Master of Science, Miami University, 2024, Biology

Recent studies show root trait plasticity within species, suggesting differences in root response to ecosystem heterogeneity. The multi-axis root economic spectrum framework (RES) proposes that most root trait variation is explained by phylogeny and ecosystem conditions. We evaluated architecture and morphology in tree species in a long term, nitrogen (N) x phosphorus (P) fertilization study. Root traits differed between taxa and responded to nutrient addition. Red maple roots were less branched, produced fewer tips, and were thicker than roots of the species beech and birch. In both taxa, branching density, total root tips, average diameter, and the root length fraction in the 0-0.25 mm diameter class were lower in response to P. Most of these effects were reversed in response to N+P. Our findings show these species shift root growth to acquisitive traits when P limitations is alleviated but become conservative in response to N+P. This highlights the need to consider whether root growth is single or co-limited in ecosystems due to different effects of N x P interaction on root traits. We must continue refining the multi-axis RES framework to better account for within species plasticity in response to ecosystem conditions.

Master of Science, The Ohio State University, 2024, Environment and Natural Resources

Strip-mining has extensive impacts on vegetation and soil. Reclaimed mineland soils are often highly compacted and depleted of plant-available nutrients and organic matter. Such sites are often revegetated with low-diversity mixtures of non-native grasses and forbs. The combined effects of competitive non-native species and poor quality soils often creates challenges for restoration. Nevertheless, there is significant interest in enhancing the ecosystem function of former minelands to enhance biodiversity and carbon sequestration. We studied a reclaimed coal mine in eastern Ohio to determine whether prairie restoration in such settings would affect the recovery of key soil health indicators. Four prairies and adjacent unrestored grasslands were sampled along 100m transects that intersected perpendicular to the prairie patch boundary. We surveyed vegetation cover and aboveground biomass within eight 1m2 quadrats spaced along each transect. Soil cores were collected at each quadrat along with penetrometer readings to measure soil carbon content, bulk density, and compaction. Contrary to our expectations, soil percent carbon was greater in the upper horizons of unrestored grasslands. However, root and aboveground biomass carbon stocks were greater in restored prairies, with elevated biomass carbon being associated with a high percent cover of C4 prairie grasses. Bulk density was not significantly different between restored and unrestored areas, although greater root biomass was associated with reduced bulk density. Penetrometer resistance also saw no significant spatial trends, but was lower in the upper horizons where C4 grasses were dominant. Results suggest that, while prairies yielded larger carbon stocks in biomass, effects on soil carbon and compaction were minimal. Future research should examine what site-specific factors may determine whether prairie restoration yields significant effects on soil health.

Doctor of Philosophy, The Ohio State University, 2024, Environment and Natural Resources

Soils are a non-renewable resource, which is the foundation of all ecosystems. Mismanagement of soil particularly in agro-ecosystems has degraded soil. To guide management of soils, to remediate soils, and enable optimal agricultural production, soil health indicators are needed. The objective of this dissertation was to determine the potential of biological and other soil properties to predict soybean yields. The central approach was based on soil samples from farmers' fields instead of long-term experimental sites (LTES). Farmers' fields in this study represented diverse management practices that exist in the agricultural sector. Soil Health (SH) measurements that are calibrated and that can consistently detect land management are lacking which was shown in Roper's et al. (2017) 2017 publication that found existing SH tests (CASH, Haney) had limited ability to identify agronomic land management practices at a North Caroline LTES. And that they were poorly correlated with crop yields. This means that the quote by the Soil Health Institute “There is no standardized measurement for Soil Health in the United States” is still true. Extensive research has found certain soil enzyme assays to be quite sensitive for detecting land management effects and exhibit seasonal stability. The currently promoted SH indicator scores have limited or inappropriate biological indicators (e.g. microbial biomass and respiration). The latter measurements vary too much on a seasonal basis due to weather variation or a recent short term soil management event (e.g. high organic inputs, disturbance). Thus, the global objective of this dissertation was to determine the potential of biological soil properties, specifically enzyme activities and microbial community biomarkers to quantify SH. Enzyme activity has the added advantage over most other soil biological measurements, that it can be run on air-dried soil and furthermore is relatively simple. This is attractive to commercial labs who wa (open full item for complete abstract)

