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Low greenhouse gases emissions associated with high nitrogen use efficiency under optimized fertilization regimes in double-rice cropping systems.
- Source :
-
Applied Soil Ecology . Apr2021, Vol. 160, pN.PAG-N.PAG. 1p. - Publication Year :
- 2021
-
Abstract
- The optimization of fertilization management has the potential to improve crop yield, reduce greenhouse gas (GHG) emissions and enhance nitrogen agronomy efficiency (NAE). However, less is known about whether these benefits can be simultaneously achieved by optimizing fertilization regimes in Chinese croplands. We carried out a year-round field experiment to measure methane (CH 4) and nitrous oxide (N 2 O) fluxes, crop yield and NAE under different fertilization regimes in a subtropical double-rice cropping system. Relative to the conventional chemical N fertilizer application (F), alternative fertilization strategies significantly decreased N 2 O emissions by 26–78% when averaged across the options of chemical N fertilizer application with reduced rates (RF, 30% off), chemical N fertilizer fully replaced by organic N fertilizer with reduced rates (OF, 30% off) and chemical N fertilizer fully replaced by controlled-release N fertilizer with reduced rates (CF, 30% off), with the largest mitigation potential occurring in OF-treated plots, but comparable extents between the early- and late-rice seasons. Soil CH 4 emissions had no consistent response to alternative fertilization regimes, showing contrasting seasonal patterns between in the early- and late-rice seasons. Alternative fertilization options consistently increased NAE by 7–36% and 30–38% in the early- and late-rice seasons, respectively, and this benefit was maximized in OF-treated plots. Direct emission factors of N fertilizer for N 2 O and the combined greenhouse gas intensity (GHGI) of N 2 O and CH 4 were negatively related to NAE while rice yield was positively related to NAE. Our findings suggest that optimized fertilization strategies especially through the option of chemical N fertilizer fully substituted by organic N fertilizer can reconcile low climatic impact and high NAE, but without compromising yield in double-rice cropping systems. • Soil GHG emissions were linked to NAE in double-rice under different fertilization regimes. • Soil N 2 O emissions showed a significant decrease by 26–78% across optimized fertilization regimes. • Optimized fertilization alternatives consistently increased NAE in double-rice cropping seasons. • Direct EFs of N 2 O and annual combined GHGI of CH 4 and N 2 O were negatively related to NAE. • Organic N substitution stood out to reconcile low SGWP and high NAE of double-rice production. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09291393
- Volume :
- 160
- Database :
- Academic Search Index
- Journal :
- Applied Soil Ecology
- Publication Type :
- Academic Journal
- Accession number :
- 148432320
- Full Text :
- https://doi.org/10.1016/j.apsoil.2020.103846