Effects of biochar and biogas residue amendments on N2O emission, enzyme activities and functional genes related with nitrification and denitrification during rice straw composting

Nanyi Wang; Mukesh Kumar Awasthi; Junting Pan; Shilin Jiang; Fachun Wan; Xu Lin; Binghua Yan; Jiachao Zhang; Lihua Zhang; Hongli Huang; Hui Li

doi:10.1016/j.biortech.2022.127359

Effects of biochar and biogas residue amendments on N₂O emission, enzyme activities and functional genes related with nitrification and denitrification during rice straw composting

Bioresour Technol. 2022 Aug:357:127359. doi: 10.1016/j.biortech.2022.127359. Epub 2022 May 23.

Authors

Nanyi Wang¹, Mukesh Kumar Awasthi², Junting Pan³, Shilin Jiang⁴, Fachun Wan⁵, Xu Lin¹, Binghua Yan¹, Jiachao Zhang⁶, Lihua Zhang¹, Hongli Huang¹, Hui Li⁷

Affiliations

¹ College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China.
² College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
³ Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
⁴ College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410029, China.
⁵ College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.
⁶ College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China. Electronic address: [email protected].
⁷ State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410029, China.

PMID: 35618192
DOI: 10.1016/j.biortech.2022.127359

Abstract

This study was carried out to determine the response characteristics of N₂O emission, enzyme activities, and functional gene abundances involved in nitrification/denitirification process with biochar and biogas residue amendments during rice straw composting. The results revealed that N₂O release mainly occurred during the second fermentation phase. Biogas residue amendment promoted N₂O emission, while biochar addition decreased its emission by 33.6%. The nirK gene was abundant through composting process. Biogas residues increased the abundance of denitrification genes, resulting in further release of N₂O. Biochar enhanced nosZ gene abundance and accelerated the reduction of N₂O. Nitrate reductase (NR), nitrite reductase (NiR), N₂O reductase (N₂OR), and ammonia monooxygenase (AMO) activities were greatly stimulated by biochar or biogas residue rather than their combined addition. Pearson regression analysis indicated that N₂O emission negatively correlated with ammonium and positively correlated with nosZ, nirK, 18S rDNA, total nitrogen, and nitrate (P < 0.05).

Keywords: Biochar; Biogas residue; Composting; Enzyme activity; Functional gene.

MeSH terms

Biofuels
Charcoal
Composting*
Denitrification / genetics
Nitrification
Nitrous Oxide / analysis
Oryza* / genetics
Soil / chemistry

Substances

Biofuels
Soil
biochar
Charcoal
Nitrous Oxide