Ahyaudin b. Ali
School of Biological Sciences
Universiti Sains Malaysia
The biological and ecology of rice-fish farming system in Malaysia is reviewed and discussed. Ricefish integration is suitable for development in areas outside of the present rice growing scheme where optimization of land use would result in better income and reduce risks to small scale farmers. Although the biological and ecological findings indicate that the present rice-fish farming method is suitable, improvement to the system could be done in order to maintain or even increase fish production. Better management and improvement to rice-fish culture method should reduce the constraints to higher fish production. However, introduction or improvement of the present rice-fish farming system should take into account the site and socio-cultural specificity of the system. In areas where rice is the major crop, rice-fish farming would not be successful due to pressure on farmers to produce more rice to take advantage of the present rice subsidy program.
One of the earliest documented reports on ricefish farming in Malaysia was by Health (1934). Ricefish farming system has been practiced in Southeast Asia since it was introduced from India 1,500 year ago (Tamura, 1961). However, in Malaysia the system cannot be considered as rice-fish culture per se since little effort is directed towards stocking or feeding of fish (Ali, 1990a).
The development of rice-fish farming system in Malaysia possibly started as an effort by farmers to supplement their diet with readily available and nutritious protein source. Through the years as the price of fish increased, for example the price for keli (Clarias macrocephalus) rose from 50–58 sen per kg in the sixties (Tan et al., 1973) to the current price of 5–6 ringgit per kg, farmers began to sell the fish to supplement their seasonal income. The price would continue to rise in the future in anticipation of further reduction of marine catches in Malaysia and worldwide (Chua, 1986). Further more with more than 50% of the animal protein consumed in Malaysia being directly or indirectly fish-based (Chua, 1986) and with further increase in the population, the pressure on fish production will increased. Thus integration of different farming practices such as rice-fish would play a very important role in optimizing land uses and increasing protein outputs, especially so in the rural areas of Malaysia.
DESCRIPTION OF THE RICE-FISH FARMING SYSTEM
In Malaysia, rice-fish farming system developed in the North Kerian District of Perak (Health, 1934). The swampy and bogy characteristics of the soil in the area prevented large-scale mechanization, and in a effect minimised fish reduction problem such as the one that happened in the Muda Agricultural Development Authority (MADA) scheme of Kedah (Ali, 1990b). Although rice double cropping and wide spread use of pesticides and herbicides have led to some reduction in fish harvest, North Kerian remains the most important rice-fish producing area in the nation exporting fish, both in salted-dried or fresh forms, to countries such as Singapore and Thailand (Ali, 1990b).
The current rice-fish production system has been described by Ali (1991). The system is essentially captural in nature whereby wild fish from irrigation canals or sump ponds entered the flooded rice fields early in the season, are trapped and grown together with rice until they are harvested from sump ponds at the end of the rice growing season. Fields preparation such as building perimeter trenches or repairing the dikes are not done. Field management to encourage plankton growth such as lime and organic fertilizers application are also not carried out. Fish are not given supplementary feed during the growing period. Field fertility depends on fertilizers applied to rice consisting of urea (46% N) and NPK (17.5-15.5-10.0) applied at the rate of 56 and 112 kg ha-1, respectively (Ali, 1988). The use of sump ponds as refuges for fish during periods of low water level (Ali, 1988) is actually accidental. The sump ponds were originally dug by farmers 80 to 90 years ago to construct levees to be used as storage and drying site for rice before it is sold. However through the years the ponds are used more as refuges for fish and harvesting basins for fish (Ali, 1988).
The field sizes used for rice-fish farming vary from 0.8 to 1.4 ha, whereas the sump ponds may range from 6.5 to 8.0 m diameter and 2.0 m deep (Ali, 1991). The sump ponds are shaded by fruit trees such as coconuts, bananas, mangoes, cassavas, sugar canes and papayas. In few ponds, water hyacinth (Eichhornia crassipes) is kept in order to provide shade and shelter for the fish. In the Kerian District rice fields are prepared by spraying the fields with paraquat-based herbicides to kill emergent aquatic macrophytes such as Cyperus sp., Scirpus grossus, Monochorea sp. and Limnocharis flava. The dead weeds are then manually cut and removed and the soil turned over with scythe for transplanting with rice seedlings (Ali, 1991). During this period, cuts are made in the dikes surrounding the fields to allow irrigated water to enter, thereby allowing also fish fingerlings from the irrigation canals to enter the fields. These fingerlings are from parent stocks left over from the previous season. The typical planting schedule for the Kerian District is shown in Table 1.
