Project MINAGRIS aims to fight the hidden battle for soil health
Tiny fragments of plastic, invisible to the naked eye, are increasingly infiltrating soils worldwide. Originating from mulching films, irrigation pipes, and even vehicle tires, these microplastics enter agricultural lands largely unnoticed. Yet, they carry the potential to fundamentally alter the very foundations of farming. This hidden threat is drawing the attention of farmers, scientists, and policymakers alike, all working together to understand and counteract its effects. At the forefront of this effort is the European research project MINAGRIS (Micro- and Nano-Plastics in Agricultural Soils). Its specific mission is to uncover the extent and consequences of plastic pollution in soils.
MINAGRIS is coordinated by Wageningen University in the Netherlands and runs from September 2021 until August 2026. The project unites twenty European partners in a shared mission to tackle this pressing issue. It is funded entirely by the European Union with a contribution of โฌ6.9 million.
Farmers caught between innovation and contamination
Farmers find themselves in a paradoxical situation. While plastics have boosted agricultural productivity over the years, they now threaten the health of the soils upon which farming depends. Despite this, many farmers feel unequipped to address the problem. Surveys conducted by MINAGRIS reveal that over a third of European farmers lack sufficient information about the impact of plastics on soil health. More than two-thirds are unaware of existing regional or national initiatives aimed at tackling this challenge. The stakes could not be higher. Soil is a non-renewable resource on human timescales. Its degradation threatens to reduce crop yields, diminish water retention, and ultimately compromise the ecosystem services it provides.
The transformation of plastics from useful agricultural tools into soil contaminants happens quickly. Plastic mulches and irrigation tubes break down in the fields, while wind, rain, and routine farming activities disperse microplastics into the soil. Tire wear from nearby roads adds yet another often overlooked source of pollution. Actually, they release millions of microscopic particles into fields along roadsides. Once embedded in the soil, these microplastics interact with its chemical, physical, and biological systems, sometimes with alarming effects.
What plastics do to soil
A revealing study from the MINAGRIS team focused on earthworm casts – nutrient-rich deposits vital for maintaining soil structure and fertility. The presence of microplastics altered the chemical composition of these casts and influenced the bacterial communities within. However, these effects were mostly temporary. Researchers tested various microplastics, including conventional polyethylene, compostable plastics, and PBAT. They observed that initial increases in soil pH, ammonium levels, and dissolved organic carbon subsequently diminished over time. The key takeaway is that while microplastics can disrupt soil chemistry and microbiology in the short term, the core bacterial communities appear resilient and gradually restore balance. However, the long-term accumulation of these materials remains a serious concern, particularly for soils with less capacity to recover.
Another significant finding from MINAGRIS concerns soil water repellency (SWR). It is a condition in which soil resists absorbing water, severely affecting plant growth.
In the figure: SWR test on soil contaminated with LDPE microplastics_ Photo credit!ล pela ลฝeleznikar
Conventional microplastics are highly water-repellent. They can exacerbate this issue by disrupting the soilโs natural water dynamics, reducing its ability to retain moisture. Conversely, starch-based plastics seem to have fewer adverse effects, pointing toward possible safer alternatives for agricultural use.
The challenge grows even more complex when considering โforever chemicalsโ such as PFAS (per- and polyfluoroalkyl substances), found in plastic packaging and everyday consumer products like cosmetics and detergents. These chemicals persist in the environment and can accumulate in soils. Promising research led by Professor Edoardo Puglisi of the Catholic University in Piacenza, in collaboration with Professor Giancarlo Renellaโs group at the University of Padua, has identified around 20 species of PFAS-degrading bacteria. These bacteria, which are not typically harmful to humans, could potentially offer an ecological means to reduce PFAS contamination in soils and living organisms, pending further study.
Farmers ask for knowledge (and actively participate)
At the heart of the issue lies a fundamental need for better information. While farmers are motivated to reduce plastic use and manage waste responsibly, many lack access to clear, actionable knowledge about the risks plastics pose to soil health and sustainable alternatives. MINAGRIS surveys reveal that 86% of farmers are actively trying to minimize plastic use. Yet they also call for more technical guidance on how plastics interact with soils, which alternatives are viable, and how to navigate evolving regulations. Without this guidance, the threat of microplastic pollution could continue to grow unseen beneath the fields.
To bridge this knowledge gap, MINAGRIS has introduced citizen science initiatives. Such as the SoilPlastic app, which empowers farmers to participate directly in monitoring soil health. The app allows farmers to record their sightings of plastic in soils. With these records, they will help scientists to gain a better understanding of the impacts of plastic residues on soil health.
A holistic approach to research, tools, and policy
Looking ahead, MINAGRIS is breaking new ground by connecting plastic pollution with soil microbiology, water dynamics, and farming practices in a holistic way. The project is expanding field studies to validate laboratory findings across diverse European soils, developing smart labeling systems to help farmers choose safer plastic products, and enhancing citizen science platforms for wider soil monitoring. These efforts also aim to inform policymakers, helping to close regulatory gaps and promote a circular economy for agricultural plastics.
It is no longer a question of whether microplastics are present in agricultural soilsโthey undoubtedly are. The urgent question is how to manage their impacts effectively and prevent further degradation of this vital resource. The innovations pioneered by MINAGRIS, from biodegradable materials to participatory monitoring tools, offer promising pathways for mitigation but also call for a cultural shift. Plastics must be used with greater caution, farmers must be equipped with accurate knowledge, and policies must be designed to protect the soil, ensuring it remains resilient and capable of supporting life.
In this ongoing battle against microplastic pollution, soil is not merely a passive victim. With informed action and collaborative efforts, it can adapt, recover, and continue to nurture future generations.
In the figure: Soil core sampler containing a 25!cm water
repellent sandy column, as shown by the water drops
remaining on the soil surface (Dekker et al, 2009).
References
- Li, T., Cui, L., Xu, Z., Liu, H., Cui, X., & Fantke, P. (2023). Micro- and nanoplastics in soil: Linking sources to damage on soil ecosystem services in life cycle assessment. Science of The Total Environment, 904, 167455
- Huerta Lwanga, E., Beriot, N., Corradini, F., Silva, V., Yang, X., Baartman, J., Rezaei, M., van Schaik, L., Riksen, M., & Geissen, V. (2022). Review of microplastic sources, transport pathways and correlations with other soil stressors: A journey from agricultural sites into the environment. Chemical and Biological Technologies in Agriculture, 9, 20
- Testing soil water repellency on your farm: Guidance for farmers https://minagris.eu/project/testing-soil-water-repellency-on-your-farm-guidance-for-farmers/
