The Secret of El Dorado and Terra Preta
When I was a child, I used to go camping with my family. We were lucky enough to be able to have a campfire at least a a couple of times per trip. I remember seeing the fireplace the next morning and being fascinated by what was in there. All the wood that had been put on the night before was no longer there. Just a pile of ash and some black looking sticks. They looked just like the sticks and logs we had put on the night before but they were much lighter and they made this funny 'tink' noise when you dropped them. That was charcoal. I tried writing with it. It worked, sort of. But other than that, I didn't think too much about it.
It wasn't until many years later that I learnt about the incredible power and potential of those little black sticks. And that is where we come to the story of El Dorado and Terra Preta.
When you think of the Amazon, you think of lush rainforests and primitive tribes living in small villages as hunter gatherers. But that is nowhere near the whole story. For a start, the soil in the Amazon rainforest is very poor. It's amazing how nature is able to build such a beautiful and functional ecosystem on soil that is overly poor and overly clay based. But it does.
But there are parcels of land in the Amazon region that are incredibly rich. Some of these parcels are small, just a couple of acres and some much larger. This soil is known as Terra Preta.
A Highway in the Amazon
Through exploration of the Amazon region, there appeared the remnants of ancient highways that lead to villages which seemed to defy explanation. Why would such a large road system be needed for such a small village? And who built them?
Through various research and exploration, a theory emerged. There were large towns and villages in the Amazon region. Some of those towns and villages were large and densely packed with people. The small villages that remained were the remnants of them. The exploration of the region by Francisco de Orellana and his brigatine of 50 men had brought small pox and other viruses never encountered by the Amazonians which decemated the population and the rainforest had quickly absorbed those villages.
So, an interesting story especially during this time of COVID-19. But what does this have to do with my campfire sticks?
During the exploration of the Amazon and research into this lost civilization of El Dorado, they came across these pockets of land called Terra Preta - "black soil". The locals loved this land. It would grow healthy, viable crops with almost no effort by the farmers. It was so valued by the locals that it was even mined and sold to help farmers in other areas.
This was the soil that supported the civilization of El Dorado and those ancient people had created it. They had managed to find a way to enrich the poor quality soil of the Amazon in such a way that it sustained a large and growing population and the quality of the soil stayed rich and viable for over 500 years. In fact those that mined the soil would tell of how the soil would 'regrow' after being mined.
An Ancient Knowledge Revealed
Additional Information
The secret of El Dorado and Terra Preta is charcoal. When the soil was examined, it was found to have up to 10% charcoal content. Simple as that.
But before you go starting a campfire and sowing the burnt sticks into the ground, we need to explain how charcoal becomes biochar. Charcoal is created by pyrolysis. Basically, cooking the organic substance (most commonly wood) with a lack of oxygen to the point where all that is left is the carbon. Our method is by loading a chamber with wood, sealing the chamber and then burning other wood around it (from the top down) until the inner chamber wood is turned into charcoal.
Not very difficult and the method also ensures that there is minimal release of greenhouse gases (using chamber in chamber and top down burning means that the majority of gases are burnt off).
Now if we put the charcoal straight into our soil, we would see an immediate difference. The texture and water retention of the soil would improve. But the plants would not grow well at all. Until about two years later. Then there would be a marked improvement in plant growth and health.
And this is the magic of how charcoal becomes biochar.
The microscopic image of charcoal on the left shows exactly why biochar is so important in the making of Terra Preta. When mesured out, a piece of charcoal measuring 2.54 cm has enough surface area to cover two football fields.
The area available and the shape of it means that it becomes a perfect home for microscopic sized organisms.
The same type of microscopic sized organisms that are vital to healthy soil.
When charcoal is added to the soil, the microscopic organisms are attracted to it and set up home. Which means that they are no longer available to the plants, unless conditions are just right (enough nutrients, water and sunlight).
Charcoal to Biochar
In the ancient Amazon region, there were large areas covered with sewerage and charcoal. After a period of time, the charcoal was removed and added to the soil and this created Terra Preta.
By inoculating the charcoal, they had created biochar.
The biochar was filled with micro-organisms that were immediately available to the soil around it. With the biochar as their home, the micro-organisms could assist the soil and plants around them. When conditions were less than ideal (drought, flood etc), the micro-organisms would retreat to the biochar and stay safe and healthy. Biochar was their home and safe haven.
And this improvement lasts hundreds of years. With biochar and a regular (usually about once a year) addition of nutrients, soil can stay healthy, vital and grow healthy and vital plants.
Carbon Negative Biochar
According the the Collins English Dictionary, the definition of carbon negative is "causing a net reduction in the total amount of carbon dioxide in the atmosphere".
Biochar is carbon negative due to it's method of creation and it's use in the soil. By creating through pyrolysis, most of the gases are burnt off before entering the atmosphere. The biochar is then mainly carbon which is added to the soil. Due to it's high ability to house and nuture micro-organisms, it improves the soil and plant life around it. With the increased micro-organism life and improved plant health, the soil has better texture and increased carbon content.
So by adding biochar to your soil, you are creating a nutrient rich environment for your plants which will allow them to add more carbon to the soil. With minimal disturbance (we recommend no-till farming/gardening methods), your soil will sequester much more carbon than was used to create it.
Inoculated Biochar
We are actively working to improve our soil using biochar. We also want to help others to do the same. Whether you have just a couple of pot plants or a large garden area, we recommend using biochar to improve your soil and plant health.