Performance and Biodegradation in Soil of Novel Horticulture Containers Made from Bioplastics and Biocomposites

Abstract

<jats:p>The container-crops industry relies heavily on single-use plant containers made from petroleum-based plastics, most of which contribute to the solid waste stream in landfills. Plant containers made from biorenewable materials have potential to be more sustainable, but most commercially available biocontainers are either not durable enough for common production cycles or do not effectively biodegrade in soil after use. In 2012 and 2013, we evaluated 28 novel biocontainers (injection-molded prototypes) for their performance during plant production and their biodegradation in soil at two sites with dissimilar soil and climate in Iowa and Nevada, and we compared their performance to that of commercially available biocontainers. Prototype containers made of blends or composites of polylactic acid (PLA) or polyhydroxyalkanoates (PHA) performed well during crop production, and many showed an effective rate of biodegradation in soil. Their rates of biodegradation in Nevada were either similar or lower than they were in Iowa, but the highest rated containers were acceptable for use in both locations. Adding biobased fibers of distiller’s dried grains with solubles or corn stover to form composite materials improved biodegradation over that of the base polymers (PLA or PHA) and had little effect on container performance under greenhouse conditions. Many of the injection-molded prototypes performed as well as the petroleum control containers during crop production, yet biodegraded at similar or faster rates than commercially available fiber containers.</jats:p>

Effectiveness of Biopolymer Horticultural Products for Production and Postproduction Nutrient Provision of Garden and Bedding Crops and Container Ornamentals

“…Although some horticulturists have made efforts to recycle or reuse petroleum-based plastic containers, it is currently estimated that 98% of containers end up in the solid waste stream after only one use (Chappell and Knox, 2012;Kratsch et al, 2015). This practice results in the consumption and landfill disposal of more than 1 million tons of petroleum-based plastic in the form of horticulture containers each year in the United States (Schrader, 2013(Schrader, , 2016a.…”

Quantifying the Effects of Crop-cultural Practices on Growth and Development of Herbaceous Annuals and Perennials in Novel Bioplastic Biocontainers

“…TerraShell/OP47 (Summit Plastics), a wheat starch-based container with a minor PLA component (Nambuthiri et al, 2015), and SoilWrap (Ball Horticultural Co., West Chicago, IL, USA), a PHA-based bioplastic sleeve (Mohan, 2010), are the most commonly known commercial bioplastic plant containers. Growth and quality of plants produced TerraShell/OP47 or SoilWrap containers have been reported as similar to or greater than plants produced in petroleum-based plastic containers Kratsch et al, 2015;Villavicencio, 2010).…”

“…Appearance of containers after multiple weeks in greenhouses has been reported as unchanged for both types of containers or similar to petroleum-based plastic containers (Kratsch et al, 2015;Villavicencio, 2010). Additionally, data on container biodegradation exist only for TerraShell/OP47 containers (Kratsch et al, 2015), and containers were reported as 3.1-10.3% degraded after 6 weeks in greenhouse crop production and 24 weeks buried in soil. A manufacturer of PLA-based plant containers has marketed bioplastic containers under the trade name TWBP-05 (Nanjing Beautystone Import & Export Co., Nanjing, China) though no research has been conducted using these containers or container quality.…”

“…Mechanical properties of PHA are very similar to those of petroleum-based plastics, though applications and widespread use are limited due to the relatively high cost compared to conventional petro-chemical plastics (Liu et al, 2011). In contrast to PLA, however, PHA is biodegradable in soil under ambient conditions and degrades rapidly in composting systems (Kratsch et al, 2015;Madbouly et al, 2014;Schrader et al, 2016b).…”

“…Researchers have developed bioplastics from plant protein sources such as soybean (Glycine max) that can be compounded with other bioplastics and molded into plant containers (Kratsch et al, 2015;Yang et al, 2015a). Plant protein-based polymers, unlike bioplastics derived from microbial fermentation of sugars (i.e.…”