Research Projects

Integrated Sustainable bioEnergy Pathways (ISEP) Project .
As part of the ISEP (.pdf) project, Dr. Emily Heaton, Dr. Lisa Schulte, Dr. Matt Darr, Dr. Guiping Hu, and Dr. Lizhi Wang aim to create a nation-wide framework for assessing tradeoffs associated with different bioenergy conversion pathways and characterize interactions between lignocellulosic energy resources with their growth environment. These collaborators also aim to characterize interdependence of the plant production system (including genetic resources), the harvest-storage-transport logistics, and the conversion system, in the context of environmental services and socioeconomics.October 2014 Progress Report and 2014 Deliverables.

Regional Biomass Feedstock Program – Switchgrass.
This is one of several trials to assess switchgrass productivity around the U.S (Sun Grant Initiative). The experiment is conducted using a randomized complete block design (n=4) with three N treatments on 1.5 acre plots for a total area of ~20 acres. Metrics evaluated include input costs (fuel use, seed, fertilizer, etc.), seedling establishment and biomass yield. Lead P.I. Dr. Vance Owens, South Dakota State University. Funded by the DOE North Central Sun grant Initiative.

Comparison of perennial bioenergy cropping systems.
As part of the CenUSA project, post-doc Cathi Bonin is investigating the potential of improved bioenergy switchgrass, low-diversity mixtures and high-diversity mixtures to produce biomass along with ecosystem services as compared to continuous corn. The experiment is done in a replicated design using one-acre plots on marginal land, with and without the addition of biochar. Impact on soil and greenhouse gases is done by collaborator Dr. David Laird of Iowa State University.

Invasive potential of Miscanthus.
Similar to the project below, this project is conducted in collaboration with Dr. Allison Snow of Ohio State University, and uses a combination of field and molecular experiments to understand the likelihood that improved Miscanthus varieties will become weedy in the Midwest. Dr. Cathi Bonin conducts some of her post-doctoral research on both of these projects. Funded by the NIFA BRAG program.

Invasive potential of switchgrass.
Conducted in collaboration with Dr. Allison Snow of Ohio State University, this study uses a combination of field and molecular experiments to understand the likelihood that improved switchgrass varieties will become weedy in the Midwest. Gene flow studies will determine pollen dispersal distances while seed survival, establishment and plant fitness studies determine the ability of new varieties to outcompete existing cultivars and wild ecotypes. Funded by the NIFA BRAG program.

Foliar nutrient leaching.
A series of experiments have been designed to evaluate how foliar nutrient leaching changes during plant development in response to seasonal precipitation by simulating rainfall to the aboveground portions of perennial grasses, switchgrass (Panicum virgatum L.) and miscanthus (Miscanthus × giganteus). As part of her M.S. degree, Ruth Burke, is working on closing the nutrient budget to better understand feedstock nutrients that are harmful in conversion technologies. Management decisions such as harvest timing and nutrient applications can be directly improved; conceptually, this will help fine-tune current nutrient-use efficiency estimates and cycling models.

The Landscape Biomass Project.
Assistant Research Scientist, Nic Boersma began supporting all field activities at the Landscape Biomass Project site in 2012, representing official research engagement of the Heaton lab in the research at this site (finally!). This project compares different biomass cropping systems (switchgrass, corn, aspen trees, soon Miscanthus and biomass sorghum) grown across a topographic gradient, i.e. from the top of a hill to the bottom. A large, multi-disciplinary team is investigating the interaction of landscape and cropping systems from many angles. Ultimately, we aim to understand trade-offs expected with strategic integration of perennial crops in agricultural landscapes. Funded in part by Iowa EPSCoR.

Internal switchgrass N cycling.
This study was a closer look at the timing and spatial distribution of switchgrass internal N cycling. Conducted by Danielle Wilson for her MS degree (Wilson, 2012) she elucidated the way pools of total N in above- and below-ground tissues change throughout the growing season, and also found that feedstock N content had a direct impact on fast pyrolysis products like bio-oil and biochar (Wilson et al., 2012). Funded by Phillips66.

Identifying optimal environmental conditions for growth of M. × giganteus stem cuttings.
Substituting stem pieces for rhizomes could revolutionize M. × giganteus planting, but no information exists on environmental conditions for growth. As part of his PhD dissertation, Nic Boersma measured growth of stem pieces under varied temperature and light regimes in controlled environment chambers. He found that the bottom five nodes of M. × giganteus grown in warm temperatures were as effective in producing new plants as rhizomes, thus presenting a path to increase the multiplication rate of M. × giganteus at least five-fold, without ever digging a hole (Boersma & Heaton, 2012)!

Field comparison of M. × giganteus planted from greenhouse plugs vs. rhizomes.
Continuing his quest to improve the efficiency of M. × giganteus planting techniques, Nic Boersma planted greenhouse plugs and rhizomes into a replicated complete block design at three locations in Iowa. Propagule type did not impact above- or belowground biomass, establishment losses, or winter losses. Yields averaged 24.7 Mg ha^-1 (Part 1, Boersma & Heaton, 2014), (Part 2, Boersma & Heaton, 2014)

Miscanthus Cold Tolerant Line Evaluation.
This project began in March 2010 to evaluate the cold tolerance of 10 varieties of Miscanthus provided by Mendel Bioenergy Seeds. Tissue cultured individuals were planted in a split-plot randomized complete block design with four replications. Morphological and productivity data collected for Muhammad Aurang zaib's MS degree showed significant variability in growth dynamics and yield between varieties, presenting opportunity to optimize cultivars used in temperate climates (Aurang zaib, 2012).

M. × giganteus establishment in nurse crops.
This project began in 2009 to inform planting methods on highly erodible land. Current recommended planting practices for M. × giganteus places plants ~ 1 m apart in a clean, tilled seed bed, making erosion a major concern during crop establishment. Companion crops planted between M. × giganteus plants may hold soil and provide ecosystem services until M. × giganteus plants mature. Two types of Miscanthus × giganteus propagules, greenhouse plugs or rhizomes, were planted into one of ten nurse crop treatments in May 2009. Measurements include establishment metrics such as nurse crop stand density, light interception, M. × giganteus survival rate and biomass yield of all crops. Funded by the DOE North Central Sun grant Initiative.