Agricultural Plastics in the Circular Economy: What Happens to Greenhouse Films After the Season?

For two types of film, this approach reaches its limits. The first is greenhouse films. They have only recently been fully integrated into the ERDE system, which means collection rates are still low. A large proportion still ends up as waste or is incinerated rather than entering the circular economy. The second is thin mulch films, which lie flat on the field. They are often paper-thin, slit and covered with soil at the edges. Anyone trying to collect them after harvest ends up tearing them into shreds – and those shreds stay in the soil. According to the same NABU study, mulch films alone leave around 9 kilograms of plastic per hectare per year in agricultural land. And what is torn and embedded in the soil can hardly be recycled.

This is the crux of the problem: not every film can simply be collected and recycled. One is still too new to the system, the other too thin to recover. For manufacturers and suppliers, the question is: how do you keep these films out of the waste stream – and out of the soil? There are two very different answers. Depending on the film, one or the other will apply.

The first route focuses on durability. Agricultural films have a tough job: intense sunlight, extreme heat and aggressive chemicals such as sulphur and chlorine from crop protection products. All of this takes its toll on the material until it becomes brittle and tears. Heat and light stabilisers can help here. They halt the damaging chain reaction within the plastic before it takes hold. BASF, for example, offers the stabilisers Tinuvin NOR 356 and Tinuvin NOR 211 AR for this purpose. They are designed for greenhouse films that must withstand years of sun and pesticide exposure.

The logic is straightforward: what lasts longer needs to be replaced less often – meaning less waste per season. A second trend that such stabilisers support is downgauging: thinner films with equivalent performance. Less material, longer service life, better recyclability – these go hand in hand. For greenhouse films, this effect is particularly significant, as they are already in use for several years. Rather than degrading in place, they are collected at the end of their life and recycled. And the longer they last, the less frequently a new one is needed.

The second route reverses the logic entirely. Some films do not need to be collected at all – they break down in the soil on their own. Biodegradable plastics are decomposed by microorganisms into water, CO₂ and biomass, leaving no microplastics behind. This is precisely the approach taken by the "Huminmulch" project at Fraunhofer UMSICHT: a biodegradable mulch film containing humic substances. After the season, it and its nutrients are absorbed into the soil. For thin mulch films that are almost impossible to recover from the field, this could be a way out. There is no longer any need to collect them – and yet no plastic fragments remain in the soil.

The catch: biodegradable does not always mean biodegradable in the same way. How quickly and completely a film breaks down depends heavily on soil conditions and weather. For PLA, the range spans from near-complete breakdown within 180 days to virtually none over an entire year. Standards therefore provide clarity. The DIN EN 17033 standard applies specifically to mulch films: in soil at 20 to 28 °C, at least 90 percent must have disappeared within a maximum of 24 months. The "OK biodegradable SOIL" certification from TÜV Austria sets slightly stricter requirements. An important distinction is "industrially compostable" (standard EN 13432): what breaks down in a composting facility does not automatically do so in a field.

The two routes are not in competition. They suit different applications. Biodegradable films are most effective where collection and recycling are barely feasible – that is, for thin mulch films. Their market share remains very small, at one to two percent. Nor are they automatically the more sustainable option: the German Federal Environment Agency notes that bio-based plastics do not necessarily perform better across their entire life cycle.

For thick, multi-year films, the situation is reversed. Greenhouse, thermal and asparagus films can be cleanly removed from the field and recycled to a high standard – asparagus films last an average of six to eight years. Here, the combination of durability and organised collection is clearly the better approach. NABU puts it plainly: recycling keeps the raw material in the loop; composting removes it. For greenhouse films at the end of the season, this means specifically: additives extend their service life. And the better systems like ERDE are at capturing them, the more likely they are to become a new raw material rather than waste. There is no single perfect solution – but for many films, there is the right one.

The ERDE initiative (Erntekunststoffe Recycling Deutschland) is the take-back and recovery system for agricultural plastics, founded in 2013. It is run by IK Industrievereinigung Kunststoffverpackungen, operated by RIGK GmbH and funded by manufacturers.

In 2026, more than 700 collection points and over 160 partners are available across Germany. Farmers drop off their used films clean and sorted by type – at significantly lower cost than incineration. All films collected through ERDE are recycled entirely through mechanical processes within Europe.

In 2025, this amounted to 37,342 tonnes, saving around 37,042 tonnes of CO₂ equivalents. Through a voluntary commitment to the Federal Environment Ministry, the industry aims to collect more than 75 percent of all silage and stretch films by 2027.

• EU – binding: The REACH restriction on intentionally added microplastics (Regulation (EU) 2023/2055, in force since October 2023) prohibits microplastics in many products. Transitional periods apply to agriculture: from October 2028, certain fertilisers not covered by EU rules may no longer contain microplastics; from October 2031, the same applies to plant protection products and treated seeds. Only biodegradable polymers will remain permitted.
• Basel Convention – binding (international): Since January 2021, the Plastic Waste Amendments regulate the cross-border trade in plastic waste. Exports – such as collected agricultural films to recycling facilities abroad – are only permitted with prior consent from the receiving and transit countries.
• FAO – voluntary: The Voluntary Code of Conduct for the Sustainable Use and Management of Plastics in Agriculture has been available in preliminary form since February 2025. It is not binding and has not yet been formally adopted by the FAO Committee on Agriculture (COAG), but is open to countries for voluntary application. It is based on the 6R principle: Refuse, Redesign, Reduce, Reuse, Recycle, Recover.
• OECD & UN – data foundation and outlook: The OECD's Global Plastics Outlook provides the figures and policy scenarios underpinning many regulatory frameworks – without itself being binding. In parallel, UN member states have been negotiating a global plastics treaty since 2022; as of 2026, an agreement has yet to be reached.

Author: Jennifer Meyer | K-Mag

Jennifer Meyer is a member of the K editorial team and is interested in the stories behind trends and technologies in the plastics industry. What drives her? The question of how plastics are changing—and what that means for people. With her eye for detail and a passion for sustainable concepts, she creates content that not only informs but also sparks curiosity.