Ph.D., Antioch University, 2024, Leadership and Change

The study sought to ascertain whether introducing democracy has adversely impacted Indigenous cultural practices in Ghana or whether the path to democracy has enhanced, shaped, or strengthened aspects of the country's Indigenous culture. The study sheds some light on the realistic, symbolic, and pervasive threat(s) that transitional or Indigenous societies like Ghana undergoing the process of democratization face and must deal with. More specifically, the study provides some insights into how traditional societies, where Indigenous values and practices are held with some reverence and esteem, can be integrated into liberal democratic institutions to potentially ameliorate cultural tension and political discord that often accompanies the process of democratic and electoral transitions. The study also provides a rich context to explain and dispel some of the pernicious stereotypes and perceptions about countries that strive to build a suitable system of governance by combining aspects of their Indigenous culture and liberal democratic tenets. The primary scholarly contribution of the study is a greater understanding of how Indigenous cultural norms, as informal institutions, shape the trajectory and consolidation of democratization in sub-Saharan Africa. This dissertation is available in open access at AURA (https://aura.antioch.edu) and OhioLINK ETD Center (https://etd.ohiolink.edu).

Master of Science (MS), Bowling Green State University, 2024, Geology

Soil is at the center of two linked global environmental problems: climate change due to anthropogenic carbon emissions and soil degradation caused by anthropogenic landscape alteration, with 37% of global land and 52% of land in the United States used for agriculture. A robust understanding of soil dynamics can aid in making sustainable management decisions to maximize soil potential for both fertility and carbon sequestration needs. Soil organic matter (SOM) is often used as a proxy for soil health, with humic substances (HS) comprising most of SOM and driving reactivity and recalcitrance in the soil, depending on composition. HS have historically been challenging to analyze due to low solubility and widely varying molecular size, leading to the use of operational definitions and unclear models. Recent advances in spectroscopic techniques, however, have led to the development of sequential fractionation techniques, like the humeomics methodology, that progressively break bonds within the HS structure, allowing for greater characterization and understanding of composition. In this study, SOM from an organically managed farm soil was qualitatively and quantitatively characterized using the humeomics sequential methodology, extracting six primary fractions and two residual fractions. All fractions were characterized for nutrient (TOC, TN, and TP) content, FTIR was used to assess functional groups present, and EEM-PARAFAC analyzed fluorophore groups to calculate descriptive indices and model components. Analysis indicates the SOM within the farm soil is weakly humified, labile, and biologically available, with most OC and N present in the weakly-bound fractions of the SOM structure. Future research could focus on characterizing and comparing soils from conventionally managed agricultural soils, different BMP regimes (including amendment with dredged material), as these are factors known to contribute to variations in SOM quality and nutrient cycling.

Bachelor of Arts (BA), Ohio University, 2024, Environmental Studies

Educated students and community members become informed consumers that can reshape our food system. The OHIO Student Farm works to educate students on sustainable agriculture practices and provides hands-on learning opportunities. This thesis explores the benefits of local food systems in addition to regenerative and sustainable agriculture practices. Not all students are aware of the benefits of supporting sustainable local farms and that OHIO has a student farm. To increase awareness and connect students to regeneratively and locally grown food, I restarted the OHIO Student Farm's farmers market in Baker University Center. Based on the data from the survey I conducted of the market attendees, this market increased access to local produce for students, faculty, staff, and community members and educated them on the benefits of purchasing locally and supporting farms that use regenerative practices. In addition to surveying the market attendees, I also surveyed past students of the Sustainable Agriculture course that takes place on the OHIO Student Farm. The results showed how valuable hands-on learning is when it comes to getting students engaged in environmental issues like sustainable food. In addition to reestablishing the market, I also started the Student Farmers student organization to connect students that are interested in sustainable and local food with the OHIO Student Farm and local food organizations. As a result of this project and research, more students have been connected with the OHIO Student Farm, have increased access to fresh produce, and are more knowledgeable about how they can build a more sustainable food system.

