Study finds ‘biodegradable’ bioplastics remain in the soil and contaminate farmland

14 November 2023

Findings on the longevity of “biodegradable” bioplastics in agricultural soils, contradicting industry norms, have been revealed in a scientific study by Wageningen University in the Netherlands. The research, revealed serious doubts regarding the biodegradability credentials of bio-based plastics.

The study sampled eight flower farms in the Netherlands and eight coriander farms in Spain, and found about 48 different types of microplastics in the tested samples. The soil samples gathered from the ditches surrounding the agricultural fields revealed the concentration of about 3,000 microplastics per gram of sediment, which means an environmental microplastic accumulation. Of the microplastics detected, 61% came from fossil fuels, whereas the remaining 39% were of biological origin.

The research revealed that these “biodegradable” plastic mulches remain in the soil for longer than the industry-prescribed two-year degradation period, in clear contradiction to the EN 17033 standard. For this reason, the research leader calls for further investigation. In addition, the study’s findings call into question the credibility of biodegradability statements linked to bio-based plastics, and require urgent action to address the worrying impact of bio-based plastics on agricultural soils and the wider environment.