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Spatial And Temporal Trends In Diet For Pinfish (Lagodon Rhomboides) From Turtle Grass (Thalassia Testudinum) Beds With Contrasting Environmental Regimes In The Lower Laguna Madre, Texas, Maximiliano Barbosa

Theses and Dissertations

Seagrass meadows in far South Texas are dominated by turtle grass (Thalassia testudinum), and juvenile pinfish (Lagodon rhomboides) are abundant grazers of seagrass epifauna. As they grow, pinfish exhibit an ontogenetic dietary shift and begin consuming increasing amounts of plant material. In this study, contrasting environmental regimes in two seagrass meadows were examined to identify how they might affect pinfish diets, diet shifts, and growth across the growing season. The eastern site was sheltered from prevailing southeasterly winds by a barrier island, while the western site was shallower and subjected to higher wind energy and turbidity. …

Soil Properties That Influence The Occurrence Of Hydrogen Sulfide Toxicity In Rice Fields, Julia Marie Fryer

Graduate Theses and Dissertations

Rice (Oryza sativa L.) producers face many challenges throughout each growing season. Hydrogen sulfide (H2S) toxicity is a physiological disorder where sulfate (SO42-) is excessively reduced to the toxic gas, H2S. This can reduce yield and, in severe cases, result in crop death. The main research objectives were to: i) understand chemical and physical characteristics in soils prone to H2S toxicity, ii) determine influential soil characteristics on the incidence of H2S toxicity, iii) determine ammonium sulfate ((NH4)2SO4) fertilizer additions influence on H2S toxicity, and iv) predict when and where H2S will occur. Three greenhouse experiments were conducted using Arkansas field …

Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner

OES Faculty Publications

To assess phytoplankton nutritional status in seasonally oligotrophic waters of the southern Mid-Atlantic Bight, and the potential for rain to stimulate primary production in this region during summer, shipboard bioassay experiments were performed using natural seawater and phytoplankton collected north and south of the Gulf Stream. Bioassay treatments comprised iron, nitrate, iron + nitrate, iron + nitrate + phosphate, and rainwater. Phytoplankton growth was inferred from changes in chlorophyll a, inorganic nitrogen, and carbon-13 uptake, relative to unamended control treatments. Results indicated the greatest growth stimulation by iron + nitrate + phosphate, intermediate growth stimulation by rainwater, modest growth …

Sensitivity Analyses For Simulating Pesticide Impacts On Honey Bee Colonies, A. Carmen Kuan, Gloria Degrandi-Hoffman, Robert J. Curry, Kristina V. Garber, Andrew R. Kanarek, Marcia N. Snyder, Kurt L. Wolfe, S. Thomas Purucker

United States Environmental Protection Agency: Publications

We employ Monte Carlo simulation and sensitivity analysis techniques to describe the population dynamics of pesticide exposure to a honey bee colony using the VarroaPop+Pesticide model. Simulations are performed of hive population trajectories with and without pesticide exposure to determine the effects of weather, queen strength, foraging activity, colony resources, and Varroa populations on colony growth and survival. The daily resolution of the model allows us to conditionally identify sensitivity metrics. Simulations indicate queen strength and forager lifespan are consistent, critical inputs for colony dynamics in both the control and exposed conditions. Adult contact toxicity, application rate and nectar load …

Do Precision Chemical Amendment Applications Impact Sodium Movement In Dryland Semiarid Saline Sodic Soils?, Tulsi P. Kharel, David E. Clay, Cheryl Reese, Thomas Desutter, Doug D. Malo, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Expanding sodicity and salinity problems have placed many northern Great Plains (NGP) soils at the sustainability tipping point. This study assessed the impact of chemical restoration on water and salt transport in undisturbed soil columns collected from three hillslope model landscape positions. The backslope (Redfield), footslope (White Lake), and toeslope (Pierpont) soils had moderate (3.27 ± 0.59), high (7.3 ± 3.34), and very high (13.29 ± 3.2) sodium adsorption ratio (SAR_e) values, respectively. The soils were treated with KBr and one of four soil amendments (none, H₂SO₄, CaSO₄, and CaCl₂). …

Emerging Export Markets For High Quality Alfalfa Hay, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

The exporting of hay from country to country has been evolving for many years. When we look at today’s exports of American hay, we see that the majority of it takes place off the west coast.

