What is Amazonian Dark Earth (ADE) also known as Terra Preta

Introduction

Amazonian Dark Earth (ADE) also known as Terra Preta ('black soil' in Portuguese), is highly fertile ancient man-made soil found in areas of the Amazon basin. With its exceptional fertility, scientists have been studying ADE in the hope of recreating the long-lost recipe for use in modern agricultural soils.

In this article, we delve into the mysteries of ADE and explore the role of biochar in recreating its soil magic.

What is Amazonian Dark Earth (ADE) or Terra Preta?

ADE, also known as Terra Preta, refers to the remarkably fertile soils found in the Amazon basin. These soils have captivated scientists who seek to understand their unique composition and reproduce their fertility in contemporary agriculture.

Recreating the Fertility of ADE

While some scientists believe it will take centuries to recreate ADE soils. Tony, a passionate advocate disagrees. He firmly believes we can achieve success in a single growing season, just as our ancestors did.

Introducing Biochar to Create Amazonian Dark Earth

To convert your local soil into Amazonian Dark Earth:

• Clayey soil: add 10-20% of SF40 Biochar Multi-purpose Compost
• Sandy soils: add 10-20% of SF60 SF60 Biochar Soil Improver Compost.

These biochar products offer a modern approach to replicating the exceptional fertility of ADE.

This is the iconic image of ADE:

The typical forest soil is on the left and the black, super fertile soil is on the right.

Unveiling the Dark Secret of ADE

Scientific studies reveal that the dark color of ADE is attributed to charcoal present in the soil. The practice of adding charcoal to these soils dates back over 2,000 years. ADE patches vary in size and can be found across extensive areas, resembling numerous small farms.

The Age of Terra Preta

Amazonian Dark Earth is estimated to be between 1000 and 2000 years old. Its ancient origins have fascinated researchers who continue to explore its secrets.

Understanding the Secrets of ADE's Fertility

The key to ADE's exceptional fertility lies in its unique characteristics of two components:

The Role of Charcoal, or Biochar:

Biocahr is a crucial component of Terra Preta. Biochar is a form of charcoal specifically produced to enhance soil using sustainable and environmentally sound techniques. Its porous structure provides a habitat for soil microbes and helps decrease soil acidity. Biochar can also slowly release nutrients when soaked in nutrient-rich liquid.  For more detail about biochar, see our 'What is biochar' blog.

The Role of Humus:

Another vital aspect of Terra Preta's fertility is its significantly higher level of Humus (in the Soil Organic Matter (SOM) compared to the surrounding soils. While the surrounding soils have around 3-5% SOM, ADE boasts an impressive 10% SOM. This high humus in the SOM content contributes to the long-term sustainability of soil fertility.

Cracking the Recipe for ADE

The ancient recipe for Terra Preta is lost to time, but researchers have made progress in replicating its fertility. Adding biochar alone has yielded inconsistent results while combining charcoal and compost has shown more promise. However, compost alone does not provide a lasting increase in soil fertility. The missing link lies in understanding how the stable humus fraction of soil organic matter is enhanced within ADE.

A Hypothesis on the Creation of Amazonian Dark Earth

Considering the value of charcoal as fuel, it seems improbable that our ancestors used it extensively in soil improvement. Instead, a hypothesis suggests that the fertility of ADE was derived from "midans," which were toilet pits filled with waste materials like clay pots, bones, fire ash (fire ash contains around 50% charcoal), and food waste. These pits acted as compost heaps and the resulting compost, rich in humus, was spread on agricultural plots based on observations of the cause and effect of plants growing on and around the midans. The missing part of the Amazonian Dark Earth (Terra Preta) recipe (based on our work) is the need for a humification agent in the composting process.

Making Terra Preta (ADE) today

Recreating Terra Preta is indeed possible within a single year or growing season. To achieve this, create Biochar Super compost by incorporating SoilFixer Colloidal Humification Agent into your composting process. Then add 10-20% by volume of the resulting "Biochar Super Compost" to your soil. For more information on "how to make Terra Preta" follow this link.

Conclusion

The ancient mysteries of the Amazonian Dark Earth continue to captivate scientists and enthusiasts alike. By understanding the significance of biochar and humus-rich composting methods, we can strive to recreate the remarkable fertility of Terra Preta. Unlock the secrets of ADE, experiment with biochar, and embark on a journey toward sustainable soil fertility and bountiful harvests.

Note: This article serves as a general guide to the concepts of Amazonian Dark Earth and biochar. For detailed instructions and assistance, reach out to our team for more information.