Research Training Fellowship Program Environmental Quality Foci

Primary advisor: Dr. Mahdi Al-Kaisi malkaisi@iastate.edu
Associate Professor of Soil Management/Environment

Description of the research opportunity: The proposed project will assess impacts of corn biomass harvest for bio-economical uses on soil and water quality. Society is facing problems due to over-reliance on imported fossil fuels, increasing levels of greenhouse gases in the atmosphere, and reduced water quality. Government and the private sector are encouraging development of new technologies for utilizing lignocelluloses’ materials in energy or feed uses. Corn production in Iowa and the Midwest annually exceeds 50 million acres and, therefore, the economic incentive for harvesting biomass for bio-economical uses is increasing significantly (i.e., sugar production, ethanol, animal feed, energy production, and other products). The practice of removing total crop biomass or residue after grain harvest (stover) for feeding is somewhat established, whether in Iowa as a major corn state in the Midwest. However, the impacts of the potentially large-scale complete removal of corn plants or stover after grain harvest on the sustainability of crop production and environmental conservation in large areas of the country are not well known. The effects of this practice on soil properties, greenhouse gasses emissions, carbon (C) soil sequestration, needs for additional fertilization, and water quality associated with potential increases of soil erosion and surface runoff need evaluation. A lack of well-documented research evaluating impacts of biomass removal, in particular of corn stover after grain harvest, makes this study very valuable in providing research-based information on the consequences of such practices. Researchers and producers are uncertain about the resulting impacts of reduced C sequestration, soil quality, recycling of macronutrients such as, nitrogen (N), phosphorus (P), and potassium (K), and water quality. Biomass removal can result in increased nutrient removal and fertilization needs due to increased soil and nutrient loss with surface runoff.

The main objectives of this study are: (1) establish well-defined residue removal practices for economic uses and their impacts on soil C dynamics, C sequestration, nutrients (N, P, and K) recycling in soils, and fertilization needs of a following crop, (2) evaluate different levels of biomass removal practices on nutrient loss due to soil erosion and surface runoff, and (3) assess the utilization of field and regional scales models for evaluating soil C dynamics (EPIC model, Century model, etc.).

Description of the training opportunity: Student (s) involve in this project will work closely with team of scientists from the Agronomy Department and other departments across the university that are involved in the bio-energy research. The student will be trained in multidiscipline areas of soil fertility, crop production, soil chemistry, plant physiology, soil microbiology, and other related scientific disciplines. In addition student will receive training in field and lab measurements and data collection, statistical analysis, presentations at international and national conferences, and publishing in refereed journals. This research program will offer significant training in the area of soil carbon dynamics of coupled approach of field and laboratory studies that would utilize innovative and novel ideas in research methodology of determining the impact of row cropping systems on greenhouse gases emissions and soil C dynamics. State of the art equipment will be employed, including field soil CO2 emission analyzer (LICOR-6400), dissolved total organic carbon analyzer (TOC), and gas chromatography (GC) instrument. Over the past 7 years, many graduate students completed their graduate degrees in the area of soil carbon dynamics and cropping systems in my research program and examples of the published work can be viewed at this link:

http://extension.agron.iastate.edu/soilmgmt/PubsRefereed.html

Desired skill set:The student should have excellent scientific training in the disciplines of soil science, agronomy or other related fields. The student should have strong interest in studying the interface between agriculture production and the environment by addressing the consequences of residue removal for bio-economical use on the environment. The student must have excellent written and oral communication skills; the ability to work independently and within a team of different disciplines.

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Research focus: Physics-based evaluation of soil water content with in-situ and remote sensors.

Primary advisor: Dr. Brian Hornbuckle bkh@iastate.edu

Description of the research opportunity: The agricultural US Midwest is profoundly affected by the hydrologic cycle. Ample supplies of clean water are essential for humans and animals, and sufficient levels of soil moisture are critical for the growth of plants. Better observations of the hydrologic cycle are needed to monitor these resources that sustain life.

Current remote sensing technologies like satellite cameras and weather radars can be used to observe many aspects of the hydrologic cycle. New microwave remote sensing instruments may be able to detect a particularly important (and currently unobserved) aspect of the terrestrial hydrologic cycle, soil water content. Observations of soil moisture have the potential to vastly improve our understanding of land surface hydrology. For example, maps of soil moisture would enable us to determine: how soil moisture variations influence the amount of precipitation that soaks into the soil to replenish ground water; how the balance of precipitation that does not infiltrate transports agricultural chemicals and eroded soil out of the field and into streams, rivers, lakes, and other water bodies; and how variations in soil moisture are related to weather and climate, especially subsequent precipitation and periods of drought and flooding.

