Effect of organic materials and lime application on cadmium uptake by ryegrass (Lolium multiflorum Lam.) in cadmium polluted acid soils

Abstract

In the present study, the combined effect of organic materials and lime on cadmium uptake by ryegrass (Lolium multiflorum Lam.) was investigated in three cadmium polluted acid soils with different cadmium concentrations. Two sources of organic materials, peat and compost, with three levels (0, 2.5 and 5%) and four levels (0, 2, 4 and 6g CaCO₃ kg^-1 soil) of lime were designed. The cadmium content in the shoot of ryegrass decreased with increasing level of lime or organic materials in each treatment. Compost had a better effect on reducing cadmium uptake than did peat, partially resulting from higher pH of the former (7.47) than the latter (5.03). At the same lime level, Cd content in the shoot was reduced more by joint application with compost or peat compared to lime alone. These results suggest that application of organic materials combined with higher rate of lime is more effective in decreasing Cd uptake.