Zinc and Cd Accumulation by Corn Inbreds Grown on Sludge Amended Soil1

Abstract

AbstractInbred lines of corn (Zea mays L.) differ in accumulation of Zn and Cd in leaves and grain. The capacity to accumulate Zn and Cd may be under genetic control. Twenty corn inbreds were planted in replicated control and sewage sludge amended, field, lysimeter plots to obtain information on uptake of Zn and Cd in leaves and grain.Sludge treatments had significantly increased concentrations of both Zn and Cd in the plow layer of soil. Mean total concentrations of Zn ranges from 68 to 454 mg/kg and of Cd from 0.3 to 20.6 mg/kg in the surface of Blount silt loam (Aerie ochraqualf, fine illitic, mesic) soil for control and maximum sludge treated plots, respectively. Concentrations of Zn and Cd in leaves of all inbreds were significantly increased on maximum sludgetreated plots. Zinc concentrations in leaves ranged from 61.8 mg/kg in B77 to 281.8 mg/kg in Oh43 and leaf Cd ranged from 2.5 mg/kg in R805 to 62.9 mg/kg in B37. Concentrations of Zn and Cd in grain of inbreds (except H99 for Zn and H99, Oh545, and R805 for Cd) were increased by higher concentrations of sludge borne metals in soil. Concentrations of Zn in grain varied from 33.8 mg/kg for H99 to 70.0 mg/kg for A619 and Cd varied from 0.08 mg/kg for R805 to 3.87 mg/kg for B37. Inbreds accumulating relatively high levels of Zn in leaf and grain tissue did not always accumulate high concen trations of Cd or vice versa. Mechanisms for controllin absorption of Zn and Cd appeared to be independent each other.