Terra Preta is Portuguese for "black earth" or so is called an anthropogenic soil in the Amazon Basin, more precisely a Hortic Anthrosol. This soil system is enriched not only with carbon in the form of charcoal, but also with a variety of nutrients. The natives of the Amazon region achieved this by running an almost perfect and loss-free recycling economy. All the wastes that were produced in the settlements, started from their own faeces to the food residues, garden waste, animal bones and other animal wastes, were regularly applied to the garden beds in combination with the remains of wood charcoal. In addition, they regular used mud from the Amazon. The charcoal functioned like a sponge, which held the nutrients in the extremely permeable soil. With the Amazon mud, fresh minerals and trace elements were always replenished, the bones and animal waste mainly supplied calcium and phosphorus.
All these leavings were either applied directly to the soil or stored in heap and leave to gain a certain decomposition or composting process before the application. Especially due to the remnants of wood charcoal production, there was almost no loss of nutrients and the soil system was enriched with nutrients more and more over the centuries. A special kind of garden culture supported this process, yet fruit trees were planted, including fruit bushes and field fruits such as maize, beans and pumpkin as permaculture. Because of this soil structure and the prevailing root diversity at the same time the fields were extremely productive, the soil was always covered and the strong rainfalls could not wash out the nutrients. These soil systems have therefore been more fertile from year to year despite their high productivity!
A very important part in every soil system is a huge diversity of soil life, like the earthworms. With their vertical channels, they provide not only the stability of the soil, but also for the water to penetrate the soil well and quickly. In a living soil, there is an incredible giant network of fungal threads that also stabilize the soil and are very important for the nutrient supply to the plant roots. There is another microbiology in each soil layer, specially adapted to the existing living conditions. Wastes lying on the surface protect the soil and serve as a source of food for an army of soil organisms.
If you are interested in more detailed information on the subject of Terra Preta, please read the publications of Dr. Bruno Glaser from the University of Halle. He is the leading Terra Preta scientist in the German-speaking world and has worked intensively with our producer the company Sonnenerde for the last 4 years.