Terra Preta Soils

In recent years archaeologists in South America discovered plots of ground, called Terra Preta soils, that are amazingly fertile and productive. What is more amazing is that these plots of ground were manmade by the Inca Indians before Columbus discovered the Americas. Despite being in the rainforest where soils are depleted rapidly, these plots of ground are still very fertile hundreds of years later. What is the secret? Charcoal. Charcoal will remain in the soil for hundreds or thousands of years and not degrade away. It also provides a habitat for microbes in the soil. We have been fascinated by what we have read about Terra Preta soils and decided to do some experimenting with charcoal in our garden and also in the chicken bedding. So far we have made six batches of charcoal. For more information about Terra Preta soils, this is a link to a good article:
www.acresusa.com/toolbox/reprints/Feb07_TerraPreta.pdf


This is our charcoal retort/kiln. Inside are five 55 gallon metal barrels  filled with split wood to be made into charcoal. Lids are put on the barrels and each barrel has a one inch hole in the bottom. The barrels are placed on a metal rack with wood put under and around them. As the fire burns under and around the barrels, it causes the wood inside the barrels to char. The gases released from the charring process escape through the hole in the bottom, fueling the fire and reducing the amount of wood needed to fuel the fire. By burning the escaping gases from the charring process, it significantly reduces the amount of black smoke that is typical in charcoal making. After the first half hour, there is little smoke as the fire burns with intense heat. After two hours the charring process is complete. We let the charcoal cool down overnight and open the barrels the next day.

Our oldest son, Joel, showing a barrel of finished charcoal.