Doctor of Philosophy / Department of Agronomy / Ganga M. Hettiarachchi / Urban gardens have been a popular re-use option in the transformation of brownfields—located in older industrialized cities and near peri-urban developments. They provide accessible, available, and affordable supplies of fresh fruits and vegetables, effectively reducing the enigma of “food deserts” across U.S. cities. However, direct (soil ingestion, inhalation) and indirect (soil-plant-human) human exposure concerns about real or perceived trace element contamination in urban soils persist due to previous use. Elevated lead (Pb) and/or arsenic (As) concentrations were found at two (Tacoma and Seattle, WA) urban gardens. The Tacoma site was contaminated with Pb (51 to 312 mg kg-1) and As (39 to 146 mg kg-1), whereas soil Pb at the Seattle site ranged from 506 to 2,022 mg kg-1, and As concentrations were < 20 mg kg-1. Experimental design at both sites was a randomized complete block with a split-plot arrangement (main plots: biosolids/compost vs. non-amended control; sub-plot: plant type). Tacoma site treatment included a Class A biosolids mix (TAGRO) with dolomite. The Seattle site was amended with Cedar-Grove Compost (CGC) plus dolomite. Efficacy of biosolids/compost amendment in reducing Pb and As concentrations was evaluated using root, leafy, and fruit vegetables. Soil Pb and As bioaccessibility were also evaluated. Food chain transfer of Pb and As in vegetables due to surface contamination of produce samples were evaluated on the basis of cleaning procedures. A laboratory incubation study and a controlled greenhouse experiment were conducted on soils collected from the Tacoma site. Effectiveness of addition of laboratory synthesized ferrihydrite (Fh: iron oxyhydroxide) and TAGRO mix, each alone or in combination were screened and tested on the Pb and As co-contaminated Tacoma soil. Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy studies of Pb and As were conducted on incubation study samples to understand treatment-induced Pb- and As-speciation changes. Dilution of soil Pb (10 to 23%) and As (12 to 25%) were observed for biosolids amendment at the Tacoma site, while CGC amendment resulted in 20 to 50% dilution in soil Pb at the Seattle site. Biosolids and CGC amendments reduced Pb concentrations in the vegetables by 50% to 71%. At both sites, Pb concentrations of root vegetables exceeded the MLs established by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Arsenic concentrations in vegetables were below an estimated ML and were reduced by 46% to 80% when grown on biosolids amended soils. Laboratory cleaning further reduced Pb and As food-chain transfer in vegetables grown in contaminated urban soils. Laboratory incubation and greenhouse studies showed dissolution of Pb in TAGRO plus Fh, and Pb concentrations in Fh amendments were significantly lower than the other amendments. Bioaccessible Pb and As were low. Significant reductions in bioaccessible As were observed when soils were amended with both TAGRO and Fh. X-ray absorption spectroscopy results indicated that chloropyromorphite-like (stable Pb phosphates) phases were the most dominant Pb species. Arsenic existed mainly as As5+, scorodite (FeAsO4•2H2O)-like species in all the treatments ranging from about 60% (control) to about 70% (TAGRO plus ferrihydrite). Amendments utilizing both biosolids and Fh significantly reduce human exposure risks present in urban soils contaminated with Pb and As.

Master of Science / Division of Biology / Martha E. Mather / In contrast to well documented adverse impacts of large dams, little is known about how smaller low-head dams affect fish biodiversity. Over 2,000,000 low-head dams fragment United States streams and rivers and can alter biodiversity. The spatial impacts of low-head dams on geomorphology and ecology are largely untested despite how numerous they are. A select review of how intact low-head dams affect fish species identified four methodological inconsistencies that impede our ability to generalize about the ecological impacts of low-head dams on fish biodiversity. We tested the effect of low-head dams on fish biodiversity (1) upstream vs. downstream at dams and (2) downstream of dammed vs. undammed sites. Fish assemblages for both approaches were evaluated using three summary metrics and habitat guilds based on species occurrence in pools, riffles, and runs. Downstream of dams vs. undammed sites, we tested if (a) spatial extent of dam disturbance, (b) reference site choice, and (c) site variability altered fish biodiversity at dams. Based on information from geomorphic literature, we quantified the spatial extent of low-head dam impacts using width, depth, and substrate. Sites up- and downstream of dams had different fish assemblages regardless of the measure of fish biodiversity. Richness, abundance and Shannon’s index were significantly lower upstream compared to downstream of dams. In addition, only three of seven habitat guilds were present upstream of dams. Methodological decisions about spatial extent, and reference choice affected observed fish assemblage responses between dammed and undammed sites. For example, species richness was significantly different when comparing transects within the spatial extent of dam impact but not when transects outside the dam footprint were included. Site variability did not significantly influence fish response. These small but ubiquitous disturbances may have large ecological impacts because of their potential cumulative effects. Therefore, low-head dams need to be examined using a contextual riverscape approach. How low-head dam studies are designed has important ecological insights for scientific generalizations and methodological consequences for interpretations about low-head dam effects. My research provides a template on which to build this approach that will benefit both ecology and conservation.

