Spatial repartition and contamination assessment of heavy metal in agricultural soils of Beni-Moussa, Tadla plain (Morocco)

The focus of this study is to determine the degree of soil pollution in Beni-Moussa irrigated perimeter. The soil is sampled at 25 various stations all through the perimeter to analyze a set of physical–chemical parameters like pH, organic matter (OM), carbonate content (CaCo3), granulometry, magnetic susceptibility at low frequency (χLF) and heavy metals (Zn, Cr, Pb, Cu, As, Ni, Cd, and Fe). Pollution indices (Geo-accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), pollution Load Index (PLI), and potential ecological risk assessment (PER) are used to evaluate the degree of pollution. The achieved results imply that the soil is alkaline, rich in OM and CaCo3, and has a silt texture. The soil EF and CF were: Cu > As > Ni > Zn > Cr > Cd > Pb. The PLI values indicate anthropogenic contamination originates from human and agricultural activities located around Ouled Ayad, Had Bou Moussa, and Afourer. Moreover, χLF is significantly positively correlated with PLI. The results further attest that PLI can be estimated from χLF through the following equation PLI=0.8χLF+1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{PLI}} = 0.8\chi {\text{LF}} + 1$$\end{document}