Decomposition of carbon adsorbed on iron (III)-treated clays and their effect on the stability of soil organic carbon and external carbon inputs
| العنوان: | Decomposition of carbon adsorbed on iron (III)-treated clays and their effect on the stability of soil organic carbon and external carbon inputs |
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| المؤلفون: | William R. Horwath, Xia Zhu-Barker, Mengyang You, Timothy A. Doane |
| المصدر: | Biogeochemistry. 157:259-271 |
| بيانات النشر: | Springer Science and Business Media LLC, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | Total organic carbon, chemistry.chemical_element, Mineralization (soil science), Soil carbon, Decomposition, chemistry.chemical_compound, Montmorillonite, chemistry, Environmental chemistry, Environmental Chemistry, Kaolinite, Clay minerals, Carbon, Earth-Surface Processes, Water Science and Technology |
| الوصف: | The interaction of organic carbon (OC) with clay and metals stabilizes soil carbon (C), but the influence of specific clay-metal-OC assemblages (flocs) needs further evaluation. This study aimed to investigate the stability of flocs in soil as affected by external C inputs. Flocs representing OC-mineral soil fractions were synthesized using dissolved organic C (DOC) combined with kaolinite (1:1 layer structure) or montmorillonite (2:1 layer structure) clays in the absence or presence of two levels of Fe (III) (named low or high Fe). Flocs were mixed with soil (classified as Luvisol) and incubated with or without 13C labelled plant residue (i.e., ryegrass) for 30 days. The CO2 emissions and DOC concentrations as well as their 13C signatures from all treatments were examined. Total C mineralization from flocs was approximately 70% lower than non-flocced DOC. The flocs made with montmorillonite had 16–43% lower C mineralization rate than those made with kaolinite with no Fe or low Fe. However, when flocs were made with high Fe, clay mineralogy did not significantly affect total C mineralization. A positive priming effect (PE) of flocs on native soil OC was observed in all treatments, with a stronger PE found in lower Fe treatments. The high-Fe clay flocs inhibited ryegrass decomposition, while the flocs made without clay had no impact on it. Interestingly, flocs significantly decreased the PE of ryegrass on native soil OC decomposition. These results indicate that the adsorption of DOC onto clay minerals in the presence of Fe (III) stabilizes it against decomposition processes and its stability increases as Fe in flocs increases. Flocs also protect soil OC from the PE of external degradable plant C input. This study showed that Fe level and clay mineralogy play an important role in controlling soil C stability. |
| تدمد: | 1573-515X 0168-2563 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::ce75a76eb7eea23a8207a6097494c710 https://doi.org/10.1007/s10533-021-00873-w |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi...........ce75a76eb7eea23a8207a6097494c710 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 1573515X 01682563 |
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