Abstract: In this article , the interaction among biosystem, soilsystem and watersystem in the whole ecologicsystem of lowland lake field are described. And in the mean time, the soil characters, potential resource dominance about lowland lake field are analysed. Lower water and soil temperature, bad aerate penetrability and worse structure cause soil presenting strong reducibility. Containing large amount of toxic reducing substance, the soil went against growth of crops such as rice. The amount of microorganism lower than normal soil observably, organism in the soil mineralization is very slowly, the nitrogen supplying is weakness too, lack of phosphorus and zinc fearfully. The biocharacter of aquatic economical plant nelubo nucifera possesses dominance of upgrowth spiracle which assuring the need of respiration and metabolization for the plant in the water, in the mean while, improving aerate penetrability and estate of reduceoxidation, enhancing activity of the soil microorganism accerlerating mineralization of the organism. In terms of ecosystem advantages in lowland, cropsystem, soilsystem and watersoil system was compared and analysised,with the results of crop biomass: Nelumbo nucifera﹥Zizania caduciflora﹥Trapa bispinosa﹥Oryza sativa,and crop yields: Nelumbo nucifera﹥Zizania caduciflora ﹥Trapa bispinosa﹥Oryza sativa.Dominant in crop system was optimized,and the key nutrient elements were regulated (N:P:K 16:16:16).According to the characyeristics of watersoil system, biological coexistence model was constructed, and the measures to make fall use of resource advantages in lowland lake as well as the developmental model were put forword. These would help improve the whole level of the ecosystem′s integrative developmental benefit in lowland lake.

Key words: waterlogged lowland, ecosystem, lotus root