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The goal of the research was to determine the concentration of lead, copper, cadmium, zinc and iron in the soil of different pH, the degree of contamination in the intensive production of Elstar apples, as well as the impact of soil contamination on the concentration of heavy metals in fruits and apple juice. The stationary research was conducted during 2014-2015 in the fruit nursery Špionica near Srebrenik (Bosnia and Herzegovina).
Along with the standard agro-technology, acidification and calcification of soil were applied, as well as the simulation of soil contamination with heavy metals, on the experimental plot of apple plantations. The concentrations of heavy metals in the soil, fruits and apple juice were measured on an atomic absorption spectrophotometer (Analyst 200) and inductively coupled plasma by optical emission method ICP-OES (Optima 2100 DV) and by standard analytical methods. In tilted layer of soil in the width of the treetop, the heavy metal concentration ranged from 9.60 mg/kg for lead, 26.76 mg/kg for copper, 34.23 mg/kg zinc and 17852.00 mg/kg for iron. There was no cadmium. After zero soil sample analysis the acidity of sample soil were increased or decreased with ammonium sulfate, i.e. acidification (1.2 kg per apple tree) and with lime, i.e. calcification (3.2 kg per apple tree) and treated with solution of each metal in an amount of 800 mL per tree (10 mL of pure solution mixed with 10 L of distilled water). In soil samples where the acidification were done average concentration of heavy metals were: lead 12.70 mg/kg, copper 36.97 mg/kg, zinc 61.03 mg/kg and iron 24.00 mg/kg. In soil sample where the calcification were done average concentration of heavy metals were: lead 13.87 mg/kg, copper 38.50 mg/kg, zinc 65.03 mg/kg and iron 26193.00 mg/kg. In Elstar apples grown on demonstration plot, the highest was iron content with an average of 15 mg/kg. The content of zinc ranged from 2.36 to 4.40 mg / kg, with an average copper content of about 0.70 mg / kg while the lead content was 0.41-0.70 mg/kg. In juice, produced from the Elstar apples grown on the basic soil copper content was highest 0.668 mg/kg and that is the highest value recorded from all the values in the juice in general. The concentrations of these heavy metals in the soil before the experiment were below the maximum allowable concentration (MAC) for powdery-loamy soil. After acidification, calcification as well as simulation of soil contamination with heavy metals, there was a noticeable increase in the concentration of heavy metals in the soil, but after experiment concentrations of heavy metals in fruits and apple juice were very low, far below MAC. This research has shown that even with heavy metals in the soil there is no risk to consumers health to consume such fruits and products because coefficient of heavy metal transfer from the soil to the fruits is very low, below the limit values.