The production and characterization of bagasse biochar (Saccharum officinarum Linn) in this study was carried out through pyrolysis for 4 hours at a temperature of 1100C. The purpose of this research was to determine the biochar capacity of bagasse (Saccharum officinarum Linn) as an ameliorant for improving fertility in marginal lands, especially in West Kalimantan, namely peatlands. The capacity of biochar as an ameliorant in this study is known based on gravimetric analysis, which has a moisture content of 0.38%, ash content of 2.42%, volatile content of 0.53%, fixed carbon (cf) 97.02%. Meanwhile, from the results of SEM-EDX characterization there were 100% carbon compounds and the presence of pores in the form of micro pores. And the results of FTIR characterization have the absorption of functional groups of organic compounds at wave numbers (cm-1) 3448.72 from the Ogroup OH streching, 2978.09 and 2931.80 CH bending groups of cellulose compounds, 2368.59 and 2276 C≡C bending groups lingnin compounds and 1620.21 and 1435.04 groups of C=O and C=C streching compounds of lingninsellulose and hemicellulose

Research has been carried out on the characterization of biochar pores produced from bagasse through a pyrolysis process at a temperature of 110oC for 4 hours, using the Scaning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX) method. The biochar of sugarcane pulp produced is then tested for its ability to absorb nitrogen content (% N-total), with the source of N is urea fertilizer through the Kjedhal method based on SNI (2801: 2010), and the source of nitrogen from a solution of ammonium sulfate (NH4)2SO4 by the titrimetric method. The SEM measurement results showed that the biochar pores were uniform and micro-sized, while the peat pores were macro in size and irregular. EDX results show that biochar is composed of 100% carbon, while peat soil consists of carbon compounds (C), Oxygen (O) Silica (Si) and Aluminum (Al). Both of biochar and peat have moisture content of 0.38% and 11.79%, ash content of 2.42% AND 24.44%, volatile content of 0.53% and 5.23% of bound or fixed carbon (cf) of 97.02% and 58.53%. The results of the biochar capacity test applied to peat soils can increase the pH of the peat from 5 to 6.5 with the ability to absorb N-total from urea (NH2)2CO and N-total fertilizer sources from ammonium sulfate (NH4)2SO4 solution of 38% - 66%, and 56.5% -84.5%.