Bonding strength of plant and microbial precursors to mineral-associated soil organic matter
EMSL Project ID
51789
Abstract
Soil organic matter (SOM) provides ecosystem services such as soil fertility and climate mitigation, holding the key to agricultural sustainability in a rapidly changing world. Despite the important contribution of SOM to soil development and health, the underlying mechanisms of its accumulation are vague. Biomolecules from plants and microbes can accumulate on mineral surfaces through organo-mineral interactions, the strength of which likely depends on both organic compound and mineral reactivities. Traditionally the strength of organic matter-mineral associations is examined using sequential solvent extractions, which are inherently biased by molecular compatibility with the selected solvent. An alternative method is to use thermal desorption to assess the strength of organo-mineral interactions. A recent study using thermal desorption found that the higher the desorption energy to break organo-mineral bonds, the longer the residence time. We propose to do the first science experiment on a new capability that couples pyrolysis-gas chromatography mass spectrometry (Py-GC/MS) and Mössbauer spectroscopy analyses to achieve a compound-specific understand of the bonding strength of diverse biomolecules on pure minerals scaled to field soil. We understand that the most persistent SOM molecules bind directly to mineral surfaces and therefore should have the highest desorption energy. Our proposed research will address a key knowledge gap by using an innovative approach that bridges scientific fields and spans spatial scales to address controls on carbon sequestration in biofuel croplands.
Project Details
Start Date
2020-11-19
End Date
2023-10-01
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members