Journal article

Publication year: 2021

Pages: 471-483

Journal: Biology and Fertility of Soils

Volume number: 57

Issue number: 4

ISSN: 0178-2762

DOI Link: https://doi.org/10.1007/s00374-021-01542-8

Publisher: Springer

Abstract: 
A N-15 tracing incubation study was carried out using a sandy loam soil without (control) and with field-aged biochar (biochar) to investigate the mechanisms underlying the effects of field-aged biochar on nitrous oxide (N2O) emissions. During the incubation, carried out at 40%, 60%, and 80% water-filled pore space (WFPS), cumulative N2O emission decreased from 24.13-26.40 mu g N kg(-1) in the control soil to 18.27-23.94 mu g N kg(-1) in the biochar soil, with a reduction of 9.3-24.3%. The contribution of autotrophic nitrification to total N2O production was 81.8-87.6% in the control soil under 40-80% WFPS, which was significantly reduced by field-aged biochar to 67.1-78.6%. Under 60% WFPS, the gross rates of autotrophic nitrification and gross mineralization were reduced from 11.95 and 4.43 mu g N g(-1) d(-1), respectively, in the control soil to 7.32 and 0.60 mu g N g(-1) d(-1), respectively, in the biochar soil. The field-aged biochar increased the NH4+ immobilization rate by 440%, primarily by immobilizing NH4+ into the recalcitrant organic N pool. Both the turnover rate of NH4+ mineralization-immobilization and the ratio of nitrification to NH4+ immobilization were reduced under biochar amendment, consequently lowering the supply of NH4+ for nitrifiers. In addition, compared with the control soil, the gross rate of NH4+ adsorption was significantly higher in the biochar soil. Taken together, our results suggest that field-aged biochar contributes to mitigating N2O emissions, primarily by decreasing the autotrophic nitrification rate through a reduced NH4+ supply due to increased mineral N immobilization and adsorption and lowered organic N mineralization.

Harvard Citation style: Liao, X., Müller, C., Jansen-Willems, A., Luo, J., Lindsey, S., Liu, D., et al. (2021) Field-aged biochar decreased N2O emissions by reducing autotrophic nitrification in a sandy loam soil, Biology and Fertility of Soils, 57(4), pp. 471-483. https://doi.org/10.1007/s00374-021-01542-8

APA Citation style: Liao, X., Müller, C., Jansen-Willems, A., Luo, J., Lindsey, S., Liu, D., Chen, Z., Niu, Y., & Ding, W. (2021). Field-aged biochar decreased N2O emissions by reducing autotrophic nitrification in a sandy loam soil. Biology and Fertility of Soils. 57(4), 471-483. https://doi.org/10.1007/s00374-021-01542-8