Abstract:In order to investigate the characteristics and structure of maize straw biochar-based fertilizer, this study self-prepared maize straw biochar-based fertilizer, and further identified the effects of biochar addition on appearance features, surface functional groups and compositions of biochar-based fertilizers. The results showed that there was an abundant pore volume, and the disorder surface was increased with increased amount of chemical fertilizer added. The total pore volume and average pore size were ranged in the range of 2.1–3.3 cm3/kg and 49.7~56.3 mm, and 2.8 cm3/kg and 2.9 nm, respectively. The C-O-C, -COOH, -CH3 and -CH2 were disappeared after the biomass was carbonized, which implied that the chemical fertilizer only affected the elemental composition but didn’t affect its original molecular structure of biochar. Compared with biochar, the biochar-base fertilizer had lower C and H contents and higher contents of N and O, which were in the range of 47.7%–68.4%, 20.2%–28.2%, 59.5%–82.6% and 164.0%–228.8%, respectively. For element components, there’s an increase trend for H/C, O/C and (N+O)/C of biochar based fertilizer. In conclude, chemical fertilizer has been adsorbed onto the pores of biochar without changing the framework, structure and functional group contents of biochar, however, the changes in element components can increase the water retention and adsorption capability of biochar-based fertilizer.