Polyethylene microplastic: impacts on ryegrass seed germination and seedling development

Area of Science:

• Environmental Science
• Agricultural Science
• Ecotoxicology

Background:

• Microplastic pollution is a growing global environmental issue.
• Agricultural ecosystems are particularly vulnerable to microplastic contamination.
• The impact of microplastics on forage crops like perennial ryegrass is not fully understood.

Purpose of the Study:

• To investigate the effects of polyethylene (PE) microplastics on perennial ryegrass (Lolium perenne L.) growth.
• To determine how different concentrations and particle sizes of PE microplastics affect ryegrass.
• To assess the impact of microplastics on seed germination, water uptake, and biomass accumulation.

Main Methods:

• A hydroponic system was used to grow perennial ryegrass.
• PE microplastics of varying concentrations (0–1000 mg/L) and particle sizes (200 nm, 25 μm, 200 μm) were applied.
• Control groups with no microplastics were maintained for comparison.

Main Results:

• PE microplastics significantly inhibited ryegrass seed germination, especially at smaller particle sizes (200 nm).
• Microplastic presence disrupted normal water uptake in ryegrass seedlings.
• Biomass accumulation was suppressed, with effects intensifying at higher microplastic concentrations.

Conclusions:

• Polyethylene microplastics negatively impact perennial ryegrass seed germination and seedling growth.
• Both the concentration and particle size of microplastics are critical factors influencing the extent of damage.
• Microplastic contamination poses a significant threat to forage production in agricultural ecosystems.