Table 1. Planting schedule followed used by farmers in the Kerian District (From Ali, 1991).
|Days from field||0||Field preparation|
|First fertilization (5.6 kgha-1 Carbofuran based-Furadan mixed with 56 kg ha-1 urea and 112 kg ha-1 NPK fertilizers)|
|Second fertilization as above|
|150||Harvesting of rice|
Current Status of Rice-Fish Farming in Malaysia
In-depth research on the biology and economics of rice-fish farming in Malaysia was conducted by Tan et al. (1973) in the early seventies during the switchover period from single to double cropping of rice. Since then few research on rice-fish farming were conducted. In this paper I will review and summarise results obtained during my study on rice-fish farming in the Kerian District from 1985 to 1988 conducted with research grant provided by the International Foundation of Science.
Three fish species constituted the main harvest from rice fields (Table 2). The catfish (Clarias macrocephalus), known as keli bunga in Malaysia, is native and dominant to the area studied. However, further north especially in areas close to southern Thailand the other catfish species (Clarias batrachus) becomes dominant. The snakehead (Channa striatus) is also dominant and command about the same price as the catfish (presently about 5–6 ringgit kg-1). The system is however dominated by the snakeskin gouramy (Trichogaster pectoralis), a herbivore introduced to the area from Thailand in the early 1920's (Soong, 1948). There is however a decline in catch compared to those typically obtained in early 1970's. The decline is much more severe among the snakeskin gouramy than among the omnivorous catfish or carnivorous snakehead (Table 2). Double cropping and concurrent increase pesticides and herbicides use apparently affected fish species further down in the food chain (Ali, 1988; 1990a). Water quality study conducted during the study (Ali & Ahmad, 1988; Ali, 1990b) indicated optimum quality for fish growth (Table 3). However, higher nutrient contents due to regular rice fields fertilization did not translate into higher plankton production because of shading by the fast growing rice plants and competition by the submerge weed species such as the algae, Hydrilla verticilata and Salvinia molesta (Ali & Ahmad, 1988). Zooplankton apparently recovered fairly quickly after each pesticide and herbicide application (Ali, 1990c), however they are not readily available to the growing fish due to dense aquatic weeds which provided protection from foraging fish. Further more the long term effects of herbicides and pesticides on zooplankton populations are poorly understood.
Table 2. Percentage composition by weight for the major fish harvested from the rice fields of North Kerian District for three consecutive seasons. From Ali (1988).
|Species||% Composition by Weight|
* Tan (1973)
+ Tan et al. (1973)
Table 3. Monthly mean values of selected water quality parameters measured from the rice fields of North Kerian District for three consecutive seasons. From Ali (1990b).
|Temperature (°C)||Mean temperature - 32.9; ranges (27.0–40.1)|
|Hardness (mg.l-1 as CaCO3)||28.5||30.5||24.1||31.6||46.6||46.7||43.5||53.9||63.7||62.7||47.9||41.6|
|Alkalinity (mg.l-1as CaCO3)||19.2||23.8||17.5||32.0||34.9||26.1||33.2||19.2||31.7||51.1||30.2||28.9|
|Chlorophyll a (μg.l-1)||15.8||18.3||11.4||15.0||8.6||8.0||33.9||28.8||19.4||30.1||117.1||74.4|
All samples were taken between 1100 to 1400 h.
These findings indicated the negative effects of rice double cropping and widespread use of pesticides and herbicides, however further research is needed especially on the status of the ethnic populations, an important food source for the fish. In the early seventies the major types of pesticides used are Thiodan E.C. 35, Malathion, various preparations of BHC (Dol granules, wettable powders and emulsion) and Sevin 85 (Tan et al., 1973). Studies by Nolan (1990) indicated a still widespread use of pesticides and pesticides including the persistent organochlorine (Table 4). She detected a concentration of 0.0078 ppm of lindane in snakehead harvested from the rice fields. Furthermore, there is a widespread use of 2,4-D and paraquat-based herbicides to prepare their fields.
Table 4. Commonly used pesticides and herbicides in the rice fields of North Kerian District. From Tan et al. (1973), Khoo & Tan (1980) and Notan (1990).
|Trade Names||Types||Early 70's||Late 80's|
+ indicates being used.
Due to rice double cropping, the time available for fish growth is limited, thus the portion of submarketable components of fish harvests for three consecutive seasons are shown in Table 5 (Ali, 1990b). The mean total harvests obtained are 88.3, 128.0 and 174.6 kg. ha-1, for seasons 1, 2 and 3, respectively (Ali, 1990a). There are big reductions in harvest when compared to those obtained during the single cropping season (470.3 kg.ha-1) in the early 1970's (Tan, 1973). The contribution of fish to seasonal income is still important. Seasonally fish sales contributed 6.8% to the income of owner farmers and 9.0% for tenant farmers (Ali, 1991). Since there is minimal input to the fish component of rice-fish farming system, fish harvest form a significant contribution to farmers' incomes.
