Chemical Composition of Spring Rapeseed Grown in Copper-contaminated Soil Amended with Halloysite and Zeolite

The purpose of this study was to determine the effect of soil contamination with copper doses of 0, 150, 300, and 450 mg.kg^-1 of soil and the application of zeolite, raw and modified halloysite on the biomass of spring rapeseed and the content of nitrogen compounds and macronutrients in the above-ground parts of the tested plants. The content of macronutrients in plants was determined spectrophotometrically. The applied soil amendments and copper doses led to significant variations in the concentrations of the analyzed nutrients in spring rapeseed. Zeolite and halloysite were most effective in increasing the average above-ground biomass of the tested plants. Zeolite had a beneficial effect on the content of total nitrogen, ammonia nitrogen and phosphorus in the above-ground parts of spring rapeseed. Raw halloysite increased the content of sodium and calcium, whereas modified halloysite contributed to an increase in the nitrogen, potassium, sodium, calcium and magnesium content of the tested plants.