Impact Of Heavy Metals (Copper, Cadmium, Mercury, And Lead) On the Fertility, Microbiological Activity, And Crop Productivity of Irrigated Meadow Soils: A Literature Review from An Ecological and Food Security Perspective

Abstract

Heavy metal contamination of soils has emerged as one of the most pressing global environmental challenges, with irrigated meadow soils being particularly vulnerable due to their intensive agricultural use and proximity to industrial zones. Among the most hazardous elements, copper (Cu), cadmium (Cd), mercury (Hg), and lead (Pb) significantly disrupt soil fertility, alter microbiological activity, and reduce crop productivity, thereby threatening ecological stability and food security. This review synthesizes recent scientific literature to examine the pathways through which these heavy metals accumulate in irrigated meadow soils and their subsequent impacts on soil biochemical properties, microbial diversity, and plant growth. Evidence from multiple studies indicates that excessive concentrations of Cd, Pb, and Hg adversely affect soil enzymatic activities and beneficial microbial communities, while Cu, though essential in trace amounts, becomes phytotoxic at higher levels. The review also highlights how contaminated soils contribute to the bioaccumulation of heavy metals in crops, posing risks to human health through the food chain. Furthermore, it evaluates current monitoring practices and bioremediation approaches, including phytoremediation and microbial-assisted remediation, as sustainable strategies for mitigating heavy metal pollution. Overall, this article emphasizes the need for integrated ecological and agricultural policies to prevent further soil degradation and to ensure food safety in regions affected by industrial emissions and intensive irrigation practices.