2020-2021
Students supported by DWFI study a wide variety of topics related to water and food security. Below, you’ll find students’ summaries of their work and the impact it may have in achieving more food security with less pressure on scarce water resources.
Jodi Delozier
Ph.D. candidate in Human Dimensions, School of Natural Resources
Title: An Investigation of the Individual, Collective, Institutional, and Environmental Changes that Occur as a Consequence of Stakeholder Engagement
Advisor: Mark Burbach, Geo-scientist, UNL School of Natural Resources
Local communities have the motivation, competency, and collective ability to address and solve water and agricultural problems. However, improved communication and engagement can accelerate progress towards solutions. This research helps communities in identifying factors that affect diverse participation in finding solutions, providing training for engagement, and helping policymakers prioritize resources for increased food security and conservation of natural resources.
Benjamin Ndayambaje
Ph.D. candidate in Natural Resource Sciences, School of Natural Resources
Title: Linking child stunting, microbiome, livestock health and water quality: a One Health study in Rwanda
Advisor: Elizabeth Van Wormer, Assistant Professor, UNL School of Natural Resources
In Rwanda, 38% of children under five suffer from chronic malnutrition. Gut microbiome, livestock, and poor water quality are potential factors contributing to malnutrition, which can affect cognitive development in children. Researchers found that by linking child stunting and these other factors; understanding the role watersheds play in high malnutrition rates in Rwanda; and enhancing child health and development through evidence-based interventions, educational and livelihood outcomes can be improved greatly.
Chuyang Liu
Ph.D. candidate in Civil Engineering
Title: Influence of Climate and Agricultural Clustering on Groundwater Contamination by Trace Organics
Advisor: Yusong Li, Associate Professor, UNL Civil Engineering
Atrazine, one of the herbicides widely detected in surface water and groundwater, poses a threat to the local ecosystem. Researchers found that climate variability has a huge impact on atrazine accumulation and changing soil properties may mitigate this problem, helping farmers adapt to climate change with sustainable water resources.
Nafyad Kawo
Ph.D. candidate in Natural Resource Sciences, Specialization: Hydrological Sciences
Title: Integrating Hydrologic Modeling and Geophysical Characterization to Improve Water Management Tools
Advisor: Jesse Korus, Assistant Professor, UNL School of Natural Resources
Quaternary glacial aquifers account for 5% of U.S drinking water and are the primary water sources for irrigation in many agricultural regions, including eastern Nebraska. Glacial sediments are highly diverse, making them problematic for groundwater management planning and modelling them requires large amounts of data and sophisticated methods. However, airborne electromagnetics has shown promise in providing vital information to model these aquifers and find aquifer-to-aquifer connections. This information can be used to aid decision-making regarding groundwater irrigation and the impact of groundwater pumping on the environment — resulting in protected and available drinking water and a stable ecosystem.
Fernanda Souza Krupek
Ph.D. candidate in Agronomy
Title: Assessing site-specific impacts of cover crops on water cycling using high-resolution imagery and ground based data
Advisor: Andrea Basche, Assistant Professor, UNL Agronomy & Horticulture
Protecting soil with cover crops in between periods of regular crop production can prevent soil erosion, retain soil nutrients, and make cash crops less sensitive to weather changes. Researchers found a way to use aerial imagery to better understand cover crops’ site-specific effect on cash crops’ growth during the season. They found that cover crop effectiveness is site-specific and aerial imagery — as a diagnostic tool — can tell us how the cash crop performed throughout the growing season.
Early results show that larger cover crop biomass can suppress growth in soybeans, but do not generally reduce yields. Giving farmers access to this information can help them manage their crops in the best way for that particular field and foster healthier soils, improved water infiltration and better land management.
Qiao Hu
Ph.D. candidate in Natural Resource Sciences, SNR
Title: Using small Unmanned Aircraft System (UAS) to promote precision conservation and sustainable agricultural practices in the Rainwater Basin, Nebraska
Advisor: Zhenghong Tang, Professor, UNL College of Architecture
Wetlands provide natural water quality improvement, flood protection and shoreline erosion control, as well as recreation and natural products. Wetland monitoring and assessment is critical to manage and protect these important resources, but traditional wetland mapping is labor and expertise-intensive. Drones (UAVs) and artificial intelligence (AI) cost less, provide high spatial resolution imagery, and automate wetland mapping. Thus, timely and accurate wetland status can be assessed, maintaining healthy habitats for local wildlife and vegetation communities.
