Understanding soil carbon: How plants and animals increase carbon stocks in healthy soils

Last month Regenerate Outcomes brought together a group of experts to answer your questions on the role of carbon in regenerative farming and how it can be used to generate income through the sale of high quality carbon credits. 

Over the coming weeks we will be following up with a series outlining some of the key information presented by the panel.

First up is Blain Hjertass, from our mentoring partner Understanding Ag, who has been practising regenerative farming in Saskatchewan, Canada, for 20 years.

You can watch the full webinar with Blain and the rest of the panel in the video below.

‘The solution is more green in the world’

"These days engineers are all very excited about geo-sequestering carbon using technology,” says Blain.

“My answer to that one is that a green leaf uses the Sun's energy and does exactly the same thing for free. The solution to our mess is more green in the world, it’s that simple. 

“We have sunshine shining on green leaves and they make photosynthesis and they take CO2 and hydrogen or water and they make C6H12O6, which is glucose.

Keeping living plants in the soil longer is key to increasing soil carbon

“That glucose comes down into the roots and leaks out into an area called the rhizosheath. There's a feeding frenzy here and all of the life in the soil tends to congregate around plant roots and this rhizosheath.”

This life includes mycorrhizal fungi, which benefit from the carbon produced by the plant roots and in return supply the plant with nutrients. 

"The other way that plants feed is through a process called rhizophagy where they literally take bacteria and suck them in through the cell through super oxidation,” says Blain. 

“They actually take the energy out of the cytoplasm and spit the bacteria out and the bacteria are still alive and they can go around and recycle.”

The key principles of regenerative farming

"The principle of diversity is absolutely critical to success,” says Blain.

“What most of us do in farming is we have a monoculture. Every plant germinates on the same day.

“They all need nitrogen or phosphorus or zinc and they all need it at the same time. If an insect comes along, it's going to be in heaven because every plant is the same and it's got a free lunch. 

“You contrast this with the way Mother Nature created the system where there is great diversity and all the plants share resources. Probably the biggest thing that we can do is try to figure out rotations that get more diversity into our system. 

“If you want to put carbon into our soil, we need to have diversity and keep things greener for longer. More roots give you more soil carbon. That's how simple it is.

“If we aren't feeding the microbes underneath our feet, our soil health is actually going to be declining. We're going to be taking carbon out of our system and putting it back up into the atmosphere, because these bugs are still alive and they're going to start chewing on organic matter.”

Another key principle is to avoid disturbance, whether that is by tillage or overgrazing.

"The other thing that's a disturbance is high rates of synthetic fertilizers. If you're pouring high rates of nitrogen on that tends to be very negative to soil health,” says Blain.

Protecting the soil with ground cover is also vital to protecting soil life, which will begin to shut down if it becomes too warm and water evaporates.

Similarly, bare soil will not absorb water as well as that which has living plants growing in it. 

It is also vital to bring ruminant livestock onto the land.

Livestock are vital to promoting healthy soils

"There's microbes on every leaf. Livestock are eating the microbes and then they poop some of it out and they're spreading microbes around,” says Blain. 

“If I leave dead grass lying on the surface it would probably take a year before it would recycle, depending on how long it is.  It might even take several years. I can run that through the rumen of a cow and I can recycle that in three days.”

At the same time, animals also trample organic matter into the soil, as well as breaking rootlets with their tongues, releasing sugar and promoting more life. 

Following these principles will result in increased soil carbon, as well as healthier soils, plants and animals, resulting in more resilient farm businesses. 

Restoring soil, increasing carbon

"It's pretty exciting to think that finally, after years of degenerating soils around the world, we have now finally figured out how to begin the process of regenerating,” says Blain. 

“If we do this, we're going to also solve our climate problems and we're going to put a lot of carbon back into that soil.”

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Regenerate Outcomes supports farms to transition to regenerative agriculture. Please get in touch to find out more about how we can help you.