Project 3: Assessing Links Between Social Environmental Justice Issues and FEWS in Semi-Arid Regions

Project 5: Agrivoltaics: Integrating Horticulture and Photovoltaics in the Field and Green Roof Systems

Today, farmers in both urban and rural locations are faced with many challenges, such as land/space availability, extremes in weather, water limitations, consumer connection to food, dependence on fossil fuels, and food security. Applications in photovoltaics can help resolve these challenges by growing food crops underneath solar panels. The rise in solar popularity, efficiency, and transparency is creating opportunity for co-location of agriculture and photovoltaics, also known as agrivoltaics. In this project, we will identify the micro-climate and expected yield of crops underneath variable transparent solar technology. The result will lead to development of various applications that will increase marketability, sustainability, efficiency, and value of crop production. The trainee on this project will collect agricultural data, including temperature and water impacts, and also human dimensions of agrivoltaics adoption through qualitative methods. A replicated solar array is installed at ARDEC South and a green roof system is installed at the Foothills campus under existing solar panel arrays. This proposed project will include collecting environmental data such as photosynthetically active radiation (PAR), soil/substrate and air temperatures, soil/substrate moisture percentage, and crop fresh and dry weights. This project will begin in 2022 and will help to describe the benefits and tradeoffs of the microenvironment created by agrivoltaics, specifically crop water use and the interaction with temperature, in the field and in green roof systems.

Advisors

• Mark Uchanski (Horticulture & Landscape Architecture)
• Jennifer Bousselot (Horticulture & Landscape Architecture)
• Diego Pons (Anthropology & Geography)

Systems Perspective

Growing food and generating power, as in agrivoltaics, in a changing climate while conserving water requires not only agricultural and technical perspectives but also human dimensions to ensure adoption. These interactions and potential feedbacks demand a holistic, systems approach to understand and address potential tradeoffs and implications that could come with the wider adoption of agrivoltaics systems in urban and rural settings.

Interdisciplinary Aspects

In addition to the water, food, and energy nexus inherent in the co-location of photovoltaics and vegetable crops in irrigated cropping systems. We plan to focus on crop water use in agrivoltaics in the field and in green roof systems to address water limitations expected with climate change. We will use a mixed methods approach to understand perceptions and likelihood of adoption of agrivoltaic systems.

Project 6: Understanding Linkages between Energy, Air Quality, and Animal Health

Project 7: Forest Fire Impacts on Headwater Quality in the Rocky Mountains

Forests are well known for providing sources of energy and clean water as well as helping agricultural production through soil protection and water provision. However, the frequency and severity of forest fires has increased in recent decades, creating a heavy social and economic burden on millions of people across the United States. These forests provide valuable ecosystem services such as drinking water provision, carbon sequestration, erosion prevention, and climate change mitigation estimated at trillions of dollars a year. However, from 2008-2017 the estimated losses due to wildfires was roughly $20 billion, not including the loss of these services. The 2018 Colorado wildfires resulted in one of the worst years in history and fires such as the 2016 Beaver Creek Fire and 2018 Ryan Fire in northern Colorado have disturbed and contaminated sensitive headwater ecosystems. This catchment receives atmospherically deposited mercury originating from upwind coal-fired power plants that accumulates in forest soils and vegetation and is re-mobilized following fire events. This pool of mercury (Hg) can be transported into surface waters and sediments, and thus pose risk to ecosystems, agriculture and human health.

The major goal of this project is to develop a fundamental understanding of how forest fires impact microbial, chemical and physical processes that control transport of nutrients (N and P), toxic metals (Hg), sediment and organic carbon into headwater streams. In this project, students will compare sites burned during the Ryan Fire with unburned control sites. Advanced chemical analysis and metagenomics will be used to generate new knowledge on feedback and hydro-biogeochemical cycles in burned forested watersheds. Watershed hydrology and sediment flow models will be developed for application of other fire-impacted sites and results will be used to inform land restoration and water quality management decisions. Students will be exposed to ecosystem services valuation approaches needed to determine how wildfires influence the value of water delivered from forest watersheds. Additionally, project involvement with management agencies and local and regional stakeholders will promote understanding of the links between forest conditions and water supply and help guide decisions about how to sustain high elevation watersheds.

