Phosphorus fractionation in soil and sediments along a continuum from agricultural fields to nearshore lake sediments: Potential ecological impacts

作者：Noll Mark R^*; Szatkowski Aimee E; Magee Erin A

来源：Journal of Great Lakes Research, 2009, 35: 56-63.

DOI：10.1016/j.jglr.2008.08.004

• Phosphorus
• Fractionation
• Soil
• Sediment
• Nearshore
• Macrophytes

The movement of phosphorus (P) from agricultural fields to streams and deposition in the nearshore of the lake presents a Continuum of related physical and chemical properties that act to partition P into different physico-chemical fractions. We investigated changes in soil and sediment P fractionation as material was eroded from predominantly agricultural fields, transported via stream sediments, and deposited in a nearshore lake environment. Total phosphorus content of the soils and sediment decreased from field soils with an average concentration of 553.81 mg P kg(-1) to 202.28 mg P kg(-1) in Stream sediments to 67.47 mg P kg(-1) in lake sediments. Significant changes in P fractionation occurred during erosion, transport, and deposition of the particulate or sediment phase. The fractionation of P within the soils and sediments changed significantly from aluminum and organic matter associated P dominant in field soils to calcium associated P dominant in nearshore lake sediments. Various physical and chemical processes appear to be responsible for these trans formations which impact the mobility and bioavailability of P. A significant amount of P was lost from field soils as they were transported and deposited. This P has either become available to biota or deposited in deeper portions of the lake system. Ultimately, the impact of P export on the nearshore lake environment may be influenced by the changes in P fractionation that occurred during transport and deposition and by the influence of macrophytes on the biogeochemical cycling of P in the sediment.

• 出版日期2009