Mobility and leaching of heavy metal through soil layers as affected by application of different levels of Cd, Ni and Pb on corn plants
2012
El-Azab, M.E. | Awad, E.A.M. | Mohamed, I.R. | Osman, F.A.
A laboratory experiment was designed to study the mobility of heavy metals through soil layers by corn plants. This experiment were conducted at the National Research Center (NRC) in order to satisfy the objectives of the current investigation. The obtained results can be summarized as follows: 1. The application of NPK fertilizers increased the fresh and dry weight of corn plants as compared with the application of heavy metals. 2. The small additions of heavy metals (H.M) with NPK fertilizers resulted in an increase in the dry matter production of com shoots. By increasing the added amounts of Cd, Ni and Pb, the dry matter production decreased, and it was the lowest in the heavy metal treatment as the recorded reductions were obtained with 150 pprn, 100 ppm and 50 ppm, respectively. 3. The reduction in corn growth was associated with an increase in heavy metals concentration in corn shoots. The percentages of increases were 115-161 %, 115-174% and 10-37% for Cd, Ni and Pb, respectively as percent of their corresponding controls. 4. The data showed that in the presence of heavy metals in the soil, the overdosing of fertilizers would increase the concentration of heavy metal inside the plant tissues. So, it is recommended not to overdose fertilization as it causes the introduction of larger amounts of heavy metals into the food chain, which indicated the accumulation of large amounts of Cd, Ni and Pb in the soil. 5. The DTPA-extracted heavy metals at the end of the experiment increased in the surface layer of the soil column. 6. The low additions of Pb and Ni (50 ppm) stimulated the growth of corn plants and the dry matter production increased 2 and 3 times as compared with the control treatment in the soil, respectively. 7. By increasing Cd or Ni or Pb-levels, the production of dry matter,shoots, decreaed.
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