Absorption capacity of nitrogen and phosphorus of aquatic plants and harvest management research

In order to investigate the fact how harvesting aquatic plants affects the removal of nitrogen and phosphorus.Canna glauca,Hydrocotyle vulgaris,Sparganium stoloniferum,Myriophyllum verticillatum and Juncus effusus were selected for the study in ecological ditch,absorption capacity of nitrogen and phosphorus were tested and each plant was divided into harvested and non-harvested plots.The results showed that,seasonal dynamics of the uptake of total nitrogen and phosphorus by aquatic plants changed in a single-peak curve,C.glauca is highest,the absorption capacity peak value of nitrogen and phosphorus were 75.97 and 13.52 g/m2,respectively;Removing biomass,total nitrogen and phosphorus of aquatic plants through repeated cutting were several times single cutting,the changes in the range of 3.62-6.72 times.In addition to S.stoloniferum,the harvest can improve the removal rate of nitrogen and phosphorus in sediment of other aquatic plants.Compared with the non-harvested plot,the harvest can improve the removal rate of sediment total nitrogen and phosphorus in the following order: C.glaucaM.verticillatumH.vulgarisJ.effususS.stoloniferum.Therefore,appropriate harvest measures can not only transfer nutrients of plants,but also conducive to the recovery and growth of plants and improve the removal rate of sediment total nitrogen and phosphorus.