Beyond clay: Towards an improved set of variables for predicting soil organic matter content

Craig Rasmussen; Katherine Heckman; William R. Wieder; Marco Keiluweit; Corey R. Lawrence; Asmeret Asefaw Berhe; Joseph C. Blankinship; Susan E. Crow; Jennifer Druhan; Caitlin E. Hicks Pries; Erika Marin-Spiotta; Alain F. Plante; Christina Schadel; Joshua P. Schmiel; Carlos A. Sierra; Aaron Thompson; Rota Wagai

doi:10.1007/s10533-018-0424-3

Beyond clay: Towards an improved set of variables for predicting soil organic matter content

Biogeochemistry

By: Craig Rasmussen, Katherine Heckman, William R. Wieder, Marco Keiluweit, Corey R. Lawrence, Asmeret Asefaw Berhe, Joseph C. Blankinship, Susan E. Crow, Jennifer Druhan, Caitlin E. Hicks Pries, Erika Marin-Spiotta, Alain F. Plante, Christina Schadel, Joshua P. Schmiel, Carlos A. Sierra, Aaron Thompson, and Rota Wagai

https://doi.org/10.1007/s10533-018-0424-3

Links

More information: Publisher Index Page (via DOI)
Open Access Version: Publisher Index Page
Download citation as: RIS | Dublin Core

Abstract

Improved quantification of the factors controlling soil organic matter (SOM) stabilization at continental to global scales is needed to inform projections of the largest actively cycling terrestrial carbon pool on Earth, and its response to environmental change. Biogeochemical models rely almost exclusively on clay content to modify rates of SOM turnover and fluxes of climate-active CO₂ to the atmosphere. Emerging conceptual understanding, however, suggests other soil physicochemical properties may predict SOM stabilization better than clay content. We addressed this discrepancy by synthesizing data from over 5,500 soil profiles spanning continental scale environmental gradients. Here, we demonstrate that other physicochemical parameters are much stronger predictors of SOM content, with clay content having relatively little explanatory power. We show that exchangeable calcium strongly predicted SOM content in water-limited, alkaline soils, whereas with increasing moisture availability and acidity, iron- and aluminum-oxyhydroxides emerged as better predictors, demonstrating that the relative importance of SOM stabilization mechanisms scales with climate and acidity. These results highlight the urgent need to modify biogeochemical models to better reflect the role of soil physicochemical properties in SOM cycling.

Additional publication details
Publication type	Article
Publication Subtype	Journal Article
Title	Beyond clay: Towards an improved set of variables for predicting soil organic matter content
Series title	Biogeochemistry
DOI	10.1007/s10533-018-0424-3
Volume	137
Issue	3
Year Published	2018
Language	English
Publisher	Springer
Contributing office(s)	Geosciences and Environmental Change Science Center, John Wesley Powell Center for Analysis and Synthesis
Description	10 p.
First page	297
Last page	306
Google Analytic Metrics	Metrics page