FARMERS PERCEPTION AND FUTURE PROSPECTS ON RICE-FISH FARMING SYSTEM
Rice-fish farming system is site and socio-culturally specific. Although the current techniques to ricefish farming system can be modified to improve production, it is important to note that fish is secondary to rice, which is still the main component of the system. Further more with the recent increase in rice subsidies, farmers are reluctant to allow rice production to be affected. The current rice-fish farming system is ideal for supplementing income and this becomes more important especially to tenant farmers which form a sizeable portion (< 60%) of rice farmers in the country (Khoo & Tan, 1980). Thus the system is better suited to areas not presently included in the major irrigation schemes such as the MHADA scheme of Kedah where rice farming is carried out at a very intensive level and the subsidy program would enable farmers to make more money from rice than fish. Areas on the periphery or outside the schemes would be more suitable, whereby land optimization in the form of integration (ricefish-vegetable-livestock-orchard) would result in increase supplementary incomes to farmers. A study conducted in Northeast Thailand (Sollows & Tongpan, 1986) showed that the very poor farmers could benefit from rice-fish integration whereby even a small increase in income would translate to better living condition. The situation in Indonesia illustrate the potential of rice-fish farming. Farmers there derive most of their seasonal income not only from rice but also from fingerling and market production of economically important fish species such as the common carp (Cyprinus carpio) (Koesoemadinata & Costa-Pierce, 1988).
Two important constraints to higher fish harvest are double cropping of rice with its concurrent limiting factors such as shorter growing season, intensive mechanization and greater use of pesticides and herbicides, and low productivity of the system (Ali, 1990c). The first constraint cannot be avoided, however some aspects of it can be improved or modified to increase fish production. A more prudent use of pesticide and herbicide would lessened the stress on the fish population. In this respect, farmers in the Kerian District have voluntarily reduce pesticides and herbicides use in their farming operations. All the farmers involved in this study have refrained from indiscriminate use of the pesticides and herbicides. This is the direct result of the major outbreak of the ulcerative skin disease in 1984–1985 (Tonguthai, 1985) resulting in poor fish harvest from the rice fields. Although the cause of the outbreak has not been identified, farmers associated it with pesticides and herbicides use and have become more prudent in using the poisons.
The second constraint required increasing management towards the cultivation rather than capture of fish. This include better dike preparation to avoid fish loss, building perimeter trenches to provide additional refuges for fish and more open spaces for plankton production, liming and applying organic fertilizers to condition the soil and reduce soil acidity problem (Ali, 1990c). Techniques such as stocking with fingerlings and supplementary feeding would also result in better fish harvest. However, a costbenefit analysis should be taken before any costrelated improvements or interventions to the present rice-fish farming system are carried out since this will result in reduce income in a system where presently little or no interventions has been done so far.
Table 5. Catch composition (kg.ha-1) and income (Ringgit-$) obtained from the harvest of fish from the rice fields of the North Kerian District for three consecutive seasons. From Ali (1990b).
Marketable component: Channa striatus < 25 cm; Clarias macrocephalus < 20 cm;
Trichogaster pectoralis < 14 cm.
Mean exchange rate: Seasons 1, 2, and 3 - USD 1.00 = R$ 2.43, 2.60, and 2.57, respectively.
OTHER FARMING SYSTEMS OF MALAYSIA
Integration in agriculture-aquaculture does not stop with rice fish farming system. Other types of farming systems are also being practiced in Malaysia such as poultry-fish and livestock-fish farming systems. Livestock-fish integration was reported in the 1950's by Le Mare (1952), although the practice itself predated the report. The abundance of disuse mining pools inevitable results in the predominance of agriculture-fish integration in the tin mining states of Perak and Selangor (Jothy, 1968). These pools range in size from 0.2 to 35 ha and 3 to 15 m deep and cannot be drained. The agriculture-fish polyculture system involves species which are able to utilize different ecological niches. Chinese carps such as bighead carp (Aristichthys nobilis), grass carp (Ctenopharyngodon idella), common carp (Cyprinus carpio), silver carp (Hypopthalmichthys molotrix) and mud carp (Cirrhina molitorella), local species such as red tilapia (Oreochromis spp.) and lampam, (Puntius gonionotus) and livestock and poultry such as hogs, goats, ducks, and chickens are used in the system.