An Integrated Pest Management Ipm Approach In Alfalfa Production Systems, Lee H. Townsend

Kentucky Alfalfa and Stored Forage Conference

Alfalfa lends itself to an integrated pest management (IPM) approach for alfalfa weevils and potato leafhoppers, the two key insect pests of the crop. Both species live in most alfalfa fields every summer. However, alfalfa can tolerate low levels of their feeding without costly yield or quality loss.

Foreword Of Kentucky Alfalfa And Stored Forages Conference [2018], Christopher D. Teutsch, Christi L. Forsythe

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

Warming Deferentially Altered Multidimensional Soil Legacy Induced By Past Land Use History, Weiling Dong, Alin Song, Xueduan Liu, Bing Yu, Boren Wang, Yuqiu Lu, Yanling Li, Huaqun Yin, Jianwei Li, Fenliang Fan

Agricultural and Environmental Sciences Faculty Research

The legacy effects of previous land use and climate history may affect current soil function. However, the manner in which these legacy effects of land use are modulated by the subsequent climate remains unclear. For this reason, we investigated how the legacies of soil multiple functions left by conversion of grassland to agricultural management were mediated by climate warming with a reciprocal transplant approach. The overall legacy was further separated into the contributions by changes in the abiotic properties of the soil (abiotic process) and microbial community (biotic process). We here hypothesized that warming may mediate the legacy effects of …

Cover Crops And Fertilization Alter Nitrogen Loss In Organic And Conventional Conservation Agriculture Systems, Rebecca E. Shelton, Krista L. Jacobsen, Rebecca L. Mcculley

Horticulture Faculty Publications

Agroecosystem nitrogen (N) loss produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, conservation agricultural management practices aimed at reducing N loss are increasingly adopted. However, the ecosystem consequences of these practices have not been well-studied. We quantified N loss via leaching, NH₃ volatilization, N₂O emissions, and N retention in plant and soil pools of corn conservation agroecosystems in Kentucky, USA. Three systems were evaluated: (1) an unfertilized, organic system with cover crops hairy vetch (Vicia villosa), winter wheat (Triticum aestivum), or a mix of the two (bi-culture); (2) an organic …

Past Role And Future Outlook Of The Conservation Reserve Program For Supporting Honey Bees In The Great Plains, Clint R.V. Otto, Haochi Zheng, Alisa L. Gallant, Rich Iovanna, Benjamin L. Carlson, Matthew D. Smart, Skip Hyberg

United States Geological Survey: Staff Publications

Human dependence on insect pollinators continues to grow even as pollinators face global declines. The Northern Great Plains (NGP), a region often referred to as America’s last honey bee (Apis mellifera) refuge, has undergone rapid land-cover change due to cropland expansion and weakened land conservation programs. We conducted a trend analysis and estimated conversion rates of Conservation Reserve Program (CRP) enrollments around bee apiaries from 2006 to 2016 and developed models to identify areas of habitat loss. Our analysis revealed that NGP apiaries lost over 53% of lands enrolled in the CRP, and the rate of loss was highest in …

Phosphorus Limitation Of Aboveground Production In Northern Hardwood Forests, Shinjini Goswami, Melany C. Fisk, Matthew A. Vadeboncoeur, Mariann Garrison-Johnston, Ruth D. Yanai, Timothy J. Fahey

All Materials

Forest productivity on glacially derived soils with weatherable phosphorus (P) is expected to be limited by nitrogen (N), according to theories of long-term ecosystem development. However, recent studies and model simulations based on resource optimization theory indicate that productivity can be co-limited by N and P. We conducted a full factorial N × P fertilization experiment in 13 northern hardwood forest stands of three age classes in central New Hampshire, USA, to test the hypothesis that forest productivity is co-limited by N and P. We also asked whether the response of productivity to N and P addition differs among species …

