Mitigation of soil N2O emissions by decomposed straw based on changes in dissolved organic matter and denitrifying bacteria

Sasa Zuo; Di Wu; Zhangliu Du; Chuncheng Xu; Yuechen Tan; Roland Bol; Wenliang Wu

doi:10.1016/j.scitotenv.2023.167148

Mitigation of soil N₂O emissions by decomposed straw based on changes in dissolved organic matter and denitrifying bacteria

Sci Total Environ. 2023 Dec 20:905:167148. doi: 10.1016/j.scitotenv.2023.167148. Epub 2023 Sep 19.

Authors

Sasa Zuo¹, Di Wu², Zhangliu Du², Chuncheng Xu³, Yuechen Tan⁴, Roland Bol⁵, Wenliang Wu⁶

Affiliations

¹ Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Department of Agricultural Engineering, College of Engineering, China Agricultural University, Beijing 100083, China.
² Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
³ Department of Agricultural Engineering, College of Engineering, China Agricultural University, Beijing 100083, China.
⁴ Beijing Key Laboratory of Wetland Services and Restoration, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China.
⁵ Institute of Bio- and Geosciences, Agrosphere (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; School of Natural Sciences, Environment Centre Wales, Bangor University, Bangor LL57 2UW, UK.
⁶ Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. Electronic address: wuwenl@cau.edu.cn.

PMID: 37730058
DOI: 10.1016/j.scitotenv.2023.167148

Abstract

The return of decomposed straw represents a less explored potential option for reducing N₂O emissions. However, the mechanisms underlying the effects of decomposed straw return on soil N₂O mitigation are still not fully clear. Therefore, we used a helium atmosphere robotized continuous flow incubation system to compare the soil N₂O and N₂ emissions from four treatments: CK (control: no straw), WS (wheat straw), IWS (wheat straw decomposed with Irpex lacteus), and PWS (wheat straw decomposed with Phanerochaete chrysosporium). All the treatments have been fertilized with the same amount of KNO₃. Furthermore, we also analyzed i) the chemodiversity of soil dissolved organic matter (DOM), ii) the nirS, nirK, and nosZ gene copies and relative abundances of denitrifying bacterial communities (DBCs), and iii) the specific linkages between N₂O emissions and DOM and DBC. The results showed that the WS, IWS and PWS treatments increased N₂O emissions compared to the CK treatment. However, applying decomposed straw to soil, especially straw treated with P. chrysosporium, effectively decreased the soil N₂O and increased N₂ emissions compared to WS and IWS. Moreover, the IWS and PWS treatments increased the CHO composition, but they decreased the CHON and CHOS compositions of heteroatomic compounds of DOM compared with the WS and CK treatments. Furthermore, the WS, IWS and PWS treatments all significantly increased the nirS and nosZ gene copies compared with the CK treatment. Additionally, compared with the other treatments, the PWS treatment significantly shaped the DBC and led to a higher relative abundance of Pseudomonas with nirS and nosZ genes. Meanwhile, Network analysis showed that the mitigation of N₂O was closely related to particular DOM molecules, and specific DBC taxa. These results highlight the potential for decomposed straw amendments to mitigate of soil N₂O emissions not only by changing soil DOM but also mediating the soil DBC.

Keywords: Denitrifying bacterial communities; Dissolved organic matter; Nitrous oxide emissions; Wheat straw; White-rot fungus.

MeSH terms

Bacteria
Denitrification
Dissolved Organic Matter*
Nitrous Oxide / analysis
Soil Microbiology
Soil*

Substances

Soil
Dissolved Organic Matter
Nitrous Oxide