Structure and function of managed, semi-natural, and natural grassland ecosystems. Landscape-level nutrient exchange, ecosystem-level carbon and nutrient cycling, and plant community responses to disturbance. Scientific basis for agroecology, farms as ecosystem units, cellulosic biofuel cropping systems, grazing effects on pasture and prairie.
Biomass feedstock is a major consideration in second-generation (cellulosic) biofuel development. While there is hope that systems based on polycultures and perennial species may emit less N2O than conventional agricultural crops, this reduction may be contingent on previous land use and conversion methodology, phase and length of establishment, soil type, and management of inputs and production processes. My research aims to provide direct comparisons of N2O fluxes between potential bioenergy feedstock systems and evaluate the relationship between daily N2O flux and environmental factors.
I oversee all farming and experimental operations at the Wisconsin Integrated Cropping Systems Trial (WICST) in addition to managing a network of bioenergy cropping systems trials throughout WI. WICST is a long-term (29 y), large scale (60 ac) cropping systems experiment designed to evaluate the trade-offs of alternative agricultural productions strategies and issues of agricultural sustainability in organic and conventional farming systems. My current work involves analysis and publication of data from WICST and the bioenergy trials as it pertains to the productivity, profitability, and environmental impact of alternative agricultural production strategies for feed and fuel.
In addition to my research responsibilities I teach two courses for the University of Wisconsin’s 132 year old Farm and Industry Short Course. These courses cover the production and management of grain crops (corn, soybean, wheat) and forage crops (alfalfa, clovers, pasture).
My main role is to analyze soil extracts for lipids and amino sugars by gas chromatography (GC) and GC-combustion isotope ratio mass spectrometry as a means of profiling soil microbial communities and tracing carbon flow through soil ecosystems; I also maintain and repair a variety of instrumentation. I frequently train students how to operate, maintain and repair analytical instrumentation and how to process and evaluate data. .
Net ecosystem carbon balance and litterbag decomposition with rye and bluegrass cover crops in no-till corn.
Decomposition processes when ants are excluded from a restored prairie (collaboration with Tania Kim and the Gratton Lab).
Incubation of 10 corn genotypes to evaluate decomposability under varying traits.
I am currently pursuing a PhD in Environment and Resources through the Nelson Institute for Environmental Studies and working as part of the Great Lakes Bioenergy Research Center. My current research focuses on understanding plant and soil carbon dynamics in model bioenergy systems. Specifically, I am using several methods to partition plant-based autotrophic soil respiration from microbe-based heterotrophic soil respiration in order to better constrain ecosystem carbon balances. Additionally, I am using a soil density fractionation scheme to track changes in soil carbon pools after the first five years of biofuel crop establishment. My research seeks to improve our understanding of the plant-soil carbon continuum in bioenergy systems as well as to inform ecological modeling efforts. Read more on my website.
Healthy Prairies Project, Department of Ecology, Evolution, and Behavior, University of Minnesota
