Implications of production and agricultural utilization of biochar and its international dynamic

Much attention recently focus on biochar as a kind of soil amendment, slow-release carrier for fertilizer and carbon sequestrating agent. Biochar can sequestrate carbon in soil for hundreds to thousands of years, and improve the physical and chemical properties and activity of microbes, soil fertility, and delay nutrient release of fertilizer, as well as reduce nutrient losses from fertilizer and soil, and alleviate soil pollution. Both pyrolysis and gasification of biomass can yield biochar. However, the maximum yield of biochar occurs in slow pyrolysis and hydrothermal carbonization, which can produces bio-oil and syngas, and ulteriorly upgraded them into hydrogen, biodiesel or chemicals. So it can reduce dependence of human on fossil energy or raw materials. Agricultural utilization of biochar produced from waste biomass is carbon-negative process which has multi-win benefits for human being. Much work on the biochar produced by pyrolysis of waste biomass and its agricultural utilization were done abroad. In China, much work was done about bioenergy acquired from pyrolysis of biomass, but less attention was paid on the production and agricultural utilization of biochar. In the future, China should take the strategy for sustainable development of bioenergy, environment and agriculture through biochar production from slow pyrolysis or hydrothermal carbonization of waste biomass and its utilization in agricultural