Advisors

• Thomas Borch (Soil & Crop Sciences)

• Mike Wilkins (Soil & Crop Sciences)

• Tim Covino (Ecosystem Science & Sustainability)

• Chuck Rhoades (Soil & Crop Sciences; Forest & Rangeland Stewardship; US Forest Service, Rock Mountain Research Station)

• Travis Warziniack (Agricultural & Resource Economics; Forest & Rangeland Stewardship; US Forest Service, Rock Mountain Research Station)

• Patty Champ (Agricultural & Resource Economics; US Forest Service, Rock Mountain Research Station)

Systems Perspective

This project includes systems level analysis of forest fire impacts on soil health and headwater quality in order to provide information critical for improving and sustaining food-energy-water systems in semi-arid regions.

Interdisciplinary Aspects

This project integrates soil chemistry, hydrology, microbiology, forest ecosystem ecology, ecosystem services valuation and socioeconomic approaches to help understand the consequences of forest fires on watershed conditions and water quality in semi-arid regions. Close collaboration with the U.S. Forest Service, farmers, and water managers plays an integral role in this project.

Project 8: Decarbonization of Heat for the Food and Beverage Industry

In the U.S., the food and beverage industry consumes 1.8 quads of primary energy, accounting for almost 2% of national energy consumption. Half of this energy is for fuel consumed onsite with 0.8 quads used to directly make process heat or provide steam from boilers and combined heat and power units. 88% of the primary energy used to provide heat are from fossil-derived natural gas or coal. As a result, nearly all of the onsite greenhouse gas (GHG) emission from the food and beverage industry come from the generation of heat. Furthermore, because food product safety is critical, water used to make steam is rarely reused in these industrial processes. In the U.S., total water withdrawals from the beef, poultry, pork, and dairy industries are 266 billion gallons per year, accounting for 4% of the total water withdrawals in the industrial sector.

In the proposed research topic, the InTERFEWS trainee will perform a multi-faceted investigation to identify achievable pathways that decarbonize heat in the food and beverage industry. The trainee will assess the largest contributors to GHG emissions from heat that includes understanding the technical, economic, and social challenges. First, they will understand material and energy process flows for key industries to identify significant GHG-heat contributors that are calibrated to existing national estimates. These results will enable the trainee to evaluate alternative technologies using a combination of thermodynamic, heat transfer, fluid flow, and economic analyses. Next, the trainee will work to identify the non-technical social challenges that prevent the industry from rapidly adopting decarbonized solutions for industrial heat. They will work with their advisers to develop and administer an effective survey with key entities within the food and beverage industry. This will allow the trainee to understand potential resistance to – and incentives for – adopting appropriate technologies. The trainee will integrate these assessments to develop a national strategy for the most rapid and effective industrial heat decarbonization strategy, including the identification of technical approaches that can be broadly applied to make the most impact.

Advisors

• Todd Bandhauer (Mechanical Engineering)
• Jason Quinn (Mechanical Engineering)
• Sybil Sharvelle (Civil & Environmental Engineering)
• Jesse Burkhardt (Agricultural & Resource Economics)
• Jennifer Cross (Sociology)

Systems Perspective

Solutions for steam decarbonization must integrate disparate systems (facility water systems, boiler systems, utility infrastructure, wastewater and solid waste treatment systems) together and quantify the impact of the changes to the cash flow and consumption footprint, while understanding sociological constraints.

Interdisciplinary Aspects

The trainee will work with MECH professors to develop technological solutions, collaborate with a CEE professor to better understand renewable energy generation solutions from waste products, Ag and Resource Economics and MECH professors for LCA and TEA, and a SOC professor to develop effective surveys to identify barriers to and incentives for technology adoption.

Project 9: Anaerobic Treatment of Organic Wastes for Resource Recovery

Organic waste material such as municipal fraction organic waste (e.g. food waste and yard waste), food processing wastewater, and manure from animal feeding operations can be treated anaerobically to generate methane or organic acids. Organic acids can be converted into high value products such as fuel or plastics. At the same time, nutrients such as nitrogen and phosphorus can be recovered from the waste material to further enhance resource recovery. Little is understood about the systems level impacts of recovering methane versus more financially valuable organic acids. Uncertainty in whether to focus technology development on methane or organic acid production is currently inhibiting advancement in the field. Further, tradeoffs exist between generation of different products from organic waste material. For example, maximizing nitrogen recovery can alter pH in a way that is inhibitory for methane production. A trainee will develop resource recovery technologies for FEWS and assess tradeoffs between recovery of different products. Technologies and processes will be developed to enhance resource recovery from organic wastes, while also understanding systems level considerations of those technologies. This research can inform high level policy decisions that impact research and development of anaerobic technology for resource recovery.

