| Abstract: | The phosphorus adsorption capacity of 20 peat soils and those soil properties likely to influence it (Al, Fe, Ca, Mg, pH, ash content) were studied. Phosphorus adsorption was correlated only weakly to the site type classification of peatlands. However, the P adsorption was strongly correlated with the concentration of Fe in the peat. Thus, soil chemical analysis should be used to support site type classification in order to assess the effectiveness of peatlands to adsorb P. When expressed on a volume basis, the P adsorption capacity varied from 7 kg ha‐1 to 673 kg ha‐1 in the 0–30 cm layer. Compared with the amounts of P used in practical peatland forest fertilization in Finland (40–45 kg ha‐1), the P adsorption capacity of several peat soils studied was substantially lower. It was thus concluded that slowly soluble P fertilizers or applications <40–45 kg ha‐1 should be used where the P adsorption capacity is low. |
