grass and maize bran raised mean yields from ponds by a factor of 3 (approximately 3 t/ha/yr) compared with farmers ponds (approximately 1 t/ha/yr) using maize bran. Fish yields from ponds receiving pumpkin leaves (1 t/ha/yr) (Chimatiro and Costa-Pierce 1991) are similar to farmers' ponds. Pumpkin leaves are available when maize bran is not, so it could prove a valuable substitute.

TABLE 5 Harvest Summary for Polyculture of Oreochromis shiranus, Tilapia rendalli, and Cyprinus carpio in 14 Ponds in Zomba District (June-August 1989)

 

Oreochromis shiranus

Tilapia rendalli

Cyprinus carpio

Harvest biomass (kg/pond, kg/ha)

Mean

18 (524)

6 (141)

12 (354)

Median

15 (324)

4 (76)

9 (225)

Range

1-40 (57-2,391)

1-17 (13-558)

4-23 (96-1,551)

Harvest production (kg/halyr)

Mean

526

154

364

Median

321

94

211

Range

66-1,948

16-574

136-1,264

 

Mean number of days between harvests: 345 (range: 177-448); mean pond size: 565 m² (range: 70-1,564 m²).

Identification of locally available materials as pond inputs has proved an important and successful element of the research program. Examples shown above indicate how sustainable aquaculture at smallholder levels could develop.

 

TABLE 6 Growth Summary for Oreochromis shiranus, Tilapia rendalli, and Cyprinus carpio in Polyculture Ponds in Zomba District (June-August 1989)

 

Oreochromis shiranus

Tilapia rendalli

Cyprinus carpio

Fish sold (g)

Mean weight

20.9

26.6

293.1

Median weight

16.4

16.3

275.3

Range

(6-53)

(6-93)

(174-543)

Fish not sold (g)

Mean weight

5.5

6.2

131.5

Median weight

5.2

5.1

143.2

Range

(1-14)

(1-13)

(52-257)

All fish (g)

Mean weight

13.9

20.1

238.6

Median weight

9.8

10.7

246.6

Range

(6-36)

(5-57)

(63-543)

 

Note. The mean weights of each fish species in 16 ponds were averaged to get the overall means, medians, and ranges above. Hence, these figures are showing between-pond variations.

 

TABLE 7 Mean and Ranges of Net Yields of Fish Ponds, Costs, and Incomes of Fish Farmers in

Malawi Using On-Farm Resources (Chikafumbwa et al., Unpublished)

 

Mean Yields

Cost of Input

Income

Inputs

Input Rates

(kg/hatyr)

Range

(US$)

(US$)

Napier grass (NG)

100 kg DM/ha/day

1,405

647-2,195

14.58

34.00

Maize bran (MB)

3% MBWD

1,726

406-2,368

2.65

41.77

NO/MB

As above

3,013

2,726-3,299

17.23

82.70

Waste pumpkin leaves*

50 kg DM/ha/day

1,444

1,372-1,616

12.6

35.06

Maize stover compost/FWA**

3% MBWD; 2.5 t/ha

750

710-790

7.38

18.20

Smallholder farmers using MB

When available

NA

400-500

2.65

10.89

Smallholder farmers using MB

When available

951

241-3,336

2.65

23.01

 

*Cost of waste pumpkin leaves based on labor input to harvest waste leaf **FWA= Fuelwood ash and agricultural limestone combination

NA=Data not available

MBWD= Mean body weight per day

[1] Cost of fresh fish, 1991 retail prices @ US $1.21

[2] Cost of maize bran @1 US $0.04/kg dry matter @10% moisture

[3] AL= Agricultural limestone @ US $0.04/lcg

[4] FWA (Fuelwood ash) = No cost: a waste resource from household cooking fires

[5] Cost of maize compost based on labor input @US $0.81/day to construct compost heap; purchase of bamboos for pile aeration @US $0.13/bamboo

[6] Napier grass cost based on labor input to cut grass @US $0.81/day

[7] Costs of inputs are per kg/yr per 200 m² pond (2 fish crops/yr; 1 ha pond)

[8] Income is per 200 m² pond (2 fish crops/yr; 1 ha pond)

Other Potential Research Areas

In the current situation of high population densities and land shortage, more marginal land will have to be brought into production by using it for enterprises such as aquaculture. Lightfoot (1990) points out that new ways of utilizing land to help regenerate environments is urgently needed. He suggests that biological diversification of farms and improved nutrient cycling by incorporating aquaculture could help achieve this objective.

Integration of aquaculture on smallholder farms might help to create sustainable, regenerative farming systems (Lightfoot 1990). Most farmers practicing aquaculture in Malawi have vegetable gardens and rice fields adjacent to ponds. It would require very little effort to interlink these enterprises for mutual benefit.

On-station research and demonstrations have been directed to look at the potential of integrating fish with crops (rice, vegetables, maize) and animals (goats, chickens). Malawian farmers also have difficulty harvesting fish. Appropriate harvesting technologies must be suitable to the income and labor resources available to farmers. One research area for focus was harvesting tools and techniques such as reed seine, basket traps, plunge baskets, and recruit removal (Kaunda 1991).

Another important aspect that has led to low yields is the poor growth performance of the two major cultivated species, O. shiranus and T. rendalli. Research studies have started on utilization of the large Lake Malawi tilapias, particularly O. karongae ("chambo") and catfishes, such as Bathyclarius sp. (Msiska 1991).

The research program is attempting to develop new indigenous systems of aquaculture based on the existing farming system and resource base of the Malawian rural farmer. The combination of new inputs, new fish species, and new systems of integration based on local resources has the potential to produce a more productive, indigenous, and sustainable aquaculture for smallholder farmers.

Farmer Participatory Research

A major problem facing any research project attempting to improve smallholder farming systems is encouraging farmers to adopt new enterprises and modify and integrate existing ones. The ICLARM/FD project has avoided presenting technology packages to farmers. African agroecosystems are highly complex and no one enterprise or technology is going to be applicable over a wide range of farming systems. To ensure that research priorities meet the farmer's agenda, the farmer must be able to assess the technologies and systems being designed by researchers.

