Wei Zhang - Effect of Soil Reduction on Phosphorus Sorption of an Organic-Rich Silt Loam

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  Publication Details (including relevant citation   information): Zhang, Wei, Faulkner, Joshua W., Giri,   Shree K., Geohring, Larry D., Steenhuis, Tammo S., Soil Sci.   Soc. Am. J., 2010, 74 (1), pp   240-249

  Abstract: Phosphorus flux from agricultural   landscapes to surface waters may cause eutrophication. In the   northeastern United States, P transport largely depends on P   sorption of soils in variable source areas or in land treatment   systems. Soil redox fluctuation commonly occurs in these areas.   Nevertheless, the effect of soil redox on P sorption has been   variable in the literature. This study investigated P sorption of   an organic-rich northeastern glaciated silt loam (Langford) under   air-dried, field-wet, and reduced conditions using batch P   sorption experiments. Additionally, the influence of farm   wastewater on soil P sorption was studied. Major results   indicated that soil reduction increased the maximum amount of P   that can be sorbed (S max) and decreased the aqueous P   concentration at which P sorption and desorption are equal   (EPC0), both determined from a modified Langmuir isotherm model.   The slightly reduced field-wet soils had no significant   difference in S max due to limited soil reduction. Using the   diluted wastewater as the sorption solution matrices instead of   0.01 mol L-1 KCl solution, the soils generally exhibited greater   S max and lower EPC0 except for the EPC0 of a reduced surface   soil, implying more complex P sorption in the field. Identified P   sorption mechanisms include phosphate precipitation, ligand   exchange with organic matter, and adsorption onto Fe hydroxides.   Transformation of Fe compounds during soil reduction is primarily   responsible for the changes in soil P sorption.

  Address (URL): https://www.crops.org/publications/sssaj/abstracts/74/1/240