Two Powerful Ways Soil Soaks Up Carbon Dioxide

My previous article discussed the role of carbon dioxide (CO2) in our atmosphere and how it helps maintain a range of temperatures that enable life on earth.

The amount of CO2 in our atmosphere now is at 414 parts per million (ppm), which is the same as saying 0.0414% of the total atmosphere that we live in. Which doesn’t sound like much, but, it does just the right job with just the right amount. According to ice cores, CO2 had never gone above 300 ppm for millennia until fossil fuels started getting used for energy. And it’s been rising rapidly since scientists started measuring it in the 1950’s.

Many scientists say that a level of 350 ppm is as high as we should get without truly dire consequences. And when you think of the weather-related events happening this summer, we’ve gotten a glimpse what truly dire may mean.

But scientists have found that soil has the ability to soak up a lot of carbon dioxide. It is estimated that by restoring the world’s soils we can get CO2 levels back to 350 ppm within 15 years.

Let me describe exactly what goes on in the soil to soak up CO2.

Table of Contents

The first powerful way to soak up CO2 depends on microbes in the soil

Plants absorb carbon dioxide from the atmosphere through their leaves. They take up water and minerals from the soil through their roots. The combination of CO2, water, and minerals allow the plant to manufacture sugars and carbohydrates, and all the other components of the plant body, including sweet fruits and protein dense seeds.

But there’s one incredible process that makes it all work. It starts with the roots. The little white root hairs on all the roots do all the absorption of water and nutrients. They exude some of the plant’s sugars, to form a film around them. This film is composed of the right kind of sugars that attract and encourage the growth of the right kind of soil microorganisms (microbes) that in turn excrete nutrients in the right form for the plant’s root hairs to absorb and use.

Got that? What this means is, the roots of the plant grow their own microbes to supply themselves with the nutrients they need. As though they’re doing their own farming.

The microbes in soil include zillions of bacteria, protozoans, nematodes, algae, archea, and others. I’ll talk of fungi in a bit.

After all the microbes have eaten and been eaten, what ends up is a substance called humin. Humin is made of a lot of carbon, doesn’t get eaten, and remains fixed in the soil for very long-term storage. It also improves soil structure to allow air and water to penetrate the soil, keeping microbes healthy and happy.

Unless the soil is damaged.

The second powerful way is from fungi, especially mycorrhizal fungi

Like little traveling sales people, filaments of mycorrhizae knock on the doors (roots) of their perfect customers and offer a great exchange.

They offer a plethora of nutrients, harvested from far and wide, even water from distant resources if times get tough. All for those things for the sugars the plant is able to produce.

Once granted an agreement by the roots, the tiny mycorrhizal filaments, team up with root hairs and get to work.

The long filaments of the fungus grow and reach out far and wide to keep its plant partners supplied. They have the ability to dissolve rock minerals and decay organic matter and turn these components into nutrients the host plants need.

In exchange, the filaments get the carbon building blocks for building the fungus body, which enables the fungus to grow large. Very large. Some fungi have been observed to grow several miles wide. And they live very long. Some for thousands of years! This makes for a lot of carbon stored in the soil for the long term!

Unless the soil is damaged.

We humans have done a lot of damage to the soil

Compaction by machinery, building, and paving, kills off microbes. It reduces the oxygen in the soil and breaks the fungal hyphae.

Tillage exposes the soil microbes to sun and air and kills them off. The humins and microbes get broken down and release CO2 back into the atmosphere.

Even fertilizing takes a toll on microbial life. It replaces the microbe farming the roots do so they don’t need to do that job. The plants become dependent on fertilizers and the microbes lose their food source from the roots, reducing their numbers. Less humin gets made.

So we must practice good soil stewardship

Regenerative agriculture is the type of agriculture that maximizes the microbes in the soil to grow more nutritious food, improve the CO2 absorption of the soil, water infiltration, and retention, and increase productivity.

Work to improve your own soil in your landscape and garden to increase the microbe population. Add compost to soil and mulch with organic matter to create a steady supply of fodder for microbes to break down and feast on.

Switch to organic fertilizers if you’re not confident in not fertilizing. They supply some nutrients and even microbes to help get things started. Then cover the fertilizer with organic materials like composts or wood chips.

Go to soilfoodweb.com to read more and to watch a number of short videos that explain so much more.

For the more adventurous I highly recommend the book Teaming with Microbes * by Jeff Lowenfels and Wayne Lewis. It will make you love the beauty of the soil’s microbes!

The film Kiss the Ground , available on Netflix, and the book by the same name *, by Josh Tickell, show all about regenerative agriculture works and gets CO2 fixed into the soil.

*I earn a small commission when readers purchase the products I recommend through my links… I only recommend products and services I have experience with and feel my readers will benefit from. This enables me to spend the time needed to give you good information… to help our beautiful planet!