Exposure of Farmers to New Technologies

Part of the ICLARM/FD program has been focused on the methodology required to engender farmer participation in the research. One approach has been to encourage farmers to visit and assess on-station experiments and comment on the range of aquaculture options on offer. Farmers are given freedom to express their feelings about the technologies and make suggestions for new lines of research, or modifications to existing research. Farmers are able to explain to project personnel which technologies are most appropriate for their farming system.

On-station open days with farmers are organized with a workshop where farmers lead the discussion and help researchers to reformulate research objectives. This occurs after the farmers have viewed a "basket" of technologies on offer. Showing respect for farmers' opinions and knowledge helps to win their confidence and makes it easier for both researchers and farmers to work together to develop appropriate aquaculture technologies and systems.

The effect of open days on technology research and transfer has been documented by Noble and Rashidi (1990). In May 1990, the first open day was held at the National Aquaculture Center (NAC) with 29 farmers. Six months later, 54 farmers were interviewed: 29 who had been to the open day, and 25 who had not, and 76% of the former were operating more than one technology in their ponds, but only 32% of the latter. Exposure to technologies and a variety of pond management strategies enables farmers to pick options that suit their local circumstances.

However, the open days are only one aspect of farmer-researcher interaction. Farm visits to evaluate bioresources, technology performance, and impact are all part of an on-going dynamic, which has led farmers to adopt new aquaculture technologies more readily and new entrants coming into aquaculture.

Rice-fish Integration

A particularly effective example of this type of process and farmer-researcher interaction is with rice-fsh integration. In December 1990, farmers were shown an experimental rice-fish pond at the NAC. Until that time, farmers had never seen rice and fish grown together. They were shown harvests of both crops on the same day. At a workshop to discuss rice-fish, the farmers were excited by the idea, but heavily critical of the experimental setup. The researchers encouraged them to draw their own designs (Figures 3a, 3b, and 4). These were very sophisticated and demonstrated that farmers were capable of contributing effective ideas even in an area where they had no experience.

Farmers quickly realized that the most effective arrangement was to be able to easily decouple rice and fish and have an efficient means of concentrating fish in deeper waters away from rice. They had come, in one day of exposure, to the same conclusions reported by dela Cruz (1990) in a large collaborative research program by IRRI and ICLARM in the Philippines.

In response to farmers' criticisms and suggestions, a second rice-fsh pond has been built to their design at NAC. This incorporation of farmers' ideas in the on station research program has helped to forge a strong collaborative link between researchers and farmers.

In February 1991, a field survey showed that of the 17 farmers that came to the rice-fish day, eight (47%) had started rice-fsh ponds. Yields were good (ranges: 2.4-4 t/ha/yr for rice, 1.5-2.4 t/ha/yr for fish) and farmers stated they were higher than normally expected. Nutrient-rich pond muds and reduction of water and weed constraints probably contributed to the high rice yields. Four farmers were so impressed that they have started a dry season crop of rice.

We are seeing the evolution of an indigenous rice-fish farming system. Farmers have adopted a technology that is new, but very relevant to their farming environment. They have modified the technology to make it more efficient and started to operate new management strategies that have never before been tried (i.e., two crops of rice per year).

It is particularly exciting that farmers who have not been to open days at the NAC are starting to adopt indigenous technologies that have been developed by farmer-researcher interaction. Some of the new rice-fish farmers are in a large rice-growing area where farmer-to-farmer diffusion of technology can occur rapidly. This is resulting in new entrants to aquaculture through rice-fish integration as well as existing fish farmers adopting this new system for their ponds.

What is evident is that the success of the research program with regard to rice-fish has been aided by the sensitivity and understanding researchers have shown for what is feasible in agriculture-aquaculture integration on Malawian farms. The researchers presented these ideas to farmers and allowed them to decide the applicability of rice-fish integration to their farming situation.


FIGURE 3a. Malawian farmers' drawing of a possible rice-fish arrangement (two farmers composed the drawing)


FIGURE 3b. Sloping field makes it easier to drive fish into the pond, then rice can be harvested afterwards. (This is the author's interpretation of farmers' drawing)

Monitoring and impact assessment of rice-fish and use of other technologies by farmers is now being carried out. Farmers are modifying technologies they have seen at the NAC to suit their own circumstances. Part of the on-farm research program will be to determine if such changes are effective in leading to sustainable aquaculture systems and whether they have wider applicability across the broad spectrum of Malawian farming systems.


FIGURE 4. Rice-pond arrangement designed by two farmers. Rice field is sloped towards central trench and trench slopes toward pond.

Conclusion

The core of the ICLARM/FD research program is farmer-participation, emphasizing on-station research and implementing on-farm experiments. Lightfoot (1990, 1991) points out that this is essential if sustainable aquaculture systems are to be developed.

As most farmers in Malawi operate their smallholdings at, or close to, subsistence level, farmer participation is essential for aquaculture development to be fully integrated into the farming system. The diversity of farming strategies and agroecosystems in Malawi precludes the use of general aquaculture packages. Success in aquaculture development will be achieved by taking a flexible, evolutionary approach to production of appropriate technology for smallholders. This can be achieved only by farmer collaboration in modifying new and existing aquaculture systems to suit a variety of local farming conditions.

Farmer participation in the research program has many facets ranging from farmer visits to on-station experiments, to farmer workshops both on-station and on-farm, and farmer-researcher experiments on farm. This dynamic interchange helps to ensure that research objectives are in line with the needs of farmers.

It is hoped that this farmer-first approach in the research program will lead to indigenous sustainable aquaculture systems for Africa that not only produce fish, but enhance the productivity of the whole farming system.

Acknowledgments

The authors thank the ICLARM research staff and technicians who assisted in field research and with the farmer open days, particularly Sloans Chimatiro, Fredson Chikatumbwa, and Daniel Jamu; Brian Rashidi and his staff of the National Aquaculture Center, Malawi Department of Fisheries, for their collaboration in the research program; and Clive Lightfoot, Roger Pullin, and Jay Maclean for their helpful comments on the manuscript. This research program is funded by the Deutsche Gesellschaft fur Technische Zusammenarbeit (GTZ) GmbH, Eschborn, Federal Republic of Germany. The authors also thank the Office of Research, USAID, for funding the network meeting and publication of this paper.

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World Bank. 1989. Malawi national rural development program. Technical Issues Review, Rep. No. 7539-MAI, Washington, DC.

