The Effects of Zinc Fertilization on Cadmium Concentration in Wheat Grain

Abstract Although the effect of Zn in soil on Cd uptake by plants has been studied extensively, there appears to be no consensus in the literature about the interactions. Furthermore, the majority of investigations have studied soils containing elevated concentrations of Cd or Zn as a result of pollution, e.g., the application of sewage sludge to the soil. The accumulation of Cd by wheat (Triticum aestivum L.) grain grown at nine sites across South Australia was investigated. Applications of low rates of Zn fertilizer (up to 5.0 kg Zn ha−1) were found to markedly decrease the Cd concentration in wheat grain grown in areas of marginal to severe Zn deficiency. No further significant decreases in Cd concentration in grain occurred at higher rates of applied Zn. Effectiveness of applied Zn on grain Cd concentration decreased with tune since application. Grain Cd concentrations decreased with fresh and residual applications of Zn fertilizer (up to 5.0 kg Zn ha−1). Soil tests may provide useful guides to situations where Cd concentrations in grain may be beneficially decreased by Zn applications.