Advisors

• Sybil Sharvelle (Civil & Environmental Engineering)
• Chris Goemans (Agricultural & Resource Economics)
• Thomas Bradley (Mechanical Engineering)
• Susan De Long (Civil & Environmental Engineering)
• Jim Ippolito (Soil & Crop Sciences)

Systems Perspective

This project includes systems level analysis of impacts of resource recovery products from organic waste material to broadly assess FEWS impacts and carbon footprint.

Interdisciplinary Aspects

Trainees will gain knowledge not only on technology development, but also skills to develop models to assess tradeoffs. Economics and policy are deeply embedded in this project.

Project 11: Local Oil Refinery Study

This project is one component of a larger study examining the environmental, social, and health impacts of a local oil refinery. The facility is located in Commerce City, Colorado, in a predominantly Latinx area of the city and has been notorious for its environmental impacts. Recently, these have included illegal releases of effluents that rained down on nearby communities, which led to fines collected by the Colorado Department of Public Health and Environment. These fines were used to fund community-based efforts to address the refinery’s record and community impacts – including a competitive call for proposals that led to funding this study.

As a community-based study, we work directly with (and for) Cultivando, a community-based organization in Commerce City. This portion of the study examines the sociological, environmental justice, and health aspects of living near the refinery. We will conduct in-depth interviews, ethnography and participant observation, PhotoVoice, and other qualitative and community-based methods, drawing data from the households living closest to the facility. This study may also involve content analysis, archival and regulatory analyses, and other methods that could be utilized by the trainee. The project will have one Program Manager and four Research Assistants, but trainees could assist with conducting a component of the research. Bicultural and bilingual Spanish-speaking students will be an especially good fit for this project. (This project is in partnership with Cultivando and Dr. Ramona Beltran at DU.)

Advisors

• Stephanie Malin (Sociology)
• Ramona Beltran (Graduate School of Social Work at DU)

Systems Perspective

The project is utilizing a systems-level view of the impacts of oil refineries by including a variety of disciplinary approaches, including air quality and monitoring, social science and environmental justice, environmental and public health, medical records monitoring, and community-based methods.

Interdisciplinary Aspects

This project is deeply interdisciplinary. The social science portion of this project is one component, with others focusing on real-time, multi-sited air quality monitoring, medical record analysis, examination of PFAS in drinking water, and environmental health.

Project 12: Expanding Evaluation of Decentralized Wastewater Systems to Include Solids Treatment and Nutrient Recovery

Our group has performed research to inform the safe, effective implementation of decentralized wastewater reuse in urban settings including development of risk-based treatment guidance and life cycle assessments of alternative scenarios. To date, the work has focused on treatment and reuse of liquid, with the assumption that residual solids are released to existing centralized sewers. Moving beyond the transitional phase of decentralized adoption will require incorporation of technologies and systems to process solids safely and effectively, including recovery and reuse of nutrients. Potential solutions may include treatment options for residual solids as well as alternative approaches for wastewater collection such as urine diversion. Previous work in our lab found that while anaerobic membrane bioreactors (AnMBR) are able to produce enough biogas to decrease their energy impact relative to other treatment systems used for onsite water reuse (e.g., aerobic membrane bioreactors) this benefit is offset by the costs associated with the additional unit processes required to address AnMBR’s limited ability to remove nutrients—mainly nitrogen. Source separation of nutrient rich urine, therefore, may have cascading potential benefits on subsequent processing. System level assessment of a broad range of alternative scenarios for collection, treatment, and reuse of both liquid and solid components of wastewater will inform the design of decentralized approaches. The proposed work would link InTERFEWS students with EPA Office of Research and Development scientists and CSU faculty in developing and accessing such scenarios, providing students with experience in creative systems thinking related to urban infrastructure and application of life cycle and risk assessment tools. Results will be shared with stakeholders (utilities, public health regulators) interested in the adoption of decentralized systems, providing students with further experience in translating research and potential opportunities for future test beds for evaluating promising designs.

Advisors

• Sybil Sharvelle (Civil & Environmental Engineering)
• Jay Garland (EPA)
• Michael Jahne (EPA)
• Cissy Ma (EPA)
• Thomas Bradley (Mechanical Engineering)

Systems Perspective

This effort expands the perspective of decentralized urban wastewater systems beyond the current focus solely on water reuse to include broader consideration of the residual solids and associated nutrients. The proposed work focuses on a systems perspective including life cycle impacts of alternative scenarios, including cumulative energy use, global warming potential, and eutrophication impacts.

