Distribution Characteristics Of Phosphorus And The Feature Research Of Adsorption/Release In Poyang Lake Wetland Soil

Wetland soil is one of the abiotic elements that constitute wetland ecosystem.The distribution of phosphorus forms and its migration and transformation behavior of the wetland soil have not only played a very crucial role on eutrophication status and ecological functions of wetlands.But also researching on wetland soils act for the protection of Poyang Lake. The Poyang lake wetland soil phosphorus behavior research has a key role on wetland conservation.This paper selects 17 soil samples from the Poyang Lake Wetland, by the analysis of distribution of phosphorus forms and the simulation research on phosphorus adsorption-released,we get the following conclusions:The TP content of Poyang Lake wetland soil is in the range of 128.95-1858.72mg/kg, Phosphorus forms including the OP and IP, TP mainly exist in the form of IP, its content is between 180.08 ~ 1421.97 mg/kg, 94.59 percent of TP. IP mainly exist in the form of Fe/Al-P, its content is between 112.22~1117.68 mg/kg,75.31 percent of TP. Ca-P content is between 0.66~17.56 mg/kg, 0.9 percent of TP.OP content is between 43.12~142.5 mg/kg, 10.12 percent of TP. Through correlation analysis, the content of TP and OP and IP and Fe/Al-P has significant correlation, in various forms of phosphorus, OP, IP and Fe/Al-P a significant positive correlationIt shows that by fitting the effect of a Langmuir equation fitting and simplified Elovich equation on soil phosphorus adsorption are good, the correlation coefficient of two fitting equations were above 0.9.Isothermal adsorption curve on the Adsorption of phosphorus by Poyang Lake wetland soils can be used by Langmuir equation and Freundlich equation. When the water is low phosphorus content, it exist the phenomenon which resolve the phosphorus in the adsorption process.Environmental factors have a very important impact on phosphorus adsorption of the wetland soil;phosphorus adsorption is endothermic reaction when temperature increment it is conducive to the adsorption of phosphorus; pH has a great influence on the adsorption of phosphorus in the sediments; when in acidic or neutral phosphorus adsorption growed greater than slightly alkaline environment.Adsorption of phosphorus increased with the increasing concentrations of soil.Laboratory simulated the environmental factors on wetland soil phosphorus release that has the following conclusions:(1) increasing temperature that helps increasing the release of wetland soil phosphorus.(2) When the water is in neutral conditions that is unfavorable for soil phosphorus release, when it is in the acidic or alkaline conditions that can contribute to soil phosphorus release.(3) disturbance on soil phosphorus release is a physical process, which increasing the release rate of phosphorus at high speed, the maximum emission is 2.77 times than the norm.(4) In the light conditions, the maximum emission of wetland soils is 1.82 mg / kg, than the maximum emission reduction of phosphorus 2.43 mg / kg when in no light. The light conditions are not conducive to the release of wetland soil.(5) In the case of microorganisms, the maximum release of phosphorus is 4.25 mg / kg which is 3.5times than that without microbial conditions. Wetland soil phosphorus release in the absence of microorganisms which is less than the microbial environment.