Assessing Microbial Contributions to N2O Impacts Following Biochar Additions

Agronomy

Xiurong Lin³  Kurt A. Spokas¹  Rodney T. Venterea¹  Renduo Zhang²  John M. Baker¹  Gary W. Feyereisen¹ 

[1] United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Soil and Water Management Unit, St. Paul, MN 55108, USA; E-Mails:;School of Environmental Science and Engineering, Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, Guangdong 510275, China; E-Mail:;Guangdong Environmental Monitoring Center, Guangzhou, Guangdong 510030, China; E-Mail:

关键词: biochar;    nitrous oxides;    soil fungi;    iron;   

DOI  :  10.3390/agronomy4040478

来源: mdpi

【 摘 要 】

Varying degrees of soil nitrous oxide (N₂O) mitigation have been observed following biochar applications. Laboratory incubation experiments were conducted using soils from agriculture, forest, prairie, and a sterilized sand to examine the relative contributions of bacteria and fungi to this N₂O alteration. Selective chemical inhibitors were used to distinguish the relative contributions of fungal and bacterial groups to N₂O production/suppression in each soil type following a fast-pyrolysis macadamia nut shell biochar (10% w/w) addition. Overall, suppressed production of N₂O was initially observed between the agricultural and prairie soils following biochar addition and stimulation of N₂O production was observed in the biochar amended forest soil. However, if the N₂O production that was observed in the biochar control (sterile sand and biochar = 4.2 ± 0.7 ng-N g⁻¹ day⁻¹) was subtracted from all treatments, N₂O production following biochar addition was consistently lower in all soils following biochar additions. In terms of the microbial contributions, there were no significant differences in N₂O production between the microbial inhibitor treatments, despite CO₂ production rate differences. Therefore, the response in the N₂O production to biochar could not be directly attributed to a particular microbial group (fungi or bacteria). These results suggest the presence of abiotic production or consumption routes for nitrogen species in biochar amended soils.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.