Ecological Impacts of Plastic Waste on Sorghum sp. Production near Open Dumps in Cities of the Sahelian Arid Zone of Cameroon

Abstract

The accumulation of plastic waste in agricultural soils in Sahelian arid zones is a major environmental and agronomic challenge. Due to extreme climatic conditions, these plastics degrade slowly and release microplastic particles as well as various chemical compounds affecting soil quality and, by extension, crop productivity. This study examines the effects of plastic waste on the production of Sorghum sp. grown near open dumps at different distances (100 m, 500 m and 2000 m) in Sahelian cities in northern Cameroon. The analyses show that plastic pollution alters soil quality, modifies nutrient bioavailability and impacts sorghum germination, growth and yield. The greater the distance to the dump, the less the negative effects are marked. The germination rate is reduced by 40% at 100, by 25% at 500 m, and by 10% at 2000 m. Grain yield, a 48% drop was recorded in SFP (950 kg/ha) compared to the control site (1830 kg/ha) due to the accumulation of microplastics and pollutants in the soils of the exposed plots. The decrease in leaf water content in SFP (53%) reflects an increased water deficit due to the disruption of soil water retention. The increase in proline content (4.4 µmol/g in SFP) is an adaptive response to water stress, indicating that plants experience more intense physiological stress in the presence of plastic pollution. These results highlight the need for plastic waste management measures and sustainable agricultural practices to limit these impacts.

Keywords: Plastic waste, Sorghum sp., soil pollution, agricultural yield, Sahelian zone of Cameroon