 

Low-Input Technologies For Rural Aquaculture Development In Bangladesh

M.V. Gupta

International Center for Living Aquatic Resources Management (ICLARM)

Makati, Manila, Philippines

Abstract

Fish is the main animal protein source for the people of Bangladesh. In spite of vast water resources, fish production is in decline, resulting in protein-energy malnutrition. Farmers participating in on-farm research developed low-input sustainable aquaculture practices that benefit the poor farmers, who constitute the bulk of the population.

Farmer-oriented studies have confirmed the viability of culturing silver barb (Puntius gonionotus) and nile tilapia (Oreochromis niloticus) in seasonal ponds. Productions of 1,2052,156 kg of P. gonionotus per ha were obtained in 3-6 months using rice bran as supplementary feed. While a production of 2,138-3,554 kg/ha/6 months was obtained in on-station experiments with cultures of O. niloticus, using various supplementary feeds and fertilizers, studies rearing O. niloticus were undertaken in farmers' seasonal ponds, resulting in production of 1,441-2,343 kg/ha in 4-6 months, using rice bran as supplementary feed and fertilizers. Results of a survey conducted to study the socioeconomic impact and farmers' assessment of culturing nile tilapia in seasonal ponds revealed that 70 % of the fish produced were consumed on-farm, and only 23 % of the fish sold was enough to meet operational costs. The overall return on investment was 334%.

Integration of poultry rearing (500 chicken/ha) with carp culture in perennial ponds proved to be economically feasible and resulted in the production of 5,044 kg of fish and 6,676 kg of chicken (live weight) per ha in one year.

Introduction

Fish is the main and cheapest animal protein source for the 110 million people of Bangladesh. Besides nutritional value, fisheries play an important role in the economy of Bangladesh in terms of employment, income generation, and foreign exchange earnings. It is estimated that about 8% of the population depend on fisheries for their livelihood (Planning Commission 1978). The number of households engaged in subsistence fishing is about 10.8 million (DOF 1990).

Despite its importance in nutrition, per capita consumption of fish is low -- about 7.9 kg/yr at present (World Bank 1990). In recent years, there has been a decline in per capita availability of fish, resulting in protein-energy malnutrition because of the increasing human population and decreasing yields from wild capture fisheries due to overexploitation of stocks and environmental degradation. Rural people, who depend on fish catches from the wild, have been most affected. Moreover, average fish consumption figures do not reflect the situation in rural areas: per capita consumption among the rural poor is about 4.4 kg/yr, and for the urban elite is about 22.1 kg/yr (World Bank 1990).

Against this backdrop of declining fish availability, the country has vast water resources: for example, ponds, oxbow lakes, floodplains, rivers, and reservoirs. There are more than 1.3 million ponds covering 146,000 hectares. In addition to these official figures, there exist vast numbers of small ponds and ditches (< 600 m² in area). A majority of rural households have backyard ponds or ditches that have high potential for aquaculture.

Realizing the need for increased fish production and the limitations from marine and inland capture fisheries, the government of Bangladesh is stressing increased production through freshwater aquaculture. The government has set a target production of 308,000 tons by 1994-1995 (an annual growth rate of 10.9%), as compared to a production of 153,000 tons from pond aquaculture during 1988-1989.

The International Center for Living Aquatic Resources Management (ICLARM), with funding from the United States Agency for International Development (USAID), is assisting the Bangladesh Agricultural Research Council (BARC) and the Fisheries Research Institute (FRI) in developing low-input aquaculture technologies. Resource-poor small-scale farmers constitute the bulk of the population in Bangladesh, and hence the major emphasis in project activities is on farmer-participatory on-farm research for developing aquaculture practices that would optimize resource use and maximize production. The project actively involves non-governmental organizations (NGOs) in the on-farm research activities and undertakes impact studies. Some of the activities undertaken and the results obtained are presented here.

Short-Cycle Species Culture in Seasonal Ponds

Many seasonal ponds, ditches, burrow pits, and roadside canals exist in the country. Most of these are lying fallow, covered with obnoxious aquatic weeds, and represent health hazards. At present, the yield from these waters is only 100-200 kg/ha of fish. Two of the reasons for their underutilization are: (1) farmers believe that seasonal waters are not suitable for aquaculture; and (2) the traditional culture species, viz., Indian carp (Catla catla, Labeo rohita, and Cirrhinus mrigala) do not grow well in these seasonal waters. Nile tilapia (Oreochromis niloticus), a hardy fish that can survive under poor water conditions, is resistant to disease, is a good converter of organic wastes into high quality protein (Stickney et. al. 1979, Balarin and Haller 1982, Pullin and Lowe-McConnell 1982), and is suitable for culture in derelict ponds of Bangladesh. Puntius sp. is in much demand in Bangladesh, but the locally available P. sarana is not a good species for culture because of its poor growth. Puntius gonionotus, with faster growth, would be suitable for culture in seasonal waters. Hence, the need for introducing short-cycle species into the culture system was identified. Oreochromis niloticus and P. gonionotus were introduced into Bangladesh in 1974 and 1977, respectively, but have not been established as cultured species until recently, since there were no developed management practices. Research undertaken in the last two years has revealed that these species could give high production with low-value inputs (mostly agricultural residues and by-products) and are suitable for culture in seasonal waters.

Culture of P. gonionotus in Seasonal Ponds

On-station studies were undertaken for culture of P. gonionotus in six ponds of 360 m² each. Pond preparation included draining, application of lime at the rate of 200 kg/ha, filling with water, and releasing fingerlings of average size 8-10 g, at a density of 16,000/ha. The ponds were divided into two groups, each with three ponds. The first three ponds were fertilized with cattle dung at the rate of 1,500 kg/ha, and triple super phosphate (TSP), with 46% N and urea with 42% P (2:1 ratio) at the rate of 50 kg/ha/fortnight. Organic manure was alternated with the inorganic fertilizers. No supplementary feed was given. The second group of ponds did not receive fertilization, but the fish were fed daily with rice bran at the rate of 5% of the standing fish biomass. The fish were harvested from the ponds after five months of culture. While an average production of 1,953 kg/ha was obtained from ponds where supplementary feed without fertilizers was given, ponds that received fertilizers, but no supplementary feed, only produced an average of 689 kg/ha.

During these on-station studies, discussions were held with farmers and local NGOs who showed keen interest in participating in research. They felt that their near-zero return from underutilized water resources could be improved with on-farm resources. Eight farmers having homestead ponds of 160-600 m² in size, and with an average depth of 0.9 m, were selected as cooperators for the culture of P. gonionotus.

