Environmental impact of biodegradable and non-biodegradable agricultural mulch film: A case study for Nordic conditions

PurposeBiodegradable mulch film is considered an environmentally friendly alternative to non-biodegradable-based mulch film for agricultural use. The purpose of this study is to compare the environmental impact of non-biodegradable mulch film to biodegradable mulch films for use in Nordic conditions, including assessing their plastic pollution potential.MethodsA life cycle assessment was conducted to calculate the potential environmental impacts of the films, while the plastic pollution potential was assessed with a dynamic material flow analysis, considering degradation over time and fate to various environmental compartments. The plastic pollution potential was based on empirical degradation data in Nordic conditions.Results and discussionThe results of the LCA and MFA analyses show that the use of non-biodegradable material in Nordic conditions leads to the lowest environmental impacts and pollution if it is fully collected after use. In fact, biodegradable mulch film leads to higher environmental impacts over its life cycle in most environmental impact categories. However, comparing environmental burdens from non-biodegradable and biodegradable mulch film is difficult due to the lack of data on biodegradable films. The results further highlight that biodegradable films will reach a dynamic equilibrium (a plateau phase) in soils in Nordic conditions between the degradation of old film and the application of new film, if not enough time is given for the films to entirely degrade. Farmers would need to apply biodegradable films with several years of interval, if the films should be entirely degraded.ConclusionsThis study supports the recommendations that biodegradable plastic has potential when used as mulch film, but these recommendations should be situation-specific, depending on farmers' ability to handle the mulch film properly. The authors highlight that the LCA results are uncertain due to limited data availability and encourage the biodegradable plastic industry to be more transparent by making their LCIA data available.