Microplastics in vineyard soils: Input pathways and spatial distribution under different management practices

Abstract

Research on microplastics (MPs, 5000–1 µm) in the environment has been increasing lately since plastic pollution has become a global issue. However, for soil science microplastic research is still a new field and certain areas and soil systems have been underestimated so far. By now, studies on MPs in soils focused on common agriculture and the associated plastic input sources, whereas there are no existing publications on MPs in special cultures like viticulture soils, which is the object of study in this project. Several vineyards in the Mosel and Saar Wine Region (Rhineland-Palatinate) around the city of Trier have been sampled in a field campaign in February 2023. With this study serving as a very first investigation, the amount and composition of microplastics in vineyard soils of organic and conventional management practices will be assessed and compared. Our research also focuses on the spatial distribution of MPs along the vineyard hill slope at different slope positions, including erosive and depositional areas, as well as the distribution pattern in two different depths. Results will also be correlated with the measured soil parameters. Quantification of MPs and identification of their polymeric composition is done with µFTIR and ATR-FTIR, following an enhanced MP extraction protocol using NaBr solution (1.5 g cm-3) for density separation and oxidation protocols for organic matter dissolution. Possible input pathways will be estimated and the provenance is investigated using random sampled macroplastic collected at the vineyards. We expect first results on MP quantification and further insights on the MP abundance within viticulture systems in summer 2023, which will be presented within our contribution.