Biochar - Remediation of acidic and compacted soils

Biochar refers to organic matter which has undergone thermal decomposition of biomass in oxygen-limited conditions. In other words, it is charcoal which has been plough into soils to increase the soil quality for agricultural purposes. It has been experimented by soil scientists in poor agriculture soils - i.e. acidic, compacted and waterlogged soils, and found to be effective in improving the soil quality and subsequently harvest. 

Flow diagram of Biochar production and uses. Taken from Tang, J.C. et al. (2013)

Biochar is not a new invention, it is a traditional agricultural practice in many countries such as India and Japan. Recently, much attention has been given to biochar as the ploughing of biochar into soils increase soil fertility, porosity, acidity and subsequently harvest. These positive effects have been met with enthusiasm as biochar is an inexpensive form of soil remediation, organic waste can be well utilized and carbon can be stored in soils. 

Tang, J.C. et al. (2013) examined the organic matter and temperatures used in the production of biochar as these two factors are seen to cause a difference in biochar quality. According to the paper, biochar produced by rice straws at higher temperatures have larger surface areas which will improve soil sorption of nutrients for plants. Zargohar and Dalai (2008) improved the sorption capacity of biochar by steam activation, however, this is not a choice for poor farmers. In fact, most poor farmers may not even be able to afford biochar because of the costs involved to employ techniques which are not polluting are high.  Further research and development into environmentally friendly economical production of biochar necessary for promoting the use of biochar to substantial farmers. 

References
Tang, J., Zhu, W., Kookana, R., & Katayama, A. (2013). Characteristics of biochar and its application in remediation of contaminated soil. Journal of bioscience and bioengineering, 116(6), 653-659.
Azargohar, R., & Dalai, A. K. (2008). Steam and KOH activation of biochar: Experimental and modeling studies. Microporous and Mesoporous Materials,110(2), 413-421.