Pond preparation included liming at the rate of 200 kg/ha, three days after which cattle dung was applied at the rate of 1,500 kg/ha. Five days after application of cattle dung, the ponds were stocked with P. gonionotus fingerlings of 7.5 - 10 g size, at a density of 15,000/ha. The farmers were asked to feed the fish daily with rice bran at the rate of 5% of standing crop and fertilize the ponds at fortnightly intervals with cattle dung at the rate of 1,500 kg/ha. However, it was observed during the culture period that fertilization of ponds was irregular, and on certain days they could not feed the fish due to lack of rice bran in the household. The fish were sampled at monthly intervals and the ponds were harvested after 4-6 months of rearing, depending on the water availability in the ponds. The production for 4-6 months rearing ranged from 1.2 to 2.1 t/ha (Table 1). The cost of production worked out to Tk.13/kg (US $ 1 = Tk. 36) of fish against a market price of Tk. 50/kg. These studies have shown that production can be increased by as much as 10 times with very low investment, and that the system can be managed easily by poor farmers.

 

 

TABLE 1 Culture and Production Details of Puntius gonionotus in Farmers' Seasonal Ponds

Pond no.

Pond Size (m²)

Stocking Density

Size at Stocking (g)

Size atHarvesting (g)

Culture Period (month)

Gross Production(kg/ha)

1

160

15,000

8.0

99.2

4

1,437

2

600

15,000

10.0

88.5

6

1,666

3

400

15,000

9.0

84.0

6

1,205

4

280

15,000

9.5

118.0

6

2,156

5

360

15,000

8.0

120.8

6

1,644

6

160

15,000

10.0

97.4

3

1,375

7

320

15,000

7.5

94.7

6

1,266

8

600

15,000

8.0

106.0

6

1,558

 

Culture of O. niloticus in Seasonal Ponds

Studies were undertaken at the FRI, Mymensingh, in ponds of 280 m² each, to evaluate the production potential of O. niloticus under different feeding and fertilization regimes. Ponds were stocked with fingerlings of 10-11 g size, at a density of 20,000/ha. Production of 2,739 kg/ha/6 months was obtained with rice bran as supplementary feed but without pond fertilization, while production was 2,128 kg/ha/6 months when ponds were fertilized with 1,500 kg/ha/fortnight of cattle dung, alternating with 50 kg of TSP and urea (2:1 ratio)/ha/fortnight. However, all fish were undersized (average size 52 g + 19) when raised only with fertilization (Table 2). When 40% of the rice bran in supplementary feed was substituted by mustard oil cake, the production increased to 3,554 kg/ha/6 months, with 11.2% undersized fish (Table 2).

TABLE 2 Details of Oreochromis niloticus Production under Different Management Systems

Stocking Density

Size at Stocking

Feed

Fertilization

Production(kg/ha/6 months)

Total

(fingerlings/ha)

(g)

   

Undersize

Market

 
       

Fish

Size Fish

 
       

(<80 g)

(>80 g)

 

20,000

10.0

Rice bran TSP and urea

-

700

2,038

2,738

20,000

10.5

-

Cattle dung,

2,138

-

2,138

20,000

11.0

Rice bran 60%

-

400

3,154

3,554

     

+ mustard oil

-

   
     

cake 40%

     

 

These on-station studies indicate the potential for culturing O. niloticus in seasonal ponds, but studies under farmers' conditions were also felt necessary. For this purpose, six derelict seasonal ponds were selected that were adjacent to homesteads. These ponds had not been used for fish culture previous to this study. The size of the ponds ranged from 80 to 320 m², with a maximum water depth of 1 m. The ponds were cleared of weeds before the onset of rains and lime was applied at the rate of 200 kg/ha. After filling with rainwater, the ponds were stocked with fingerlings of 5-10 g size at a density of 20,000/ha. The farmers were advised to feed the fish daily with rice bran at the rate of 5% of the standing crop. Three farmers were asked to fertilize the ponds with cattle dung at the rate of 1,500 kg/ha at fortnightly intervals and the other three farmers were asked to fertilize the ponds with TSP and urea (2:1 ratio) at the rate of 50 kg/ha/fortnight. However, the farmers could not adhere to these feeding and fertilization regimes due to lack of resources and inputs during certain days. The culture period ranged from 4 to 6 months, depending on the availability of water in the ponds.

The ponds were harvested when the water level went below 30 cm. Gross production ranged from 1,500 to 2,343 kg/ha in 4-6 months from ponds that received inorganic fertilizers, while production ranged from 1,441 to 1,925 kg/ha in 4-6 months from the ponds that received organic manure (Table 3). It is difficult to assess the effect of organic and inorganic fertilizers on production, as the farmers did not adhere strictly to the suggested fertilization schedules. However, the study indicated an average net benefit ranging from Tk. 38,250 to 72,750/ha (US $1,062 - 2,020/ha) in 4

months.

TABLE 3 Culture and Production Details of Oreochromis niloticus in Farmers' Seasonal Ponds

Pond Size

Fertilization

Stocking Density

Size at Stocking

Size at Harvesting

Culture Period

Gross Production

(m²)

   

(g)

(g)

(month)

(kg/ha!)

80

TSP + urea

20,000

5.0

82.2

6

2,000

120

TSP + urea

20,000

10.0

89.0

6

2,343

80

TSP + urea

20,000

7.0

95.7

4

1,500

120

Cattle dung

20,000

8.5

97.2

4

1,441

120

Cattle dung

20,000

8.0

98.1

6

1,925

120

Cattle dung

20,000

10.0

126.0

4.5

1,594

 

These results created wide interest among farmers and extension agents. An NGO, Bangladesh Rural Advancement Committee (BRAC), with technical assistance from the project, extended the technology to 309 farmers (32% women) in one district. Subsequent to implementation of the program, the project undertook a survey of 113 farmers to assess the production and economics of the operation. The study revealed Table 4) that the inputs (feeds and fertilizers) applied by the farmers were much lower than had been suggested and even then, they obtained a gross average production of 1,391 kg/ha/6.5 months. While cost of production amounted to Tk. 9,223/ha (US $256), average net return was Tk. 30,860/ha (US $875.23/ha), showing the economic viability and high returns from resources that formerly gave near-zero returns.

