Trace Element Status and Environmental Implications of Soils and Zea mays from Farmed Dumpsites in the Bamenda Metropolis, North-West Cameroon

Abstract

This study assessed some physicochemical and trace element properties of soils and Zea mays from farmed dumpsites in the Bamenda metropolis, North-West Cameroon. The growth in population and metal workshops in Bamenda has resulted in the dumping of large quantities of wastes on agricultural soils. Thus, the fear of these agricultural soils and crops being contaminated by waste dumped on them is a call for concern because most of the populations rely on agriculture for survival. A soil and Zea mays sample each was collected from three farmed dumpsites (Nkwen, Mankon, and Bamendakwe) in the Bamenda metropolis and analyzed for physicochemical and trace element properties using standard procedures. The results of physicochemical analysis revealed that the soils had pH values ranging from 5.63 to 7.49, average organic matter, low total nitrogen, high C/N ratio, and high CEC, and the soil textural class was clay loam for soils of Nkwen and sandy loam for soils of Mankon and Bamendakwe. The content of bases in Zea mays was high compared to those in the soil. The concentration of Fe (14635.6 µg/g) in soils of Bamendakwe and Cu (157.17 µg/g) and Zn (1438.36 µg/g) in soils of Mankon had values which were above the permissible limit. The concentration of Zn (114.48 µg/g) in the plant sample of Mankon together with the concentration of Fe in all three plant samples had values above permissible limits. Natural origins and domestic waste were identified as the major sources of trace metals in the soils. Thus, there are potential health hazards related to consuming crops from such soils. Bioremediation techniques can be used to recover heavy metals from such soils. Furthermore, the mobilization of nutrient ions and immobilization of heavy metals by induced liming could be important in sustainable agricultural production and soil environmental protection of the soils studied.