Green manuring combined with zeolite reduced nitrous oxide emissions in maize field by targeting microbial nitrogen transformations.
Sci Total Environ
; : 175382, 2024 Aug 07.
Article
em En
| MEDLINE
| ID: mdl-39127210
ABSTRACT
Green manure is a crucial strategy for increasing cereal yield and mitigating environmental burden while reducing chemical N fertilizer. To effectively tackle climate change, finding ways to reduce nitrous oxide (N2O) emissions from green manuring systems is vital. Herein, field and 15N labeled microcosm experiments were arranged to investigate the effect and mechanisms of green manuring and zeolite application on N2O emission. Both experiments comprised four treatments conventional chemical N (N100), 70â¯% chemical N (N70), N70 with green manure (N70â¯+â¯CV), and N70â¯+â¯CV combined with zeolite (N70â¯+â¯CVâ¯+â¯Z). Compared with N100, both N70â¯+â¯CV and N70â¯+â¯CVâ¯+â¯Z maintained maize yield, cumulative N2O emissions decreased by 37.7â¯% and 34.9â¯% in N70â¯+â¯CVâ¯+â¯Z in 2022-yr and 2023-yr, and by 12.8â¯% in N70â¯+â¯CV in 2022-yr. Moreover, the reduction of N2O emission primarily occurred after incorporating green manure. The N100 and N70â¯+â¯CV demonstrated a similar transformed proportion of chemical N to N2O (i.e., 4.9â¯% and 4.7â¯%) while reducing it to 2.7â¯% in N70â¯+â¯CVâ¯+â¯Z. Additionally, a mere 0.7â¯% of green manure N was transformed to N2O in both N70â¯+â¯CV and N70â¯+â¯CVâ¯+â¯Z treatments. Compared with N100, both N70â¯+â¯CV and N70â¯+â¯CVâ¯+â¯Z decreased the relative abundances of ammonia oxidation microbes, increased denitrifier and the ratios of (nirKâ¯+â¯nirS)/nosZ and norBC/nosZ. Furthermore, compared with N70â¯+â¯CV, N70â¯+â¯CVâ¯+â¯Z decreased the relative abundances of N2O-producer and the ratios of (nirKâ¯+â¯nirS)/nosZ and norBC/nosZ in denitrification. These findings revealed that the reduction of N2O emissions resulting from green manure replaced chemical N was mainly due to weakened nitrification, while zeolite reduced N2O emissions attributed to enhanced conversion of N2O to N2. Moreover, certain key N-cycling functional bacteria, such as Phycisphaerae, Rubrobacteria, and Thermoflexia, were positively correlated with N2O emission. In contrast, Dehalococcoidia, Gammaproteobacteria, and Betaproteobacteria were negatively correlated with N2O emission. This investigation uncovered the underlying mechanisms for effectively reducing N2O emissions through green manure combined with zeolite.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China