Master of Science / Department of Agronomy / Charles W. Rice / Biotic interactions among mycorrhizal fungi, nematodes, plants and other microbial communities can have significant effects on the dynamics of C and nutrient cycling. The specific objectives of this study were (1) to evaluate the effects of grazing and mycorrhizal symbiosis on the allocation and storage of C, especially for plant above-and belowground biomass, (2) evaluate the biotic rhizosphere interactions and their role in C cycling, (3) determine the soil microbial community structure as a result of the plant-mycorrhizal symbiosis, and (4) determine the effect of mycorrhizal fungal abundance on soil aggregation. The soil for the experiment was sampled from the Ap horizon of a fine-silty, mixed, superactive, mesic Cumulic Hapludolls located at Konza Prairie Biological Station, Manhattan KS. The experiment was a three-way factorial in a complete randomized block design with four replications. The three factors were mycorrhizae (M), nematodes (N), and phosphorus (P). In a greenhouse study, 96 microcosms (52×32×40cm) were planted to Andropogon gerardii Vit. so that a third of the microcosms could be destructively sampled at the end of each growing season for three years. Plant biomass was separated into aboveground, rhizomes, and roots. All components were dried and weighed at harvest. Mycorrhizal fungi and P increased plant aboveground biomass, while nematodes decreased plant aboveground biomass compared to non-inoculated controls. As expected, P increased plant root biomass, while mycorrhizae increased plant rhizome biomass. Nematodes decreased both above- and belowground biomass. Phospholipid and neutral lipid fatty acid (PLFA and NLFA) analysis were determined for both soil and roots. Water-stable aggregates were separated using a modified Yoder wet-sieving apparatus and analyzed for mass, total C and N, and the isotopic composition of C. There was a positive relationship between AM fungal abundance in the soil and the mass of the largest macroaggregates (>2000µm) after the 3rd year (r=0.67). The effect of roots on the macroaggregate (>2000µm) fraction was not apparent. Phosphorus significantly increased smaller macroaggregates (250-2000µm), along with significantly enhanced plant root biomass, which indirectly demonstrated the effect of roots on the formation of macroaggregates (250-2000µm). The addition of P induced more plant derived C into the aggregates than the non-P amended microcosms as suggested by the [superscript]13C content of the aggregates. Our results confirmed the importance of biotic and abiotic interactions among mycorrhizae, nematodes, and phosphorus on plant growth and the resulting effect on the soil C cycle and soil aggregation.

Master of Arts / Department of Landscape Architecture/Regional and Community Planning / Lee R. Skabelund / This report presents one approach for increasing understanding, appreciation and protection of watersheds by individuals living within the urban-to-rural lands interface. The purpose of the study is to provide guidance to developing and implementing a driving tour of environmentally sensitive land around Clinton Lake and the Upper Wakarusa Watershed (UWW). Although the tour is particular to the UWW, the principles will be useful to planners and watershed advocates working to promote water quality improvement in other geographic areas. A first step in increasing community involvement to restore and protect watersheds is developing a broader public understanding of what watersheds are and their integral part in daily life. By taking a driving tour (literally or virtually), participants can see firsthand how a watershed functions and the values it provides to people and ecosystems. Two key ingredients in the planning process are public participation and clearly defined goals. Public participation begins with awareness of an issue that impacts lives. The first step in engaging the public is to develop a framework for making residents aware that watersheds are a critical part of their environment and the health of their community. The driving tour of the Upper Wakarusa Watershed should help residents and visitors experience a “sense of place” related to the watershed by achieving three over-arching goals: Develop meaningful themes that engage the residents and visitors in learning about watersheds and give insight to their relationships with the watershed. Introduce concepts that are relevant to the lives of residents and visitors and their understanding of a watershed. Generate a stronger “sense of place” as it relates to the Upper Wakarusa watershed. The driving tour in this report has been designed to serve as a broad blueprint for future implementation. The route was devised to take advantage of area resources, especially those on public land, while adhering to guidelines proven successful in promoting rural areas such as the Flint Hills and Cheyenne Bottoms. The actual implementation of the Upper Wakarusa Watershed Driving Tour is expected to be led by local coalitions, and the precise route should be adjusted as necessary.