Nawaraj Shrestha
Ph.D. candidate in Natural Resource Sciences
Advisor: Aaron Mittelstet, Assistant Professor, UNL Biological Systems Engineering
Title: UNL Quantifying the Impact of Eastern Redcedar Encroachment on Recharge in the Nebraska Sandhills
Eastern Redcedar is a native tree species used mainly for windbreaks that has proliferated into the grassland of the Nebraska Sandhills. With the removal of fire as a management practice, Redcedar are invasive — it can tolerate drought, penetrate to deeper depth to access water and nutrients, and can therefore outcompete grassland species. It’s spread can change aspects of the grassland’s ecosystem, like groundwater recharge — vital for Nebraska’s economy and well-being.
Our research uses satellite images to identify the current levels of spread and aids decision-makers in identifying areas with a higher potential of encroachment. They can then target resources to mitigate the problem, rather than focusing on random locations — keeping current ecosystems intact and groundwater recharge safe.
Balkissa Ouattara
Ph.D. candidate in Public Health
Advisor: Eleanor Rogan, Professor, UNMC College of Public Health Department of Environmental, Agricultural & Occupational Health
Title: Possible Effects of Nitrate Contaminants in Nebraska Waterways on Human Health
Atrazine and nitrates have been linked to adverse health outcomes in humans, including methemoglobinemia in infants and certain types of cancers. Showing pediatric cancer incidences within Nebraska watershed boundaries — rather than using traditional methods like census districts or zip codes — has greater environmental relevance and may provide new insights into exposure to waterborne agrichemicals. This data will give a rationale for developing efficient private well monitoring programs, resulting in children's reduced exposure to high atrazine and nitrate concentrations in water, and thereby reducing disease incidence.
Henry Doku
Ph.D. candidate in Agronomy & Horticulture, Specialization: Plant Breeding & Genetics
Title: Phenomic and genomic analysis of drought-responsive traits in wheat
Advisor: Harkamal Walia, Associate Professor, UNL Agronomy & Horticulture
Growers frequently use the nitrate form of nitrogen fertilizer to enhance plant growth— but, there’s a limit to how much they can apply without harming the plant and the environment. Researchers found that nitrate application beyond the levels of 10mM can negatively affect growth, when water uptake by the plant is reduced. However, the amount of nitrate applied had little effect under drought conditions. Farmers can use this information to determine the correct amount of nitrate to apply to their fields.
Researchers also found that some genes could be an indicator to monitor the response of a plant to nitrate levels in the field. This finding can help in breeding nitrogen-efficient crops in the future. Both actions result in reduced fertilizer use, minimizing groundwater pollutants and the environmental and health risks that come with them.
Jackson Stansell
M.S. candidate in Agricultural & Biological Systems Engineering
Title: SENSE Nitrogen Management 2.0: Promoting Adoption of Sensor-based Nitrogen Fertilization of Corn through the NE On-Farm Research Network
Advisor: Joe Luck, Associate Professor, UNL Biological Systems Engineering
Farmers apply nitrogen fertilizer through their irrigation systems —called fertigation — in order to grow more corn. But, applying too much or too little can result in lost profits and environmental harm. If farmers knew the best times and rates to apply, they could minimize these effects.
Researchers have found that imagery — combined with data showing soil properties and measuring non-fertigation nitrogen applications — can provide weekly guidance on when the crops need nitrogen fertigation. This method is called sensor-based fertigation management.
Researchers created an automated software that shows farmers this information to help them when making fertigation decisions, saving them money and time; keeping yields intact; and protecting the environment. Ultimately, this leads to greater incomes and improved quality of life for farmers and a protected natural environment than continues to provide clean drinking water.
Matthew Thompson
Ph.D. candidate in Civil Engineering with specialization in Environmental Engineering
Title: Environmental sustainability assessment of small Nebraska water resource recovery facilities: water reuse opportunities
Advisor: Bruce Dvorak, Professor, UNL Civil Engineering & Biological Systems Engineering
Many small towns struggle with old and inefficient wastewater treatment facilities, which will soon need upgraded to protect human health and local ecosystems. Researchers evaluated different wastewater systems to find which options provide the most sustainable footprint. They found that in most cases, water reuse can reduce negative impacts to natural resources while recycling useful nutrients. This can help communities, engineers, and state regulators build more eco-friendly infrastructure.
