The effect of phosphate fertilizer on heavy metal in soils and Amaranthus caudatus

摘要

The study examines the effect of Phosphate fertilizer on heavy metals in soils and Amaranthus Caudatus. Pot experiment was carried out to assess the effect of Phosphate fertilizer on heavy metal uptake by Amaranthus Caudatus. Single Super Phosphate fertilizer (SSP) was applied at the rates of 0, 60, 80 and 100kg fertilizer/ha and replicated three times in a completely randomized design. The parameters measured were plant height, number of leaves, and heavy metals (Cu, Zn, Cd, Pb and Ni) concentration in the soil before and after the experiment, heavy metal concentration in the stem and roots of the vegetable used were also measured. The results of this experiment shows that there were no significant difference in plant height and number of leaves among the treatments considered, but the number of leaves increases from the second to the fourth weeks after sowing before it begin to decline. Only Cu, Zn and Cd were taken up by the root and stems of the vegetable with Zn having the highest concentration at 100kg/ha and 80kg/ha level of application for stem and root respectively. The concentrations of all the metals (Cu,Zn, Pb and Cd ) increases in the soil after the experiment except for Nickel. Increase in the concentration of Zinc in the soil was more pronounced than other metals. It is therefore recommended that Phosphate fertilizer should be analyzed to determine the concentration of heavy metals before its application to the soil for plant growth.