Within the next five years, the first two satellites capable of measuring soil moisture will be launched. In 2008, the European Space Agency will fly a microwave remote sensing satellite named the Soil Moisture and Ocean Salinity (SMOS) mission. In the United States, the National Research Council has strongly encouraged NASA to commence preparation for a similar satellite mission that would be ready in approximately 2012. Iowa State is a member of the SMOS satellite team. We also expect to play a major role in the subsequent NASA mission. Hence Iowa State has an unprecedented opportunity to contribute to the study of the terrestrial hydrologic cycle in the next decade.

There are still significant challenges to be overcome in soil moisture remote sensing, however. For one, the quantitative aspects of remotely-sensed observations of soil moisture at not well known. We have a good qualitative understanding of the relationship between soil moisture and the remote sensing signal. But we do not understand how to compare measurements of soil moisture, soil type, and vegetation made with high confidence at small scales (a square meter or less) to the large spatial scales (hundreds of square kilometers) that a satellite instrument will measure.

A team of scientists from Iowa State, the USDA's National Soil Tilth Laboratory, and the University of Iowa have developed a NASA-funded remote sensing study site near campus. This site is heavily instrumented with soil moisture, evapotranspiration, and precipitation sensors. Our objective is to quantitatively compare in-situ measurements of soil moisture made on the ground with observations of soil moisture made remote sensing instruments. This process is called validation. We hypothesize that remotely-sensed observations can best be validated with ground-based measurements through the use of rigorous statistical methods that account for variability in the primary data and ancillary data.

To test this hypothesis, we need students to rigorously characterize various in-situ methods of soil moisture measurement (impedance, time-domain reflectometry, neutron activation) and measurements of other linked processes such as vegetation (leaf area index) and soil surface roughness (laser scanner) that are made at the site using physical methods. Furthermore, students will need to test and perhaps create models that relate these measurements to other variables that can be obtained from information that already exists (soil texture, current satellite measurements) over larger space and time scales. Finally, comparisons between the in-situ and remotely-sensed measurements will be made, and models will be developed to scale these measurements in space and time.

Description of the training opportunity: Students participating in this research will directly interact with scientists at Iowa State and the National Soil Tilth Lab, as well as NASA research centers, and the American and European remote sensing communities through two upcoming satellite remote sensing missions. Students will receive training in field measurements at the validation site, training in laboratory measurements, and training in advanced statistical methods, modeling, and the physical theory. Students will make presentations at international technical conferences and publish results in top research journals. Students will meet regularly with collaborators to discuss research activities.

Desired skill set: Excellent quantitative skills commensurate with a degree in any physical science discipline, any engineering discipline, or statistics. Good physical science background and/or a strong desire to study environmental science. Excellent communication skills; the ability to work independently; the ability to develop a creative approach to solving a problem; and the willingness to work with a team of interdisciplinary scientists.

Supplemental resources:
Krajewski et al., 2006. A remote sensing observatory for hydrologic sciences: A genesis for scaling to continental hydrology. Water Resources Research. doi:10.1029/2005WR004435.

Hornbuckle and England, 2005. Radiometric sensitivity to soil moisture at 1.4 GHz through a corn crop at maximum biomass. Water Resources Research. doi:10.1029/2003WR002931.

Dr. Brian Hornbuckle: http://www.public.iastate.edu/~bkh/

The Soil Moisture and Ocean Salinity mission: http://www.esa.int/esaLP/LPsmos.html

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Research focus: Soil Carbon and Soil Carbon Dioxide Emissions

Primary advisor: Dr. Robert Horton rhorton@iastate.edu

Description of the research opportunity: Soil carbon is intimately tied to the natural dynamics of temperature and water moving in and through the soil system. To date much of the work on soil carbon dioxide fluxes considers only simple diffusion under isothermal conditions. Because fluxes of carbon dioxide are also driven by water, temperature, and pressure influences, it is crucial to develop an improved measurement approach that considers coupling of these processes. Such an approach will improve our understanding of carbon dynamics at multiple temporal and spatial scales.

