The temperature is relatively high in winter but low in summer. There are many cloudy and rainy days and yearly changes in light, heat, and water are synchronized. All these conditions are conducive to growing rice and fish. The longer growth period for fish and the good overwintering conditions allow a sound farmland ecosystem can be established to increase the production of rice and fish. These areas are, to various degrees, poor, barren, highly acidic, sticky, sandy, muddy, and cool and therefore do not produce high yields of rice.
Fish farming improves the soil and rationally uses the land to produce more rice.
Fish farming is profitable and has the potential to improve the economic situation of farmers, particularly in mountainous areas. In 1984, a survey was conducted of 20 farming households in Danzai County that covered about 1.32 ha of rice fish farms. In the future, rice fish farming will undoubtedly supply a large portion of the fisheries production in Guizhou, especially in mountainous areas where there are large ricefields but few ponds or reservoirs. It is important to develop rice fish farming and to establish systems for technology extension and for the production and supply of improved varieties. Improvement of the common carp variety must continue.