iMulch: Eine Untersuchung des Einflusses von Polymeren auf ein terrestrisches Ökosystem am Beispiel von in der Landwirtschaft eingesetzten Mulchfolien

@article{Wolf2025,

title = {iMulch: an investigation of the influence of polymers on a terrestrial ecosystem using the example of mulch films used in agriculture},

author = {Carmen Wolf and Mike Wenzel and Björn Fischer and Ralf Bertling and Erich Jelen and Dieter Hennecke and Karlheinz Weinfurtner and Martina Roß-Nickoll and Henner Hollert and Antonia Weltmeyer and Kristina Bitter and Pauline Ruiz and Dusica Banduka and Jochen Tuerk and Lars M. Blank},

doi = {10.1186/s12302-024-01050-0},

issn = {2190-4715},

year  = {2025},

date = {2025-12-00},

urldate = {2025-12-00},

journal = {Environmental Sciences Europe},

volume = {37},

publisher = {Springer Science and Business Media LLC},

abstract = {Background



This article provides an overview of the iMulch joint project, which analysed the use of polyethylene (PE) and biodegradable mulch films made of a polylactide (PLA) and polybutylene adipate terephthalate (PBAT) on agricultural land as a source of microplastic. The development of a detection methodology using Raman spectroscopy and thermo-extraction desorption gas chromatography mass–spectrometry (TED-GC–MS), the adsorption behaviour, ageing in drainage water and soil, their transport behaviour in lysimeters, ecotoxicity, uptake in plants, a life cycle assessment (LCA) and upcycling were considered.

Results



The PE film tested showed hardly any degradation or fragmentation during the ageing tests. The biodegradable films showed incipient degradation after 8 weeks in drainage water and initial degradation after 12 weeks in soil ageing experiments. Additionally no degradation could be detected in the lysimeter test within the 24 months analysed. The biodegradable films could be metabolized in laboratory tests with some microorganisms present in the soil. This indicates that these films can be degraded in the environment if the conditions for degradation are optimal. No microorganisms or fungi that could degrade the PE film within a respective period of time were detected in the soil. Adsorption of the tested substances was not observed. Incorporated in soil, mulch film microplastic showed retention of extractable pesticides. In the ecotoxicological tests, both film types showed no acute toxic effects in the earthworm Eisenia fetida and the springtail Folsomia candida. Endocrine activity was observed in eluate samples from both films. However, aged films showed fewer effects than non-aged films.

Conclusion



Both types of film show no transport or degradation in the tests under real conditions, which means that they remain in the upper soil layer, where they are available to soil organisms and can lead to high concentrations in the future. As the biodegradable film could be degraded, at least under ideal conditions, we recommend its use. However, proof of degradation must first be verified under real field conditions. In addition, we recommend the use of thicker conventional mulch films to minimize the emission of plastic particles. For this purpose, a minimum lower limit for the material thickness should be defined.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{SEIDEL2025119345,

title = {Sorption to mulch film decreases bioavailability of two model pesticides for earthworms in soil},

author = {Antonia Seidel and Isaac Heimbach and Thomas-Benjamin Seiler and Henner Hollert and Lars M. Blank and Martina Roß-Nickoll},

url = {https://www.sciencedirect.com/science/article/pii/S0147651325016902},

doi = {https://doi.org/10.1016/j.ecoenv.2025.119345},

issn = {0147-6513},

year  = {2025},

date = {2025-01-01},

urldate = {2025-01-01},

journal = {Ecotoxicology and Environmental Safety},

volume = {306},

pages = {119345},

abstract = {Microplastic pollution and its environmental consequences have been a research topic for decades. Alongside sewage sludge and compost, mulch films are one of the most important sources of organic matter in agricultural soils. As microplastics accumulate in these environments, they increasingly interact with other agrochemical contaminants, such as pesticides. The consequences of the combined presence of mulch film microplastic and pesticides, especially on bioavailability and toxicity, still need to be understood. We investigated the interaction of pesticides with polyethylene mulch films by choosing the neonicotinoid Thiacloprid and the fungicide Tebuconazole in their commercial formulations as plant protection products, serving as representative hydrophobic and hydrophilic substances. The impact of PE microplastic (150 mg/kg) on both pesticides’ extractability and earthworm mortality was determined. The hypothesis is that microplastics reduce pesticide bioavailability in soil. Hence, reduced earthworm toxicity might be observed. Acute toxicity testing with Eisenia fetida showed a slight decrease in toxicity while MPP was present, shifting the LC50 from 110.3 to 120.6 mg/kg (Tebuconazole) and 20.3–22.6 mg/kg (Thiacloprid). The chemical analysis after two-time extraction of test soil with CaCl2 and then solvents confirmed the reduced availability of pesticide in the presence of MPP. Our research shows that microplastic at application-relevant concentrations can retain pesticides and reduce pesticide toxicity. These findings impact pesticide efficiency in soils that accumulate microplastic, potentially requiring the adaptation of agricultural practices. This study underscores the need for further research and mitigation strategies as our understanding of the interactions between pesticides and microplastics in soil evolves.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Weltmeyer2024,

title = {Different mulch films, consistent results: soil fauna responses to microplastic},

author = {Antonia Weltmeyer and Martina Roß-Nickoll},

doi = {10.1007/s10661-024-13096-x},

issn = {1573-2959},

year  = {2024},

date = {2024-10-00},

urldate = {2024-10-00},

journal = {Environmental Monitoring and Assessment},

volume = {196},

publisher = {Springer Science and Business Media LLC},

abstract = {Agricultural activities contribute to plastic pollution, with unintentional introduction and intentional use of plastic mulch films leading to the accumulation of microplastic particles in soils. The lack of removal techniques and scarce information on the effects on soil organisms, especially for biodegradable mulch films, necessitate an assessment of potential effects. This study aimed to elucidate the effects of mulch film microplastic on soil fauna by investigating reproduction output and subcellular responses before and after recovery from exposure. Two common soil organisms, Folsomia candida and Eisenia fetida, were exposed to petroleum-based polyethylene (PE) and biodegradable polylactic acid/polybutylene adipate terephthalate (PLA/PBAT) microplastic for 28 days, according to OECD guidelines 232 and 222, respectively. Juvenile numbers revealed no polymer- or concentration-dependent effects on E. fetida and F. candida reproduction after exposure to up to 5 and 10 g/kgdw soil, respectively. To provide a more sensitive and early indication of sublethal effects, subcellular responses in E. fetida were analyzed. Glutathione S-transferase (GST) activity increased with rising microplastic concentration; however, catalase (CAT), acetylcholine esterase (AChE) activity, and reactive oxygen species (ROS) did not differ from control levels. Further, the more environmentally relevant PE polymer was chosen for in-depth assessment of subcellular response after 28-day microplastic exposure and subsequent 28 days in uncontaminated soil with E. fetida. No significant differences in biomarker activity and stress levels were observed. We conclude that mulch film–derived microplastic did not adversely affect earthworm and collembolan species in this scenario, except for a slight induction in the detoxification enzyme glutathione S-transferase.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}