| Recent research has demonstrated that P losses through subsurface pathways may reach concentrations that stimulate eutrophication. The objective of this study was to qualitatively analyze the effects of selected soil characteristics on P mobility. Both intact and packed soil columns (0-15 cm) were collected from six fields with varying land use and cropping histories. The columns were leached with deionized water and an aqueous P solution using wetting and draining periods. PO43--P load (kg ha -1) and cumulative P losses were determined. The results confirm that the major factors influencing P sorption are soil texture, soil test P, and Al and Fe content. As well, P loading into tile drainage under conventional and no-till systems with liquid dairy manure and inorganic fertilizer additions was measured over two years. No significant differences in PO4 3--P concentrations and loading were identified. |
