Supercharged soil could pull carbon right out of the air
A simple seed treatment could drastically increase the amount of atmospheric carbon captured by crops, and store it underground for longer
- By Delle Chan source: Wired.co.uk
Friday 26 March 2021
Fundamentally, two of the world’s most pressing challenges, climate change and soil degradation, boil down to a simple imbalance: there is too much carbon in the air, and not enough in the ground. And for Guy Hudson and Tegan Nock, the solution is patently obvious.
The duo are the co-founders of Soil Carbon Co, an Australian agritech startup specialising in what it terms “microbe-mediated carbon sequestration” – a method of removing carbon from the atmosphere via microbial fungi and bacteria. The technology in question? A biological treatment applied to seeds that converts atmospheric carbon into a more stable compound which can then be stored deep in the ground – potentially for centuries.
The star ingredient in the seed treatment is a blend of microbial fungi called “dark septate endophytes”, which live symbiotically in the roots of the host crop and grow along with the plant. Their primary function is to convert carbon dioxide absorbed through photosynthesis into fungal melanin compounds, which are less susceptible to breaking down upon contact with water. These compounds are then deposited in soil microaggregate – tiny clumps of soil that provide an oxygen-free environment conducive to long-term carbon storage. As Nock explains, it creates a win-win situation for both air and soil. “Carbon increases the water holding capacity of the soil, and also helps capture and retain nutrients beneficial to plants, translating into higher yields and better productivity,” she says.
Nock and Hudson stress that Soil Carbon Co’s technology is rooted in rigorous science – as demonstrated by the fact that its affiliate SoilCQuest, a non-profit research institution, is also its largest shareholder. “This ensures that we have the integrity and scientific robustness that we feel is really required in climate technology,” says Hudson. Investors are sold: in June 2020, Soil Carbon Co raised AUD$10 million (£5.5m) in seed funding in a round led by Horizons Ventures, the private investment arm of Hong Kong tycoon Li Ka-shing.
This capital injection is enabling Soil Carbon Co to go mainstream. Nock and Hudson are currently trialling their seed treatment on crops such as canola, soybean and wheat in Australia and the US, and hope to bring it to market later in 2021. In addition, they are working with partners to integrate their technology into existing agricultural supply chains. “Our timeline is dictated by the climate crisis, so we are working very hard to expedite the process,” says Hudson. “The most important thing is to get our technology into the hands of as many growers as possible.”
Fortunately, a major selling point of Soil Carbon Co’s technology is that it is low-cost and easy to adopt, unlike many of the regenerative agriculture methods being practised today, such as no-till farming. Essentially, all farmers have to do is inoculate their crops with the microbes – which will be sold in freeze-dried form – and let nature take its course. What’s more, it is highly scalable. “You already have a workforce of about a billion farmers globally, who spend every day working at the intersection of atmosphere and soil, and who deeply understand that interface,” says Hudson. “You also have ready infrastructure in the form of crops, which are effectively like small fans, constantly sucking carbon down into the soil. This all means that we have the capacity to draw down enormous amounts of carbon within a short time-frame.”
It’s certainly an elegant solution – one that could help avert climate catastrophe and sow the seeds for a greener future. “Hopefully, our technology will buy the rest of the world some time to transition away from fossil fuels and to a cleaner economy,” says Hudson. “While it is not going to solve climate change, we want to give humankind a fighting chance.”
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