Interdisciplinary Aspects

This research integrates technical analysis with public health, carbon footprint, and policy considerations.

Project 13: Robust Monitoring, Reporting and Verification for Soil Carbon Sequestration in Rangelands

As the United States accelerate efforts to mitigate the accumulation of carbon in the atmosphere, a strong understanding of the true greenhouse gas consequences of improved rangeland management and a robust process for monitoring, reporting and verifying carbon credits are necessary. Despite grazing of extensive rangelands being one of the dominant land uses globally, the soil carbon and net greenhouse gas consequences of regenerative management strategies remains poorly quantified. There are numerous reasons including the nature of management decisions, lack of investment, and size of properties. At the same time rangelands and, in particular, adaptive grazing management on rangelands have been largely left out of emerging theories of soil carbon cycling focusing on biological transformations; essentially handicapping our ability to understand and predict carbon sequestration in response to adaptive grazing management. In addition to uncertainty around carbon sequestration, a gap remains in our understanding of the economic behavior driving rangeland management decisions related to soil carbon. Thus, it is urgent that we develop carbon offset potentials with acceptable accuracy and quantifiable uncertainty. Coupled with economic information, carbon offset potentials can inform the economics and policy required for adaptive rangeland management to achieve environmental goals while increasing profitability and resilience in the livestock sector.

In order to catalyze the development of quantitative indices of carbon sequestration and economic potential in rangelands, we propose a combination of top-down and bottom-up research tools that will address fundamental and applied science gaps in rangeland carbon cycling. Specifically, we aim to: (1) Evaluate the effects of adaptive management on soil carbon sequestration, (2) Advance our understanding of mechanisms driving soil carbon dynamics, (3) Improve predictions to more accurately evaluate the soil carbon sequestration potential, (4) Develop cost effective monitoring, reporting, and verification tools to enable rangelands to participate in emerging carbon markets, and (5) Integrate economic decision-making with the improved soil stock information to examine the economic potential for adaptive management and to identify policies that align private and societal values.

Advisors

• Francesca Cotrufo (Soil & Crop Sciences)
• Megan Machmuller (Atmospheric Science, Colorado Climate Center)
• Dale Manning (Agricultural & Resource Economics)

Systems Perspective

The project utilizes a holistic and scientifically rigorous approach that aims to identify how the adoption of adaptive management practices impact ecological outcomes and climate mitigation potential in rangelands, including the assessment of water and nutrient cycling and greenhouse gas balance. With the collaboration of stakeholders and researchers across multiple disciplines and organizations, this project will address the social, environmental, and economic sustainability of adaptive management in Colorado rangelands.

Interdisciplinary Aspects

The research outlined here brings together strategic collaboration of producers, land-managers, and researchers from multiple fields including ecology, agricultural and resource economics, agronomy, soil science, process based and AI-based modeling, and remote sensing. Our project aims to produce the data and tools needed for regulatory carbon markets and policy; incentivizing regenerative management with rigorous science and an approach that is efficient, broadly applicable, and economically viable.

Project 14: Integrating Solar Energy into Dryland Agriculture – Innovation at the Food-Energy-Water Nexus

In low rainfall regions of the world, water, not land, is the resource most limiting agricultural production making precipitation management key to sustainable dryland agriculture. In contrast, solar energy generation, a renewable energy source that is most efficient in low rainfall regions, is land-use intensive. The substantial land requirement for solar energy combined with the “water not land” limitation of dryland agriculture can be synergized by using the area occupied by solar panels to harvest and redistribute rainfall – resulting in increased yields. Rainfall redistribution in dryland agriculture has the potential to permit growth of higher value crops which, when combined with reliable income from solar energy generation, reduces economic risk for land-owners, and rural dependency on fossil fuels. While this novel agro-energy approach is conceptually appealing, there are many challenges to overcome. These include:

1. Understanding how rainfall redistribution from the co-location of solar panels with crops will alter soil moisture patterns, plant water relations and water use efficiency, plant growth and yield;
2. Designing an efficient, low cost water collection and redistribution system utilizing commercially available solar panels;
3. Conducting plant growth simulation modeling and/or economic analyses that integrated crop yield and energy production to assess the trade-offs associated with a range of solar panel-crop configurations.

