The increasing use of traditional agricultural plastic mulch films (PMs) has raised significant environmental concerns, prompting the search for sustainable alternatives. Soil-biodegradable mulch films (BDMs) are often proposed as eco-friendly replacements; however, their widespread adoption remains contentious. This review employs a comparative life cycle assessment perspective to evaluate the environmental impact of PMs and BDMs across their production, use, and end-of-life stages, providing strategies to mitigate their impact on agroecosystems. BDMs generally exhibit lower energy use and greenhouse gas emissions than PMs but contribute to greater land-use demands. Reported eutrophication and acidification potentials are less consistent, varying based on feedstock types and the scope of assessment of BDM, as well as the end-of-life management of PM. The environmental burden of both mulch types is influenced by the life cycle stage, polymer composition, farming practices, additives, film thickness, and local climatic conditions. The manufacturing stage is a major contributor to energy use and greenhouse gas emissions for both PMs and BDMs, despite their shared benefits of increasing crop yields. However, post-use impacts are more pronounced for PMs, driven by end-of-life strategy and adsorbed waste content. While starch-based BDMs offer a more sustainable alternative to PMs, uncertainties regarding the residence time of BDM residues in soil (albeit shorter than PM residues) and their effects on soil health, coupled with higher production costs, impede widespread adoption. For BDM end-of-life, soil biodegradation is recommended. Energy and material recovery options are crucial for PM end-of-life, with mechanical recycling preferred, although it requires addressing eutrophication and human toxicity. This review discusses these complexities within specific contexts and provides actionable insights to guide the sustainable integration of mulch films into agricultural practices.

Recent developments in biodegradable mulches (BDMs) provide a sustainable and eco-friendly alternative to persistent polyethylene (PE) mulches, addressing plastic pollution and disposal challenges; however, BDM degradation requires an extended period for complete mineralization under natural in-situ conditions. This study investigates the potential of thermophilic anaerobic digestion (AD) as an alternative to the in-situ degradation of BDMs. Two commercially available BDMs were evaluated in batch AD, initial characterization, and post-AD analysis of digestate were carried out for remaining fragments and liquid. In the TGA, a major weight loss in both BDMs at 400 °C indicated a high polybutylene-adipate-co-terephthalate (PBAT) content (>70 %), along with biobased polymers. After 160 days of digestion, cumulative methane yields were 226 and 129 mL CH₄/g VS for BDM Samples 1 and 2, respectively. These values correspond to 36 % and 25% of their respective theoretical methane potentials (628 and 508 mL CH₄/g VS) due to the low biodegradability of PBAT. FTIR analysis of BDM fragments showed similar spectral features with some shifts and new peaks (OH group) due to hydrolysis. The biomethane potential (BMP) tests showed no accumulation of volatile fatty acids (VFA), but soluble chemical oxygen demand (sCOD) increased due to partial biodegradation. Further analysis detected different monomers of PBAT, such as 1,4-benzenedicarboxylic acid, in the liquid phase of the digestate. This suggests that while most of the particles disintegrated (>98 % size reduction), the thermophilic anaerobic microorganisms were not able to mineralize BDMs completely, thus requiring further treatment.

Biodegradable mulch films (BDMs) can reduce agricultural plastic waste, but their environmental benefits depend on film composition, material properties, and end-of-life (EoL) management. This study conducted a cradle-to-grave life cycle assessment of poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA; PPLA) and poly(butylene adipate-co-terephthalate)/thermoplastic starch (PBAT/TPS; PTPS) mulch films in California strawberry production. Three BDM EoL scenarios were evaluated: soil biodegradation (SB), composting (CP), and anaerobic digestion (AD), with landfilled polyethylene mulch film (PEM-LF) as baseline. CP and AD were modeled as complementary routes for the recoverable film fraction. BDM scenarios reduced cradle-to-grave impacts by 7.50-9.02% relative to PEM-LF per functional unit, increasing to 12.32-18.21% on an equal areal-weight basis, through reductions in fossil fuel depletion, eutrophication, and ecotoxicity. PEM-LF performed worst because PEM manufacturing advantages were outweighed by LF ecotoxicity and eutrophication burdens. SB provided the greatest benefit by avoiding waste collection and disposal and crediting biomass formation as soil amendment. AD also performed favorably through biogas energy recovery, especially PTPS-AD, which was comparable to SB. CP was the least favorable BDM EoL strategy but remained better than PEM-LF. This study identified fossil-derived polyester content as the main target for reducing BDM manufacturing impacts, as PBAT contributed >90% of PPLA impacts and 68-96% in PTPS, including about 93% of global warming potential in both. Sensitivity analysis showed that lower fossil-derived polyester content, greater AD biomethane potential, shorter EoL transport distances, and greater SB biodegradation improved BDM performance. This study informs sustainable mulch use and waste management decisions by growers, policymakers, and waste managers.

Anaerobic digestion (AD) offers a potential route for integrating biodegradable plastics (BDPs) into circular agricultural waste management, but suitability depends on conversion of the complete material under practical digestion conditions. This review evaluates BDP compatibility with AD and engineering strategies to improve treatment. BDP conversion in AD generally requires depolymerization and hydrolysis to soluble products, initiated by surface microbial or enzymatic attack for some polymers, followed by microbial conversion to methane. The rate and extent of conversion depend on polymer chemistry and structure, crystallinity, chain mobility, hydrophilicity, material form and formulation, digestion temperature, and anaerobic microbial activity. Poly(hydroxybutyrate) (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) show high compatibility, while thermoplastic starch (TPS) and accessible cellulose-based materials undergo substantial conversion. Poly(lactic acid) (PLA) is strongly hydrolysis-limited under mesophilic conditions, whereas poly(caprolactone) (PCL) shows pronounced temperature-dependent conversion, with thermophilic conditions generally improving degradation. Poly(butylene succinate-co-adipate) (PBSA) converts more readily than poly(butylene succinate) (PBS) but remains incomplete without pretreatment. PBS and poly(butylene adipate-co-terephthalate) (PBAT) are poorly compatible. Polymer blends are often limited by their least-degradable major fractions. Fragmentation or mass loss does not indicate complete conversion, and polymer persistence does not necessarily indicate process instability. Reactor configuration and treatment should therefore target polymer-specific limitations through controlled co-digestion and loading, optimized particle size, targeted pretreatment, microbial acclimation or enrichment, appropriate temperature and staging, and AD-oriented material formulation.