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| Titel |
Assessing biogeochemical effects and best management practice for a wheat–maize cropping system using the DNDC model |
| VerfasserIn |
F. Cui, X. Zheng, C. Liu, K. Wang, Z. Zhou, J. Deng |
| 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. 1 ; Nr. 11, no. 1 (2014-01-07), S.91-107 |
| Datensatznummer |
250117106
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| Publikation (Nr.) |
 copernicus.org/bg-11-91-2014.pdf |
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| Zusammenfassung |
| Contemporary agriculture is shifting from a single-goal to a multi-goal
strategy, which in turn requires choosing best management practice (BMP)
based on an assessment of the biogeochemical effects of management
alternatives. The bottleneck is the capacity of predicting the simultaneous
effects of different management practice scenarios on multiple goals and
choosing BMP among scenarios. The denitrification–decomposition (DNDC) model
may provide an opportunity to solve this problem. We validated the DNDC
model (version 95) using the observations of soil moisture and temperature,
crop yields, aboveground biomass and fluxes of net ecosystem exchange of
carbon dioxide, methane, nitrous oxide (N2O), nitric oxide (NO) and
ammonia (NH3) from a wheat–maize cropping site in northern China. The
model performed well for these variables. Then we used this model to
simulate the effects of management practices on the goal variables of crop
yields, NO emission, nitrate leaching, NH3 volatilization and net
emission of greenhouse gases in the ecosystem (NEGE). Results showed that
no-till and straw-incorporated practices had beneficial effects on crop
yields and NEGE. Use of nitrification inhibitors decreased nitrate leaching
and N2O and NO emissions, but they significantly increased NH3
volatilization. Irrigation based on crop demand significantly increased crop
yield and decreased nitrate leaching and NH3 volatilization. Crop
yields were hardly decreased if nitrogen dose was reduced by 15% or
irrigation water amount was reduced by 25%. Two methods were used to
identify BMP and resulted in the same BMP, which adopted the current crop
cultivar, field operation schedules and full straw incorporation and applied
nitrogen and irrigation water at 15 and 25% lower rates,
respectively, than the current use. Our study indicates that the DNDC model
can be used as a tool to assess biogeochemical effects of management
alternatives and identify BMP. |
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