This research project will lay the ground work for a new agro-energy paradigm in semi-arid regions – based on the principle that increasing both water-use-efficiency and the diversity of how solar energy is harvested, via both plants and photo-voltaic cells, can increase total yield (calories harvested as food/forage and energy) and the economic well-being of land owners.

Advisors

• Alan Knapp (Biology)
• Christopher Goemans (Agricultural & Resource Economics)
• Allan Andales (Soil & Crop Sciences)
• Jay Ham (Soils & Crop Sciences)
• Meagan Schipanski (Soil & Crop Sciences)
• Jesse Burkhardt (Agricultural & Resource Economics)
• Mark Uchanski (Horticulture & Landscape Architecture)
• Gene Kelly (Soil & Crop Sciences)
• Melinda Smith (Biology)

Systems Perspective

In order to conduct the feasibility and design optimization assessments needed for advancing the science of agrivoltaics, a systems perspective that integrates research in water use, crop/forage growth, energy production, economic feasibility, and environmental sustainability is required.

Interdisciplinary Aspects

To move this agro-energy (also known as Agrivoltaics) approach from concept to practice will require a team that includes a wide range of disciplinary skills and perspectives. The project would enable a graduate student to gain some expertise in plant growth (biology), engineering and design, renewable energy, economics and modeling.

Project 15: Modeling Feedbacks Between Irrigation Practices, Regional Climate, and Agricultural Productivity in Colorado and the Semi-Arid West

Over the past century, much of the Great Plains in eastern Colorado has undergone a transition in which the shortgrass steppe that formerly dominated the landscape has been replaced with areas of irrigated cropland and managed grazing lands. The transition to irrigated agriculture has likely had a significant influence on Colorado’s weather patterns, climate, and overall water balance. At a regional scale, there is considerable uncertainty about the possible ways in which irrigation and soil moisture impact clouds and precipitation. This is problematic for predictions of the state’s water resources and therefore future agricultural productivity, as it has been shown that runoff in the Colorado Headwaters is extremely sensitive to changes in both precipitation and evapotranspiration, and land use changes on the Great Plains have been shown to affect weather in the Rocky Mountains. Additionally, any feedbacks between irrigated agriculture and regional weather could have important impacts on crop yields. Given the state’s growing population and food demands in the face of limited water resources and changing climate, we must be able to answer the questions: How do irrigation practices affect regional weather patterns in Colorado? What affect do they have on patterns of precipitation, evapotranspiration, runoff, and storage, and the overall water balance? What could those changes mean for crop yields and decisions about what to plant and when and how to irrigate?

The main goals of this project are 1) to better understand how irrigation of agricultural fields influence land-atmosphere interactions and feed back on local and regional weather and climate in Colorado, 2) to gauge the implications of these effects on the overall water balance for the state, and 3) to assess how those potential changes may influence crop productivity and economic decision making associated with planting and watering practices. In this project, the trainee will a) use a high-resolution mesoscale numerical weather prediction model to investigate how, under current climate conditions, agricultural irrigation practices influence local and regional patterns of precipitation, evapotranspiration, and runoff, and b) model the impacts of these hydrological changes on crop yields, and c) integrate these findings with a statistical approach to examine how producers respond to weather events, such as exploring how irrigated acres, crop choice and well retirement depend on local weather and climate.

Advisors

• Peter Nelson (Civil & Environmental Engineering)
• Russ Schumacher (Atmospheric Science, Colorado Climate Center)
• Nathan Mueller (Ecosystem Science & Sustainability, Soil & Crop Sciences)
• Dale Manning (Agricultural & Resource Economics)

Systems Perspective

This project aims to identify and quantify system-wide feedbacks between agricultural practice and regional weather and climate across a diverse landscape. This requires a systems perspective that integrates agricultural decision making, economics, hydrology, land-atmosphere interactions, and land use.

Interdisciplinary Aspects

This project integrates atmospheric science, hydrology, irrigated agriculture, and economics.

