Techniques of fish culture in rice fields
a. Site selection
Following points should be taken care of for selecting the suitable site for rice-fish culture:
- The availability of adequate supply of fresh water.
- Soil having good water holding capacity and pH between 7-9.
- Avoid land which are subject to flood and landslide.
b. Dike/bund construction
- Sufficiently increased so that it can hold at least 15 cm of water.
- Should be approx.. 50 cm wide at the base, 50 cm high and 30 cm top width.
c. Trench construction
- Serves as refuge for fish when the water level drops to low, temperature of rice field is high and there is threat of predators.
- Serves as catch basins during harvest.
- In Nepal, Peripheral trench system is practices.
- In this system, a trench of 50 cm wide and 50 cm depth are constructed all around the dikes.
- Shouldn’t account more than 10% of the total area.
d. Size of rice plots:
- Constructed in such as way that independent filling and draining of water can be carried out.
- Recommended size is from 200-2000 m2.
e. Inlet and outlet construction:
- The inlets and outlets are placed diagonally opposite so that there is more circulation of water in rice field.
- Made to prevent the entry of unwanted fish, tadpoles and to prevent escape of stocked fishes.