Physicochemical properties of biochar derived from wood of Gliricidia sepium based on the pyrolysis temperature and its

Biochar (BC) represents biomass such as wood, grass, and manure, decomposed by pyrolysis typically produced under conditions of limited oxygen (O2) and low to moderate temperatures (<600??C). The application of BC to improve physicochemical properties of soil and boost plant growth is increasingly gaining attention. Most studies reporting the underlying mechanisms of BC-based soil improvement describe changes in water holding capacity based on the difference in the type of soil and intrinsic properties of the BCs. The physical and chemical properties of BC itself depend considerably on the pyrolysis temperature and the feedstock used for its production. Previous studies that investigated changes in soil physical properties due to pyrolysis at temperatures ranging between 200??C and 300??C described changes in soil water retention. In this study, we used Gliricidia sepium, a fast growth legume tree, as the feedstock for producing BC. The objective of this study was to evaluate the effects of a wide range of pyrolysis temperatures (300??C to 800??C) on the physicochemical properties of BC derived from G. sepium wood, and thereafter evaluate the effect on soil physical properties in a pot incubation test with BC produced at 400??C and 800??C in sandy soil. The physicochemical properties of BCs generated from G. sepium wood changed considerably as the pyrolysis temperature increased. A significant increase in the carbon (C)/ nitrogen (N) ratio and pH of the BC was observed at elevated pyrolysis temperatures, which may be attributed to the high total C content of the generated ash. Biochar produced at 400??C showed the most promising results by enhancing the soil fertility based on its low bulk density and high cation exchange capacity. The water holding index is significantly negatively correlated to soil bulk density so the low bulk density of produced at 400??C helps improve the water holding capacity of sandy soil in this study. Consequently, BC produced at 400??C is the most promising soil conditioner for elevating soil fertility and the water holding index. can contribute energy biomass production on oligotrophic lands consequently reducing the