Assessing the contamination of trace toxic elements in the soils of sugar beet field (Beni-Mellal, Morocco)

Abstract

Trace toxic elements concentrations (arsenic (As), boron (B), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), germanium (Ge), molybdenum (Mo), niobium (Nb), nickel (Ni), selenium (Se), zinc (Zn), yttrium (Y)) in sugar beet soils of Beni-Mellal region in Morocco were analyzed to evaluate their potential contamination level. The pollution was evaluated in three different sugar beet soils using enrichment factor (EF), geo-accumulation index (Igeo), contaminant factor (CF), potential contamination index (Cp), and pollution load index (PLI). The obtained results show that the studied agricultural soils were contaminated with various heavy metals and metalloids such as As (<8–34.5 mg kg−1), Ba (186.5–241.0 mg kg−1), B (73.0–103.7 mg kg−1), Co (24.7–34.7 mg kg−1), Ge (10.7–25.7 mg kg−1), Nb (11.5–25.5 mg kg−1), and Mo (32.3–35 5 mg kg−1). The results of EF (99.04–2.60), CF (31.81–1.43) indices showed that these soils are heavily polluted with various elements (Mo> Ge> As> B > Co) suggesting their anthropogenic source. Moreover, these elements are higher than the limits proposed by the Canadian soil quality guidelines which oblige farmers to change their farming habits in order to protect and maintain ecological balance of the soil.