Do certified soil-biodegradable agricultural mulch films show worse results in life cycle assessment compared to conventional mulch films?
Even though LCA is the most systematic way to understand the interrelation between a product system and the environment (including biodegradable products), some specific issues, related to the nature of biodegradable products, require a more detailed way to be properly addressed. Current LCA methodologies cannot be considered fully fit for purpose when it comes to comparing certified soil-biodegradable mulch films with traditional ones. LCA results are greatly case-dependent and influenced by numerous choices. Product characteristics, system boundaries and LCA modelling need to be carefully considered to allow a realistic assessment. If done so, as shown in a study by the European Commission certified soil-biodegradable mulch films perform significantly better than conventional mulch films on a cradle-to-grave basis for seven out of eight impact categories for which a comparison was possible. The ameliorative results of biodegradable mulch films, including categories like acidification and eutrophication, were also possible thanks to a lower consumption of plastic required (due to the lower thickness) and the absence of a removal and disposal phase as required for traditional mulch films.
When performing comparative LCA’s on mulch films, numerous points need to be taken into consideration, as for example:
Removed mulch films are usually heavily soiled and often additionally polluted with pesticides and fertilisers, therefore making recycling a difficult option
Soil organic carbon is removed together with natural nutrients
Microplastics accumulation of non-biodegradable mulch films
Non-removal results in reduced energy need
Certified soil-biodegradable mulch films already passed comprehensive ecotoxicity testing and strict thresholds concerning other harmful substances in line with EN17033