The dynamics of oxidoreductase activities in sediments in three polyculture models of ponds stocking mainly grass carp (Ctenopharyngodon idellus)

The health and environmentally friendly culture of feed-driven grass carp ponds is an important aspect in pond aquaculture research. In the present paper, the oxidoreductase activities and the organic matter content of the sediment in three polyculture models of ponds stocking mainly grass carp (Ctenopharyngodon idellus) were studied to evaluate the organic matter cycle efficiency. The results showed that the oxidoreductase activities and the organic matter content (loss on ignition, LOI) in the sediment fluctuated during the culturing period, especially in model 2. And among different months, the oxidoreductase activities and LOI significantly fluctuated in July and August. During the production cycle, the accumulation of organic matter to the bottom of the different polyculture ponds was not significant. According to the dynamics of the oxidoreductases activities and LOI, model 2 was a more reasonable culture method.