This title appears in the Scientific Report : 2015 

Role of Nanoclays in Carbon stabilization in Andisols and Cambisols
Calabi-Floody, M. (Corresponding author)
Rumpel, C. / Velásquez, G. / Violante, A. / Bol, R. / Condron, L. M / Mora, M. L
Agrosphäre; IBG-3
Journal of soil science and plant nutrition, 15 (2015) 3, S. 587-604
Temuco Sociedad Chilena de la Ciencia del Suelo 2015
10.4067/S0718-95162015005000026
Journal Article
Terrestrial Systems: From Observation to Prediction
OpenAccess
OpenAccess
Please use the identifier: http://dx.doi.org/10.4067/S0718-95162015005000026 in citations.
Please use the identifier: http://hdl.handle.net/2128/9593 in citations.
Greenhouse gas (GHG) emissions and their consequent effect on global warming are an issue of global environmental concern. Increased carbon (C) stabilization and sequestration in soil organic matter (SOM) is one of the ways to mitigate these emissions. Here we evaluated the role of nanoclays isolated from soil on C stabilization in both a C rich Andisols and C depleted Cambisols. Nanoclays were analyzed for size and morphology by transmission electron microscopy, for elemental composition and molecular composition using pyrolysis-GC/MS. Moreover, nanoclays were treated with H2O2 to isolate stable SOM associated with them. Our result showed better nanoclay extraction efficiency and higher nanoclay yield for Cambisol compared to Andisols, probably related to their low organic matter content. Nanoclay fractions from both soils were different in size, morphology, surface reactivity and SOM content. Nanoclays in Andisols sequester around 5-times more C than Cambisols, and stabilized 6 to 8-times more C than Cambisols nanoclay after SOM chemical oxidation. Isoelectric points and surface charge of nanoclays extracted from the two soils was very different. However, the chemical reactivity of the nanoclay SOM was similar, illustrating their importance for C sequestration. Generally, the precise C stabilization mechanisms of both soils may be different, with nanoscale aggregation being more important in Andisols. We can conclude that independent of the soil type and mineralogy the nanoclay fraction may play an important role in C sequestration and stabilization in soil-plant systems.