Increased adsorption of nickel and chromium with grape`s organs caused by different amounts of ammonia fertilizers in root zone

Previous amelioration measures of sandy deposols from open coal mine pit around Kostolac TPP (Thermal Power Plant) caused an intensive uptake of nickel and chromium in the organs of annual agricultural plants, making them not suitable for human nutrition. The investigation conducted as a pot and field experiment was with perennial plant species (grapevine), where the immobilization effects of heavy metals (Cr, Ni) were investigated. Poor substrate was supplied with N and P different rates of fertilizers, while K was constant (100 kg/ha). Phosphorus nutrition was focused on the immobilization effects on deposol Cr and Ni availability, by using increasing doses of MAP fertilizer (5.000, 15.000, 30.000 and 45.000 kg/ha). Treatment with zeolite, which has similar immobilization effect as P, was also applied with MAP fertilizer treatments. The analysis of plant material from pot experiment pointed out a significant adsorption of nickel in some organs with higher doses of MAP fertilizer, overcoming 50 mg/kg Ni threshold concentration. Mostly the highest Ni concentration was found in the grape roots with highest dose of MAP (37,71-94,61mg/kg), while the all aboveground organs with MAP treatment had significantly increased concentrations of nickel than control. This significant difference, probably due to the acidification effect (NH4+ transfer to NO3-), was more pronounced in the pot experiment rather than in the field experiment. Increased chromium concentrations was found in root system in a both type of experiments (1,25-1,77mg/kg), but at the higher doses MAP, toxic level of Cr was also found even in the leaves (6.1mg/kg in treatment MAP 30.000kg/ha). Dispute the fact that in plants exist a low Cr mobility, this indicates its possible movements in aboveground parts of plants