Duck-rice integration means growing rice and raising ducks together in the same rice paddy. Ducks can help cultivate the rice and from the ducks you can get meat. It is a traditional method of rice cultivation in Japan and some other Asian countries. Recently it has been attracting people's attention because the technique is free from chemicals and is eco-friendly.
Brooding period - usually, day-old ducklings arrive at ARI just before the rice is transplanted. Ten days after transplanting, we release them into the paddy fields. These days are considered the brooding period for the ducklings. During this time, they will be kept in a hut or small pond to get used to their new environment. The rice plants are too small and easy to push down if the ducks are released too early, however the weeds will grow up if you release too late.
Grazing period - the period in which the ducks are kept in the paddy is called the grazing period. The grazing period is two months long. After two months, the ducks grow big enough to eat the rice and push down the stalks. By this time the rice will have grown enough that no more weeding is needed. After the grazing period we remove the ducks from the paddy and ... we can get tasty meat!!
A hut for nighttime - at night, we keep the ducklings in a small hut to protect them from wild animals and coldness. We make the floor soft by spreading rice husk all over it. Inside the hut, we prepare a water pipe for drinking, and a shallow container for feed. Since our climate is cold in the spring, we also make a small room with a heater, using a small table heater called a kotatsu.
An Aigamo duckling hut at ARI, waiting for the residents to arrive.
A pond for daytime - In the daytime, we keep ducks in a small pond. During the brooding period, they need to be trained to swim, so they won’t drown in the paddy field. We dig a shallow hole, fill it with water, set a net around and above it and then run electric wires at three different heights around the net. We also fill the pond with duckweed and place a feeder next to it.
Net around the paddy field - To protect the ducks from wild animals such as racoon dogs (tanuki), dogs, cats, hawks, and crows, and also to prevent the ducks from escaping, we set up a net with electric wires around the paddy and extend strings over the top. See illustration below:
Feeding - Weeds and insects in the paddy do not provide enough food for the ducks. We give uncooked broken rice that we can't use in the kitchen or wheat every day. The amount of the feed should be adjusted according to the needs of the ducks.
There are some cases where farmers do not set fences around the rice paddy. Some large farms have fences only around duck huts, and some farmers keep the ducks in huts at night instead of using fences. In those cases, it is necessary to keep an eye on the ducks in the daytime and bring the ducks to the hut every evening.
Some farmers combine sowing and growing Azora in the paddies together with the ducks. Azora is a kind of floating plant that can fix nitrogen, serve as a green mulch, and also be a feed for ducks. However, Azora is considered an invasive alien species in Japan, so its use should be carefully considered.