Potential bioavailability of particulate phosphorus in runoff from arable clayey soils

Summary

Runoff phosphorus (P) associated with eroded soil contributes to eutrophication to some extent. The present work examines two methods for estimating the potential bioavailability of particulate P (PP) in runoff, and studies the concentrations and losses of different P forms in surface and subsurface runoff from arable soils. The potential bioavailability of PP was approximated by extraction with (i) anion exchange resin (AER-PP), giving a measure of desorbable PP under aerobic conditions, and with (ii) bicarbonate-dithionite (BD-PP), which dissolves redox-labile PP. Both methods were applied in runoff analysis without sediment preconcentration.