Sabeen Alam1, Muhammad Waqas2*, Ghanwa Maqbool2, Iqra Shaheen3, Tehreem Fatima2, Salman Khan4 and Malik Faizan Shaukat5
1Department of Horticulture, The University of Agriculture Peshawar, Pakistan; 2Department of soil and environmental sciences Muhammad Nawaz Shareef University of Agriculture Multan, Pakistan; 3Department of Botany, Punjab University, Pakistan; 4PMAS, Arid Agriculture University Rawalpindi, Pakistan; 5Department of Horticulture, The University of Haripur, KP Pakistan
*Corresponding author: waqasmalik8786@gmail.com
Soil health refers to its ability to function as a vital living system within ecosystems, sustaining plant and animal productivity while maintaining water and air quality. However, soil health is increasingly threatened by micro-plastic pollution, a human-made contaminant that accumulates in terrestrial ecosystems and affects soil quality. Micro-plastics, particularly polystyrene (PS), polyethylene (PE), and polyester (PET), may disrupt plant growth and counteract the beneficial effects of organic matter on soil aggregate stability. To investigate these effects, we conducted a soil incubation experiment on lettuce under a Randomized Complete Block Design (RCBD) with ten treatments involving micro-plastic fibers, either alone or in combination with organic matter sources such as compost, leaf litter, and wheat straw. Each treatment was replicated three times. The study analyzed changes in soil physicochemical properties, lettuce growth parameters (fresh and dry weight, root length), and soil enzyme activities including proline and catalase. Results revealed that micro-plastics alone significantly reduced soil aggregate stability, enzyme activities, and plant performance, particularly root dry and fresh weight. However, when micro-plastics were combined with organic matter, the adverse effects were minimized. Treatments with organic matter alone consistently improved lettuce growth, enzyme activity, and overall soil health compared to control. These findings highlight that while organic matter additions can partially mitigate the harmful effects of micro-plastics, high concentrations of PS, PE, and PET remain detrimental to soil quality, soil micro-biota, and plant growth. Understanding these interactions is critical to evaluating the long-term risks of micro-plastics and even biodegradable plastics in agricultural ecosystems.