Asian farmers have successfully supplied various organic materials (biomass) to their arable lands for sustainable crop p[roduction. Thanks to their long effort, Asian arable soils are known for the richness of soil organic matter, hence its high fertility. Soil organic matter plays a key role in the improvement and enhancement of soil's physical, chemical and biologiocal properties. Over the last decades, however, it is not a common practice for Asian farmers to apply organic materials to arable soil. This surely gives rise to the aggravation of soil's physical and chemical properties making it infertile.
Recently, the application of "Biochar" to soils seems to be a global trend as this enhances crop productivity, improves soil's physical and chemical properties and minimizes greenhouse gas emission from croplands. "Biochar" as a material, is defined as "charcoal as application to soils." The word, “Biochar” is rather new even to soil scientists. However, its concept is far from new. “Biological charcoal” was actually used by a Japanese scientist to increase mycorrhizae population in soils about 50 years ago. In Taiwan, rice husk pyroly sis in low oxygen was commonly used as seedling bed for vegetables, and the charcoaled husk had to be washed repeatedly with diluted acid solution before use because of its high alkalinity.
There is a need to study carefully changes in soil’s physic al and chemical and biological properties, soil C and N dynamics, the surrounding environment- and ecosystem resiliency, and crop growth as well as changes in B iochar ’s stability to a wide range of soil types, climates, crop species, cultural practices and so forth over a long period of time .