Integrated Livestock-Fish Farming in Perennial Ponds

In rural Bangladesh, a majority of the households raise chicken or ducks for either meat or eggs. In recent years the government of Bangladesh has taken up programs to introduce high yielding varieties of poultry to replace low productive native varieties. Studies were undertaken at the FRI to study the economic viability of integrating poultry raising with fish farming under Bangladesh conditions.

Experiments were conducted in ponds of 1,000 m² in area. Broiler chickens were raised over ponds at a density of 500 chickens/ha. Three species combinations of carps, catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala), silver carp (Hypophthalmichthys molitrix), and grass carp (Ctenopharyagodon idella), were stocked in the ponds, at a density of 6,000/ha, each treatment with three replications (Table 5). The ponds were neither fertilized nor given supplementary feed, except for the chicken manure and some spilled chicken feed falling into the ponds. The chickens reached a marketable size of 1.4-1.8 kg each (live weight) in 7-8 weeks. It was possible to raise seven batches of chicken and one crop of fish in one year. Fish production ranged from 4,265 - 4,893 kg/ha/year. While gross biomass production was higher with 40% silver carp in treatment 1 (Table 5), gross economic returns were higher with 30% catla and 10% silver carp in treatment 2, due to the higher market price for catla in Bangladesh.

TABLE 4 Details of Cost of Production and Benefit of Oreochromis niloticus Culture in Seasonal Ponds by 113 Farmers

 

Average per Pond (169.38 m²)

Per Hectare

Average Water Depth (m)

1.09

1.09

Inputs:

   

Fingerlings (number)

298

17,593.00

Lime (kg)

2.06

121.62

Urea (kg)

0.30

17.71

TSP (kg)

0.68

40.15

Cattle dung (kg)

48.49

2,862.80

Rice bran (kg)

67.06

3,959.15

Costs:

   

Fingerlings (Tk.)

52.94

3,125.52

Lime (Tk.)

11.91

703.15

Urea (Tk.)

1.51

89.15

TSP (Tk.)

3.40

200.73

Cattle dung (Tk.)

12.75

752.75

Rice bran (Tk.)

73.72

4,352.34

Total: (Tk.)

156.23

9,223.64

Production:

   

Fish (kg)

23.57

1,391.55

Gross return (Tk.)

678.74

40,072.03

Net return (Tk.)

522.51

30,848.39

1 US$ = Tk. 36.00

 

These on-station studies have proved the economic viability of integrated chicken-fish farming, but have also raised some issues regarding its adoption by farmers. Will raising poultry over ponds be socially acceptable? Will the farmers be able to manage the high-yielding varieties of chicken? Will there be marketing problems for the chickens? Will the system prove economically viable under farm conditions? Will the financial resources of farmers restrict the purchase of chicken feeds?

To find answers to these questions, studies were initiated with three farmers to whom BRAC provided credit. Details of costs and returns of one of the farmers are presented in Table 6. As can be seen, a farmer could get a net benefit (excluding interest on working capital), of Tk. 12,519 (US $348) from a pond of 680 m². This study indicates that raising chickens over ponds is socially acceptable; farmers would be able to manage high-yielding varieties of chicken; the practice has proved economical; and extension agencies are willing to provide credit to farmers.

TABLE 5 Fish Production under Different Species Combinations in Integrated Poultry-Fish Farming

Species Combination

Stocking Density

Culture

Production

(fingerlings)

Period

(kg/ha)

(month)

Silver carp 40 %, rohu 20 %, mrigal 30%, and grass carp 10%

6,000

12

4,893

Silver carp 10 %, catla 30 %, rohu 20%, mrigal 30%, and grass carp 10%

6,000

12

4,492

Silver carp 30 %, catla 10 %, rohu 25 %, mrigal 25 %, and grass carp 10%

6,000

12

4,265

 

Involvement of Extension Agencies in Farmer-Participated Research

One of the constraints for aquaculture development in the past has been the poor links among farmers, extensionists, and researchers. The technology packages developed through on-station research are technically feasible and economically viable, but often fail to make an impact on the farmers because on-station research has failed to consider the resources of the smallholder farmers for whom these technologies are being developed. Therefore, extensionists also showed little interest in on-station research results. Hence, the project has been trying to involve farmers and extensionists (mostly NGOs, who play an active role in Bangladesh) in the process of problem identification and implementation of programs. This has many advantages: (1) it creates confidence among extensionists since they have witnessed successful adoption by farmers; (2) it reduces the time gap between technology development and dissemination; and (3) having been convinced of the economic viability of the operation, extension agencies are more willing to extend credit and other inputs to farmers. One example of such successful collaboration could be cited here. BRAC has been involved in farmer participatory research for culture of P. gonionotus and O. niloticus. Having been convinced of the viability of the culture operations, BRAC now extends the technology to a large number of smallholder farmers. During 1991, more than 2,000 rural women were involved in the culture of P. gonionotus alone. The project, in collaboration with extension agencies, also organizes Farmer's Days, when the operations and results of the research are demonstrated to farmers in the area.

Impact Studies

After the development of a culture system and its transfer to farmers by the extension agencies, the project undertakes studies to assess socioeconomic impact and farmers' assessment of the technology. These surveys are revealing: (1) the benefits the farmers are getting through the implementation of the technology; (2) the constraints, if any, in practicing the culture system; (3) refinements and improvements needed in the technology; and (4) the policy issues involved.

TABLE 6 Costs and Returns of One Year's Production in Integrated Broiler-Fish Farming, from a

Pond of 0.068 Hectares.

 

Costs

A. Fish Culture

   

Inputs

Quantity

Costs(Tk.)

Pond lease value

-

3,000.00

Fingerlings

408 no.

408.00

Lime

15 kg

60.00

Labor costs for harvesting

-

200.00

 

Total

3,668.00

B. Chicken

   

Chicken shed (total cost

-

600.00

Tk. 1,200; longevity 2 yrs)

   

Chicks (8 batches)

325 no.

4,875.00

Feed

1,224 kg

9,430.00

Vaccines

-

100.00

Fuel

-

260.00

Labor

-

450.00

   

-

 

Total

15,715.00*

TOTAL COSTS

 

19,383.00

 

Returns

A. Fish

343 kg

 

11,012.00

   

B. Chicken

454 kg

20,890.00

 

 
   

31,902.00

NET PROFIT

 

12,519.00**

 

*Total costs for 8 batches of broiler. cost per batch is only 1/8 of total.

