Soil extractable manganese and uptake in a natural fir stand grown on calcareous soils

Seven extractants were used to relate manganese (Mn) in soil and Mn concentrations in current year needles of Greek fir (Abies cephalonica) in a natural forest stand on calcareous soils containing free CaCO3 The extractants were ethylenetriaminepentaacetic acid (DTPA), I M NH4C2H3O2, 1 M Mg(NO3)(2), 0.05 M Ca(NO3)(2), 0.01 M Pb(NO3)(2), 0.1 M HCl and 0.1 N H3PO4. All correlation coefficients between extracted Mn and Mn concentrations in needles were significant. The inclusion of soil chemical parameters in multiple linear regression equations did not improve prediction of Mn uptake. It was found that soil pH alone was the best predictor (R-2 = 0.72) for Mn uptake followed by Mn extracted with Ca(NO3)(2) (R-2 = 0.71).