We are measuring the capacity of stable soil N pools to retain N across several land-use types in Pennsylvania, including row-crop agriculture, pastures, urban lawns, and forests.

For several decades, N cycling research has focused on the relatively small pool of labile N that is made available to plants. Because labile pools are cycled rapidly by plants and soil organisms, this research conceptualized the terrestrial N cycle as driven mainly by biological processes. Weaknesses to this approach are beginning to surface, and it is becoming clear that a full understanding of terrestrial N cycle (including plant-available N) requires new research on abiotic processes and their interactions with the very large pool of (stable) soil organic N that is not immediately available to plants.

With support from the A.W. Mellon Foundation and NSF, we tested a new conceptual model for the terrestrial N cycle that explicitly includes a stable organic N pool and its dynamics. This new model unifies several currently isolated lines of N cycling research and generates testable hypotheses related to the role of microbial and abiotic incorporation of N into stable organic matter. Our current work in this area is focused on N rentention in legacy sediments and N cycling at the Susquehanna-Shale Hills Critical Zone Observatory. See Weitzman and Kaye 2016 and 2018

The Kaye Biogeochemistry Lab believes that everyone should have equal access to science, and we strive to create an environment that welcomes and respects diversity in all its forms—including cultural, racial, religious, age, gender identity, sexual orientation, physical ability, and mental wellbeing. Read more here.

The Kaye Biogeochemistry Lab believes that everyone should have equal access to science, and we strive to create an environment that welcomes and respects diversity in all its forms—including cultural, racial, religious, age, gender identity, sexual orientation, physical ability, and mental wellbeing. Read more here.