Soil texture modifies the impact of microplastics on winter wheat growth

Abstract Purpose Research on the impact of microplastics (MPs) on plant performance has primarily focused on MP type or concentration, often neglecting the role of soil texture. Methods In this study, a 42-day experiment was conducted in which winter wheat was grown in three soils of different textures, contaminated with two types of MPs: low-density polyethylene particles (LDPE) and polyester fibers (PES) at 0.4% concentration. The effects on soil water content, nutrient levels, and plant growth were examined. Results In silty loam, LDPE reduced root length and biomass, likely due to altered soil texture, which created more macropores and reduced water and nutrient availability. PES fibers had similar effects, indicating that changes in soil porosity impacted root access to resources. In sandy loam, both MP types reduced root growth, with PES fibers causing a significant 85% reduction in root length and decreasing nitrogen content, suggesting impaired nutrient availability due to reduced nitrification. Conversely, in silty clay loam, LDPE increased root length by 4.6 times, likely due to enhanced water movement pathways, although it also increased water loss. PES fibers showed minimal positive effects on root growth but reduced nutrient content. Conclusion Overall, soil texture had a significant impact on how MP affected plant growth, as the two types of MP had different effects on different soil textures. LDPE increased macroporosity in fine soils, promoting root growth, but reduced nutrient uptake in coarse soils. PES fibers influenced soil structure, affecting water retention and nutrient availability differently in different soil types. The study highlights the complexity of MP–soil–plant interactions. Moreover, it also calls attention to rethinking soil management in the future, such as using biodegradable alternatives, applying biochar or avoiding plastic-coated controlled-release fertilizers.