Effect of pristine and Fe-modified rice husk-derived biochar on denitrification and N2O emission in calcareous arable soil

• Published in: Journal of soils and sediments 2023-06, Vol.23 (6), p.2529-2543
• Main Authors: Wang, Chaoxu, Chang, Zhilin, Liu, Yongchao, Li, Yuankun, Chen, Qibin, Liu, Guangming
• Format: Article
• Language: English
• Subjects: Acetylene; Arable land; Bioavailability; Biological fertilization; Calcareous soils; Carbon/nitrogen ratio; Charcoal; Denitrification; Earth and Environmental Science; Emission analysis; Emissions; Environment; Environmental Physics; Ferric chloride; Fertilization; Greenhouse gases; Incubation; Iron; Mitigation; Nitrate reductase; Nitrates; Nitrite reductase; Nitrous oxide; Physicochemical processes; Physicochemical properties; Rainfall; Reductases; Reduction; Rice; Sec 5 • Soil and Landscape Ecology • Research Article; Soil; Soil conditions; Soil dynamics; Soil properties; Soil Science & Conservation; Soils
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-023-03506-x

Purpose The objective of the study was to explore the effect of pristine (rice husk-derived biochar produced at 500 ℃ by a Japanese company, JBC) and FeCl 3 -modified biochar (JBC-Fe) and its application rate on denitrification and N 2 O emission in calcareous arable soil and the potential mechanisms. Methods After biochar preparation and characterization, JBC or JBC-Fe was thoroughly mixed with the soil at the mass ratio of 2% or 5%, which were defined as JBC-2%, JBC-5%, JBC-Fe-2%, and JBC-Fe-5%, respectively, and a control treatment without any biochar addition was also arranged. After 7-day preincubation, an 8-day microcosm incubation experiment was carried out consecutively under the condition of facilitating denitrification. N 2 O and N 2 O + N 2 emission rates were determined, and the distribution pattern of N 2 O and N 2 , as the end products of denitrification, was distinguished by the acetylene inhibition method. The dynamic changes of soil physicochemical properties and the activities of nitrate reductase and nitrite reductase during incubation were also explored. Results Results showed that both JBC and JBC-Fe promoted soil cumulative N 2 O + N 2 and N 2 O emission during the 8-day incubation. Compared with JBC-2%/JBC-5%, the cumulative N 2 O + N 2 emission of JBC-Fe-2%/JBC-Fe-5% significantly increased by 9.83%/41.21% and the cumulative N 2 O emission significantly increased by 465.98%/147.68%, respectively ( p