Mineralogy and Soil Organic Matter Composition as Drivers of Reactive Nitrogen Emissions from Midwestern Hardwood Forest Soils
EMSL Project ID
51118
Abstract
The overall goal of this proposal is to investigate how plant-microbe-mineral interactions drive emissions of reactive nitrogen from soils. Fluxes of reactive nitrogen oxides [NOy = NO + NO2 + HONO] from soil are poorly studied due to their highly reactive nature, yet they play a major role in nutrient cycling, regional air quality and global climate. We aim to uncover the biotic and abiotic factors that determine reactive N fluxes in central hardwood forests, using an approach that combines field studies and laboratory experiments with unique state-of-the-art analytical capabilities available at EMSL. Our guiding hypothesis is that reactive N emissions are controlled principally by two factors: 1) the activities of soil microbes that associate almost exclusively with certain tree species and 2) the underlying soil mineralogy. To test our hypothesis, we will: (1) Determine the relationship between soil mineralogy and soil organic matter (SOM) composition on soil outgassing of NOy and N2O in field experiments, and (2) determine how SOM-mineral interactions affect N availability and mineralization rates in different soil fractions and in the presence of two different groups of mychorrizal fungi. The proposal will take full advantage of the unique capabilities in mass spectrometry and nuclear (para)magnetic resonance spectroscopy developed at EMSL and will build on our previous collaborations with both laboratories. Work at EMSL will provide needed characterization of SOM chemical composition and SOM-mineral interactions that will help us link (via multivariate regression and principle component analysis) the SOM composition, mineralogy, to observed N storage and loss to the atmosphere via outgassing. The successful project will inform efforts to expand the project to include additional sites, increase sample size, and establishing seasonal trends in SOM composition and soil NOy fluxes. It will also provide preliminary results for proposal(s) to fund continuation of the work. Detailed mechanistic information obtained from this work will be critical for accurately modeling the fate of N in reactive transport and climate models.
Project Details
Project type
Exploratory Research
Start Date
2019-11-26
End Date
2021-06-30
Status
Closed
Released Data Link
Team
Principal Investigator