Abstract
Soil contaminated with heavy metals, including nickel is one of the consequences of an intensively developing civilization is the contamination of the natural environment. The purpose of the conducted research was to determine the influence of nickel applied in doses of 0, 80, 160, 240 i 230 mg Ni . kg-1 soil and additives in the form of zeolite as well as natural and dried halloysite on the content of mineral elements in maize (Zea mays L.). The doses of the nickel as well as a type of neutralizing substance used both influenced phosphorus, potassium, sodium, calcium, and magnesium content. Contamination of soil in the amount of 240 mg Ni · kg-1 resulted in the highest increase of phosphorus in maize. Modified halloysite added to soil with doses of 160 and 240 mg Ni · kg-1 soil caused almost a twofold increase in phosphorus content of maize when compared to plants without the addition of neutralizing substances.
Modified halloysite also had a positive effect on the accumulation of potassium in the above-ground parts of maize, especially in plants exposed to the lowest analyzed dose of nickel (80 mg · kg-1 soil). Among the substances applied to neutralize nickel contamination, the application of modified halloysite was shown tobe the most effective and increased the average calcium content by 29 %. Plants in the group without neutralizing additives and doses of nickel of 160 and 240 mg · kg-1 soil respectively were characterized by the highest Mg content in the above-ground parts of the plant. The application of sorption substances had a positive effect on the average content of magnesium in the above-ground parts of maize. The addition of modified halloysite led to the highest increase in the average level of magnesium in the tested plant when compared to the control group. Zeolite and natural halloysite also had a positive effect, although to a smaller degree.