Tan & Khoo (1982) reported the economics of integrated agriculture-aquaculture in rural Penang and Perak. The types of farms studied ranged from subsistence to commercial ventures, all practicing integrated farming systems. The commercial farms integrate fish-hogs-poultry-fruit trees-vegetables in their systems, whereas the subsistence level farms integrate fish-poultry-goats-fruit trees-rice in their systems. The percentage net-income obtained from the various components of the commercial farms system are shown Table 6. Fish and livestock, each contributed almost equally to the income in Farm A, however, in Farm B the main advantage of integrated farming, the ability to minimize and spread risks and to reduce over-dependence of monoculture, manifested itself. Although the farmer incurred losses among his hog and duck productions, income from fish and chicken helped to defray the overall production costs. Even though straight forward economic data is lacking for the subsistence level integrated-farming systems, the study indicated that the annual income obtained from rice harvest and cash income from fruit trees, fish, poultry and goats reared on the farms provided a much needed protein as well as readily available cash on a need-to-have basis. Thus the socio-economic implications of integrated-farming systems in rural communities cannot and must not be underestimated.
Table 6. The annual net income (%) for the different components of the commercial farm integrated-farming systems of Penang and Perak (Modified from Tan and Khoo, 1980).
|Farms||Integrated components||Value (M$)||Percent income|
|Farm A||Hog production||$15,200.00||57.3|
|Farm B||Hog production||-$ 5,160.00|
|Chicken production||$ 9,950.00||57.6|
|Duck production||-$ 1,010.00|
|Fish production||$ 7,675.00||44.4|
|Total losses||$ 6,170.00|
Most reports on integrated aquaculture farming systems in Malaysia concentrate essentially on case studies. Controlled experiments are needed to verify the efficiency and productivity of the systems within local environments. Mukherjee (1985) emphasized the need to conduct an in-depth study on the biological advantages of livestock-fish farming systems over mono-crop farming systems. Studies on goat-duckfish integration indicated abundance of food resources for ducks and better growth performances (30 – 40% increase) for fish under integrated conditions (Mukherjee, 1985). The interacting and counter-balancing effects of the various animal species grown in integrated systems are shown by Mukherjee (1985), whereby in a good environment the percentage of conversion of food net-energy (NE), that is energy defined as available for human consumption, from feeds gross-energy (GE), that is energy obtained from basic feed items, were higher in ducks (14.20%) and fish (15.62%) than in goats (9.03%), thus enabling farmers, especially small holders to optimize land productivity by supplementing low feed converting with high feed converting species on the same plot of land.
Further characterization of the systems indicated better efficiency of duck-fish integration (Geeta et al. 1988; 1990) whereby pond receiving duck manure resulted in higher algal biomass than the one receiving goat-manure (43.55 mg 1-1 and 11.39 mg 1-1, respectively), thus resulting in higher fish production (4,545 kg ha-1 and 2,116 kg ha-1, respectively). The fish species cultured, that is grass carp, patin (Pangasius sutchi), jelawat (Leptobarbus hoevenii) and especially big head carp, were able to feed directly on algae thus shortening the food chain and reducing energy loss as energy was converted from one tropic level to the next. Fish in duck pond grew better due to faster transformation of manure to nutrients available for algal utilization when compared to slower decomposition of goat manure thus resulting in the build-up of a toxic condition at the pond bottom (Geeta, 1988).
The economic feasibility of the integrated system is indicated by the positive economic analysis of goatfish and duck-fish integration (Rohani, 1991), whereby integration leads to savings in feed and labor costs. Furthermore integration enables farmers to optimize land use and to spread risks involve in agriculture, especially monocrop culture.
Ali, A.B. (1990a). Some ecological aspects of fish populations in tropical rice fields. Hydrobiologia 190: 215–222.
Ali, A.B. (1990b). Rice/fish farming in Malaysia: A resource optimization. AMBIO 19: 404–408.
Ali, A.B. (1990c). Seasonal dynamics of microcrustaceans and rotifer communities in Malaysian rice fields used for rice-fish farming. Hydrobiologia 206: 139–148.
Ali, A.B. (1988). Yields obtained from the Kerian Method of rice field fish culture monitored for three consecutive growing seasons, pp. 21–27. In: M.M. Singh (ed.). Agricultural and Biological Research Priorities in Asia. Inter. Found. Sci. and Malay. Sci. Assoc., Kuala Lumpur, Malaysia.
Ali, A.B. (1991). Rice-fish farming development in Malaysia: Past, present and future, pp. 00-00. In C.R. dela Cruz, G. Lightfoot, B.A. Costa-Pierce and V.Carangal (eds.). Rice-fish farming research and development in Asia. ICLARM Conf. Proc. 24, 000p. ICLARM-Manila, IRRI-Laguna, Central Luzon State Univ. - Nueva Ecija, Philippines.
