Effects of Slow Pyrolysis Biochar on CO₂ Emissions from Two Soils under Anaerobic Conditions

Abstract

The amendment of sandy Haplic Arenosol and clayey loam Gleyic Fluvisol with two rates of biochar derived from the slow pyrolysis of wood feedstock was evaluated under anaerobic conditions in a 63-day laboratory experiment. The rates of biochar were 15 and 30 t ha−1. Both rates of biochar were applied either with or without 90 kg ha−1 of nitrogen fertilizer (NH4NO3). Soils with no amendments were used as control treatments. Our results showed that only the incorporation of 15 t ha−1 of biochar, compared with the control treatment, led to a significant (p p −1 did not result in significant changes in volumetric water content in either type of soil. In the sandy soil, CO2 emissions were significantly (p −1 with N fertilizer compared with the control and N fertilizer treatment. In the clayey loam soil, the combined application of both rates of biochar with N fertilizer caused no significant increase in CO2 emissions compared with the control and N fertilizer treatment. The incorporation of 30 t ha−1 of biochar into the sandy soil contributed to a significant (p 2 flux compared with the control treatment. Application of 15 and 30 t ha−1 of biochar into the clayey loam soil led, respectively, to a significant (p 2 fluxes compared with the control treatment.

Keywords

• biochar
• sandy soil
• clayey loam soil
• CO₂ emission
• water content