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| Titel |
Modeling the impact of agricultural land use and management on US carbon budgets |
| VerfasserIn |
B. A. Drewniak, U. Mishra, J. Song, J. Prell, V. R. Kotamarthi |
| 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 ; 12, no. 7 ; Nr. 12, no. 7 (2015-04-09), S.2119-2129 |
| Datensatznummer |
250117891
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| Publikation (Nr.) |
 copernicus.org/bg-12-2119-2015.pdf |
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| Zusammenfassung |
| Cultivation of the terrestrial land surface can create either a source or
sink of atmospheric CO2, depending on land management practices. The
Community Land Model (CLM) provides a useful tool for exploring how land use
and management impact the soil carbon pool at regional to global scales. CLM
was recently updated to include representation of managed lands growing
maize, soybean, and spring wheat. In this study, CLM-Crop is used to
investigate the impacts of various management practices, including
fertilizer use and differential rates of crop residue removal, on the soil
organic carbon (SOC) storage of croplands in the continental United States
over approximately a 170-year period. Results indicate that total US SOC
stocks have already lost over 8 Pg C (10%) due to land cultivation
practices (e.g., fertilizer application, cultivar choice, and residue
removal), compared to a land surface composed of native vegetation (i.e.,
grasslands). After long periods of cultivation, individual subgrids (the
equivalent of a field plot) growing maize and soybean lost up to 65% of
the carbon stored compared to a grassland site. Crop residue management
showed the greatest effect on soil carbon storage, with low and medium
residue returns resulting in additional losses of 5 and 3.5%,
respectively, in US carbon storage, while plots with high residue returns
stored 2% more carbon. Nitrogenous fertilizer can alter the amount of
soil carbon stocks significantly. Under current levels of crop residue
return, not applying fertilizer resulted in a 5% loss of soil carbon. Our
simulations indicate that disturbance through cultivation will always result
in a loss of soil carbon, and management practices will have a large
influence on the magnitude of SOC loss. |
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