The biogeochemical cycles of soils impact global climate, water quality, food production, and many other ecosystem services. These services arise from complex interactions among microbes, plants, minerals, and physical components of ecosystems. Unpacking these interactions is an exciting challenge with important implications for understanding and managing environmental change.

Our research spans the intersection of biology and Earth science. We take an interdisciplinary approach to understanding mechanisms of soil organic matter decomposition and persistence, nutrient cycling and water pollution, and production of greenhouse gases. We address these issues from both basic and applied perspectives, where possible with an eye towards “use-inspired basic research.” Many interesting questions in soil biogeochemistry are not easily confined (or answered) within a single ecosystem type. To that end, our work  spans a broad range of ecosystems, including tropical rainforests, intensive agricultural landscapes, wetlands, and boreal peatlands (among others).

Main research themes

• What factors control the persistence and microbial transformations of soil organic matter (SOM)?
  

  • Reconciling old and new paradigms of soil organic matter: the contentious role of lignin
  • Iron as a driver of organic matter stabilization and losses in dynamic redox environments
    
  • New applications of high-resolution isotope measurements: quantifying shifts in soil metabolism in diversified cropping systems

• Greenhouse gas emissions and nutrient cycling in intensive agricultural landscapes
  

  • Predicting hot-spots and hot-moments of nitrous oxide fluxes in hydric soil landscapes to reconcile bottom-up and top-down emissions budgets
  • Quantifying the disproportionate impacts of cropped depressional wetland soils on catchment-scale nutrient loads
  • Plumbing the greenhouse gas budgets of tile drained ecosystems

• Plant-microbial interactions in the rhizosphere
  

  • Environmental implications of novel constitutive N-fixing microbes in the corn rhizosphere
  • Geochemical engineering in the rhizosphere: implications of dynamic organo-mineral associations for nutrient availability