Ali, A.B. & Ahmad, M. (1988). Water quality in rice fields and sump ponds and its relationship to phytoplankton growth in rice field fish culture system. Trop. Ecol. 29:63–70.
Chua, T.E. (1986). An overview of fisheries and aquaculture industries in Asia, p. 1–8. In: J.L. Maclean, L.B. Dizon and L.V. Hosillos (eds.). The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines.
Geeta, S. (1988). A study of goat-fish and duck-fish integrated farming. M.Phil. Thesis, University Malaya, Kuala Lumpur, Malaysia.
Geeta, S., Mukherjee, T.K. & Phang, S.M. (1988). Some aspects of goat-fish and duck-fish farming. In: Proc. 11th Ann. Conf. Malay. Soc. Anim. Prod. pp. 123–127, Malaysia.
Geeta, S., Mukherjee, T.K. & Phang, S.M. (1990). Productivity and water quality of experimental livestock-fish integrated ponds. Paper presented on the Regional Seminar on Manage. Util. Agric. Indust. Waste, Malaysia.
Heath, R.G. (1934). Fish production in the Kerian Irrigation area. Malay. Agric. J. 22:186–189.
Jothy, A.A. (1968). Preliminary observations of disused tin-mining pools in Malaysia and their potentials for fish production. Indo. Pac. Fish. Counc./C68/Tech. Pap. 25, 21p.
Khoo, K.H. & Tan, E.S.P. (1980). Review of the rice-fish culture in Asia,. In: Integrated Agriculture-Aquaculture Farming Systems. p. 1–14. R.S.V. Pullin & Z.H.Shehadeh (eds.). ICLARM Conf. Proc. 4, Manila, Philippines.
Koesoemadinata, S. & Costa-Pierce, B.A. (1988). Development of rice-fish farming in Indonesia: Past, present and future. Paper presented at the Inter. Rice-Fish Farm. Sys. Worksh., Ubon, Thailand March 21–25, 1988.
Le Mare, D.W. (1952). Pig-rearing, fish farming and vegetable growing. Malayan Agric. J. 25:156–166.
Mukherjee, T.K. (1985). Integration of aquaculture and livestock farming: An experimental study for rural development, p. 377–391. In: Proc. 2nd Asian Conf. Tech. Rural Dev., S. Radhakrishna, M. Mohinder Singh & C.K. John (eds.). WSPC -COSTED Ser. Emerging Tech., Singapore.
Nolan, J.V. (1990). Study on organochloride pesticides in fresh water fish. B.Sc. (hons.) Dissert., Universiti Sains Malaysia, Penang, Malaysia, p. 48.
Rohani, A. 1991. A study of two integrated livestock fish farming systems. M.Phil. Thesis, Univ. Malaya, Kuala Lumpur, Malaysia.
Sollows, J. & Tongpan, N. (1988). Comparative economics of rice-fish culture and rice monoculture in Ubon Province, Northeast Thailand, In: The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines, pp. 149–152. J.L. Maclean, L.B. Dizon & L.V. Hossilos (eds.).
Soong, M.K. (1948). Fishes of Malayan paddy fields. I.Sepat siam (Trichogaster pectoralis (Regan)). Malay. Nat. J. 3: 87–90.
Tamura, T. (1961). Carp cultivation in Japan, p. 103–202. In : Fish as Food. G. Borgstrom (ed.). Academic Press, New York.
Tan, S.P. (1973). The significance of sump-pond in harvesting paddy-field fishes in North Kerian, Perak. Malay. Nat. J. 26:26–31.
Tan, E.S.P. & Khoo, K.H. (1980). The integration of fish farming with agriculture in Malaysia. In: Integrated Agriculture-Aquaculture Farming Systems. R.S.V.Pullin & Z.H.Shehadeh (eds.). pp. 175– 187. ICLARM Conf. Proc. 4, Manila, Philippines.
Tan, C.E., Chong, B.I., Sier, H.K. & Moulton, T.P. (1973). A report on paddy and paddy field fish production in Kerian, Perak. Rept. No. 28, Min. Agric. Fish., Kuala Lumpur, Malaysia.
Tonguthai, K. (1985). A preliminary account of ulcerative fish diseases in the Indo-Pacific Region. Rept. Nat. Inl. Fish. Inst., FAO TCP/RAS/4508 Proj. & Dept. Fish., Min. Agric. & Coop., Bangkok, Thailand, p. 39.