Abstract: In the life history of submerged macrophytes, sediment supplies them growth medium and large amount of nutrients, and exerts long-term and far-reaching effects on their growth and development. In this paper, sediment samples collected from Beili Lake of China were amended (covering with sandstone, Phoslock, or clay), and planted with submerged macrophyte Vallisneria rtalans, aimed to study the effects of sediment amendment on the growth of the macrophyte.All the three amendment measures had little effects on the chemical properties of the sediments,but obvious effects on their physical properties. The mean biomass, mean shoot height, and root/shoot ratio of V. natans growing on the sediments covered with sandstone, Phoslock, and clay differed significantly (P<0.001), with the highest biomass and shoot height on the sediment covered with sandstone. The root indices (surface area, volume, tip number, and  length) also showed the promotion effect of sandstone cover on the growth of V. natans. Covering sediments with Phoslock and clay had little effects, and even, inhibited the growth of V. natans. It was suggested that using sandstone to amend the sediment of Beili Lake could be more appropriate.

Key words: colistin sulfate, soil microbial biomass carbon, community structure, phospholipid fatty acid.