**Excluding interest on working capital.


FIGURE 1. Encouragement factors for tilapia culture as reported by farmers surveyed

A survey of 113 farmers of the total 309 farmers who have taken to O. niloticus culture in their homestead ponds and ditches has revealed that: (1) a pond of 170 m² (average size of tilapia ponds) can produce on an average 23.5 kg of fish, which is almost equivalent to the national annual consumption of low-income rural households with six family members; (2) 70% of the fish produced is consumed on-farm, thus improving the nutrition of farming families; (3) revenue from 23 % of fish sold was enough to meet the operational costs; and (4) return on investment was 334% indicating economic viability of the operation. Ninety percent of the farmers surveyed indicated that they were happy with the technology and wanted to continue, while 10% favored discontinuing. The farmers pointed out several economic, technical, and social benefits as encouragement factors Figure 1). One common observation made by all of the farmers was the small average size of O. niloticus at harvest. They would like to know ways to control breeding in O. niloticus and have larger fish. As a consequence, studies are in progress to control fry production through introduction of a carnivore, Gariepinus lazera, into the production system.

Acknowledgments

The author thanks the Office of Research, USAID, for funding the network meeting and publication of this paper.

References Cited

Balarin, J.D. and R.D. Haller. 1982. The intensive culture of tilapia in tanks, raceways and cages. pp. 265-355. in Muir, J.F. and J.J. Roberts. (ed.). Recent advances in aquaculture. Westview Press.

Department of Fisheries (DOF). 1990. "Fish Catch Statistics of Bangladesh," 1987-88.

Planning Commission. 1978. The Two-Year Plan: 1978-80. Planning Commission, Government of the People's Republic of Bangladesh, Dhaka.

Pullin, R.S.V. and R.H. Lowe-McConnell. 1982. The biology and culture of tilapias. Proceedings of the International Conference on the Biology and Culture of Tilapias. Bellagio, Italy. International Center for Living Aquatic Resources Management, Manila, Philippines.

Stickney, R.R., J.H. Hesby, R.B. McGeachin, and W.A. Isbell. 1979. Growth of Tilapia nilotica in ponds with differing histories of organic fertilization. Aquaculture 17: 189-194.

World Bank. 1990. Bangladesh Fisheries Sector Review. Report no. 8830-BD.

 

Hungarian Integrated Aquaculture Practices

Z. Jeney

Fish Culture Research Institute

Szarvas, Hungary

Abstract

Increased production costs, environmental impact problems, and utilization of poor quality soils were the main reasons for the development of integrated aquaculture in Hungary. Fish-cum-duck culture, aquacultural rotation, and the use of different sources of manure in aquaculture systems are the typical forms applied.

In monoculture, 300-500 ducks/ha can increase common carp production by 140-175 kg/ha. In polyculture utilizing silver and bighead carps, a fish yield of 2 t/ha can be achieved without supplemental feeding, and 1,000-1,200 kg of ducks (2.0 to 2.4 kg each) can be produced simultaneously.

A three-phase aquacultural rotation has been developed for areas with poor quality sodic soils. The first phase, lasting 2-3 years, is the double meat production. It is a kind of fish-cum-duck culture with a polyculture of fishes, and results in an approximately 300% increase in total meat production (duck and fish). The second phase is the "forage-crop production on pond-bottoms," lasting 4-5 years. A mixture of alfalfa and red clover proved to be the most economical when raised on the dried bottoms of the same ponds. In the third phase, rice is produced on pond bottoms, resulting in 50-100% higher yields than the average for the country. After three years of rice culture the rotation system starts again.

The use of manure in fish ponds has the "lowest level" of integration with fish culture. Solid and liquid pig manure, fermented chicken manure, as well as domestic sewage water have been tested and are partly applied in Hungary.

Introduction

Asia has been the cradle of different forms of integrated crop-livestock-ftsh farming systems (I:)elmendo 1980, Dela Cruz 1980, Sinha 1986). Although there have been attempts to utilize these systems around the world (North America -- Buck et al. 1979, Latin America -- Pretto 1985, Western Europe -- Muir 1986), probably only the Israeli (Schroeder 1980, Hepher and Pruginin 1981, Sinha 1986) and the Eastern European practices (Muller 1978; Woynarovich 1979, 1980a,b; Kintzly and Olah 1981; Kintzly et al. 1983; Olah 1986; Varadi 1990) are comparable to the Asian version.

The aim of this review is to characterize Hungarian integrated aquaculture practices and briefly to compare them With the Asian practices.

Integrated Aquaculture Systems

In general, integrated aquaculture systems have several advantages and disadvantages, as listed in Table 1.

TABLE 1 Integrated Aquaculture: Advantages and Disadvantages (Muir 1986)

Advantages

Disadvantages

Shared use of resources

Mismatch of production cycles

Elimination or reduction of waste problems

Possible overloading or undersupply

Reduced cost of production

More complex, less definable systems

Improved operation of components

Divided management goals

Wider opportunities

Limitations in potential sites

Low-cost heating and growth

Public health problems

 

Use of chemicals

The different systems show great variety in size and complexity. Several attempts have been made to classify the integrated aquaculture systems. Muir (1986) grouped them into three main types, depending on where the aquaculture is integrated (Table 2).

TABLE 2 Integrated Aquaculture Systems (Muir 1986)

Agricultural

Industrial

Sanitation

Vegetable

Space

Sewage

Rice, cassava, wheat, crop leaves, palm, rubber, ipil-ipil

Use of land, shelter, security

Nutrients, floc, organic matter

Animal

Water

Waterways

Pigs, ducks, chickens, sheep, goats, cows, buffalo, rabbits, geese

Reservoirs, process water irrigation channels

Aquatic vegetation

 

Heat

 
 

Power stations, furnaces and ovens, breweries, distilleries

 
 

By-products

 
 

Breweries, distilleries, agricultural processors

 

 

Further divisions have been made according to the level of integration (Barash et al. 1982), the basic components of integration (Dela Cruz 1980), and whether integration is direct or indirect (i.e., if the components are some distance apart, or if intermediate processing is required to integrate them), or whether the integration is parallel or sequential (i.e., if components run at the same time or if, e.g., fish crops run alternately with agricultural crops). Sinha (1986) grouped these according to the site of integration (Table 3).

