Phosphorus Sorption By Sediments From Wetlands in Indiana.

Phosphorus sorption by sediments from wetlands in Indiana Abstract Author: Jing Wang Email: wang1593@purdue.edu The ability of wetlands to function as sinks or sources for phosphorus (P) has been the subject of much debate. Adsorption to soils is one of the dominant mechanisms of P storage in wetlands. We measured the ability of a small, natural wetland at Purdue¡¯s Agronomy Center for Research and Education (ACRE) in West Lafayette, Indiana to store P in the sediments. The ACRE wetland is 1.2 ha in area and receives agricultural drainage water from its surrounding watershed. Seventeen 40 cm sediment core samples were collected from the wetland in summer 2013. The existing orthophosphate and total phosphorus concentration were analyzed for two different parts of the sediment core, the upper part (20 cm length) and the lower part (20 cm length). The spatial distribution of P in the wetland was determined and sorption isotherms are used to determine the ability of the sediments to take additional P. The total P sorption results in the wetland sediment-cores determine whether the sediments in the wetlands are saturated with phosphorus or not. Therefore, this work will help with management planning to prevent the wetland from being a source of phosphorus and transporting excess phosphorus downstream causing serious ecosystem problems. Moreover, determining the P sorption of the upper part of the sediment-core, will contribute to initial planning for further research on wetland plants.