Aerobically digested sewage sludge was applied to corn at different rates (0, 10, 20, 30, and 40 ton/fed.). At maturity, number of ears per plant, ear length, ear weight, cob weight, number and weight of kernels per ear, kernel index, kernel yield per plant, volume of 100 kernels, and kernel density were recorded. Corn grains were analyzed for Pb, Cd, Ni, and Cr content. Increasing sludge rates increased significantly the initial growth, cob weight, total chlorophyll, chlorophyll-a in leaves, lead and nickel in kernels. No significant differences were observed for other characters. The concentrations of Pb, Cd, Ni, and Cr in corn grain due to sludge application were generally higher than the normal concentration values.
Amal W. Amin and Fatma K. Sherif , 2001. Heavy Metal Contents in Maize as Affected by Sewage Sludge Application Morphological Characters and Yield. Pakistan Journal of Biological Sciences, 4: 1451-1455.