THE CRITICAL LEVELS AND THE MAXIMUM METAL UPTAKE FOR WHEAT AND RICE PLANTS WHEN APPLYING METAL-OXIDES TO SOIL

Wheat is more sensitivity to CdO and ZnO compared with rice plant. The yield of wheat decreased by 30 % in the presence of 30 ppm Cd, but that of rice plants by only 8 %. The critical levels of meal uptake by wheat and rice plants for applying metal oxides to soil (CdO, ZnO, PbO) were determined. The highest concentration obtained for wheat grain was 141 µg/g Cd at the Cd 10, 000 ppm in soil. This value is higher the value of 4.97 µg/g for unpolished rice and higher than any other we have seen in the reports for treatment with CdO. Also, as concentration of more than 1.0 µg/g Cd in wheat was obsertced at 5 ppm Cd, while similar concentrations for rice plants were observed at 30 ppm Cd in soil. © 1990 by Marcel Dekker, Inc.