<p>In order to comprehensively evaluate potential GHG emissions and reduction of applied carbonized waste biomass, a Prospective Life Cycle Assessment (PLCA) was conducted. This evaluation quantified the carbon sequestration and GHG (CO₂, N₂O, CH₄) reduction effects of two crop residue biochar-based products (biochar and biochar-based fertilizer) from their production to application stages, including applications in diverse soils (black soil, loess, and laterite) for cultivating paddy and other crops respectively. Results showed that the slow pyrolysis process was the main source of GHG emissions due to electricity consumption. Biochar-based fertilizers exhibited higher GHG emissions than biochar because of the additional energy required for extra processing steps. In addition, under the low-carbon scenario with a higher share of clean energy, GHG emissions at the production stage were significantly reduced compared to those under the baseline scenario. At the usage stage, the GHG emissions varied significantly with soil and crop types. In laterite, biochar-based fertilizers for paddy cultivation effectively reduced GHG emissions, while biochar for other crops increased GHG emissions; in black soil, the GHG emissions reduction of biochar in paddy fields was superior to that of biocharbased fertilizers; in loess, for both paddy and other crops, the GHG emissions reduction of biochar was more pronounced. This study indicates that soil physicochemical properties directly affect the GHG reduction efficiency of biochar-based products, resulting in potentially different GHG emissions or reduction in different soil-crop systems.</p>