Master of Science / Department of Agronomy / Nathan O. Nelson / Phosphorus (P), an essential nutrient for plant growth and animal needs, has been identified as an ubiquitous water quality impairment in the United States. In Kansas, a major agricultural state, P loading to the surface waters is a top priority because of the critical role of P enrichment in eutrophication processes and resultant water quality degradation. The objective of this study was to quantify the P sorption and desorption of both stream sediments and upland soils in two Kansas watersheds with contrasting degrees of animal agriculture; Upper West Emma Creek (UWEC) and Red Rock Creek (RRC) watersheds. In-stream sediments were collected from banks, pools, riffles and depositional features. Soils were sampled from wheat, row crop, pasture, and manure-amended fields. Stream water samples were taken under baseflow and storm flow conditions. Our analyses of sediments and soils included equilibrium P concentration at zero net P sorption (EPC[subscript]0), maximum adsorption capacity (P[subscript]max), anion exchange extractable P (P[subscript]lab) and degree of P saturation (DPS). Water samples were analyzed for dissolved reactive phosphorous (DRP). Bank erosion pins were installed in order to estimate bank erosion rates in both watersheds. Results showed that in-stream sediments do not have much more sorption capacity remaining indicated by low P[subscript]max and high DPS. A comparison between mean P[subscript]lab of stream sediments (8.8 mg P kg[superscript]-1 soil) versus field soils (61.2 mg P kg[superscript]-1 soil) reflected that they represent a relatively minor long-term P supply. Of the stream sediments, bank soils had the highest Plab concentrations (24.8 mg P kg[superscript]-1 soil) and would be the largest in-stream P source. Manure-amended fields had the highest Plab (118.6 mg P kg[superscript]-1 soil) due to continued inputs of manure-based P; therefore, representing a large available P pool. Bank erosion contributed about 41% and 11% of the total sediment load in UWEC and RRC respectively. Sediments loads indicated that RRC has more upland sediment inputs than UWEC. Moreover, DRP during storm flow was higher at RRC than UWEC, indicating higher P inputs in RRC from upland soils. Finally, in order to minimize P inputs to the stream system, bank stabilization should be addressed in UWEC and upland best management practices should be implemented in RRC.

Doctor of Philosophy / Department of Horticulture, Forestry, and Recreation Resources / Dale J. Bremer / Jack Fry / Increasing water scarcity may result in greater irrigation restrictions for turfgrass. Drought tolerance and recovery of Kentucky bluegrasses (Poa. pratensis L.) (KBG) were evaluated during and after 88 and 60 day dry downs in 2010 and 2011, respectively, under a rainout shelter. Changes in green coverage were evaluated with digital images. Green coverage declined slowest during dry downs and increased fastest during recoveries in the cultivar ‘Apollo’, indicating it had superior drought tolerance. Electrolyte leakage, photosynthesis, and leaf water potential were evaluated in 7 KBG cultivars during and after the dry downs. Soil moisture at 5 and 20 cm was measured. There were generally no differences in physiological parameters among cultivars during or after dry down. The highest reduction in soil moisture at 5 and 20 cm was in Apollo, suggesting it had a better developed root system for mining water from the profile during drought. Weed prevention and turfgrass establishment of ‘Legacy’ buffalograss (Buchloe dactyloides [Nutt.] Engelm.) and ‘Chisholm’ zoysiagrass (Zoysia japonica Steud.) grown on turf reinforcement mats (TRM) was evaluated. ‘Chisholm’ zoysiagrass stolons grew under the TRM; as such, use of TRM for this cultivar is not practical. Buffalograss had 90% or greater coverage when established on TRM in 2010 and 65% or greater coverage in 2011; coverage was similar to that in oxadiazon-treated plots at the end of each year. ‘Legacy’ buffalograss plugs were established on TRM over plastic for 3 weeks, stored in TRM under tree shade for 7, 14, or 21 days, and evaluated for establishment after storage. In 2010, plugs on mats stored for 7 days had similar coverage to the control, but in 2011 displayed similar coverage to plugs stored on TRM for 14 or 21 day treatments. Green leaf are index (LAI) is an important indicator of turfgrass performance, but its measurement is time consuming and destructive. Measurements using hyperspectral radiometry were compared with destructive measurements of LAI. Results suggest spectral radiometry has potential to accurately predict LAI. The robustness of prediction models varied over the growing season. Finding one model to predict LAI across and entire growing season still seems unrealistic.