Osler Antonio Ortez-Amador
Ph.D. candidate in Agronomy
Title: Isolating Primary Factors for Corn Ear Formation Issues
Advisor: Roger Elmore, Emeritus Professor, UNL Agronomy & Horticulture, and Justin McMechan, Assistant Professor, UNL Entomology
Growers have reported corn ear abnormalities resulting in grain losses in recent years. New abnormalities have been observed that have never been reported before. The causes are still in question, but researchers’ early results indicate that weather, genetics, and management are responsible. Understanding the causes, making recommendations to growers and reducing these issues will help produce more with less, while taking good care of resources.
Khulan Batsukh
M.S. candidate in Earth Sciences, Specialization: Hydrogeology
Title: Estimating Groundwater Recharge in Mongolia by Vadose Zone Modeling
Advisor: Vitaly Zlotnik, Professor, UNL Earth & Atmospheric Sciences
Measuring groundwater recharge is essential to managing land and water resources in Mongolia, but it can be expensive, time-consuming and labor-demanding. Researchers currently use various methods to calculate the recharge without using in-field measurements, but the practices are often lacking in developing countries, such as Mongolia. In this study, researchers developed the crop coefficient specific to Mongolia and used it to calculate evapotranspiration. They used the vadose zone numerical model by inputting the calculated evapotranspiration, precipitation and other inputs to quantify groundwater recharge in specific locations. This new knowledge can help better assess groundwater resources and be used in future water balance studies, agricultural practices, climate models and water resources management.
Katie Bathke
Robert and Karla Baltzell Student Innovation Awardee
Title: The Development of Bacillus subtilis as a Biological Control Agent for Bacterial Leaf Streak
Advisor: Gary Yuen, Professor, Department of Plant Pathology
Bacterial leaf streak is a corn disease new to the U.S. and first confirmed in Nebraska in 2016. It can result in lesions on the plant’s leaves and cause reduced yields. Researchers found that strains of a bacteria naturally found in the soil promote plant growth and encourage defense mechanisms within the plant — which also eliminate or reduce the severity of bacterial leaf streak. Further research is needed, but growers may be able to control bacterial leaf streak by applying this bacterial strain, ensuring yields for food and energy are not affected.
Jagadeesh Puvvula
Ph.D. candidate in Environmental Health
Title: mproving the Knowledge of Drought and Health in the United States
Advisor: Jesse Bell, Professor, UNMC College of Public Health
About half of Nebraska's land is used for crop production, with one-quarter of the state's land used to grow corn. Atrazine — the second most used herbicide in the U.S. — is routinely used to maximize corn production. But, agrichemical run-off after a rain can contaminate surface and groundwater sources.
Nebraska ranks as the eighth-highest in age-adjusted pediatric cancer in the U.S. and researchers were motivated to evaluate any association between atrazine and pediatric cancer. They found higher pediatric cancer incidence among watersheds in Nebraska's eastern and more agriculturally intense region compared to the state average, suggesting a significant association between pediatric cancer and atrazine concentration in water. Further studies based on personal exposure sampling can help us understand the relationship between atrazine and pediatric cancer and reduce instances of pediatric cancer in the future through effective management.
Kierstin Blomberg
Ph.D. candidate in Natural Resource Sciences, School of Natural Resources
Title: Improved Water Management through Better Understanding of Irrigation Impacts on Precipitation in the Northern Great Plains
Advisor: Rezaul Mahmood, Professor, UNL School of Natural Resources
Irrigation is a vital component in Nebraska’s agricultural leadership. However, it is not fully understood how irrigation impacts its surrounding environment, especially in terms of precipitation. Modeling and studying previous growing seasons can help growers and policymakers understand how to best use limited water resources for irrigation and highest crop production. Plus, knowing how irrigation impacts precipitation can give us further insight into climate change.
