Effects of Heavy Metals on Agronomic Attributes of Some Selected Cereal Crops (Zea mays and Sorghum bicolor)

Aims: To investigate the effect of Heavy metals on the growth of Zea mays (Z. mays) and Sorghum bicolour (S. bicolour).

Study Design: Laboratory-experimental design was used in this study.

Place of Study: The heavy metal polluted soil samples were collected from Crush Rock Industries Ishiagu, Ebonyi State, Nigeria, while control soil samples were obtained from the Zoological Garden of the Department of Applied Biology and Biotechnology, Enugu State University of Science and Technology.

Methodology: The seeds of the two plants were collected from the Enugu State Ministry of Agriculture. The experimental setup consisted of 16 contaminated potted soils, 8 each for Z. mays and S. bicolor. Another 8 potted soils not contaminated with heavy metals served as control. Fourteen days after germination, the following growth parameters were measured (in cm); plant heights, number of leaves, stem girth, and leaf area.

Results: The polluted soil sample was slightly acidic; (pH was 6.34±0.29). It had a higher cation exchange capacity (21.80±0.33), Cd (25.18±0.34), Cr (10.20±0.21), Cu (28.54±0.49), Pb (9.92±0.36), but lesser soil organic carbon (0.87±0.10). Plant samples cultivated in contaminated soil showed the least favourable vegetative growth.

Conclusion: Comparing the results obtained from the control sample, it was deduced that these heavy metals have adverse effect on the vegetative growth of Z. mays and S. bicolor.