Department of Biology, West Virginia University, Morgantown, West Virginia, USA.
Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Ecol Lett. 2024 Jan;27(1):e14331. doi: 10.1111/ele.14331. Epub 2023 Oct 28.
Plant-microbe interactions in the rhizosphere shape carbon and nitrogen cycling in soil organic matter (SOM). However, there is conflicting evidence on whether these interactions lead to a net loss or increase of SOM. In part, this conflict is driven by uncertainty in how living roots and microbes alter SOM formation or loss in the field. To address these uncertainties, we traced the fate of isotopically labelled litter into SOM using root and fungal ingrowth cores incubated in a Miscanthus x giganteus field. Roots stimulated litter decomposition, but balanced this loss by transferring carbon into aggregate associated SOM. Further, roots selectively mobilized nitrogen from litter without additional carbon release. Overall, our findings suggest that roots mine litter nitrogen and protect soil carbon.
根际中的植物-微生物相互作用影响土壤有机质（SOM）中碳氮的循环。然而，这些相互作用是否会导致 SOM 的净损失或增加，目前仍存在相互矛盾的证据。部分原因是由于活体根系和微生物在田间如何改变 SOM 的形成或损失方面存在不确定性。为了解决这些不确定性，我们使用种植在芒草中的根和真菌生长芯来追踪放射性标记的凋落物进入 SOM 的过程。根刺激凋落物分解，但通过将碳转移到团聚体相关的 SOM 中来平衡这种损失。此外，根从凋落物中选择性地获取氮，而无需额外释放碳。总的来说，我们的研究结果表明，根从凋落物中获取氮并保护土壤碳。
