Journal article

Publication year: 2022

Journal: Agriculture

Volume number: 12

Issue number: 11

eISSN: 2077-0472

Open access status: Gold

DOI Link: https://doi.org/10.3390/agriculture12111940

Publisher: MDPI

Abstract: 
Biological nitrification inhibition (BNI) in the tropical grass Brachiaria humidicola could reduce net nitrification rates and nitrous oxide (N2O) emissions in soil. To determine the effect on gross nitrogen (N) transformation processes and N2O emissions, an incubation experiment was carried out using N-15 tracing of soil samples collected following 2 years of cultivation with high-BNI Brachiaria and native non-BNI grass Eremochloa ophiuroide. Brachiaria enhanced the soil ammonium (NH4+) supply by increasing gross mineralization of recalcitrant organic N and the net release of soil-adsorbed NH4+, while reducing the NH4+ immobilization rate. Compared with Eremochloa, Brachiaria decreased soil gross nitrification by 37.5% and N2O production via autotrophic nitrification by 14.7%. In contrast, Brachiaria cultivation significantly increased soil N2O emissions from 90.42 mu g N2O-N kg(-1) under Eremochloa cultivation to 144.31 mu g N2O-N kg(-1) during the 16-day incubation (p < 0.05). This was primarily due to a 59.6% increase in N2O production during denitrification via enhanced soil organic C, notably labile organic C, which exceeded the mitigated N2O production rate during nitrification. The contribution of denitrification to emitted N2O also increased from 9.7% under Eremochloa cultivation to 47.1% in the Brachiaria soil. These findings confirmed that Brachiaria reduces soil gross nitrification and N2O production via autotrophic nitrification while efficiently stimulating denitrification, thereby increasing soil N2O emissions.

Harvard Citation style: Xie, L., Liu, D., Müller, C., Jansen-Willems, A., Chen, Z., Niu, Y., et al. (2022) Brachiaria humidicola Cultivation Enhances Soil Nitrous Oxide Emissions from Tropical Grassland by Promoting the Denitrification Potential: A 15N Tracing Study, Agriculture, 12(11), Article 1940. https://doi.org/10.3390/agriculture12111940

APA Citation style: Xie, L., Liu, D., Müller, C., Jansen-Willems, A., Chen, Z., Niu, Y., Zaman, M., Meng, L., & Ding, W. (2022). Brachiaria humidicola Cultivation Enhances Soil Nitrous Oxide Emissions from Tropical Grassland by Promoting the Denitrification Potential: A 15N Tracing Study. Agriculture. 12(11), Article 1940. https://doi.org/10.3390/agriculture12111940