Abstract

Microplastics (MPs) can act as vectors of contaminants such as fungicides and trace metals. Their presence in water or soil might affect fruits and vegetables, while interactions between MPs and copper (Cu) nanoparticles might pose greater risks to soil properties, plant development and yield. The objective of this study was to evaluate the effect of the presence of MPs and Cu nanoparticles on plant growth and yield of strawberry, as well as on soil microbiological properties. The experiment was carried out in pots in a greenhouse; the soil was contaminated with polyethylene MPs and Cu nanoparticles. The design was completely randomized with four treatments (control, MPs, Cu, and Cu + MPs). Six months after planting, significant changes were observed in terms of plant height, stem diameter and root surface area. When compared to the control treatment, the MPs treatment resulted in a 27 % decrease in plant height, lower stem diameter values in all the contaminant treatments, and decreases in root surface area by 20 %, 21 % and 17 % in the MPs, Cu, and Cu + MPs treatments, respectively. Regarding number of inflorescences, total number of fruits, fruit weight and total aerial biomass, the MPs, Cu, and Cu + MPs treatments were statistically lower than the control (p < 0.05). The soil dehydrogenase activity decreased by 30 % due to the combined application of MPs and Cu nanoparticles, but this was not observed when MPs or Cu nanoparticles were applied alone, evidencing possible effects on the biological activity of the soil. Significant differences were found in acid phosphatase and urease activities in the Cu treatments with respect to the control and MPs treatments except for soil respiration. It can be concluded that the presence of Cu nanoparticles combined with polyethylene MPs favored a greater Cu availability in the soil and root Cu accumulation of strawberry plants.