Accumulation of synthetic, non-biodegradable plastic materials in the environment is of major environmental concern. While plastic accumulation in aquatic systems is well documented and has received considerable research interest, comparatively little is known about plastic accumulation in terrestrial systems. Among these, agricultural soils may receive direct inputs of plastics because plastics are heavily used in agriculture to increase crop yields. One major application of polymers in agriculture is their use as mulch films (approximately 1 million tons/year in 2001). These films are typically made of non-degradable polymers (e.g. low-density polyethylene) that, if not completely removed from agricultural fields after use, pose a high risk for accumulating in soils.
Usage of plastics materials that biodegrade in soils is a promising alternative to avoid accumulation of plastics in agricultural soils. Polyesters composed of repeated units of aliphatic diols and aliphatic diacids or of aliphatic diols and aliphatic and aromatic diacids represent commercial materials that have promising properties for replacing problematic polyethylene based materials in agriculture.
In this collaborative project (Dr. Michel Sander, Prof. Kristopher McNeill, ETHZ) we plan to advance a more concise understanding of the fate of biodegradable polyesters in soils.