The spatio-temporal variability of soil microplastic distribution and erosion-induced microplastic export under extreme rainfall event using sediment fingerprinting and 7Be in intensive agricultural catchment

Summary

This study characterised the spatio-temporal distribution of soil microplastics across an intensive agricultural catchment in China and quantified their erosion-induced export during extreme rainfall events. Using sediment fingerprinting and 7Be tracing, the researchers identified land-use-converted cropland and conventional crop farmland as the primary sources of microplastic accumulation and export, accounting for approximately 50% of total microplastic transport. The findings suggest that targeted land-use management, particularly in recently converted agricultural areas, should be prioritised to mitigate microplastic pollution from soil erosion in intensive farming systems.

Regional applicability

Whilst the study was conducted in China, the mechanistic findings regarding microplastic accumulation and erosion-induced export in intensively managed agricultural systems are likely transferable to United Kingdom arable and horticultural regions. UK intensive farming areas with similar rainfall intensity and soil erosion vulnerability would benefit from comparable source apportionment and land-use targeted mitigation strategies, though absolute microplastic loads and land-use patterns differ.

Key measures

Soil microplastic abundance by land use type; microplastic export loads under extreme rainfall; sediment fingerprinting using 13C analysis; beryllium-7 (7Be) tracing of erosion-induced sediment transport

Outcomes reported

The study quantified spatio-temporal variability in soil microplastic abundance across different land use types and measured microplastic export loads induced by soil erosion during extreme rainfall events. Cropland converted from forest and crop farmland showed highest microplastic abundance, whilst vegetable farmland showed lowest.

Topic tags