Master of Science, The Ohio State University, 2024, Environment and Natural Resources

Soil health (SH) indicators are needed to guide sustainable agricultural management, optimize crop productivity, and to quantify public investment in soil conservation programs. Several enzyme assays have been shown to be sensitive for detecting land management and degraded soils, and as such hold potential as SH indicators. There is an advantage to running two or three assays on each sample, which can reflect different microbial or biochemical soil properties. This approach would reduce analytical expenses over doing the assays independently. Commercial labs would be interested in this assay to reduce time and labor when testing for SH. Furthermore, there is limited research on the ability of a multi-substrate assay for detecting soil management over single enzyme assays. However, a multi-substrate assay must be optimized and vetted before it can be used as a SH indicator. Therefore, the global objective of this thesis was to optimize and test an integrative multi-substrate assay using two key enzymes that have proven to be sensitive SH indicators. Chapter 1 is a literature review of SH and the potential of enzyme assays as SH indicators. To be reproducible and universal, enzyme assays are run under optimal conditions. This creates a challenge for multi-substrate assays because each enzyme activity assay is run at a different optimal buffer pH. Chapter 2 is a method-development investigation. The first objective was to determine the optimal pH for a multi-substrate assay that combined β-glucosidase (EC 3.2.1.21 β-d-glucoside glucohydrolase) and arylsulfatase (EC 3.1.6.1 arylsulfate sulfohydrolase), both of which have been shown to be sensitive for detecting soil management. The second objective was to determine the ability of this multi-substrate assay to detect soil management and have a comparable interpretation to individual enzyme assays relative to SH. The experiment had a completely randomized block design with two treatments: 1) the multi-substrate (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2024, Environmental Science

Historical and current anthropogenic activity combined with land turnovers and rampant vacancies have increased human exposure risk to contaminants. This exposure risk disproportionately affects lower income communities and can have detrimental impacts on human health, particularly children. A management solution is needed to address this widespread contamination of vacant lots. Additionally, federal and state regulators continue to lower residential soil Pb standards which will likely require new risk-based approaches to address urban soil Pb contamination. This dissertation examines three different amendment types (P amendments, Fe oxide containing amendments, and potassium permanganate (KMnO4)) for their ability to address urban Pb soil contamination and reduce human health exposure risk. Remediation strategies that can address both organic and inorganic pollutants are also needed. This is addressed in Chapter 3. This dissertation is written as a series of manuscripts to be submitted to the appropriate journals; this will be reflected by slight differences in formatting. In Chapter 1, readily available P sources (biosolids incinerator ash, poultry litter, biosolids compost, and triple super phosphate) of varying solubility were assessed as soil amendments to reduce Pb bioaccessibility and serve as an inexpensive remediation strategy for urban soil. Contaminated soil from Cleveland, OH was treated with the P soil amendments at a 1:5 Pb:P molar ratio and incubated for 3 months. A slurry analysis was also conducted to assess reduction in bioaccessible Pb independent of time. Pb bioaccessibility was evaluated using US EPA Method 1340 at pH 1.5 and the Physiologically Based Extraction Test (PBET). Treatments were largely found ineffective regardless of IVBA extraction method, incubation duration, slurry analyses, or P source. Method 1340 had one significant treatment (combined poultry litter and BIA) but only resulted in a 8% IVBA Pb reduction. The same treatmen (open full item for complete abstract)

Master of Science, The Ohio State University, 2024, Environment and Natural Resources

This research investigated hypothesized relationships between measured soil health indicators and community wellbeing. The neighborhood of Linden in Columbus, Ohio, was chosen for this study due to its consistent soil and economic legacies. Impact zones (low, medium, high), representing potential distinct levels of disturbance, were identified within each of the 11 City of Columbus Parks in Linden, and surface soils (0-15 cm) were sampled at three random points within each impact zone, gaining 100 soil samples in total. Secondly, data from the US Census American Community Survey at the census tract level in the Linden neighborhood was used to derive Social Deprivation Index (SDI) indicators. Differences in soil indicators by impact zone across all parks were tested via mixed models, while all values were compared to three benchmarks: a) EPA Background Upper Levels (BUL), b) Soil Screening Levels (SSL), and c) National Cooperative Soil Survey Bennington Series archive pedon data for A-horizons. Limited significant differences between impact zones were found for soil pH, extractible Ca2+, and K+, CEC, and extractible Na+. Soil results showed higher pH values compared to the average Bennington soil series and heavy metal concentrations above BUL for As, Ba, Ni, and Pb. Most metal values were below SSL. The limited variations observed among impact zones for heavy metals, coupled with a scarcity of values surpassing SSL, imply that historically areas within each park might have been subject to similar anthropogenic activities. SDI indicators were compared with a limited suite of soil variables through correlation. SDI indicators were significantly correlated with Co, Ni, Sr, and Zn. The significant correlations between measured soil and SDI indicators may hint at how environmental and socio-economic factors may influence each other. This potentially provides valuable insights for stakeholders in developing evidence-based strategies to promote community wellbeing and impr (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2024, Environment and Natural Resources

