Comparative Assessment of the Levels of Some Metal Ions in Soil Rhizosphere of Onion and Onion Bulb (Allium cepa l) Cultivated in Danbam Local Government Area: North East Nigeria

Abstract

Authors: Elisha Karu*, Buhari Magaji, Aishatu Umar Maigari and Fauziyya Aliyu Jibo

Levels of some metal ions (Cd²⁺, Pb²⁺, Cr³⁺, Mn²⁺ and Mg²⁺) in the soil rhizosphere and onion bulb were determined by spectroscopic techniques (Atomic Absorption Spectroscopy AAS, and UV-Visible Spectrophotometry). Comparative analysis of the results by the two techniques used shows that Cr, Cd, and Pb were not detected by atomic absorption spectrophotometer in both the soil rhizosphere and onion bulbs but Mn was detected at concentrations ranges of 9 – 12 ppm and 2 – 13 ppm in the soil and onion bulbs. Concentration of Mg²⁺ was observed to range 6 – 10 ppm and 7 -9 ppm in the soil and onion bulb respectively. Much lower concentrations were detected by the spectrophotometric determinations of Cd, Mn, and Pb in both the soil and onion bulb samples with Pb having the highest concentration (0.002 – 0.005 ppm) in the four study sites. Cr was not detected by any of the two techniques used.