Biochar research advances regarding soil improvement and crop response

Biochar is produced by heating crop residues and other organic substances under limited oxygen conditions. Because biochar is rich in nutrients and highly alkaline and stable, it has been reported to effectively reduce soil acidity, retain soil nutrients, promote nutrient uptake and enhance crop yield. This paper reviewed progress in biochar research, which (domestic or international) is at infancy stage. Because of the different methods of biochar research and various biomass carbon resources for different crops, great controversies have existed about the different roles of biochar. At present, biochar research has mainly focused on surface phenomena. As the study of such mechanism was still inadequate, researchers were required to make further explorations in this field. This review also discussed some strategies and areas for future biochar research.