Soil profile sampling and description are an important part of soil survey, mapping, and classification. In soil mapping, representative soil profiles (pedons) are used to characterize the properties of the series. A representative soil profile is the one that has normative properties within the defined range. In traditional soil survey, the surveyor has to walk in the field, expose and describe a large number of pedons and reach a conclusion about the range of properties and those that are most representative of the series. Candidate representative pedons are then sampled and morphologically described for the classification purposes and may be sampled for detailed laboratory analysis. However, designating and describing the representative soil profile is challenging for many reasons. The variability in soil properties is one of the most important reasons. In many cases, “representative pedons” may not express normative properties, and there are few examples of representative pedons being selected statistically. The traditional way of soil survey is time-consuming, and it requires resources which have become limited. The technological advance in hardware, software, and acquiring and saving data paved the road to move from the conventional to the digital soil mapping. The environmental covariates driven from the digital elevation model have widely contributed to this transfer. The purpose of this study is to adapt a spatial-statistical model by which the best representative soil profile will be designated, spatially located, and morphologically described. In this study, we used a clustering algorithm trained with environmental covariate data and identified medoids from which the best representative combinations of covariates could be identified. The gSSURGO is the best database as a source of digital soil information related to the US Cooperative Soil Survey. It offers soil information in spatial and tabular formats which can be analyzed using modern methods. (open full item for complete abstract)

Master of Science (MS), Ohio University, 2023, Plant Biology (Arts and Sciences)

The finite reserves of phosphorite, the primary mineral for production of phosphatic fertilizers, pose a risk to future food security. Alternative phosphorus (P) sources such as struvite (MgNH4PO4.6H2O) derived from wastewater can be an effective substitute for conventional synthetic fertilizers obtained from phosphorite. This study aimed to evaluate the effectiveness of struvite, recovered from municipal wastewater by electrochemical technology, in comparison to conventional fertilizers. P content and availability was assessed in the recovered struvite along with other elements to detect any heavy metals. A soil incubation study was established to determine the availability of P in three soil types among the fertilizers: recovered struvite, pipe deposit, diammonium phosphate (DAP), triple super phosphate (TSP) and rock phosphate (RP). The amount of P added to the soil was equal among all the fertilizers and extracted from the soil every two weeks for 2 months using anion exchange membranes to capture readily soluble P as well as Mehlich-3 (M3) solution for available but recalcitrant, less soluble P. The available P in the recovered struvite was nearly 15%, with 10% magnesium (Mg), and the concentration of heavy metals was negligible compared to EPA limits. Meanwhile, the P content in DAP, TSP and RP was 19.8%, 19.4% and 3.4% respectively. After 2 weeks, the amorphous form of the recovered struvite was readily soluble in all three soils. The readily soluble P (12.4 mg P/kg) in struvite-treated soils was similar (P=0.99) to DAP and TSP, but ~280% higher (P<0.05) than RP after 2 weeks. Similarly, less soluble P (34.8 mg P/kg) in struvite-treated soils was similar (P=0.99) to DAP and TSP, but 100% higher (P<0.05) than RP-treated soils after 15 days. Over the incubation duration, readily soluble P progressively declined in all treatments after 15 days and less soluble P increased in fertilizers up to 45 days before declining at 60 days. Recovered st (open full item for complete abstract)

Doctor of Philosophy, The Ohio State University, 2023, Food, Agricultural and Biological Engineering

