Pattern of Trace Metal Uptake in Pearl Millet as a Result of Application of Organic and Synthetic Fertilizers

Abstract

A pot experiment was conducted to observe the impact of the application of various fertilizers on the availability of trace metals in different parts of a pearl millet variety (YBS–98). The level of metals in the pearl millet plant (root, shoot, and grains) was analyzed by the atomic absorption spectrophotometer (AA–6300 Shimadzu Japan). Comparing different parts of millet plant Cu (3.4–4.5), Fe (62.8–73.9), Mn (23.8–44.1), Zn (22.4–43.3), Ni (4.9–7.8), and Pb (0.3–0.5) mg/kg were accumulated more in root, while Cd (0.3–1.5) mg/kg was accumulated more in grains. This shows that pearl millet phytostabilizes most of the metals in its root. The level of all metals in the pearl millet plant was within the safe limit suggested by FAO/WHO excluding Cd whose level was above the permissible limit given by the Codex Alimentarius Commission. The values of all trace metals and micronutrients were higher in mixed fertilizer treatment followed by poultry manure, cow manure, NPK, and control. The bioaccumulation factor for Mn was highest among all metals, whereas the translocation factor for Cd was greater than 1. The values of pollution load index for all metals in five treatments were found within the safe limit. The values of a health risk index for all metals in all treatments were less than 1 indicating that the manure treated pearl millet grains were free of risk for human consumption.