The soils of the Amazonian region (current day Brazil) are known to be extremely fertile. This piqued the interest of soil scientists who then set out to determine the exact reasons for the amazonian soil fertility. Soil scientists have discovered that ancient Amazonians burned crop residue & converted into a product similar to charcoal (known as Terra Preta). This product was then applied & mixed with topsoil. This terra preta gave the soil its dark color & fertility.
Modern day name for terra preta is Biochar.
Today Biochar is produced in a similar manner as ancient terra preta but by a more scientific, efficient & ecologically friendly process.
Biochar is a natural soil amendment that increases the soil fertility over a period of time.
Soil scientists have proved the following benefits of applying Biochar to soil:
All these benefits translate to an increase in yield of crops over a period of time. Although all biochars are not equal & the exact increase in yield depends on numerous factors. Increases in yields of 20-400% have been observed after the application of Biochar.
Upto 50 % (by wt) of the original biomass is converted into biochar after pyrolysis while the remaining being converted into by-products such as syngas & bio-oil. These by-products can be further treated & can be used as a source of fuel & energy.
Biochar is essentially organic matter in a stable form that does not decompose for hundreds of years. Organic matter in its natural form decomposes in a few years that results in release of carbon emissions & other greenhouse gases. Various scientists have proposed to use biochar as carbon sequestration method. Soils act as carbon sinks. Lab & field trials are underway globally to scientifically verify these claims.
Farmers burn most waste biomass at the farm level by a technique called as slash & burn. This farm waste can be collected to produce biochar. This would prevent the harmful release of greenhouse gases at the same time it would be ecology clean & efficient way to manage waste related problems.