| When phosphorus (P) is applied to soils in excess of plant P demand, P accumulation takes place. By means of P fractionation, we studied the fate of P in 35 soils that had received long-term surplus P rates as fox and mink manure P (F&MM-P), considered as a sparingly soluble P source. We compared these data with those from the same soils under a more typical P management, i.e., fields amended with soluble P sources superphosphate and dairy manure (SP+DM). Fractionation of manures according to the Hedley procedure suggested limited solubility of F&MM-P, two-thirds of the F&MM-P being soluble in acid (HCl) only. In mineral soils, surplus F&MM-P accumulated for the most part as HCl-P (poorly available), whereas in organic soils accumulation... |
