Nitrogen Systems: Policy-oriented Integrated Research and Education


Current Research

Tabitha Brown

PhD student in Soil Science
Advisor: Dr. David Huggins

Research title: Management Implications for Terrain and Soil Regulation of C and N Dynamics

Tabitha's research will focus on characterizing soil organic matter dynamics, namely carbon (C) and nitrogen (N) storage and cycling under no-tillage agriculture in the dryland Pacific Northwest. This research aims to use landscape scale and rotation based approaches to address i) individual and interacting roles of the C and N cycles; ii) inefficiencies in N management; iii) use of precision agriculture techniques for managing agroecosystem storage and cycling of C and N; and iv) implications for N and C policy. This research will be advised by Dr. David Huggins (Dept. Crop and Soil Sciences, major advisor), Dr. Jeff Smith (Dept. Crop and Soil Sciences), Dr. Kent Keller (School of Earth and Environmental Sciences), and Chad Kruger (WSU Center for Sustaining Agriculture and Natural Resources).

Ashley Hammac

PhD student in Soil Science
Advisor: Dr. William Pan

Research title: Nitrogen cycling in biodiesel feedstock production systems

Ashley is studying nitrogen fertility of canola biodiesel feedstock production. He will determine the soil nitrogen availability effect on canola grain and oil yield to develop efficient practices in a conventional canola production system. He will measure nitrogen uptake to the plant, residual nitrogen that remains in soil, and nitrogen loss via ammonia volatilization and leaching out of the root zone. Emphasis will be placed on quantifying nitrogen carry-forward and loss as a result of canola leaf litter decomposition. Yield optimization and nitrogen dynamics information will be utilized to balance economic benefit and environmental risk for these production systems. Results from the study will be used in canola biodiesel feedstock energy-balance evaluation, cost/benefit analysis, and lead to well informed bioenergy policy decision making.

Rebecca Martin

PhD student in Environmental Science
Advisor: Dr. John Harrison

Research title: Nitrogen transport from land to surface water and the bioavailability of dissolved organic nitrogen

Rebecca is interested in studying nitrogen transport from land to surface water, with particular focus on organic nitrogen. Organic nitrogen can comprise a large fraction of total dissolved nitrogen in surface water, but the potential for dissolved organic nitrogen to be available to aquatic organisms and contribute to eutrophication in streams, rivers, and coastal ecosystems is not well known. Transformations of organic nitrogen along terrestrial flow paths may alter its bioavailability, so hydrology likely plays an important role in the delivery of bioavailable organic nitrogen to surface water. Specifically, Rebecca is hoping to study the transport of dissolved organic nitrogen from agricultural fields to surface water. This research will improve our understanding of the timing and mechanisms of the delivery of biologically reactive nitrogen to surface water from non-point sources.

Devlin Montfort

PhD student in Civil Engineering
Advisor: Dr. Shane Brown

Research Title: Conceptual Change of Doctoral Students in an IGERT Fellowship

Devlin is researching how PhD science and engineering students develop conceptual understandings of nitrogen science and how their previous experience and views of knowledge and knowing change and interact with their learning. Conceptual understanding occurs through conceptual change, and is differentiated from other kinds of learning because it involves fundamental changes in the mental models and frameworks of individuals. The process of conceptual change is assumed to take place during science and engineering education, but has often been shown not to occur; education as commonly practiced does not often change individuals' pre-conceived notions of scientific and engineering phenomena. Devlin's work is focused on the long-term conceptual and epistemological changes undergone by highly educated people learning in an integrated discipline. The goal of this research is to describe conceptual changes as they occur over a much longer time period than has been studied previously in order to more fully characterize the processes and scale of conceptual change. Understanding how conceptual changes take place will ultimately lead to more effective methods for change in all learners.

Justin Poinsatte

PhD student in Botany
Advisor: Dr. Dave Evans

Research title: Carbon and Nitrogen Dynamics during Ecosystem Recovery and Succession

Justin's research is focused on changes in carbon and nitrogen dynamics on nutrient-limited areas of Mt. St. Helens. The goal of the research is to provide a better understanding of the fundamentals of soil and plant nitrogen transformations, including mechanisms of nitrogen addition and retention and the interactions between carbon availability and microbial communities. The NSPIRE program allows interactions with other fields such as atmospheric chemistry, population ecology, hydrology, and soil chemistry and provides for an open framework to incorporate interdisciplinary approaches into this research. Results will further our understanding of fundamental processes of carbon and nitrogen interactions and will lead to greater knowledge of ecosystem function, and can also be applied to restoration efforts to inform how productivity and biodiversity can be restored in disturbed areas. Finally, the young, rapidly evolving ecosystems of Mt. St. Helens can be used as a model to understand basic carbon and nitrogen cycling within the soil, which can then be applied to more complex ecosystems.