PHOSPHORUS FORMS IN ORGANIC SOILS WITH A VARYING DEGREE OF TRANSFORMATION (ON THE EXAMPLE OF THE LUBLIN POLESIE REGION)

摘要

The aim of the present study was to evaluate the content of various phosphorus forms in organic soils with various transformation degrees as well as to determine the distribution of the total phosphorus pool into its individual soil forms along with their location in the soil profiles. Three soil profiles originating from peats and collected from areas subjected to the influence of various human activities, located in the Lublin Polesie region, were the subject of the present research. A method of sequential phosphorus fractioning was applied. Three fractions of inorganic phosphorus Pi-L -labile inorganic P, loosely adsorbed; Pi-FeAl - inorganic P associated with Fe and Al; Pi-CaMg -inorganic P associated with Ca and Mg; and two fractions of organicphosphorus: Po-HuAc - organic P associated with fulvic and humic acids, and Po-Res - residual organic P. The following conclusions can be drawn from the present research: in the soils from the areas strongly transformed by man (completely dehydrated andwith an advanced muck formation process) accumulation of total phosphorus in the upper part of the soil profile takes place, accompanied by a decrease of organic forms content and an increase in the share of inorganic phosphorus forms; forest peat soilnot subjected to a direct influence of human activities was characterised by a very high total phosphorus content; the distribution of the total phosphorus pool into individual fractions in organic soils mainly depends on natural conditions such as: peat-bog character, carbonates content, and pH.