Natural biochars are alternative fertilisers that could solve three major world issues : the increasing cost of mineral fertilisers, water pollution by excessive use of mineral fertilisers, and the global warming due to carbon transfer from soils to atmospheric CO2. Biochars and carbon-rich solids formed by pyrolysis of biomass such as crop residues. Biochar can be used for soil fertilization, carbon sequestration and improvement of soil structure. Sigua et al. reported that addition of sorghum biochars increased total biomass of winter wheat by about 31% over the control plants. Their findings suggest that pyrolytic transformation of sorghum residues into sorghum biochars is a better strategy for both environmental and crop productivity improvement.
