BIOCHAR PRODUCTION AND AMENDMENT

Biochar has been widely applied in soils as an eco-friendly amendment. So far, knowledge on the biochar properties and amendment has made considerable progress by the collaboration among researchers working in different fields of study. This chapter provided a review on the biochar production technology and the commonly used feedstocks. The characteristics of biochar and the effect of biochar as a soil amendment on the soil qualities, crop yield and emission of greenhouse gases (CO 2 , N 2 O and CH 4 ) were systematically summarized. The following aspects which still need to be further resolved were identified: (i) analyzing the role of mineral including biomass-inherent mineral and exogenous mineral, in the pyrolysis process and biochar properties; (ii) revealing hydrochar production condition, properties and the effects on soil qualities and greenhouse gas emissions; (iii) identifying primary factors controlling the stability of biochar; (iv) elucidating the mechanisms for the observed changes in N 2 O and CH 4 emissions after biochar amendment.