Low-input rice-fish farming system in irrigated areas in Malaysia

Rice-fish farming system is an old tradition, practiced extensively in the North Kerian Area of Perak, Peninsula Malaysia. The area is an alluvial coastal flood plain and receives irrigated water from the Tasik Merah reservoir. The soil is primarily clay with some acidity problems. Rice is double-cropped and short season high - yielding rice varieties are used.

LARGE-SCALE TRANSECT OF THE NORTH KERIAN IRRIGATED AREA OF PERAK, MALAYSIA

There are approximately 352,000 ha or rice fields in Peninsula Malaysia, out of which 120,000 ha (34%) have sufficient water depth (15-16 cm.) for rice-fish system.

SYSTEM DESCRIPTION

· The system, which is essentially wild fish ranching, requires little labor and material inputs. Fish from the irrigation canals, ditches and rice fields are trapped early in the rice-growing season, grown together with rice, and later harvested at the end of the season.

GENERALIZED TRANSECT OF THE NORTH KERIAN IRRIGATED AREA OF PERAK, MALAYSIA - OPTION 1 -

GENERALIZED TRANSECT OF THE NORTH KERIAN IRRIGATED AREA OF PERAK, MALAYSIA - OPTION 2 -

Rice field sizes vary from 0.81 to 1.42 ha. A sump pond, which can also be a disused well or borrow pit, ranging in size from 6.5 to 8.0 m diameter, is located at the lowest part of the field. Sump pond, which is cooler and has higher dissolved oxygen content, provides shelter for fish during periods of low water level. Perimeter trenches (0.25 m wide and 0.1 m deep) may be dug around the field to enable fish to move to and from the sump pond. These open trenches also act as feeding areas for fish to feed upon zooplankton especially during the fry and fingerling stages when zooplankton is important for early growth. Mud obtained from digging the trenches is used to strengthen the dikes (0.3 m high) around the field.

Farm layout option 1

Farm layout option 2

· No supplementary feeding is provided. Fish obtain food from natural sources in the rice fields. The system fertility depends on rice fertilization which is applied twice during the growing season. Urea (46% N) and NPK (17.5-15.5-10.0) fertilizers are used at the rate of 56 and 112 kg/ha, respectively. To further increase productivity and food availability, liming of the sump pond (if required) and manuring (if available) should be done.

Material Flow option 1

Material Flow option 2

SPECIES USED

Local species

Local species grow well in rice fields. They have adapted to the shallow water, high turbidity and temperature and low dissolved oxygen conditions of the fields.

· The snakeskin goramy (Trichogasterpectoralis) is numerically the most important. This species and the three-spot goramy (T. trichopterus) are herbivore/plankton and occupy the lower rung in the food chain.

· Climbing perch (Anabas testudineus) is an insectivore.

· The catfish (Clarias macrocephalus), an omnivore, and the mudtish or snakehead (Channa strata), a camivore, are also important species.
Newly considered speclea

· Tilapia (Oreochromis spp), a herbirore/plantivore/insectivore, is ecologically suitable and economically important.

· Other species to be considered is the freshwater prawn (Macrobrachium rosenbergi).

Calendar 0P activities

During fallow season, sump pond should be depend once every five years to about 1.5 - 2.0 m deep. Perimeter trenches (0.25 m wide 'D'; & 0.1 m deep) should be dug. Dike should be raised about 0 0:4 m, liming if needed should be done and manure available should be applied

Once water is available field repartition should be done by cutting raking and removing dead woods In about 7-10 days all exits should be blocked to prevent fish from escaping.

Transplanting of rice darlings weeding should be done especially in the trenches to provide feeding area (on plantation) for young fish

First fertilization add 5.6 kg/Ha furadan (carbofuran) mixed with urea (56 kg/Ha) and NPK (112 kg/Ha). Second fertilization after 60-60 days as above

Check the richfield as WELL AS the FISH. stop ALL leakage’s to prevent fish from escaping

When rice is about reads to be harvested drain the pond to harvest the fish. Take only marketable size fish (size depends on market demand) leave smaller fish as stoke for next seasons

Seasonal calendar

YIELDS

· Fish sales provide an important supplementary income especially to tenant farmers. Contribution from fish are 6.8 and 9.0 percent for owner and tenant farmers, respectively. Since little inputs are involved, the yields contribute significantly to farmers seasonal income.

· Fish are sold to dealers who provide pump, nets and other accessories needed to harvest fish. Small fish are left behind as stock for the next growing season. Marketable size fish are: snakeskin goramy 14 cm, catfish 20 cm and snakehead 25 cm.

Estimated range of potential yields obtainable from traditional & low input systems

* Option I traditional system

Option II improvements - building trenches, deepening sump ponds improving dikes, manuring and liming of sump ponds.

** include small-sized fish which are left behind for future stocks and climbing perch which is consumed or salted as "pekasam" and sold, potential

Estimated simplified budgets for the two systems.

*Notice how in the first season, Option I has no initial costs and thus a higher net income than System II.

** However, in the second season, the costs for Option II go down and farmer gets a higher return compared to Option I.

SYSTEMS CONSTRAINTS

· Short growing season due to double cropping of rice
· Improper and excessive pesticides and herbicides' use
· Uncontrolled flooding may result to fish loss.
· No proper management/lack of manpower
· Low productivity and low-carrying capacity since no regular supplementary feeding is provided
· Distance of sump pond from house
· Conflicting government program in the form of subsidy for rice.

SYSTEM ADVANTAGES

· Provides additional food and income

· No additional expenses, except when system is modified, such as building trenches, strengthening dikes, etc.

· No major changes in normal farm practices; modifications to improve yields are adapted to the traditional practices by farmers if affordable. The no-improvement system (option 1) is sustainable for limited labor/older couple situations.

· Optimizes disuse and underutilized existing resources

· Maintains gene pool for locally valuable species.