Accumulation of phosphorus (P) in agricultural soils and subsequent losses to waterways contribute to eutrophication in surface water bodies. In agricultural lands prone to prolonged flooding during spring snowmelt, P may be released to overlying floodwater and transported to lakes downstream. Ferric chloride (FeCl3) is a potential soil amendment to mitigate P losses, but its effectiveness for flooded soils with snowmelt is not well documented. Thirty-six intact soil monoliths taken from four agricultural fields from Manitoba’s Red River Valley region were surface-amended with FeCl3 at three rates (0, 2.5, and 5 Mg ha-1) to evaluate the effectiveness of FeCl3 in minimizing P losses to porewater and floodwater. Over eight weeks of simulated snowmelt flooding, porewater and floodwater samples taken weekly were analyzed for concentrations of dissolved reactive P (DRP), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and pH. Change in redox potential was also measured weekly. With time of flooding, redox potential decreased in all soil monoliths. At early stages of flooding, the porewater pH values were significantly lower in FeCl3-amended monoliths but increased with flooding time. Porewater and floodwater DRP concentrations increased in all soils when flooded, but the magnitudes varied. Amendment of FeCl3 decreased the DRP concentrations from 17-97% in porewater and 26-99% in floodwater, with the effectiveness varying depending on the soil, FeCl3 rate, and flooding time. Amendment of FeCl3 increased porewater concentrations of Ca, Mg, Fe, and Mn. Soil amendment with FeCl3 at both rates shows promise in mitigating redox-induced P losses from flooded soils.

<p>Flooding caused by snowmelt runoff in the spring and early summer and heavy rainfall in the summer could enhance P release into nearby surface water bodies causing eutrophication. Six soil amendments were tested for their effectiveness  in reducing P release from flooded-soils. Soils were collected from the flood-prone fields in the Red River Valley region in Manitoba, Canada. The tested amendments were gypsum, magnesium sulphate, alum, ferric chloride, zeolite and manganese oxides. Intact soil columns were subjected to flooding for 8 weeks at 4<sup>o</sup>C simulating the snowmelt in the spring and the early summer and at 22<sup>o</sup>C simulating flooding occurrences in the summer.  Release of soil P into soil solution and floodwater was higher at 22<sup>o</sup>C than that at 4<sup>o</sup>C. Gypsum, magnesium sulphate, alum and ferric chloride were effective in reducing the concentrations of P in the pore- and flood-water at various capacities. Ongoing research on zeolite and manganese oxide suggests that manganese oxide was more effective in reducing soluble P concentrations in soils at early days of flooding.</p>

In this study, a series of polychlorinated dibenzofurans (PCDFs) emitted to the surrounding soil as the result of the combustion of coal and wood from the industrial steam boilers and household stoves have been identified. Levels of polychlorinated dibenzofurans (PCDF) in soil samples were measured at different sites in proximity to the municipal solid waste incinerator (MSWI) to determine baseline contamination and the contributory role of incinerator emissions. PCDF contaminants were concentrated from soil samples and isolated from other materials by chromatographic methods. PCDF isomers were identified separately by column chromatography utilizing column packed with materials such as Kieselgel/44 vol% H 2 SO 4 , Macro Alumina B Super 1, Mix. Column, Bio Beads S-X3 Gel Chromatography, Min Alumina B Super 1 C Kieselgel/AgNO 3 and their quantitative determinations were performed by GC/MS (gas chromatography/mass spectroscopy). The PCDF levels were subsequently compared with established values from previous studies.