Chemistry of Cr in Some Swedish Soils

Abstract

The study examined influence of CrO₃ applied alone or applied in combination with KH₂PO₄ on contents and translocation of Mn, Cu, Zn, Fe and Al in rye grass plants grown on two soils in a growth chamber. Mn and Zn were relatively evenly distributed in the plants, Cu was intermediary, but the contents of Fe and Al were much higher in roots than in tops of the plants. The metal contents in plants varied with treatments, but not consistently and, hence, were not helpful in identification of the normal and chlorotic plants. The larger the CrO₃ rate the more severe the chlorotic symptoms in plants and the higher the translocation of the metals on the acid soil and of Zn on the neutral soil. On the latter soil, however, translocation of Mn, Fe and Al was inhibited while that of Cu was not affected. It is considered that the high accumulation in roots of Fe and Al, resulting in very low top/root ratios of these elements, contributed to Cr toxicity in rye grass plants.

Key words:

• Cr toxicity
• chlorosis