Project 16: Sustainable Development of Rice Bran at the Food-Energy-Water-Health Nexus

White rice feeds nearly half of humanity as a staple food, and the associated agricultural practices, inputs and co-products of rice-based food systems merit attention for impacts on climate, water, energy and food security. Sustainable rice bran product development innovations at the food-energy-water nexus started 10 years ago with funding from the Bill and Melinda Gates Foundation and the National Institutes of Health to support biomedical, animal and human studies. Compelling findings from those studies for this food waste to have health properties have led to the current research opportunity that lies in various stages of development across the following countries (i.e. Guatemala, Mali, Nicaragua, India, Kenya, Cambodia, Nepal, France and Brazil). This project focuses on vulnerable populations, such as pregnant women and children that are facing food and water insecurity coupled with chronic diarrhoea and poor health outcomes. Diarrhoea caused by unsafe drinking water results in nutrient malabsorption, which is a public health problem needing practical solutions in accordance with achieving sustainable development goals.

Ryan and colleagues embrace an interdisciplinary, multi-sectoral research network approach to advance the development of rice bran as this is the world’s largest agricultural byproduct, and used as animal feed or wasted. This project will develop rice bran as an ingredient with social, sustainable enterprise opportunities across the supply chain. We will create and test heat-stabilization technologies, implement food and water safety testing protocols in local laboratories, and prototype a distribution plan for target product use in infant weaning and maternal-child feeding programs. Many countries face water scarcity, and a tremendous amount of water resources are directed towards rice crop production in irrigated and flood plain agricultural systems. Some areas have already begun integrating aquaculture into rice paddies as rice-fish co-production systems, yet impacts of agrochemicals, heavy metals and pesticides remain a concern alongside the need for standardized testing. Importantly, this project will further the post-harvest output and provide substantial value addition to the rice crop. The research infrastructure for this project spans agricultural rice production and post-harvest practices, food engineering and technologies, as well as health systems at the rural-urban interface.

Advisors

• Elizabeth Ryan (Environmental & Radiological Health Sciences)
• Kimberly Cox-York (Food Science and Human Nutrition)
• Jan Leach (Bioagricultural Sciences & Pest Management)
• Molly Lamb (Epidemiology)

Systems Perspective

This project integrates complex elements of the rice agro-ecosystem and targets populations that strive to operate with environmental sustainability when increasing food security and seeking to reduce food waste.

Interdisciplinary Aspects

This innovative approach to develop rice bran within the broader context of food-energy-water nexus issues is possible via the global co-training of students in highly engaged faculty teams from agriculture, engineering, public health and biomedical sciences.

Project 17: Improved System Level Comparison of Wastewater-Based versus Diammonium Phosphate Fertilizers

Previous work in our labs compared the emergy (the amount of energy that was consumed in direct and indirect transformations to make a product or service) requirements of struvite-based fertilizer and the commercial fertilizer production from “cradle to gate” (resource use to the factory gate). The results support the premise that nutrient recovery from municipal wastewater is a promising sustainable alternative in the water-nutrient-food nexus system management by capturing untapped resources, maximizing resource use, and optimizing the overall system efficiency. Emergy analysis shows almost one order of magnitude higher specific emergy in 1 unit of P presented in DAP than that of struvite due to the more intense use of nonrenewable resources and the high emergy embedded chemicals used in DAP production. Future research should focus on expanding the overall understanding of the benefits of nutrient recovery (N and P) when resource recovered fertilizers are compared with commercial fertilizers in field application. Further study beyond the fertilizer production phase is needed to have more complete comparisons between struvite (slow-release, low solubility in water, cost driven by the bioavailable P) and DAP (instantaneous-release, highly soluble, and higher P content) in the context of nutrient cycling. The proposed work would link InTERFEWS students with EPA Office of Research and Development scientists and CSU faculty to coduct this fuller comparison, with the goal of publication in the peer reviewed literature and sharing of results with EPA’s Office of Wastewater Management.

Advisors

• Sybil Sharvelle (Civil & Environmental Engineering)
• Jay Garland (EPA)
• Michael Jahne (EPA)
• Cissy Ma (EPA)
• Thomas Bradley (Mechanical Engineering)

Systems Perspective

The work takes a systems perspective to fully assess the relative impacts, including cumulative energy use, of recovering nutrients from wastewater versus traditional fertilizer production.

Interdisciplinary Aspects

This research assesses broad considerations associated with fertilizers derived from different sources including energy, efficacy for crop production, soil health, and social acceptability.