Container grown plants are used for nursery production, ornamental plants and increasingly for food production. In containerized plant production, soilless substrates are the growing medium which serve to anchor plants, as well as provide water, nutrients, and air for healthy root growth. The chemical and physical properties of soilless substrates have been examined in several studies, but few have studied the biological communities microbiomes in these media. Those investigating biological communities often focus on a specific group or plant response to specific pathogens. The overall microbial communities in soilless substrates have not been investigated or optimized. In this study, broad questions related to microbial communities were addressed including the composition of microbial communities, the predominant microorganisms and their dynamics, and the effects of specific components. The effects of these microbial communities and whether they are beneficial to plant health versus simply altering the physical and chemical properties were also addressed. As part of this study, experiments were conducted to determine the uniformity of the microbial community throughout the container vertical profile, and to determine if a novel leaching method could be substituted for destructive sampling to characterize microbial communities during plant growth. To address these questions, a nucleic acid based approach was used. The bacterial and fungal communities from the ii substrates were characterized by isolating total DNA, PCR amplifying 16s rRNA genes and ITS regions, sequencing them and comparing them to databases of these sequences. In one study, bacterial and fungal communities in the components of a typical commercial pine bark soilless substrate and their dynamics in mixes, with and without compost, were characterized; their impact on plant growth throughout a typical production cycle were evaluated and compared. Results showed that the microbial community composit (open full item for complete abstract)

PHD, Kent State University, 2023, College of Arts and Sciences / Department of Biological Sciences

Climate change is exerting profound and far-reaching impacts on ecosystems worldwide, encompassing both aquatic and terrestrial environments. The evolving precipitation patterns and shifting temperature regimes impact fluctuations in hydrology, resulting in shifts in redox conditions which can impact the availability of nutrients like phosphorus (P). Phosphate, the bioavailable form of P, is only present in small amounts within soils, making the biological demand greater than soil phosphate availability. The majority of soil P is present in non-labile forms including organic P and phosphate sorbed to metal oxides like iron (Fe). Microorganisms must content with geochemical and other abiotic factors to access phosphate from these non-labile sources through the use of various strategies including the secretion of enzymes, the production of phosphate solubilizing acids, as well as indirect mechanisms associated with the reduction of Fe oxides. The primary goal of this dissertation was to advance our understanding of how microorganisms access both labile and non-labile forms of P in the presence of changing hydrologic and redox conditions which impact the speciation of Fe that is present, altering phosphate availability. Specifically, I investigated 1) how phosphate availability changes across a permafrost thaw gradient (palsa, bog, and fen) in the presence of iron oxides, 2) how microorganisms access and mobilize chemically diverse phosphorus sources under contrasting redox conditions, and 3) how changes in hydrology, redox, iron mineralogy, and phosphate availability drive shifts in microbial community composition, specifically iron oxidizers, reducers, and phosphate solubilizers. In our first study assessing microbial phosphate accessibility across a permafrost thaw gradient, we found that near surface redox conditions changed as a function of permafrost thaw which impacted phosphate availability. Reducing conditions in the bog promoted the dissolution of Fe oxides, (open full item for complete abstract)

MS, Kent State University, 2023, College of Arts and Sciences / Department of Earth Sciences

Piping or internal erosion has been responsible for almost half of all dam failures worldwide. In this research, we studied the influence of grain size heterogeneity, as characterized by sediment size (d50) and the uniformity coefficient (Cu), on piping potential. A novel experimental setup was designed in-house that included sediment mass, pressure, and turbidity sensors allowing the examination of transient changes during piping events. Porosity and conductivity were analyzed in order to compare trends across varying grain size distributions. Mass values of soil lost during piping failure via a continuous mass balance and a turbidity meter to capture fines that remain in suspension were both utilized to capture the magnitude of piping failure. Minute Piping and Clogging events that are only able to be captured via the pressure transducers were recorded during this experiment, adding complexity to the onset of piping phenomena. The smaller the Cu, the less clogging events occurred before piping failure. It was noted that these minute piping and clogging events would stabilize as the sediment column reached equilibrium. This research allows for further studies to expand on these piping and clogging events as well as depicted trends between soil heterogeneity and piping potential.

