Finding alternatives for natural rubber
Guayule-based natural rubber is one of the active initiatives that Nokian Tyres is working on. We are currently testing the suitability of different guayule varieties to be cultivated in central Spain, near our new testing center in Santa Cruz de la Zarza.
As guayule originates from the desert, it can survive in very dry and poor soil conditions. It is a plant that does not exploit areas of any other vegetation or food production, on the contrary, it makes use of wastelands. We are collaborating with local farmers, universities, research institutes, and companies in Spain. Guayule is an opportunity not only for Nokian Tyres but also for the local agriculture and industry.
Currently, natural rubber that is used in tires comes from rubber trees (Hevea Brasiliensis), which are growing in areas around the equator. This results in long logistics chains for tire manufacturers located in the north. If guayule succeeds as an alternative source for natural rubber, it will shorten the transporting distance and reduce the CO2 emissions.
Conservation of natural vegetation in tropical areas would be another environmental benefit. The substantial use of toxic pesticides on rubber plantations in Southeast Asia is a problem for the environment. Also, the South American leaf blight (Microcyclus Ulei) poses problems for the cultivation. The majority of the rubber trees in Asia are clones of varieties highly vulnerable to this disease.
Guayule, however, grows in dry areas, and no major plant diseases have thus far been identified as potential problems. It is also hypoallergenic, unlike the normal Hevea rubber. This is a relief for many people working in the rubber industry, logistics, and trade.
Studying guayule
In Spain, studies have been continued: what is the best way to maintain the plant, how to fertilize it and how to remove any weeds that may compete with the plant. The results have been promising, and in 2020, the researchers have developed a sustainable way of managing the plant where no synthetic biocides are needed.
Also, researchers have made promising experiments with cultivating the plants on poor soils in total absence of irrigation. Instead of planting ahead of the hottest season of the year, the planting had been carried out in the autumn to allow the survival of the plants. To affirm the promising results, the planting was carried out again in the next fall.
The researchers are also exploring the opportunities of plant waste as a part of a circular economy project, in which all the co-products of the plant are utilized.
In January 2021, there was unusual snowfall in the region due to the Filomena storm and the Madrid region recorded the heaviest snowfall in several decades. Despite the heavy snowfall, most of the plants survived and only some replanting was necessary. The exceptional weather phenomenon provided us with important knowledge on the survival of the plant in low temperatures and the effects it has on different varieties of the guayule plant.
MIDAS is a four-year EU financed project of marginal agricultural lands, climate-resilient and biodiversity-friendly industrial crops for innovative bio-based value chains. The project started in the end of 2022, aiming to develop innovative bio-based products following a bio refinery concept and the circular use of biomass. During the MIDAS project, our target is to explore further the use of guayule-based natural rubber in tires.