I have found an ancient way to amend the soil without chemicals. The ancient Aztecs used charcoal and compost 2000 years ago to amend the poor soils of the Amazon. They called it Terra Preta. Many of these places are fertile to this day. It took scientist many years to figure out what was keeping the soil fertile and how the Aztecs did it. They found that the basic building block was charcoal. Charcoal the scaffolding for a community of beneficial microbes.
Charcoal is very porous and absorbs everything around it. The charcoal was mixed with nutrient rich waste. When these two ingredients were mixed, it created a lush environment for beneficial microbes. These living communities of microbes have continued to fertilize the soil for the past 2000 years. In fact, the farmers of the region sell up to 30% of their dirt for additional income. In 2 years, the dirt grows back.
What the farmers are doing is similar to sour dough bread or friendship bread. They know that if you keep using or dividing it, it will continue to live. But if you allow it to overgrow it will smother itself and die. The other farmers are using the Terra Preta they buy to start their own living dirt.
Today, we call it Biochar. There are many homegrown and cottage industries popping up that can provide you with this organic fertilizing method. The problem is that since the biochar industry is just starting to get a foothold in the market, the cost is on the high side for the basic homeowner. However, there are some economical DIY ways to cut the expense.
You will need:
All Natural Charcoal – no chemicals added
Face Mask – to keep the dust out of your lungs
Compost, worm casings, manure, fish fertilizer, and/or garden enzymes
Water – Preferably from rain barrels
Pit for fermentation – optional
Since the charcoal is the foundation of this fertilizing method, it is very important to choose an all natural brand. Kingsford and other commercial charcoals contain all kinds of toxic chemicals and the bricks are rock hard and very hard to crush. All natural charcoal looks like the charred leftovers from a campfire.
Crush the charcoal into the smallest pieces you possibly can. USE A FACE MASK! The charcoal is really dusty and can get into your lungs.
I use a home chipper. I can crush a 20lb bag of charcoal in about 45 minutes. A hammer and lots of elbow grease will do the same job. I have also seen people use their cars (after they have broken up the large pieces!) and run over medium sized pieces to grind them even smaller.
Place the crushed charcoal into a bucket and cover with water. It is better to have water that does not have chlorine or other city water additives, but if that is all you have then it will do. Add whatever you have that is nutrient rich – compost, manure, worm casing, fish fertilizer, garden enzymes, or all of the above. The charcoal will soak up these nutrients and create a framework for the beneficial microbes to live.
Let this nasty soup sit for at least 2 weeks. OMG! It does smell very bad! So, don’t put this in a place where it will offend you or your neighbors.
After 2 weeks pour the nasty soup into a pile of regular dirt. You can pour it directly into your garden or as you can see above, I have used an old raised bed. I will use this as part of the soil mixture to repot my house plants. This will be where I “grow” my starter and give away portions to start other people’s Terra Preta projects.
For maximum fertilizing benefits, the soil mix needs to have 10% charcoal. However, great benefits can be realized with just 2-3% charcoal.
If you want to use Biochar on your lawn:
I highly recommend aerating your yard first. That way the charcoal can get down deep into the soil. The charcoal must be the smallest you can possibly make it. Then it is possible to use a garden spreader to distribute it on your lawn. Make sure to water it in with fish fertilizer using a hose end sprayer. This is what they look like.
I plan to do this every year until the charcoal content reaches the 10% level. Then instead of chemical fertilizers I can just spray fish fertilizer and/or garden enzymes on my yard to keep it lush and green for the next 2000 years. 🙂