On-farm soil management distinctly influences the stabilization of dissolved organic carbon within soil aggregates

作者：Orracha Sae-Tun, Christoph Rosinger, Gernot Bodner, Axel Mentler, H. Mayer, Sabine Huber, Katharina Keiblinger · 年份：2024 · DOI：10.5194/egusphere-egu24-15383 · 研究领域：Soil Carbon and Nitrogen Dynamics

Dissolved organic carbon (DOC) is a highly active carbon pool which can easily be utilized by soil microbes and is thereby a crucial fraction of the soil carbon cycle. Occlusion within soil aggregates is one important stabilization mechanism of DOC in the soil and is affected by various factors including soil management and site-specific conditions. However, details about this mechanism and its regulating factors are still largely unclear. Thus, this study aims to investigate the stabilization mechanism of DOC in soil aggregates under different soil managements across varying soil textures (fine, medium, and coarse). In the study, the soil managements were categorized into three different systems depending on the degree of conservation measures implemented on the farms: state-of-the-art system (standard), conservation systems (pioneer) which were primarily characterized by intensive use of cover cropping together with crop diversification and rotation, and semi-natural grassland (reference). We employed a combination of ultrasonication and online UV-visible spectroscopy to examine the concentration of DOC released from soil aggregates decayed. The experimental setup followed the theory that the duration of low-amplitude ultrasonication energy correlates with higher aggregate stability (resistant to decay), which in return affects the stability of DOC. Influential factors were assessed from relationships with soil physico-chemical and biological characteristics. Based on the o...