Project 18: Using Active Soil Restoration to Achieve Multidimensional Management Goals Across Western US Rangelands

Ecological restoration of arid and semiarid rangelands is a pressing challenge at the Food-Water-Energy (FEW) nexus. Dry rangelands occupy 40%+ of the Earth’s surface and contain half of the world’s agricultural systems. Yet, rangelands are highly susceptible to land degradation associated with drivers including water limitation, overgrazing, and energy development. Rangeland degradation results in decreased plant and soil productivity and hydrological functioning, and thereby threatens global food security. Restoration is increasingly recognized as a key strategy for rangeland sustainability and climate adaptation. Yet, restoration success rates in dry rangelands remain very low. Seeding is a common rangeland restoration practice, but alone, rarely improves productivity. Underlying soil physical and biotic barriers to plant productivity often exist in degraded drylands (e.g., reduced soil moisture, microbial productivity), identifying soil management techniques that alleviate such barriers may be key to increasing restoration success. Since soil restoration treatments are often financially costly and involve removal of working lands from production, identification of soil restoration techniques that increase rangeland productivity, keep working lands in production, and are cost-effective for managers are needed.
RestoreNet is a co-produced restoration network that tests the effectiveness of climate-adaptive rangeland restoration techniques across environmental and land use gradients in western US in partnership with producers and land managers. Currently, RestoreNet includes 35+ restoration sites spanning 8 ecoregions in the western US and has 30+ partners including ranchers, state and federal agencies, NGOs, and Indigenous Tribes. RestoreNet has been successfully used to evaluate the utility of seed bed preparation treatments that target increased water capture and retention but has yet to incorporate soil treatments.

In this project, the InTERFEWS trainee will collaborate with RestoreNet to identify successful soil restoration strategies that balance natural resource benefits and economic impacts across water-limited rangelands. The trainee will:

1. Evaluate the effects of soil treatments on rangeland ecosystem productivity metrics.
2. Test how soil treatments interact with land use across working rangelands being utilized for grazing and solar energy development.
3. Integrate economic cost-benefit analysis to examine the economic potential of soil restoration strategies to be integrated into land management.

Advisors

• Caroline Havrilla (Forest & Rangeland Stewardship)
• Retta Bruegger (CSU Extension)
• Emily Lockard (CSU Extension)
• Seth Munson (U.S. Geological Survey)
• Hannah Farrell (U.S. Geological Survey)

Systems Perspective

The project will utilize an integrative systems approach to identify how the adoption of rangeland soil restoration practices impact ecological and economic outcomes in working rangelands. With the collaboration of stakeholders and researchers across multiple disciplines and organizations, this project will address the social, environmental, and economic sustainability of climate-adaptive soil management and restoration in western US rangelands.

Interdisciplinary Aspects

The research outlined here brings together strategic collaboration of producers, land-managers, and researchers from multiple fields including ecology, plant and soil science, and natural resource economics. Our project aims to produce the data and strategies needed for broad-scale rangeland restoration that is effective and financially feasible. Natural resource and economic modeling will be used to evaluate the impact of various restoration strategies on rangeland ecosystem services (e.g., forage production, biotic and physical soil health metrics) relative to their economic costs.

Project 19: Quantifying Tradeoffs and Synergisms Between Land-Based Photovoltaic Systems and Regenerative Grazing Systems

To build out renewable energy for a fully decarbonized future, significant non-urban land area will be needed for PV systems, up to 5% of ex-urban land. Land-based solar poses significant land use conflicts, depending on the extant land cover/land use, including impacts on food and fiber production, water use, carbon storage and biodiversity. One land use type that may be most compatible with PV are grazing lands, in that perennial grasses are compatible in stature with PV installations and provide vegetated cover that prevents soil erosion and subsequent structural degradation of the installation site. Concentrated rotational grazing is a management style that may lend itself to compatibility with PV installations.

In terms of ecosystem biogeochemistry, water dynamics and soil health, such systems represent a ‘solar savanna’ in which the panels radically alter the solar radiation environment for the underlying vegetation and consequently temperature and water dynamics, affecting plant growth, C allocation, soil organisms and biochemical processes. Moreover, the positive and negative effects of the solar panel ‘canopy’ on ecosystem state variables and processes will vary in complex ways as a function of the geography (latitude), climate, vegetation type and engineering (i.e. spacing, height, orientation of panels). Finally, the interplay of the geography/climate, engineering design, and grazing management system will determine relative tradeoffs in electricity vs livestock production and ecosystem services that will determine the net returns and economic sustainability for land owners/managers.

