Charland is newly developed land in river beds which is poor in fertility. Sugarcane bagasse (SB) biochar was produced and characterized, and its performances were evaluated on carbon sequestration and yields of maize and groundnut in charland. The bagasse after pyrolysis ≈ at 600°C temperature produced 55% biochar. The pH value increased from 6.5 (SB) to 8.8 (biochar), C from 42% to 58%, P from 0.11% to 0.23%, K from 0.83% to 1.32% and the S content from 0.12% to 0.61%; whereas the N content decreased from 2.03% to 1.17%. Seven treatments were implemented in field trials of 2016–17 and 2017–18 in Brahmaputra charland consisting of control, 100% chemical fertilizers (CF), CF+ Cowdung (10 t ha−1), CF+ biochar (5 t ha−1 broadcast), CF + biochar (10 t ha−1 broadcast), CF+ biochar (5 t ha−1 furrow application) and CF+ biochar (10 t ha−1 furrow application). Amendment was done in the year one. Results reveal that the same dose of cowdung or biochar with CF produced higher grain yields of maize and groundnut with 40–60% increase over sole CF treatment. Integrated use of 10 t ha−1 biochar with CF can ensure higher crop yield and sustained soil fertility in charland ecosystem.