TABLE 3 Main Types of the Integrated Aquaculture (Sinha 1986)

A.

Integration in the water body:

B.

Integration on the water:

 

1. Paddy-cum-carp culture

 

1. Pig-cum-fish

 

2. Integration with irrigation

 

2. Duck-cum-fish

C.

Integration near the water

D.

Fish and sewage

 

Varadi (1990) differentiated integrated aquaculture based on the size and complexity of integrated animal husbandry:

1. The small-scale, Asian type of integrated fish farming means the aquaculture activity is directly linked to one or more activities (Figure 1). The possible advantages of integrated aquaculture as cited above (Muir 1986), can really be recognized in these systems. Small-scale integration, however, does not necessarily mean complex integration. In many of the small farms, livestock are raised separately from the fish ponds and the manure is transported to the ponds.


FIGURE 1. Scheme of a typical Asian-type fish-cum-pig production unit (Varadi 1990)

2. In large-scale integrated fish farming, integration usually means only the use of manure (liquid manure) in aquaculture systems. The simple integration scheme of a fish and an animal production farm is shown in Figure 2.


FIGURE 2. The scheme of the simple integration of a fish and livestock production farm (Varadi 1990)

Aquaculture In Hungary

Aquaculture in natural waters is one of the oldest activities in Hungary. Pond fish farming became more common with the regulation of rivers in the nineteenth century. About 140,000 ha of water currently are under fishery production; 23,000 ha of that are pond surfaces. Aquaculture in

Hungary is based exclusively on freshwater, and is somewhat unusual in that freshwater fish production per capita is one of the largest in Europe (34,000 tons in 1990), while fish consumption in Hungary is only 4.2 % of the total meat consumption, and is one of the lowest in Europe (3.2 kg/per capita in 1989).

Fish farms in Hungary are using semi-intensive methods on poor soils (not suitable for other agricultural activities). The typical culture system is the carp (Cyprinus carpio L.)-dominated polyculture, with "herbivorous" fishes, such as silver carp (Hypophthalmichthys molitrix Val.), bighead (Aristichthys nobilis Rich.), and grass carp (Ctenopharyagodon idella Val.). In such systems the average total yield is 1 ton/ha.

The more valuable fishes cultured in Hungary are the European catfish or sheatfish (Silurus glands L.), the pike-perch (Stizosteidon lucioperca L.), pike (Esox lucius L.), rainbow trout (Oncorhynchus mykiss Walb.), and the eel (Anquilla anguilla L.). For pike, pike-perch, and sheatfish, special Hungarian methods of propagation and culture have been developed. The Siberian sturgeon (Acipenser baeri Brandt) and hybrids of crosses of the Siberian sturgeon with the sterlet (Acipenser ruthenus L.) are the newest and most promising fish for intensive systems. Development of culture technologies for endemic crayfishes (Astacus astacus L. and Astacus leptodactylus L.) also is a new direction in aquaculture. Meanwhile, the largest challenge met by Hungarian aquaculture is privatization. The domination of state ownership is changing. In 1989, 70% of pond surface belonged to state farms, 28% belonged to agricultural and fishery cooperatives, and less than 1% was private. Among the "users of natural waters" the ratio of the private sector is even lower. However, in spite of a general recession in Hungarian aquaculture in the last 2-3 years, in 1990, the private sector increased its production five times.

Integrated Aquaculture In Hungary

Increased production costs (primarily water and energy), environmental impact problems, and utilization of poor quality soils were the main reasons for the development of integrated aquaculture in Hungary. Fish-cum-duck culture, aquacultural rotation, and the use of manure from different sources in aquaculture systems are the typical programs.

Thus, Hungarian fish culture was integrated mainly with agricultural activities, namely vegetable culture (fish-duck-rice-alfalfa-red clover), and animal husbandry (fish-cum-duck) to include the use of manure (pig, chicken, sheep). In addition, experiments with industrial integration were initiated to utilize the heated effluents of power stations for fish culture, as well as the utilization of by-products of slaughterhouses and pharmaceutical factories for feeding fish. As an example of the integration of aquaculture with sanitation, the utilization of domestic sewage waters in fish culture was also attempted.

Fish-Cum-Duck Culture

Raising ducks on fish ponds in Europe was developed as a large-scale integration system after the Second World War when there was a serious protein shortage, and the lack of mineral fertilizers became a bottleneck to further development of pond fish culture (Woynarovich 1980b). Hungary initiated such large-scale experiments as early as 1952. The main advantages of fish-cum-duck culture compared to integration with other animals (Barash et al. 1982) include the following:

- Duck culture can be introduced easily without any substantial changes to the environment

and the facilities.

- The nutritional value of the manure is preserved because losses of N and energy due to

fermentation, evaporation, and non-reversible coagulation are eliminated.

- Feed residues are eaten directly by fish.

- Costs of collecting, storing, and transporting the manure are eliminated.

- Land area, otherwise needed for manure-producing livestock is saved.

- A solution is provided to problems of environmental pollution by animal wastes.

- The environment for manure-producing livestock is improved.

- Ducks eat natural feeds that develop in the pond.


FIGURE 3. Scheme of some typical fish-cum-duck rearing systems (Varadi 1990)

Three major duck rearing methods can be differentiated:

• Embankment rearing;

• Platform rearing; and

• Enclosure rearing, or their combination. The schemes of these systems are shown in Figure 3 (after Varadi 1990).

In Hungary, 300-500 ducks can be raised on 1 ha of water during one summer. The vegetation season (when the water temperature is higher than 15° C) is about 150 days. According to the estimation of Woynarovich (1980b) 100 kg of duck manure distributed continuously in pond water increased common carp production in monoculture by 4-S kg/ha. That means 500 ducks can increase common carp production by 140-175 kg/ha. If polyculture of fishes is applied, 1,000-1,200 kg of ducks are produced, in addition to the yields of marketable fish (common carp -- 1,000-1,200 kg/ha; silver carp -- 500-600 kg/ha; bighead -- 150-200 kg/ha). With a decrease in ratio of common carp and an increase in ratio of herbivorous fishes (silver carp and bighead) fish yields of 2 t/ha can be achieved without supplemental feeding (Woynarovich 1980b).

