SOIL MINERAL AND ORGANIC MATTER DYNAMICS

Organic matter (OM) turnover regulates the balance of carbon in the environment, including soil carbon sequestration and CO2 emissions. In soils, OM interacts with iron minerals to form strong mineral-carbon associations that influence key biogeochemical processes such as microbial activity and nutrient/contaminant mobility, inclusive of carbon mineralization to CO2. We use an array of characterization techniques, along with thermodynamic and enzymatic measurements to study the persistence and reactivity of organic matter-soil mineral frameworks. Our ultimate goal is to identify the underlying mechanisms that contribute to the resilience of OM-soil mineral assemblages.

COMPOSITION-SIZE-REACTIVITY RELATIONSHIPS IN BIOGEOCHEMICAL REACTIONS

Particle dynamics govern biogeochemical cycling by controlling the migration, stability and bioavailability of nutrients, contaminants, organic matter, and microbes in soil and water systems. We monitor the lifecycle of soil particles at the nano- and molecular-scale in order to unravel the intricate relationships between their composition, size, and reactivity. In our studies we focus on the mechanisms and rates of these reactions, with special emphasis on organic matter composition and  redox chemistry.

MICROBE-SOIL MINERAL INTERACTIONS

Microbial activity drives biogeochemical cycling. Therefore, understanding microbe-mineral interactions and how they influence soil biofilm development is paramount. We are interested in the establishment of the bacterial-mineral interface, how the size and composition of the minerals impact biofilm formation, and in turn, how microbial growth influences mineral characteristics.