After Europeans arrived in modern day South America and began to push into the Amazon’s thick jungles, they had no choice but to explore the foreign land using its waterways. The Spanish and Portuguese pioneers wrongly believed the Amazon rainforest’s vegetation was too dense to sustain settled populations or any form of agriculture. 

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These assumptions were confounded when they discovered the Amazonian’s terra preta – the “black earth”; a nutrient rich, dark soil that seemed to be thoughtfully placed in lots along the Amazon River’s veins. 

 

Some early explorers assumed it was volcanic ash that rained down from the nearby Andes, but modern studies have revealed it to be man-made and extremely beneficial. 

 

Recent scientific observations of this black earth revealed it to be rich in organic matter, with residues of plants, animal and fish bones and even manure. 

 

Its chemical makeup revealed it to be packed with nutrients such nitrogen, phosphorus, zinc, calcium and manganese. The soil was found to be three times more fertile than the surrounding soils that make up the earth-base of the prolific Amazon Rainforest. The fertile soils of the terra preta also revealed high levels of micro-organic activity.

 

The use of fire on the organic materials leaves behind nutrient-rich charcoal. And because of the porous nature of the carbon-dense materials, the soils are extremely good at retaining water. 

 

It is now understood that the black soil was made through a long process of “smouldering”, using fire to “slash and char” agricultural and domestic waste. Smouldering is an ancient technique, but its black earth by-product has never been easy or quick to make.

Today terra preta is more commonly known by its modern equivalent: OCS-Char, and it’s the environmentally friendly byproduct of HBC’s Organic Carbonisation System (OCS).