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| Titel |
Determining the optimal nitrogen rate for summer maize in China by integrating agronomic, economic, and environmental aspects |
| VerfasserIn |
G. L. Wang, Y. L. Ye, X. P. Chen, Z. L. Cui |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 11 ; Nr. 11, no. 11 (2014-06-11), S.3031-3041 |
| Datensatznummer |
250117451
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| Publikation (Nr.) |
 copernicus.org/bg-11-3031-2014.pdf |
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| Zusammenfassung |
| The concept of high yield with a goal of minimum environmental cost has
become widely accepted. However, the trade-offs and complex linkages among
agronomic, economic, and environmental factors are not yet well understood.
In this study, reactive nitrogen (Nr) losses were estimated using
an empirical model, and an economic indicator and an evaluation model were
used to account for the environmental costs of N fertilizer production and
use. The minimum N rate to achieve the maximum yield benefit (agronomically
optimal N rate), maximum economic benefit (economically optimal N rate:
economic benefit was defined as yield benefit minus N fertilizer cost), and
maximum net benefit (ecologically optimal N rate: net benefit was defined as
yield benefit minus N fertilizer and environmental costs) were estimated
based on 91 on-farm experiment sites with five N levels for summer maize
production on the North China Plain. Across all experimental sites, the
agronomically, economically, and ecologically optimal N rates
(Nagr, Neco, and Necl, respectively)
averaged 289, 237, and 171 kg N ha−1, respectively. Necl
management increased net benefit by 53% with a 46% decrease in
total environmental costs, and a 51% decrease in Nr loss
intensity from N fertilizer use (47, 65, and 38% for N2O emission,
N leaching, and NH3 volatilization, respectively) and maintained grain
yield, compared with Nagr management. Compared with
Neco management, Necl increased net benefit by
12%, with a 31% decrease in total environmental costs and a 33%
decrease in Nr loss intensity from N fertilizer use, and
maintained economic benefit and grain yield. No differences in
Necl were observed between soil types or years, but significant
variation among counties was revealed. Necl increased with the
increase in N-derived yield with an R2 of 0.83. In conclusion,
Necl was primarily affected by N-derived yield and could enhance
profitability as well as reduce Nr losses associated with the
maize grain yield. |
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