We conduct research there many times. In the system, the traditional varieties of glutinous rice seedlings saved by Dong people are used and the fish is also bred in the terrace fields. When the fish grow up to ten centimeter long, the ducklings are put into the terrace field to be raised. The glutinous rice of the system provides shade and organic food for the fish, ducks and other aquatic animals. The fish and ducks play an important role in weeding, cultivation, fertilization, oxygen supply and eating pests etc… This ecological cycle has achieved a very good economic, ecological, social and cultural benefit. “Rice – Fish – Duck Symbiotic System” of Dong People, as one part of China’s traditional knowledge and agricultural culture, has become the protection pilot of FAO Globally Important Agricultural Heritage. This system has strong practical significance and promotional value for solving the problems of the world’s agricultural ecological environmental deterioration, farmland and water pollution, agricultural products safety and so on. We discussed in detail the four benefits of this system as the following:

(1) Economic Benefits

Although the glutinous rice yield of “Rice – Fish – Duck Symbiotic System” is slightly lower than the hybrid rice systems with single species, the rice price produced by the system is 3-4 times higher than hybrid rice. Meanwhile, the fish and ducks in this system are typical “green food”, the prices of which are 2 times than ordinary varieties. The manure of fish and ducks is a good organic fertilizer for glutinous rice, which can greatly reduce the input costs of pesticide, fertilizer, feed and labor.

(2)Ecological Benefits

A lot of ecological principles are in the system. The ecological cycle greatly increased biodiversity (Fig.3), improved farmland ecosystem stability (Fig.4), to achieve sustainable development and use of land.