Abstract

Emerging evidence points out that the responses of soil organic carbon (SOC) to nitrogen (N) addition differ along the soil profile, highlighting the importance of synthesizing results from different soil layers. Here, using a global meta-analysis, we found that N addition significantly enhanced topsoil (0-30 cm) SOC by 3.7% (+/- 1.4%) in forests and grasslands. In contrast, SOC in the subsoil (30-100 cm) initially increased with N addition but decreased over time. The model selection analysis revealed that experimental duration and vegetation type are among the most important predictors across a wide range of climatic, environmental, and edaphic variables. The contrasting responses of SOC to N addition indicate the importance of considering deep soil layers, particularly for long-term continuous N deposition. Finally, the lack of depth-dependent SOC responses to N addition in experimental and modeling frameworks has likely resulted in the overestimation of changes in SOC storage under enhanced N deposition.Nitrogen addition may profoundly affect soil organic carbon (SOC), but its impact on SOC in different soil layers remains unclear. Nitrogen addition significantly enhanced SOC in the topsoil (0-30 cm), while subsoil SOC (30-100 cm) initially increased with nitrogen addition but decreased over time. These results likely imply an overestimation of soil carbon sequestration with long-term nitrogen deposition.image

Keywords

carbon cycle-climate feedbacks; carbon losses; nitrogen addition duration; soil carbon sequestration; soil profiles

Published in

Global Change Biology
2024, Volume: 30, number: 3, article number: e17247
Publisher: WILEY

SLU Authors

• Kätterer, Thomas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/gcb.17247

Permanent link to this page (URI)

https://res.slu.se/id/publ/129334