Doctor of Philosophy, The Ohio State University, 2023, Environment and Natural Resources

Soil fertility is defined as the quality of a soil which enables it to provide chemical elements in quantities and proportions for the growth of specific plants. Soil fertility is influenced by both inherent and dynamic soil properties. Inherently, Midwest soils of the United States are considered fertile, with a rich topsoil formed from Wisconsin-aged glacial parent materials. However, this inherent fertility has been depleted due to years of cultivation and inadequate management practices that has accelerated erosion and also nutrient loss. Efforts to rebuild soil fertility include improved nutrient management to provide the correct amount of nutrients for the target crop at the right time thereby minimizing losses to the environment. In Ohio, soil test analyses have been historically used to guide fertilizer additions based on crop requirements and soil availability. The Tri-State Recommendations have guided addition of major crop nutrients such as phosphorus (P), potassium (K) and sulfur (S) since 1995. These recommendations are based on rigorous field trials in representative regions of the state and use a buildup and maintenance framework, above and below a critical nutrient threshold. These recommendations varied by nutrient and crop; for instance, for most Ohio soils, S addition is not recommended while other nutrients such as P and K are added based on buildup equations whose origin remain unclear. Recently, some risk adverse farmers are deviating from current guidelines to prevent perceived S deficiencies, and while under continuing scrutiny for surface water contamination, they have failed to build STK and STP levels following the Tri-State Recommendations. Sustainable increases in crop productivity depend on reliable guidance to build soil test nutrient levels and prevent overapplication. Low STP may decrease P run-off but may negatively affect crop yields. Here we addressed some of these specific issues of nutrient management in Ohio, using a systemati (open full item for complete abstract)

Master of Science (MS), Ohio University, 2023, Environmental Studies (Voinovich)

Miscanthus x giganteus (miscanthus) is considered an ideal biomass energy crop because of its carbon (C) sequestration potential, water use efficiency, and low fertilizer requirements. Few US studies have measured long-term C sequestration of miscanthus on marginal lands on a decadal scale, and none have been conducted in southeast Ohio. The objective of this study was to measure the potential for C sequestration on abandoned agricultural land, the change in plant and soil nitrogen (N) over a decade, and the photosynthetic capacity in the tenth year of growth. The results revealed that after a decade, C was accumulated in the soil and the sequestration rates were estimated to be 0.20 Mg C ha-1y-1 and 0.54 Mg C ha-1y-1. However, the amount of C accumulated in the miscanthus plots were not statistically different from the adjacent unmanaged plots. There was also no statistically significant change in the amount of N in the baseline soils and after tillage and plowing when compared to the tenth year of growth. There was no statistically significant change in the amount of N found in plants over seven years, but variability in plant N was greater in some years relative to others. Even though the crop of miscanthus was grown without N fertilizers in this study, soil N at 0-30 cm depth was not depleted. There was no difference in plant C between sites, but the C concentration in stem tissue was statistically different over seven years. The photosynthetic capacity of miscanthus measured in this study indicated that the plants were thriving, and C assimilation for growth was consistent with the findings of prior work that evaluated the maximum photosynthetic rates of this species. The combination of soil C sequestration and sustained soil N over a ten-year period has important implications for the sustainability of biomass crops. Ultimately, this study addresses the net environmental benefit of using a perennial grass as a dedicated biomass crop on abandoned agricultural l (open full item for complete abstract)

Master of Science, Miami University, 2023, Geology and Environmental Earth Science

Fluvial terraces are vital to reconstructing past depositional dynamics within a watershed as well as determining flood and erosion risk. In the midwestern US, detailed mapping of terrace age is necessary to determine if deposition occurred during multiple distinct periods. In this study, changes to soil geochemistry over time were quantified from nine radiocarbon-dated soils spanning ~17,000 years and this relationship was used to infer soil age across a broad fluvial terrace. Regression models quantifying Fe/Ca, Zr/Ca, and Ti/Ca changes at multiple soil depths were created. Fe/Ca models returned R2 values between 0.69 and 0.97 with the lowest uncertainties compared to Zr/Ca and Ti/Ca models. Samples collected at 20-30 cm depth resulted in the highest correlation coefficient compared to samples collected at 0-10 and 60-70 cm. The mean Fe/Ca value of parent material was 0.33 with standard deviation 0.12. The models were subsequently used to infer soil age from Fe/Ca values of 388 locations on the floodplain and overbank deposits were delineated based on inferred soil age. In general, deposit age increases with increasing distance from the modern channel. Results support use of this field-based technique to map fluvial terraces at a high resolution.

