The aim of this research was to determine the total content of zinc and its fractions in arable soils of the Province of Podlasie (województwo podlaskie) and to assess the correlation between the zinc content, its fractions and physicochemical properties of soils. The research material consisted of samples taken from arable soils in 81 points of the province, with one point chosen in the majority of the districts. Each point was located on mineral soil used as arable land, without any external source of contamination like roads or industrial plants. Samples were taken after harvest, from the arable layer, determined to lie within the depth of 0-30cm. The samples were submitted to determinations of the basic physicochemical properties of soil. The content of total zinc was determined after mineralization in aqua regia, by the flame atomic absorption spectrometry method. The content of zinc fractions was determined by the BCR method. There were four fractions determined:  exchangeable, bound with oxides and hydroxides, bound with organic matter and residual zinc. The physicochemical properties of soils were highly differentiated except the grain-size composition. The content of total zinc was typical of arable uncontaminated soils and fluctuated in a wide range. The content and shares of zinc fractions in total zinc were as follows: for very light and light soil: organic>bound with oxides and hydroxides>exchangeable>residual; for medium-heavy soil: organic>exchangeable>bound with oxides and hydroxides>residual. Distribution of zinc in particular fractions was dependent to some degree on pH, content of organic matter and grain-size composition.

19.3.2014