Biochar

The origin of biochar is connected to the Amazon River basin where thousands of raised platforms of black and very fertile soil patches were first discovered by the explorer Herbert Smith in 1879 (Marris 2006). In relation to its dark color and origin, the soil was named Terra Preta de Índio (black earth of the Indian). Today, even addition of chemical fertilizers cannot maintain crop yields into a third consecutive growing season, yet these dark earths have retained their fertility for centuries. Hence, research has been focusing on the chemical and physical properties and cultural origin of terra preta. Field studies have provided evidence that terra preta was created through the use of slash-and-char techniques (Lehmann and Joseph 2009). Furthermore, research has confirmed and quantified that the carbonized organic matter in terra preta resulted from incomplete combustion. Similarly, it is well founded that terra preta contains charred plant material that has come to be referred to as biochar (Glaser et al. 2001). Because almost any form of natural organic material can be converted into biochar, considerable research is now being devoted to duplicating the formation of terra preta by creating biochar through various processes of heating plant debris in the absence of oxygen.