Research increasingly identifies agricultural land as a reservoir for microplastics. Plastic pollution in soil is difficult to detect and extremely difficult to remove once particles become mixed with soil, organic matter, plant roots and microorganisms.
An invisible but growing problem
Plastics are widely used throughout agricultural value chains. According to the FAO, agricultural value chains used approximately 12.5 million tonnes of plastic products in plant and animal production in 2019. These included greenhouse and mulching films, irrigation systems, silage films and other production-related applications. A further 37.3 million tonnes were used in food packaging.
A 2023 international analysis estimated that the upper metre of agricultural soils worldwide could contain between 1.5 and 6.6 million tonnes of microplastics originating from wastewater and plastic-mulching inputs. The authors emphasised that this is a modelled estimate and that considerable uncertainties remain.
Microplastics are rarely visible. Over time, larger plastic items do not necessarily biodegrade but instead fragment into increasingly smaller particles that become mixed into the soil. In this way, plastic becomes part of a complex environment consisting of soil particles, organic matter, plant roots, and microorganisms.
FAO’s 2025 research review found evidence that plastic pollution can affect soil structure, water movement, nutrient cycling and microbiological processes. Effects on plant growth have also been observed in some studies. However, the results vary according to factors such as the type, size and concentration of the plastic particles and the conditions in the soil.
Plastic in soil is not just an agricultural problem
Agricultural films are often highlighted as a source of plastic pollution, but plastics reach agricultural soils through several pathways. These include sewage sludge, irrigation water, atmospheric transport and organic-waste streams contaminated with conventional plastic.
Plastic fragments that are not removed during the treatment of organic waste may remain in compost or digestate that is subsequently applied to agricultural land. Soil pollution is therefore connected not only to agricultural practices, but also to how society produces, uses, collects and treats materials and waste.
Once plastic is in the soil, removal is extremely difficult
There are currently no practical methods for removing dispersed microplastics from agricultural soils on a large scale without also disturbing the soil itself. Particles become mixed with mineral matter, organic material, roots and microorganisms and cannot simply be separated again. Many conventional plastics do not biodegrade completely under natural soil conditions. Once dispersed throughout the soil, these particles cannot easily be separated from mineral matter, organic material, roots and microorganisms. With no established practical method for removing them on a large scale, preventing further plastic inputs is an essential part of addressing the problem.
Can compostable waste bags reduce the risk of microplastics in soil?
Food-waste collection is one area where the choice of bag can affect the quality of the organic-waste stream. When conventional plastic bags are used to collect food waste, plastic fragments may enter the treatment process. If they are not fully removed during pre-treatment, residues can potentially remain in compost or digestate that is later applied to agricultural land.
Certified compostable waste bags are developed for the collection of organic waste and for treatment under specified biological conditions.
Why certified compostable waste bags can be relevant
Certified compostable bags are assessed for specific composting environments. EN 13432 sets requirements for packaging recoverable through industrial composting and biodegradation, while certification schemes such as OK compost INDUSTRIAL provide independent verification against the applicable requirements.
Most Biobag waste bags are also certified according to OK compost HOME, which applies to products assessed under home-composting conditions. The certification applicable to a specific Biobag product can be found on the relevant product page. Learn more about the differences between industrial and home composting in our guide compostable certifications explained.
Certification does not mean that a product should be discarded in nature. It documents how the product performs under the conditions covered by the relevant certification.
Prevention is key to avoiding microplastics in agricultural soil
Where certified compostable waste bags are accepted and effectively treated within the local organic-waste system, they can help reduce the risk of conventional plastic bag fragments entering compost or digestate.
Their use should form part of a broader approach that includes reducing unnecessary plastic use, sorting organic waste correctly and preventing non-compostable plastics from entering biological waste streams.
Certified compostable bags are not appropriate for every plastic application. Their role is most relevant where a product is used together with organic waste and enters a compatible collection and treatment process.
From cleanup to prevention
Microplastics in agricultural soils may be less visible than plastic pollution in rivers and oceans, but the available evidence indicates that they represent a growing and potentially long-lasting challenge. Because removing dispersed microplastics from soil is extremely difficult, prevention is essential. Protecting agricultural soil starts with careful waste management and preventing persistent plastic from entering biological cycles in the first place.
