Microplastics in vineyard soils: First insights from plastic-intensive viticulture systems

Area of Science:

• Environmental Science
• Soil Science
• Ecotoxicology

Background:

• Microplastic contamination in terrestrial ecosystems, particularly specialty cropping systems like viticulture, remains understudied.
• Viticulture involves plastic-intensive management and is prone to erosion, facilitating microplastic transport.
• Understanding microplastic distribution in vineyard soils is crucial for assessing environmental risks.

Purpose of the Study:

• To investigate the presence, spatial distribution, and composition of microplastics in vineyard soils.
• To compare microplastic levels in organically versus conventionally managed vineyards.
• To identify potential sources and transport pathways of microplastics in viticulture.

Main Methods:

• Soil and surface plastic samples were collected from eight vineyards in the Moselle and Saar Wine Region, Germany.
• Microplastic extraction using wet-chemical methods followed by chemical imaging via micro-Fourier-transform infrared spectroscopy (μFTIR).
• Analysis of macroplastic samples to compare polymer composition with microplastics.

Main Results:

• Mean microplastic concentration was 4200 ± 2800 particles/kg, with a mean size of 230 ± 300 μm.
• Polypropylene (PP), polyamide (PA), and polyethylene (PE) were the most abundant polymers.
• Higher microplastic concentrations were found in topsoil and at middle and bottom slope positions, suggesting erosion-driven transport.

Conclusions:

• Erosion is a significant pathway for microplastic downhill transport in vineyards.
• While management type did not significantly affect microplastic abundance, it influenced polymer composition.
• In-situ fragmentation of macroplastics is likely the primary source of microplastics in these vineyard soils.