Doctor of Philosophy / Department of Agronomy / Charles W. Rice / Nitrogen is critical for plant growth and is a major cost of inputs in production agriculture. Too much nitrogen (N) is also an environmental concern. Agricultural soils account for 85% of anthropogenic N₂O which is a major greenhouse gas. Management strategies for N fertilization and tillage are necessary for enhancing N use efficiency and reducing negative impacts of N to the environment. The different management practices induce changes in substrate availability for microbial activity that may result in increasing or reducing net N₂O emitted from soils. The objectives of this research were to (1) integrate results from field studies to evaluate the effect of different management strategies on N₂O emissions using a meta-analysis, (2) quantify N₂O-N emissions under no-tillage (NT) and tilled (T) agricultural systems and the effect of different N source and placements, (3) perform sensitivity analysis, calibration and validation of the Denitrification Decomposition (DNDC) model for N₂O emissions, and (4) analyze future scenarios of precipitation and temperature to evaluate the potential effects of climate change on N₂O emissions from agro-ecosystems in Kansas. Based on the meta-analysis there was no significant effect of broadcast and banded N placement. Synthetic N fertilizer usually had higher N₂O emission than organic N fertilizer. Crops with high N inputs as well as clay soils had higher N₂O fluxes. No-till and conventional till did not have significant differences regarding N₂O emissions. In the field study, N₂O-N emissions were not significantly different between tillage systems and N source. The banded N application generally had higher emissions than broadcasted N. Slow release N fertilizer as well as split N applications reduced N₂O flux without affecting yield. Simulations of N₂O emissions were more sensitive to changes in soil parameters such as pH, soil organic carbon (SOC), field capacity (FIELD) and bulk density (BD), with pH and SOC as the most sensitive parameters. The N₂O simulations performed using Denitrification Decomposition model on till (Urea) had higher model efficiency followed by no-till (compost), no-till (urea) and till (compost). At the regional level, changes in climate (precipitation and temperature) increased N₂O emission from agricultural soils in Kansas. The conversion from T to NT reduced N₂O emissions in crops under present conditions as well as under future climatic conditions.

Doctor of Philosophy / Department of Agronomy / Ganga M. Hettiarachchi / Urban soils may contain harmful levels of potentially toxic contaminants. These contaminants transfer to humans via two exposure pathways: direct transfer (soil-humans by soil ingestion, dermal exposure and inhalation) and food chain transfer (soil-plant-humans). Soil amendments alter the speciation of the contaminants in soils and thereby modify their bioavailability. The objectives of this research were to access the plant availability of lead (Pb), arsenic (As), and polycyclic aromatic hydrocarbons (PAHs); bioaccessibility and speciation of soil Pb, and As; and dermal absorption of soil PAHs in contaminated urban soils; and effectiveness of soil organic amendments on reducing contaminant bioavailability. Two field experiments were conducted in Kansas City, MO and Indianapolis, IN. Both sites had elevated concentrations of Pb in soils (Kansas City site: 30-380 mg kg⁻¹ and Indianapolis site: 200-700 mg kg⁻¹) . Indianapolis site’s soils also had elevated concentrations of As (40-100 mg kg⁻¹) and PAHs (benzo[a]pyrene: 1-10 mg kg⁻¹) . A control treatment (no-compost) and compost-types (leaf compost and/or composted biosolids, non-composted biosolids, mushroom compost) were used as treatments. A leafy vegetable, a fruiting vegetable and a root crop were grown for two growing seasons. The treatments were arranged in split-plot design (main plot factor: compost; sub-plot factor plant-type). An in vitro steady fluid experiment was conducted using human skins to examine the dermal transfer of soil PAHs. The concentrations of Pb, As, and PAHs in the vegetables were low, except Pb in root crops. Compost reduced the bioaccessibility of Pb, but did not change the bioaccessibility of As. Selected soil samples were analyzed for speciation of Pb using extended x-ray absorption fine structure spectroscopy. The predominant Pb species were Pb sorbed to Fe oxy(hydr)oxide and to organic C. Stable Pb phosphates (pyromorphite) was formed during the in vitro extraction. Dermal transfer experiments showed PAHs in the contaminated soils did not transfer through the skin. Stratum conium of the skin acted as a barrier for dermal transfer of soil PAHs. In general, the risk of food chain transfer of soil Pb, As, and PAHs were low in the studied sites and can be further reduced by compost addition. Bioaccessibility of Pb and As in urban soils were low. Dermal absorption of soil PAHs was insignificant.

