Slow-Release Zeolite-Bound Zinc and Copper Fertilizers Affect Cadmium Concentration in Wheat and Spinach

Abstract

Cadmium (Cd) accumulation in crops is considered one of the major problems which agriculture faces in industrial and urban areas. This study was conducted to determine the influence of fertilization with slow-release zeolite-bound zinc and copper on the cadmium uptake of wheat (Triticum aestivum L., cv. Nandu) and spinach (Spinacia oleracea L., cv. Matador), two crops with higher tendency to accumulate Cd. The effect of different amounts of zinc (Zn) and copper (Cu), added singly or in combination to a soil previously treated with CdSO₄ was investigated in pot experiments. Combined application of Zn and Cu decreased Cd concentration in wheat grain significantly by 20%, whereas Zn-fertilization resulted in only a slightly decreased Cd concentration; addition of Cu increased grain Cd in one treatment. In the case of spinach, a decrease of Cd levels in the aboveground biomass was observed in all treatments. Combined application of Zn and Cu resulted in a 30% decrease of Cd concentration in the aboveground biomass. Therefore, fertilization with slow-release micronutrients can decrease the concentration of Cd in edible parts of crops and may thus improve quality of agricultural products grown on high Cd soils.

Keywords:

• Zinc
• Copper
• Cadmium
• Wheat
• Zeolite fertilizers

Acknowledgments

This work was supported by the EU (INCO-COPERNICUS Project METAGREC, IC 15-CT 97-0703). The authors would like to thank Walter W. Wenzel, University of Agricultural Sciences Vienna, for useful comments on the manuscript.