Rice paddies have lots of natural food for fish. This is one of the advantages of raising fish and rice together. Fish help the farmer by eating weeds and insects in the paddy field. Fish manure fertilises rice and increases rice yield.
It costs very little to keep fish in your paddies. You may even save money because keeping fish in your rice paddies reduces the need for expensive pesticides and fertilisers.
Keeping fish in rice paddies is not a new idea. Fish such as catfish or mudfish used to live naturally in rice paddies. Your grandparents may even remember catching them.
Making a pond
You will need a pond next to the paddy so the fish will have a place to go when you harvest your rice or when there is a shortage of water. Choose an area of the field that holds water. This is often the lowest spot in the field.
Your pond should be about 6 metres square and about 1 metre deep. Slope the sides of the pond to help prevent erosion. As you dig out the pond, add soil to the banks of the pond to help prevent the pond from overflowing during heavy rains.
One side of the pond should open into the rice paddy. This way the fish can swim in and out of the pond, and the pond will be a refuge for the fish when the water level is low. When you drain the paddy for the rice harvest, do it slowly to give the fish time to retreat to their pond. When the field is drained, all the fish will be in the pond and they will be easy to catch. If the fish are not yet big enough to eat, you can feed them in the pond until the field is ready for rice again.
Fish dig and swim around rice plants, searching for food. If you have just transplanted your rice seedlings, wait about ten days to three weeks before you put fingerlings in the paddy. This way the rice transplants will be well established and the fingerlings cannot disturb them.
Adapted from DCFRN Notes, No.35