Trials to introduce fish-cum-goose aquaculture into Hungary were limited.

Aquacultural Rotation

Aquacultural rotation was developed for unproductive sodic soils in Hungary by Muller (1978). Aquacultural rotation is a kind of sequential integration and may be adapted for any flat area where the soil is suitable for fish and rice culture. The optimal size of ponds is 30-50 hectares. Inner sides of the dams are to be constructed with a moderate slope (1 :5, 1 :4), thus assuring their protection. The filling and drainage system of each pond must be independent, using irrigation water and a drainage system by gravity. The pond bottom should be large enough for rice fields of 2-3 hectares. Within the rice fields the bottom-level differences should not exceed + 5 cm.

Three Phases of Aquaculture Rotation

1. Double meat production. This is similar to fish-cum-duck culture. On a fish pond of 30-50 ha, 10,000-12,000 ducks may be raised at the same time, and this can be repeated 3-4 times a year. Average weight of marketable ducks 48-50 days old is between 2,600 and 3,000 g. Natural fish yields doubled where duck rearing had been practiced for 2-3 years Table 4, after Muller 1978). Total meat production (duck and fish) of a pond with fish-cum-duck culture was 3.2 times higher than a traditional pond using a polyculture of carp and silver carp.

2. Forage-crop production on pond-bottoms. Organic matter and mud deposited during the first phase of the aquacultural rotation for 4-5 years offers an opportunity for agricultural crop production on the dry pond bottom. Muller (1978) found that leguminous plants and a mixture of alfalfa and red clover gave yields up to 85.05 t/ha of green weight. With irrigation, polyploid red clovers provided the highest yields. The soil is enriched in nitrogen and calcium by the alfalfa.

TABLE 4 Increase in Weight (kg/ha) of Fish and Ducks Raised Together (After Muller 1978)

 

Year 1

Year

2Year 3

Year 4

Increase in weight of fish

950

1,090

1,540

1,410

Natural yields

299

488

580

571

Increase in weight of ducks

420

1,529

1,960

2,107

Total increase in weight

1,370

2,619

3,502

3,517

 

3. Rice production on pond bottoms. Pond bottoms are considerably improved during the first two phases of aquacultural rotation, significantly increasing organic matter and nitrogen level. This nutrient enrichment can be favorably utilized for rice production. The third phase lasts for three years. Highest yields of rice were obtained following production of alfalfa, with mixtures of red clover. Yields were 0.7-1.0 tons higher using this combination, than those following sunflower, sorghum, and maize production. Muller (1978) achieved 50-100% higher yields using this technique than the average yields of rice in Hungary, with a maximum at the level of 5 t/ha. After three years of rice production, the dams of the rice fields are levered and fish-cum-duck production starts again.

Use Of Manure In Fish Ponds

In this case integration strictly means the application to fish ponds of manure produced elsewhere. Animals like chickens, pigs, and cows are raised in special cultural units that are not integrated into the fish farm. Since Hungary is a large pig producer, the application of pig wastes in fish ponds could be the best example of this type of integration. The utilization of pig manure in fish ponds started in the 1950s, when only common carp were stocked. At that time, a disagreeable side effect of heavy manuring often occurred, in the form of algae blooms. Since the 1970s, Chinese carp have been stocked in polyculture with the common carp (Table 5), and this problem was eliminated.

In early studies, a critical question was how much pig waste could be utilized per unit of fish pond without running the risk of a fish kill from oxygen depletion. Experience has shown that usable quantities of pig wastes in fish ponds depend on the delivery and distribution methods: 1,500-2,000 kg/ha/yr can be used when pig manure is placed in the pond in localized heaps. When a carbon manuring method is applied, however, it is possible to distribute 300-600 kg/ha of manure, 1,000-1,500 kg/ha of the thick liquid phase of the manure, or 1.2-2.5 m²/ha of commercial pig waste, over the pond surface, on a daily basis. The maximum possible waste loading in fish pond was determined to be two to three times higher than the above quantities. The total manure loading per hectare of pond surface was calculated between 40 and 80 pigs/ha (Woynarovich 1980a).

Later studies (Kintzly and Olah 1981, Kintzly et al. 1983) addressed the optimal level of the used liquid pig manure as well as the optimal polyculture structure. Biculture of silver carp with common carp (2,500 p/ha + 1,000 p/ha) gave higher yields than both the monoculture and polyculture, with a maximum yield of 2.06 t/ha/year. In monoculture the fish did not reach the 1 kg body weight that is the marketable size in Hungary. Good results were obtained when tench (Tinca tinca L.) were introduced into the polyculture.

Advantages of the methods used in Hungary are:

- Pig waste can be placed into the fish ponds during the vegetation period, while on the fields the application is possible only during late autumn.

- Fish had low levels of fat.

- The discharged water from these fish ponds met the requirements of environmental protection standards.

- Investigations of fish meat quality gave positive results.

Disadvantages of the methods used in Hungary are:

- The bottom of the ponds accumulate organic materials.

- Transport costs of liquid manure became the limiting factor for the application of this method.

- When using the drainage system, only the gravitation method was economically reasonable under Hungarian conditions (Kintzly 1991, personal communication).

TABLE 5 Typical Hungarian Polyculture Technology

   

Stocking Density

Harvesting

Yield

   

(p/ha*)

weight/g

t/ha/year

Year 1

Common carp

60,000

20-30

1.5-1.8

 

Chinese carp

     

Year 2

Common carp

20,000

250-300 (20-30)

2.5-2.7

 

Chinese carp

4,000-8,000

same (20-30)

 

Year 3

Common carp

2,000

1,000

2.5

 

Chinese carp

600-800

same

 

* p/ha = piece/hectare

Some Basic Differences Between Asian And Hungarian Integrated Aquaculture

Reasons for integration. Economic as well as environmental aspects dominate in Hungary. In Asia, a dominant reason is the increased production of animal protein for the improvement of the economic condition of farmers.

Forms of integration. In Asia, integration has a higher level of complexity, and is scattered among small-scale agricultural activities.

Future of integration. There is less prospect for integration in the near future in Hungary than in

Asia, due to current economic changes. After the ongoing changes in ownership in Hungary,

environmental issues will probably impact strongly on integrated aquaculture.

Acknowledgments

The author thanks the Office of Research, USAID, for funding the network meeting and

publication of this paper.

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