在集约化养殖条件下,由于大量投饵的残料、生物排泄物和尸体等长期积累及泥沙沉积,使池塘底部形成了一定厚度的底泥。池塘保持适当的底泥是必要的,因为底泥中含有大量营养物质。这些营养物质,一部分通过细菌分解使氮、磷等元素不断向水中溶解、释放;另一部分通过离子交换作用向水体释放。通过这些过 Under intensive farming conditions, due to the long-term accumulation of sediment, biological excrement and dead bodies, and the sedimentation of sediments, a large amount of sediment is formed at the bottom of ponds. It is necessary to maintain the proper sediment in the pond because the sediment contains a large amount of nutrients. These nutrients, part of the bacteria through the decomposition of nitrogen, phosphorus and other elements continue to dissolve in the water, release; the other part of the ion exchange to release water. Through these too