Fundamental work will be done at experimental sites being established on pasture in central Georgia, with an existing system designed for sheep grazing and a new one accommodating rotational cattle grazing. Plant (e.g., biomass C and N, LAI) and soil (SOC, POC, MaOM, texture, pH, mineral N) variables will be sampled geospatially in relation to the differential shading under the panels. Soil moisture and temperature will be continuously monitored, also geospatially. A radiation submodel will be coupled to a new 2-D version of the DayCent ecosystem model to simulate plant-soil-water dynamics. Data on ecosystem level CO2 and H2O fluxes will be measured using eddy covariance systems comparing ungrazed and grazed pastures. Field data and modeling results will be used to determine the balance between GHG emissions and SOC to inform the potential for generating C credits.

Advisors

• Keith Paustian (Soil & Crop Sciences)
• Rich Conant (Ecosystem Science & Sustainability)
• Dale Manning (Agricultural & Resource Economics)

Systems Perspective

Project will require a true systems approach that employs novel biophysical and ecosystem biogeochemical modelling and socio-economic analyses to evaluate tradeoffs and synergisms in land-based PV systems. The research findings and models developed will help to design optimal PV systems for the benefit of society as a whole (in achieving a decarbonized economy) and for the individual landowners and solar developers.

Interdisciplinary Aspects

Project will include both field-based soil/plant measurement, with laboratory analysis and soil organic matter fractionation, assessment of PV system design and novel ecosystem modeling. Economic data from both the engineered and agricultural systems will be used to analyze life cycle and financial outcomes from these systems.

Project 20: Sustainable, Electrified, and Decentralized Wastewater Treatment Systems for Pollutants Degradation and Resource Recovery

In this project, we will develop and demonstrate a modular electrochemical reactor that is capable of treating diverse wastewater streams with a wide range of ions, organics, salts, and recalcitrant compounds by combining multiple electrified water treatment units. We aim to simulate natural waste streams containing nitrate/nitrite ions (e.g., agricultural waste streams) to evaluate the performance of our electrochemical reactor. The results will be compared with synthetic matrices and target constituents of analysis to assess the performance, especially during long-term experiments using actual samples. To supplement, we will further analyze the U.S. EPA Water Pollutant Loading Tool, which includes discharge monitoring reports of municipalities, industries, and other effluent point sources. Cations with various reduction potentials can form scale on the cathode surface and deactivate the desired cathodic reduction reactions. A prime example of deactivation is the presence of calcium (Ca2+) and magnesium (Mg2+) ions in hard wastewater. As these deactivation phenomena (i.e., scale formation) by the presence of various cations and trace metal constituents in the wastewater can be observed on most electrode surfaces, it is crucial to identify the sweet spots where the applied potential is not favoring the formation of scale on the electrode surface. Various electrochemical strategies will be developed to minimize or mitigate scale formation.

The proposed electrochemical prototype is highly scalable. The components are made of cheap and abundant materials that will be manufactured with standard techniques at scale. The proposed project will address the critical bottleneck in electrochemical processes (i.e., decreasing cost and improving efficiency) by developing cost-effective electrode materials and novel electrochemical reactors that can treat or valorize constituents in the complex wastewater matrices that would otherwise be discharged into the environment. The outcome of this project will offer a versatile platform for selective treatment schemes. This project will contribute to achieving “circular water economy” using modular water treatment systems. This topic is also highly aligned with CSU’s strategic plans. These research efforts will be extensively integrated with additional education and outreach activities to develop a diverse, equitable, and inclusive future workforce for our community.

The PhD students will lead efforts to synthesize selective catalysts and design and fabricate electrochemical reactors for treatment and recovery.

Advisors

• Reza Nazemi (Mechanical Engineering)
• Thomas Borch (Soil and Crop Sciences)
• Steve Conrad (Systems Engineering)
• Thomas Bradley (Systems Engineering)

Systems Perspective

We will analyze our proposed electrochemical systems for potential integration with renewable energy sources. We will build a framework to study the social, economic, and environmental impacts of our modular treatment systems for deployment, particularly in water-stressed regions and disadvantaged and overburdened communities.

Interdisciplinary Aspects

The mentors from three different departments (Mechanical Engineering, Systems Engineering, Soil and Crop Sciences) will work closely on various aspects of this project, including synthesizing materials and electrochemical systems for wastewater treatment and resource recovery (Nazemi), advanced characterizations of treated water and solids (Borch), and dynamic evaluation of the system through a life cycle and techno-economic analyses (Conrad, Bradley).