Excessive phosphorus (P) loading is a growing water quality concern in the rapidly urbanizing Peruque Creek watershed of East-Central Missouri. In order to formulate appropriate strategies for combating accelerated eutrophication of the watershed's aquatic systems, this study was conducted 1) to evaluate the impacts of urbanization versus agricultural land uses on P-concentration in an Ozark creek, and 2) to determine the major fractions and chemical forms of P distribution. The study was designed to specially identify the effects of agricultural practices, storm water runoff, and wastewater discharge. Our results showed that particulate P accounted for over 80% of the total P at all sampling sites except for the site downstream of a suburban small community of 2,100, where a significant proportion (~50-75%) of P was observed as dissolved P. Particulate P concentrations increased in summer and fall. Of the dissolved P, ~70% was inorganic P, with the remaining as organic P. X-ray absorption near edge structure spectroscopy (XANES) analysis indicated that the dominant chemical forms of P in creek sediment varied from FePO4.2H2O and Fe4(P2O7)3 at headwaters to C18H15P, FePO4.2H2O, and Fe4(P2O7)3 downstream of the suburban community. Management practices have to be developed with specification to sources to effectively reduce P loadings to the creek.
See more of Phosphorus Chemistry in Soils: II. P Fluxes in Soil and Water Systems
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See more of The ASA-CSSA-SSSA International Annual Meetings (November 6-10, 2005)