Assessing the Response Mechanisms of Elevated CO2 Concentration on Various Forms of Nitrogen Losses in the Golden Corn Belt

Abstract Nitrogen (N) loss is a significant source of water quality pollution in alluvial watersheds. However, the mechanisms linking N loss and elevated CO2 concentration (eCO2) are not well recognized. In this study, we comprehensively calibrated the SWAT model equipped with a dynamic CO2 input an...

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Bibliographic Details
Main Authors: Yingqi Zhang, Yiwen Han, Na Wen, Junyu Qi, Xiaoyu Zhang, Gary W. Marek, Raghavan Srinivasan, Puyu Feng, De Li Liu, Kelin Hu, Yong Chen
Format: Article
Language:English
Published: Wiley 2024-07-01
Series:Water Resources Research
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Online Access:https://doi.org/10.1029/2024WR037226
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Summary:Abstract Nitrogen (N) loss is a significant source of water quality pollution in alluvial watersheds. However, the mechanisms linking N loss and elevated CO2 concentration (eCO2) are not well recognized. In this study, we comprehensively calibrated the SWAT model equipped with a dynamic CO2 input and response module to investigate the response mechanisms between multiform N losses and eCO2 in a representative large‐scale watershed. Results revealed nitrate loss under eCO2 exceeding 100% in some upstream zones under the SSP5‐8.5 scenario (P < 0.05) compared to the constant CO2 concentration. This was directly related to the great increase in hydrological variables, which were the carriers of N losses, and the intensive inputs of N fertilizer. Results also found that nitrate leaching was greater than the other two processes for future periods, peaking at 309.3%, as compared to the baseline period. The findings suggested reducing fertilizer inputs by 10%–20% was promising, especially for reducing nitrate loss through runoff and leaching by up to 17.7% and 12.2%. This study explored the mechanisms of increased N loss in response to eCO2 and provided scientific evidence for early warning and making decisions to improve water quality at a large watershed scale.
ISSN:0043-1397
1944-7973