Australian farmers grow mushrooms to recover emitted carbon dioxide

When sowing seeds, farmers spread an additional layer of crushed fungal spores. These spores attach to the roots of plants, capturing carbon that the plants absorb from the air and locking it away in an underground storage.

In a vast agricultural area exceeding 40,000 hectares in Australia, farmers are implementing an unusual method to slow down the process of climate change.

These farmers are attempting to harness the power of tiny fungi to draw carbon dioxide out of the atmosphere and store it underground.

This effort is part of a global initiative by entrepreneurs and investors to answer the question of whether the land can help clean up climate pollution.

They are employing various technologies on agricultural land, not just for cultivation but also to absorb excess carbon dioxide released over more than a century of fossil fuel burning and intensive farming.

A handful of soil from a newly sown canola field treated with Loam Bio’s fungal preparation, near Canowindra, Australia. (Source: Japan Times).

When sowing seeds, farmers spread an additional layer of crushed fungal spores. These spores will attach to the roots of plants, capturing carbon that the plants absorb from the air and locking it away in underground storage that can retain carbon for much longer than the natural carbon cycle.

This project, a product of an Australian company called Loam Bio, is one of many startups that have raised hundreds of millions of dollars in investments aimed at using land to remove carbon dioxide from the atmosphere.

In addition to companies using fungi like Loam Bio, Andes, and Groundworks Bio Ag, other startups have various methods for removing carbon dioxide.

Lithos and Mati provide farmers with crushed volcanic rocks capable of absorbing carbon to spread over their fields.

Silicate Carbon is grinding surplus concrete into fine powder, while some other companies are burning dead crop material into charcoal.

These projects have the advantage of not requiring too much work from the farmers.

“It’s quite simple,” describes Stuart McDonald, a fifth-generation Australian farmer, sharing his experience of applying a layer of fungal spores to wheat and canola seeds on his farm near Canowindra this year. “We don’t have to change much, nor do we need a large capital investment.”

All of these efforts aim to regenerate land that has been degraded by intensive agriculture over decades by restoring bacteria and minerals. While it’s still too early to assess the effectiveness of these projects, their potential is significant.

According to the Intergovernmental Panel on Climate Change, soil contains three times more carbon than the atmosphere and has the capacity to absorb over 5 gigatons of carbon dioxide each year, or 1/7 of the total carbon dioxide emitted by human activities into the atmosphere. This positions soils as the second largest carbon reservoir in the world, after the oceans.

“I believe the land will play a crucial role,” says Rob Jackson, a climate scientist at Stanford University, although he remains skeptical about whether the commitment to fungal additives in field trials can have a statistically significant impact on operating farms.

“We need to engage with billions of soil samples to make a real difference,” he emphasizes. Moreover, the agriculture sector itself accounts for up to a quarter of global greenhouse gas emissions.

Many express concerns that this technology merely treats symptoms rather than addressing the root causes of climate change.

“These cannot be an excuse for us to continue burning fossil fuels,” Jackson warns.

Tegan Nock, co-founder of Loam Bio and a sixth-generation farmer, agrees. She states, “this is just one of the things that can help buy us more time.”

The choice of Australia as a testing ground is not solely for the health of the soil. For some Australian farmers, storing carbon dioxide in the soil also earns them government payments.

At one point, McDonald, 52, transported solid waste from Sydney’s sewage to fertilize his fields and measured a small amount of carbon in the soil. However, he was uncertain how long it would be stored.

Other farmers have also observed increases in soil carbon over the years, only to return to initial levels later.

Skeptics note that soil carbon fluctuates with weather. During unusually wet years, carbon accumulates in the soil, only to dissipate in dry years. There are warnings that the carbon credits allocated to agricultural projects have been exaggerated.

Fungal Gamble

In reality, carbon exists in the soil in many different forms, but most of it is in the form of volatile organic matter. In agricultural soils, carbon originates from organic waste or manure.

It can return to the atmosphere within a few years, with droughts or wildfires capable of burning it faster and releasing carbon dioxide back into the air.

Stuart McDonald, a fifth-generation farmer, is seeking new seeds coated with Loam Bio’s fungal treatment, near Canowindra, Australia. (Source: Japan Times).

However, there are more stable forms of carbon in the soil. They bind to soil minerals and can remain for a century or longer. This is how Loam Bio’s fungi store carbon.

According to Loam Bio, the fungi will capture carbon dioxide that plants absorb from the air during photosynthesis, storing it underground and returning it in the form of nutrients that plants need.

For Alan Richardson, a soil biologist at the Commonwealth Scientific and Industrial Research Organisation, an Australian government agency, the concept of using fungi to store carbon underground makes sense.

However, it will only be effective if farmers do this annually, allowing the soil to accumulate carbon over many years. “The underlying principle behind it is sound, but whether it can be applied in practice remains uncertain,” he explains.

Nonetheless, Steve Nicholson, a farmer near Forbes, is so optimistic about this prospect that he signed a 25-year contract with Loam.

“It’s a gamble,” he admits. “But it’s a very, very good gamble.”

Loam’s technicians measured the baseline carbon in his soil in February, at the peak of the hot dry season.

They will return next February to check if the carbon levels in his soil have increased and to determine the amount of carbon in a more stable form.

Representatives from Loam Bio inform their clients that they expect to store one to two tons of stable carbon per hectare of land. After that, the Australian government-operated carbon credit agency will need to verify the amount of carbon Nicholson has added before issuing any credits.

Nicholson hopes to receive payment by July next year. His income will depend on the carbon price in Australia at that time, but he anticipates earning about 65 USD per hectare.

How Degraded is the Land?

Agriculture, the sector that feeds the world, is simultaneously devastating the planet. Land has been degraded due to deforestation, tilling, and chemical fertilization, altering much of the Earth.

Soil samples from farms are air-dried to prepare for carbon analysis at one of Loam Bio’s laboratories in Orange, Australia. (Source: Japan Times)

These changes are vividly apparent on McDonald’s farm. His ancestors, settlers from England, began tilling the land in Australia in 1888. They planted vast wheat crops, a species foreign to the continent, and raised cattle and sheep, also non-native species.

In the decades that followed, Australia became an agricultural powerhouse. But alongside this, the topsoil layers were eroded. Carbon concentrations in the soil decreased. The land became degraded.

“Soil erosion is something everyone acknowledges,” McDonald remarks. Until they can no longer accept it.

About 20 years ago, McDonald, like many of his neighbors, stopped tilling. After each harvest, he allowed the straw to decompose naturally.

According to scientific studies, this helps retain moisture in the soil and slows down erosion, but it does not contribute to carbon accumulation in the soil.

Now, climate change poses a new risk. Scientific models indicate that a hotter, drier future climate threatens to release even more carbon from the soil.

The Australian government has set a goal to reduce greenhouse gas emissions by 43% by 2030, compared to 1990 levels. Agriculture accounts for about 14% of those emissions. Thus, the agriculture sector in Australia itself must change.

Neil Westcott, a wheat and canola farmer and the mayor of a small agricultural town named Parkes, is also concerned about this future.

He aims to minimize the farm’s impact on the climate. He believes that soon he may have to do so if the government mandates reductions in greenhouse gas emissions or if foreign customers demand low-carbon crops.

Westcott, 64, has stopped raising sheep, animals that produce methane, a potent greenhouse gas, and he has spread mushroom powder over about a quarter of his 2,400 hectares of land.

However, he does not intend to sell carbon credits, instead choosing to retain them for when he needs to offset the carbon emissions from his farm.