The Impact of Microplastic Concentration and Particle Size on the Germination and Seedling Growth of Pisum sativum L.

Hydroponic experiments were conducted to investigate the effects of varying particle sizes (5 μm, 0.1 μm, and 0.08 μm) and concentrations (0, 50, 100, 200, 500, 1000, and 2000 mg/L) of polystyrene plastic microspheres (PS-MPs) on the germination and growth of P. sativum seeds in order to investigate the effects of the microplastic environment on crop seed germination and seedling growth. The findings demonstrated that PS-MPs significantly harmed P. sativum seed germination. Specifically, low concentrations or high particle sizes weakened or promoted P. sativum seed germination, indicating varying susceptibilities to PS-MP treatment at different particle sizes. The strongest inhibitory effect on growth was observed under small particle size (0.08 μm) and high concentration (2000 mg/L). Stress had less of an impact on P. sativum in environments with low concentrations of PS-MPs, but in environments with medium and high concentrations, physiological and biochemical indicators like germination rate, stem length, and root length were significantly impacted. Furthermore, the particle size and concentration of PS-MPs had an impact on the growth effect of P. sativum seedlings. The indices of P. sativum seed germination were significantly impacted by the particle size of PS-MPs, despite the fact that PS-MP concentration was low. When the concentration of PS-MPs is low, the effects of varying PS-MP particle sizes on seed germination and root length are as follows: 0.1 μm > 5 μm > 0.08 μm. The concentration of PS-MPs had a significant impact on how it affected the buildup of dry matter and photosynthetic pigment.