Biochar is attracting attention as a means for sequestering carbon and as a potentially valuable input for
agriculture to improve soil fertility, aid sustainable production and reduce contamination of streams and
groundwater. This study reviews biochar potential and problems and argues for adequate research before
hasty application leads to environmental and socio-economic damage and discourages application. There
is also a need for broad overview because research is conducted by a diversity of specialist fields
including soil chemistry, archaeology, farming extension and so forth. Research on biochar-rich
Amazonian dark earths may help identify the best raw materials (feedstock) and ways for producing
biochar for agricultural use and countering land degradation.