Master of Science (MS), Bowling Green State University, 2023, Biological Sciences

Annually, millions of tons of sediments are dredged from the US lakes and federal navigation channels to maintain the economic activity of ports and harbors. About 1.5 million cubic yards of dredged material (DM) are excavated yearly from the Western Lake Erie Basin, Ohio. After the prohibition of open water disposal of dredged material, the State of Ohio is recommending finding beneficial uses including amending farm soils. Our research investigated whether different ratios of DM amending an organic farm soil enhances the soil and corn health and crop yield. The research objectives were (1) to characterize the soil health (total organic and inorganic carbon, nutrients, bulk density) and (2) to determine crop yield and corn health (total organic carbon, nutrients, above and below biomass weight). Our soil blends consisted of 100% farm soil, 100% DM, 95% farm soil/5% DM, 90% farm soil/10% DM, and 80% farm soil/20% DM. Our results indicated that as the DM ratio increased, the cation exchange capacity, soil calcium, and total organic carbon content also increased, but the bulk density, TN, and TP in the soil decreased. The above and below corn biomass weights were higher as the DM ratio increased. The highest corn yield was observed in 100% DM. These findings demonstrate that DM has the potential to be used as an agricultural farm soil substrate.

Bachelor of Science, Wittenberg University, 2023, Biology

This study investigates the soil quality and plant diversity of a discontinued golf course in Springfield, Ohio, with the aim of assessing its potential for restoration. Led by the National Trail Parks & Recreation District, the restoration plans for Snyder Park include the establishment of wet meadows, prairies, and woodlands, which can thrive in the natural hydric soils of the former golf course. In this study, baseline soil data was collected using GIS and GPS technologies, analyzing soil texture, carbon content, nitrate nitrogen, phosphorous, potassium, replaceable calcium, humus, and pH. Plant diversity was evaluated through random sampling of quadrats. Initial observations revealed patches dominated by specific plant species, and a comparison of soil and plant characteristics across elevations was conducted. The golf course mainly consisted of the Westland soil series, which supports water retention. However, deficiencies in humus and low levels of potassium and nitrate nitrogen pose challenges for restoration. Limited native plant species adapted to moist conditions were observed, suggesting ongoing recovery from intensive land management. To sustain a natural wetland or floodplain ecosystem, restoration efforts should focus on introducing native wetland species and providing nutrient inputs, mainly nitrogen and potassium. The Snyder Park golf course holds potential for restoration, but additional measures are necessary for a successful habitat transition.

Master of Science (MS), Bowling Green State University, 2023, Geology

In the last decades, the Western Lake Erie Basin (WLEB), USA, has been experiencing harmful algae bloom (HABs) events attributed to the large export of phosphate (PO4-3) and nitrate (NO3-) loads into waterways from farmland. There is current concern about exacerbating the HABs at the WLEB by discarding dredged materials (DM) in open lake waters. The State of Ohio has prohibited open lake water disposal, and it is requesting beneficial uses for the DM, and this study is exploring amending farm soil with DM. Previous research has demonstrated benefits on soil health when Hoytville soil was amended with DM from Toledo Harbor, OH, as the DM contains adequate soil organic matter (SOM) and calcium content. This study aimed to characterize the SOM in the DM by conducting a gentle chemical sequential extraction named Humeomics. Total organic carbon, total phosphorous, total nitrogen, and organic moieties associated with the SOM organo-soluble and hydro-soluble extracted fractions were characterized. Emission and excitation matrices were collected and paired with Parallel Factor analysis (PARAFAC) to characterize SOM fluorophores. The organo-soluble fractions exhibited terrestrial humic-like, terrestrial fulvic-like, and microbial tryptophan-like components. The hydro-soluble fractions showed microbial and humic-like and terrestrial or freshwater humic-like components. TOC concentrations in the organo-soluble and hydro-soluble fractions ranged from 594,022 to 483,723 mg kg-1 and 299,777 to 60,830 mg kg-1, respectively. Total phosphorus in the organo-soluble and hydro-soluble fractions ranged from 920.32 to 509.94 mg kg-1 and 31,389 to 182 mg kg-1, respectively. And total nitrogen in the organo-soluble and hydro-soluble fractions ranged from 11,614.47 to 2,879.86 mg kg-1 and 16,505.86 to 4,087.97 mg kg-1, respectively. Fourier-transform infrared spectroscopy analysis confirmed the presence of O-H (3400 cm-1), carbonyl (1720 cm-1), alcohol (3600-3000 cm-1), alkane (2915cm-1), (open full item for complete abstract)