FACTORS INFLUENCING THE CONCENTRATION OF HEAVY METALS IN SOILS OF ALLOTMENT GARDENS IN THE CITY OF WROCLAW, POLAND

Small, family gardens, in Poland usually called allotment gardens, are a popular recreation place for town residents. Their additional function is cultivating vegetables and fruit. This paper analyses the total concentration of Cu, Pb and Zn in the soil of 180 allotment gardens in Wroclaw, one of the 5 biggest towns in Poland. The concentration of metals (12.5-659 mg Pb . kg(-1), 38.1-2103 mg Zn . kg(-1) and 12.9-595 mg Cu, kg(-1)) depends mainly on the nearby location of industrial pollution sources, but also varies with the amount of organic matter, pH and the content of plant-available macronutrients, suggesting a relationship between metal contamination and the intensity of organic or mineral fertilization and liming. Significantly higher metal concentrations have been measured in soils of allotment gardens arranged on formerly housing or industrial areas, as compared to gardens set up on arable land. Up to 35% of soils in the city zone are excessively contaminated, unsuitable for vegetable and fruit production, and require reclamation.