Effect of sulfur forms on concentrations of cadmium and nickel soluble in 1 mol HCl dm –3 in arable soils

Heavy metal contamination of arable soils remains one of the world’s most serious environmental problems. The mobility of heavy metals in soil is determined by soil condi- tions, environmental factors and human activity. The immediate and residual effects of sulfur fertilization on the concentrations of heavy metals in soil are an important conside- ration when monitoring changes in environmental conditions in agricultural areas. The objective of this study was to determine the effect of increasing doses of sulfate and elemental sulfur on changes in the concentrations of cadmium and nickel soluble in 1 mol HCl dm –3 in soil samples collected at a depth of 0-40 and 40-80 cm. A three-year field experiment was conducted on Dystric Cambisols (FAO) of the texture of heavy loamy sand. Soil samples were collected from each plot, prior to the establishment of the trials, after each harvest and before sowing the consecutive crop. The soil samples were used to determine the concentrations of Cd and Ni in soil (extractions with 1 mol HCl dm –3 , the ratio between soil and extraction - 1:10) by the AAS method using a Schimadzu AA apparatus. Irregular changes in soluble cadmium concentrations were observed in soil fertilized with sulfate and elemental sulfur. No distinct trends were noticed in response to sulfate and elemental sulfur fertilization. The effect of sulfur was noticeable only in the third year of the experiment. Sulfur application contributed to a decrease in the soluble nickel content of soil. Sulfate and elemental sulfur fertilization did not increase the levels of cadmium and nickel soluble in 1 mol HCl dm –3 . The soil can be used for growing high-quality horticultural and agricultural crops safe for human consumption.