Development and Commercialization of a Biodegradable Stabilized Growing Media

Situation or Problem: Commercial reforesters, nurseries and greenhouses are searching for ways to reduce labor and handling costs. As the industry has looked for ways to reduce labor and handling costs, growers have become more mechanized, increasingly using machines to move and transplant their plant stock. These machines cannot handle current loose soil processes. Therefore, the growing industry uses stabilized media, which is a pre-manufactured substrate (sometimes peat, composted bark and other organics; other times completely synthetic materials) bonded together into a composite structure by a polymer binder or glue. These synthetic materials and binders are often unfriendly to the environment and do not meet sustainability objectives. Additionally, many countries strictly control or prohibit the importation of growing media that contains any form of organic material such as peat moss, compost or tree bark. Rynel's Grow-Tech division manufactures stabilized media for the forestry, horticultural, and hydroponics markets. Our current product, the FlexiPlugr, is held together with petroleum-based polyurethane. While growers are satisfied with the performance of the FlexiPlug and it has one of the lowest plastic contents in the industry, the residual polyurethane still remains in the ground for some time. It is not feasible to recycle the polyurethane in growing media after the plant has been grown in it, as it would need to be separated from the organic matter (plant and substrate). Purpose: Rynel/Grow-Tech successfully completed a Phase I effort to utilize a biodegradable polymer, hereafter referred to as PLA (Polylactic Acid) as an alternative to polyurethane and peat in its stabilized media. PLA is a biodegradable polymer made from corn, grasses and other plant-based feedstocks to create plastics. The use of bio-based plastics, particularly in packaging and semi-durable goods, is increasing as manufacturers try to decrease their dependence on petroleum-based plastics, which are tied to the price and availability of oil. Bio-based are becoming more cost-competitive. Consumers are also demanding greener, more ecologically-friendly products. Since PLA is produced from the fermentation of starch-rich agricultural by-products and other renewable plant materials, PLA is a sustainable and renewable source for polymers. Rynel/Grow-Tech have successfully spun and extruded PLA-based non-wovens. We propose scaling up and refining these formulations to create a bio-based stabilized growing media for trees and plants. Commercial reforesters and nurseries prefer to start their seeds and cuttings in a renewable stabilized media-one that is at least bio-based if not also biodegradable and compostable. The purpose of this Phase II effort is to master production technologies, scale up production output and begin marketing a sustainable stabilized, biodegradable growing medium for all three Grades with a focus on the forestry market.