Daniel Gschwentner
Ph.D. candidate in Natural Resource Sciences with specialization in Applied Ecology, SNR
Title: Looking to the past to understand the future of freshwater in the Sandhills
Advisor: Jessica Corman, Assistant Professor, UNL Agronomy & Horticulture
Lakes in the Nebraska Sandhills are chemically diverse due to the roles of climate and groundwater. This diversity creates unique habitats for many aquatic organisms. However, it is unclear how life-supporting nutrients and other elements are cycled within these lakes and how this may be affected by future climate change.
Through our study of lake sediments, we can reconstruct past environments and examine how lakes have changed over time. By matching fossilized algae in lake sediments to algae currently living in different lakes, important information such as lake depth or nutrient concentrations can be assumed. Understanding how Sandhill lakes functioned in the past helps put current conditions into context and improves our knowledge of lake systems in general. We can also make educated guesses about how future climate change can affect these lakes. This information can then be used to manage lakes and freshwater resources more effectively and protect the organisms that live in them.
Wenqi Ou
Ph.D. candidate in Natural Resource Sciences, School of Natural Resources
Title: Develop scalable methods for identifying Water Use Gap of Farmlands in Midwestern States
Advisor: Yi Qi, Assistant Professor, UNL School of Natural Resources
Monitoring and reducing crop water stress can increase crop yields and respond to the agriculture system's pressure from climate change and global food demand. Crop water content as a vegetation water status indicator can help monitor crop water stress and provide irrigation management information. Researchers are now able to measure crop water content more easily and over a large region using remote sensing. By using this data to monitor crop water content and stress, growers can produce more, while using less water.
Jasreman Singh
Ph.D. in candidate in Biological Systems Engineering (Soil and Water Resources Engineering Emphasis)
Title: Using Stationary Sensor Nodes to Capture Growth and Stress in Maize and Soybean Using Infrared Thermometers and Soil Moisture Sensors
Advisor: Yufeng Ge, Associate Professor, UNL Biological Systems Engineering
The significance of this project is twofold: 1) the ability to secure near real-time information on crop and soil condition with respect to moisture & stress, and 2) integrating the near real-time UAS collected data into an adaptive model supporting a variable rate irrigation decision support system. Accomplishing both these outcomes will set the stage for further research on UAS in Nebraska. The ability to secure near real-time information to crop moisture and stress and integrating UAS-collected data into an adaptive model can serve as the foundation for future research to advance the vision for water management in agriculture across large land areas.
Suresh Pradhyun Kashyap
M.S. candidate in Biological Systems Engineering
Title: High-Frequency Unmanned Aircraft Flights for Crop Canopy Imaging During Moisture-Stress and Subsequent Irrigation
Advisor: Derek Heeren, Associate Professor, UNL Biological Systems Engineering
In order to apply the right amount of water to a crop, researchers calculate its water stress using unmanned aerial vehicle (UAV) technology by calculating crop water stress index (CWSI). These measurements are either instantaneous or an average over a short interval of time and can be influenced by passing clouds, wind gusts, or other weather incidents. High-frequency flights over longer intervals of daylight hours could provide more stable and relevant data and decrease these impacts. This would help farmers better plan their irrigation scheduling.
Researchers aim to develop a methodology that provides imagery from multiple flight times in order to assess crop water stress and development from a well-irrigated to a water-stressed period. This new knowledge could help growers know when and how much to irrigate to optimize water use and maximize yields — resulting in more yields with less resources used.
Daniel Rico
M.S. candidate in Biological Systems Engineering
Title: Power-over-Tether UAS Developed for Atmospheric Sensing
Advisor: Carrick Detweiler, Associate Professor, UNL Computer Science & Engineering
Advisor: Francisco Munoz-Arriola, Associate Professor, UNL School of Natural Resources, Biological Systems Engineering
High-resolution data about the atmosphere that is consistently updated could help growers and policymakers in making decisions related to agriculture. Currently, they rely on isolated towers and weather balloons to provide low-resolution data to forecast models.
Unmanned aerial systems (or UASs — also known as drones) that are retrofit with atmospheric sensing technology can help but have limited weight and flight duration capabilities. Researchers have now developed the tethered aircraft unmanned system (TAUS), a new system that allows UAS to deploy an array of atmospheric sensors via a power-tether combined with a station on the ground. This technology can then acquire real-time high-spatiotemporal data over hours of continuous flight in-situ. As a result, growers and policymakers have a more accurate picture of the growing environment and can maximize yields while minimizing inputs.