Biocontainer Use in Petunia xhybrida Greenhouse Production—A Cradle-to-Gate Carbon Footprint Assessment of Secondary Impacts

While biocontainers (i.e., biodegradable, plant-based containers) are marketed as being more sustainable than conventional plastic pots, little scientific literature exists to substantiate these claims. Past research has instead shown that adoption of plant-derived containers under current greenhouse production practices often leads to greater use of irrigation water, increased damage and waste during filling and shipping, and differences in plant growth. Life cycle assessment (LCA) serves as a holistic accounting of all the material/energy inputs and waste/pollution outflows associated with a given product. This paper draws on LCA methods to assess how secondary production impacts (e.g., irrigation demand) differ as container type changes. The basis for these comparisons is cradle-to-gate assessment of all of the inputs and outflows associated with production of a common annual ornamental plant (e.g., Petunia xhybrida) in a plastic container. This work does not consider the inputs and outputs of manufacturing the containers themselves, since that information is propriety in many cases. Container-specific secondary impacts derived from controlled studies were then incorporated as model parameters to assess differences in overall production global warming potential (GWP). Results show that the container itself accounts for approximately 17% of overall CO₂e (i.e., carbon dioxide equivalent) emissions during petunia production using a conventional plastic pot. Though container was a significant contributor to GWP, electrical consumption for supplemental lighting during plug production and irrigation throughout the production process proved to be the leading sources of CO₂e emissions (over 44%). Differences in GWP were only minor in comparing the use of various biocontainers with standard plastic containers for secondary production impacts. Results demonstrate that biocontainers compete with plastic pots for secondary impacts, suggesting they could potentially be more sustainable than plastic pots once pot manufacturing data are considered. Use of more efficient supplemental lighting sources, however, may ultimately have the greatest impact on overall GWP.