The Soil Carbon Sponge

03/25/2021

Continuing with Magical Carbon we now look at the magic that happens when then carbon gets into the soil. Before the carbon it's just sand or dirt, compacted rock crumbs with inaccessible nutrients trapped inside its lifeless form. It repels rain water which just runs off and is lost.

Once the carbon and its associated fungal life gets into that dirt it opens it up and brings it to life. The organic matter in the soil separates the particles creating voids into which air and water can flow. Fungi and Glomalin - from the Liquid Carbon Pathway - drive more organic matter into the dirt, changing it to become a sponge where more than half of the volume is now made up of air and water. The newly created surface area within the soil now exposes once unavailable nutrients to the microbiology that populates these new surfaces, making it available to plants. This living, thriving soil is referred to as the Soil Carbon Sponge.

Rain water is no longer repelled but it now infiltrates into the soil, filling up the voids. The water no longer runs off but is now held in the soil where it can be slowly released to plants as they photosynthesise and transpire.

The Soil Carbon Sponge gives you water, it gives you access to previously unavailable nutrients, it gives you root-ability where roots can easily make their way towards more nutrients, it gives you microbial life and it gives you resilience.

The magic of the sponge gets going at around 3% carbon in the soil, it is scary to contemplate that most of our agricultural soils are hovering around the 1% to 1,5% mark. We have become so focused on getting carbon out of the atmosphere that we forget the function of that carbon. The carbon needs to be in the soil not just to get it out of the atmosphere but to build the sponge and enable the system that nature has given us to provide food and regulate the environment.

It is crucial that we reestablish the Soil Carbon Sponge in degraded soils in as many parts of the planet as we can.