Varying degrees of soil nitrous oxide (N
2O) 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 N
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Varying degrees of soil nitrous oxide (N
2O) 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 N
2O alteration. Selective chemical inhibitors were used to distinguish the relative contributions of fungal and bacterial groups to N
2O production/suppression in each soil type following a fast-pyrolysis macadamia nut shell biochar (10% w/w) addition. Overall, suppressed production of N
2O was initially observed between the agricultural and prairie soils following biochar addition and stimulation of N
2O production was observed in the biochar amended forest soil. However, if the N
2O 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, N
2O 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 N
2O production between the microbial inhibitor treatments, despite CO
2 production rate differences. Therefore, the response in the N
2O 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.
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