Bridgestone, University of Arizona launch $70m guayule rubber project

Tucson, Arizona – Bridgestone Americas and University of Arizona researchers have teamed up to further investigate guayule-based natural rubber (NR).

The $70 million (€64 million) five-year project will focus on growing and processing the perennial desert shrub as an alternative source of NR, said the University of Arizona in a statement 8 May.

The initiative has received a $35 million funding from the US department of agriculture, which was equally matched by Bridgestone.

Kim Ogden, head of the department of chemical and environmental engineering at University of Arizona will lead the project, which aims to refine growing guayule with "climate-smart" practices.

"We want to use less water, install irrigation systems to avoid flood irrigation, use less fertiliser and educate the growers," she said.

"If you're looking at a big system life-cycle assessment, this is going to cut down on greenhouse gases," Ogden added.

Unlike annual crops, which require tilling the land every time the crops are planted or harvested, guayule is perennial.

That makes no-till and low-till farming a viable practice, which enables the storing of carbon dioxide in the soil.

In addition, guayule has natural properties that deter insects, so no insecticides are needed once the plants reach early maturity.

While the plant is a “promising” source of natural rubber, producing rubber alone is not economically viable, according to Ogden.

She, therefore, is working to find additional products that could be derived from guayule and marketed to supplement the revenues from manufacturing rubber products.

In addition to a rubber content of about 5%, guayule also has a resin content of 7% to 9%, which could be used to make natural adhesives and insect repellents.

The rest of the plant is woody biomass that could be converted into biofuel or used to make particle board.

The project aims to help growers transition to guayule crops from their traditional rotations of hay, cotton and wheat.

Bridgestone has been working with guayule in Arizona since 2012 at the company's 280-acre farm in Eloy.

The tire maker intends to expand the farm to 20,000 acres in the next few years by working with Native American farmers to grow guayule on tribal lands/

"Eventually, we hope to have plantings of around 100,000 acres, spread out across 15 or 20 facilities across the Southwest," said David Dierig, section manager for agro operations at Bridgestone.

The investment in the guayule rubber, Bridgestone explained, is part of the group’s policy to protect itself from potential supply chain interruptions.

“Having a single source for rubber globally means the supply of this critical material can be precarious and subject to market volatility,” it said.

Rubber prices are also impacted by diseases, labour costs and potential geopolitical disorder, Bridgestone added.

"There is a big risk, as well as supply chain problems, when you have all the natural rubber coming from one region of the world," according to Ogden.

"The goal for Bridgestone and for the other tire companies is to find reliable, domestic sources of rubber," she concluded.