Master of Science / Department of Chemistry / Kenneth Klabunde / Remediation of the indoor environment led to the development of novel catalysts which can absorb light in the visible range. These catalysts were prepared using the wet chemistry method known as sol-gel chemistry because preparation via sol-gel provides a homogeneous gel formation, which can be treated via supercritical drying to produce an aerogel. These aerogels have been found to have high surface areas when a combination of titania/silica is used. The increase in surface area has been shown to enhance the activity of the catalysts. Mixed metal oxide systems were prepared using titanium isopropoxide and tetraethyl orthosilicate to yield a 1:1 system of titania/silica (TiO2/SiO2). These systems were doped during the initial synthesis with transition metals (Mn or Co) to create mixed metal oxide systems which absorb light in the visible light range. These materials were assessed for potential as heterogeneous catalysts via gas-solid phase reactions with acetaldehyde. Degradation of acetaldehyde as well as the formation of CO2 was monitored via gas chromatography-mass spectrometery. To increase the activity, visible light was introduced to the system. Experiments have shown that a 10 mol % manganese doped titania/silica system, in the presence of light, can degrade acetaldehyde. The cobalt doped counterpart showed dark activity in the presence of acetaldehyde resulting in the formation of CO2 without the addition of visible light. In the hope of increasing surface area a mixed solvent (toluene/methanol) synthesis procedure was applied to the manganese doped catalyst. The resulting materials were of a low surface area but showed a significant increase in degradation of acetaldehyde. Examination of the interactions between mixed metal oxide systems and semivolatile organic compounds (SVOCs) was studied. The pollutant, triphenyl phosphate, was dissolved in n-pentane and exposed to 10 mg of a given catalyst. These reactions were monitored using UVVis. All systems but the manganese doped titania/silica system resulted in the observation of no activity with triphenyl phosphate. The manganese doped catalyst shown a peculiar activity, the increase in absorbance of the triphenyl phosphate peaks as well as the formation of a new peak.

The four papers of this dissertation explore themes related to waste prevention, the system boundaries, functional units and scale of life cycle assessments (LCAs) of municipal solid waste (MSW) management, as well as the transparency and consistency of the application of LCA methods. The first paper is a comparative analysis of the methodological choices and transparency of 20 LCAs of MSW that were recently published in peer-reviewed journals, and includes a comparison of their midpoint level impact values using statistical indicators. The second paper proposes a conceptual model, designated WasteMAP (Waste Management And Prevention), for evaluating LCAs of MSW which incorporate waste prevention. In WasteMAP, waste prevention through dematerialization is viewed as analogous to waste treatments so long as it does not affect the functional output (product services) of MSW-generating product systems. Papers 3 and 4 comprise the WasteMAP LCA case study. Paper 3 depicts product LCAs of wine and spirit packaging (conventional, lightweight and refillable, each type generating different quantities of waste) at the scale of the individual package and the municipality. At the municipal scale, the LCAs address impacts from the wine and spirit packaging supplied in the City of Toronto, Canada in 2008, and a waste prevention scenario which substitutes lighter weight and reusable containers. The lowest endpoint level impacts out of the five container types studied were associated with refillable containers and aseptic cartons. Paper 4 addresses the Toronto MSW management system and applies the WasteMAP model to allow for the comparison, on a functionally equivalent basis, of the LCA results of a reference scenario, based on 2008 data, with a scenario incorporating six types of waste prevention activities (prevention of unaddressed advertising mail, disposable plastic bags, newspapers, lightweight and refillable wine and spirit packaging, and yard waste). The findings highlight the benefits of waste prevention, and the relative significance of the decision to account for recycled content when modelling waste prevention. The endpoint level impact assessment results using the ReCiPe and Impact 2002+ evaluation methods are in keeping with the assumption in the waste hierarchy that waste prevention has a superior environmental performance.