Phosphorus binding forms in fens influenced by degree of peat decomposition

Due to a possible increasing release of phosphorus (P) in fens after re-wetting it is important to characterize different inorganic and organic P binding forms in peat substrates. Labile P, redox-sensitive P and P adsorbed to metal oxides are the inorganic P forms that could be released from the fen peat substrate by re-wetting. In peat soil samples with different degrees of peat decomposition (DPD) a sequential extraction method was carried out for the detection of P binding forms in fens. The samples have been taken from fens in northeastern Germany represented by different environmental conditions. In peat soil samples with completely humification the P concentration in each fraction is higher than in poorly humified peat. For P releases after re-wetting, completely humified horizons are decisive because they have been changed pedogenetically.