EFFET DES MICROPLASTIQUES SUR LA FERTILITE DES SOLS AGRICOLE : CAS DE LA CROISSANCE DU MAÏS (ZEA MAYS)

Microplastics, detected in an estimated 76% of agricultural soils, are emerging as a global food security threat. While plastic pollution is often associated with aquatic environments, cultivable soils particularly in poorly managed urban and peri-urban areas are increasingly affected. This study was designed to assess the impact of plastic pollution, specifically low-density polyethylene (LDPE) and polyethylene terephthalate (PET) microplastics, on soil fertility and the development of maize (Zea mays). Method: Field investigations were conducted in Yaoundé to identify local sources of agricultural soil contamination by microplastics. A controlled 24-day experiment was then carried out using seven pots divided into three groups: a control group without plastic, an LDPE group, and a PET group, each with increasing concentrations of 250 g, 500 g, and 750 g of microplastics. Key parameters measured included germination rate, plant height, leaf coloration, and soil texture. Results. The findings revealed that microplastics significantly hinder maize growth, reduce germination rates, alter leaf pigmentation, and induce progressive soil compaction, thereby limiting water and nutrient availability. Field observations further confirmed the widespread presence of plastic waste in agricultural areas, primarily originating from food packaging, bottles, plastic bags, and irrigation with contaminated wastewater. Conclusion. This study highlights the clear link between human practices, inadequate waste management, and soil contamination. It contributes to the growing body of evidence on terrestrial plastic pollution and provides a scientific warning about the threats posed by microplastics to food security and the sustainability of local agriculture.