Insights into CO 2 and N 2 O emissions driven by applying biochar and nitrogen fertilizers in upland soil.

Publisher: Elsevier Country of Publication: Netherlands NLM ID: 0330500 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-1026 (Electronic) Linking ISSN: 00489697 NLM ISO Abbreviation: Sci Total Environ Subsets: MEDLINE

Original Publication: Amsterdam, Elsevier.

Charcoal*/chemistry ; Fertilizers*/analysis ; Soil*/chemistry ; Nitrous Oxide*/analysis ; Nitrogen*/analysis ; Carbon Dioxide*/analysis; Air Pollutants/analysis ; Greenhouse Gases/analysis ; Agriculture/methods

Biochar and soil carbon sequestration hold promise in mitigating global warming by storing carbon in the soil. However, the interaction between biochar properties, soil carbon-nitrogen cycling, and nitrogen fertilizer application's impact on soil carbon-nitrogen balance remained unclear. Herein, we conducted batch experiments to study the effects and mechanisms of rice straw biochar application (produced at 300, 500, and 700 °C) on net greenhouse gas emissions (CO 2 , N 2 O, CH 4 ) in upland soils under different forms of nitrogen fertilizers. The findings revealed that (NH 4 ) 2 SO 4 and urea significantly elevated soil carbon dioxide equivalent emissions, ranging from 28 to 61.7 kg CO 2e /ha and 8.2 to 37.7 kg CO 2e /ha, respectively. Conversely, KNO 3 reduced soil CO 2e emissions, ranging from 2.2 to 13.6 kg CO 2e /ha. However, none of these three nitrogen forms exhibited a significant effect on CH 4 emissions. The pyrolysis temperature of biochar was found negatively correlated with soil CO 2 and N 2 O emissions. The alkaline substances presented in biochar pyrolyzed at 500-700 °C raised soil pH, increased the ratio of Gram-negative to Gram-positive bacteria, and enhanced the relative abundance of Sphingomonadaceae. Moreover, the co-application of KNO 3 based nitrogen fertilizer and biochar increased the total carbon/inorganic nitrogen ratio and reduces the relative abundance of Nitrospirae. This series of reactions led to a significant increase in soil DOC content, meanwhile reduced soil CO 2 emissions, and inhibited the nitrification process and decreased the emission of soil N 2 O. This study provided a scientific basis for the rational application of biochar in soil.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)

Keywords: Biochar amendment; CO(2) and N(2)O emissions; Nitrogen fertilizer; Upland soil

16291-96-6 (Charcoal)
0 (Fertilizers)
0 (biochar)
0 (Soil)
K50XQU1029 (Nitrous Oxide)
N762921K75 (Nitrogen)
142M471B3J (Carbon Dioxide)
0 (Air Pollutants)
0 (Greenhouse Gases)

Date Created: 20240415 Date Completed: 20240507 Latest Revision: 20240507

20240507

10.1016/j.scitotenv.2024.172439

38621540