Possible Objectives:

To develop a method to quantify carbon dioxide fluxes in non-isothermal soil conditions. This approach will combine new techniques for in situ measurement of soil temperature, thermal properties, water content, air-filled porosity, carbon dioxide concentration, and gas pressure with more complete models of vapor and gas fluxes (convection + simple diffusion) to quantify fluxes.
To validate the new method of measuring carbon dioxide fluxes in laboratory controlled non-isothermal soil conditions. The new method will be tested in a series of laboratory experiments using soil columns instrumented with thermo-time domain reflectometry, carbon dioxide, and gas pressure sensors.
To deploy the new method of measuring carbon dioxide fluxes in non-isothermal field soil conditions. Following laboratory testing in controlled soil columns the method will be deployed in selected field plots. Influences of soil and crop management treatments on soil carbon and carbon dioxide emissions will be quantified.

Description of the training opportunity: The student participating in this research will interact with soil scientists, crop scientists, and meteorologists. The student will actively work with a group of faculty in order to develop instrumentation measurement skills, data synthesis skills, and numerical modeling skills. The student will be encouraged to take courses in soil science (physics, chemistry, microbiology, and management), crop science (physiology and management), microclimatology, and heat and mass transfer in engineering.

Desired skill set: The student should have excellent quantitative skills and appropriate training in physical sciences at the undergraduate level. A soil science, physics, or chemical engineering background would be very helpful. The successful student should have good communication skills and be able to work effectively both alone and in collaboration with other scientists.

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Research focus: This research will investigate the ecological effects of forage production systems and forage quality on animal production efficiency, while specifically examining costs of production and profit potential for conventional grass-fed, organic grass-fed, and organic grain-fed animal production in the Upper Midwest. We propose that the research team will approach the investigations with a holistic/systems approach, in the development of the hypotheses, data collection and analysis, and the development of the conclusions and recommendations.

Primary advisor: Dr. Mary Wiedenhoeft mwiedenh@iastate.edu

Description of the research opportunity: Perennial forages in grass-based animal production systems can provide environmental benefits in the form of reduced soil erosion and increased soil quality (Burkart et al., 2005). Extended crop rotations that include small grains and forages, often associated with organic production systems, also provide soil benefits (Karlen et al., 2006). Grass-fed and organic production may offer opportunities for struggling conventional animal operations. However, even in light of expanding consumer demand (Whole Foods, 2006), animal producers have been slow to enter these production streams, most likely due to lack of information available on the production, management, and potential profitability of these systems. Investigation into forage resources and grazing management relative to profitability is critically needed.

We hypothesize that by clearly documenting the most effective forage and animal production systems, along with associated potential benefits to profitability and the environment, that we can increase the entry of producers into the grass-based and organic markets. Margaret Smith has secured a grant from the Sustainable Agriculture Research and Education (SARE) program to study these systems with two other researchers and 30 producers in Iowa, Nebraska, and Wisconsin, and to disseminate the results in all three states. She will help to direct the training fellow in on-farm analysis of systems, as well as development of budgets and case studies.

Description of the training opportunity: The Research Fellow can anticipate learning about the establishment and renovation of extended organic and/or sod-based crop rotations; soil, water, and forage biomass quality analysis; and associated concepts in animal nutrition and body scoring. The Fellow will also gain experience in enterprise budget development and analysis, as well as writing professional case studies.

Desired skill set: The ideal candidate will have a degree in environmental sciences, agriculture, or a related field. He/she will also have familiarity with the concepts of alternative/sustainable agriculture and experience with agricultural business and entrepreneurship. The candidate must be able to work directly with farmers and Extension personnel, and interested in working in a multi-disciplinary environment.

Relevant citations:
Karlen, D.L., E.G. Hurley, S.S. Andrews, C.A. Cambardella, D.W. Meek, M.D. Duffy, and A.P. Mallarino. 2006. Crop Rotation Effects on Soil Quality at Three Northern Corn/Soybean Belt Locations. Agron. J. 98:484-495.

Whole Foods. 2006. National Survey Reveals 80 Percent of Americans Eat Meat More Than Three Times per Week. May 9, 2006. Whole Foods Market IP, L.P. [Online]. Available at: www.wholefoodsmarket.com/company/pr_05-09-06.html (verified 20 August 2007).

Burkart, M., D. James, M. Liebman, and C. Herndl. 2005. Impacts of integrated crop-livestock systems on nitrogen dynamics and soil erosion in western Iowa watersheds. J. of Geophysical Research.

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