Biochar fertilizer for soil amendment and carbon sequestration

Abstract

Use of biochar fertilizer is potentially an attractive approach for soil amendment and carbon sequestration possibly at giga tons of carbon (GtC) scale. Cation exchange capacity (CEC) is an important parameter in retaining inorganic nutrients, such as K+ and NH 4+ in soil. This experimental study showed that the CEC value of biochar is related to the biomass pyrolysis temperature. Biochar materials made from the pelletized peanut hulls at pyrolysis temperature of about 400C yield the best CEC value. As the pyrolysis temperature increases over 400C, the CEC value decreases. The biochar produced from the 400C pyrolysis possesses certain binding affinity for ammonium bicarbonate (NH4HCO3) probably because of the presence of more biochar surface functional groups. Addition of ammonium bicarbonate to biochar can help neutralize the pH of biochar material potentially beneficial for certain agricultural soil applications in relation to soil amendment and carbon sequestration.