Sustainability At Sit: A Look At The Past, A Plan For The Future, Taliesin Haugh

Capstone Collection

Climate change threatens our world and way of life. Intelligent development and investment could mitigate the worst threats of climate change, while simultaneously providing continuous growth for the global economy. The New Climate Economy proposes efforts to combat this ecological collapse that would result in $30 trillion in new annual economic growth by 2030. Stockholm Resilience Center agrees, giving a framework based on global ecological systems that calls for five critical tasks that can bring growth and stability: Renewable energy

Sustainable local food production

New development models, based on what has worked globally

Reduction of wealth inequity

Education, health, and …

Impacts Of Diverse Crop Rotations And Integrated Crop-Livestock System On Soil Quality In South Dakota, Atilla Polat

Electronic Theses and Dissertations

Crop diversification can be beneficial in improving soil quality parameters. Diverse crop rotations and integrated crop-livestock systems (ICLS), are two examples of crop diversification used in this study to assess soil quality. The objectives of this study were to: (i) assess the impacts of diverse rotations on soil quality parameters, and (ii) assess the impacts of low and high stocking density on soil quality parameters. Both of the studies were conducted separately and are presented as two different chapters. To accomplish objective (i), a long-term experiment was selected which was established near Brookings, South Dakota, USA at USDA-ARS lab in …

The Global Food-Energy-Water Nexus, Paolo D’Odorico, Kyle Frankel Davis, Lorenzo Rosa, Joel A. Carr, Davide Chiarelli, Jampel Dell’Angelo, Jessica Gephart, Graham K. Macdonald, David A. Seekell, Samir Suweis, Maria Cristina Rulli

United States Geological Survey: Staff Publications

Water availability is a major factor constraining humanity’s ability to meet the future food and energy needs of a growing and increasingly affluent human population. Water plays an important role in the production of energy, including renewable energy sources and the extraction of unconventional fossil fuels that are expected to become important players in future energy security. The emergent competition for water between the food and energy systems is increasingly recognized in the concept of the “food-energy-water nexus.” The nexus between food and water is made even more complex by the globalization of agriculture and rapid growth in food trade, …

Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green

Master's Theses or Doctor of Nursing Practice

Clidastes was a large marine reptile from the Late Cretaceous Western Interior Seaway of North America. Though the remains of Clidastes have been found in the Cretaceous chalks and shales for over 150 years, little is known about their growth rates.

Osteohistology is a well-documented technique used to investigate growth in extinct animals. Previous histological studies of Clidastes have hypothesized higher growth rates in basal mosasaurids than varanids due to higher vascularity. These studies focused on adult specimens but did not look at ontogenetic changes in growth rates. Isotopic studies of Clidastes indicate high metabolic temperatures, leading to speculation these …

Chemical Composition And Suitability Of Some Turkish Thermal Muds As Peloids, Muazzez Çeli̇k Karakaya, Necati̇ Karakaya

Turkish Journal of Earth Sciences

Thermal muds have been used in many spas for the treatment of different diseases as well as to clean and beautify the skin and in different forms such as mud baths, masks, and cataplasms. Mineralogical and chemical compositions and the possible toxicity of the peloids were investigated and compared with some limits to determine whether they have any health benefits and potential applications for pelotherapeutic treatments. The studied peloid samples were collected from 19 spas in different parts of Turkey and they were classified as neutral to slightly alkaline, with a high electrical conductivity value that had a high chlorine …

Cosmic-Ray Neutron Probes On The High Plains Of Nebraska: Applications To Large Scale Agriculture, Trenton E. Franz, Darin Desilets, Ammar Wahbi

Department of Earth and Atmospheric Sciences: Faculty Publications

Cosmic-rays have some surprising applications in precision agriculture. The cosmic-ray neutron probe (CRNP), when implemented as a roving instrument, can be used to create spatial maps of soil moisture, and from these maps soil hydraulic properties can be inferred. In this work, we combine data from a mobile CRNP with laboratory samples to make spatial predictions of soil hydraulic properties for select field sites around the state of Nebraska. These maps, which focus on wilting point and field capacity, can, in turn, be used to determine the optimal timing and application rates for irrigation farmers, many of whom have the …

Can Increasing Grass-Fungal Endophyte Symbiotic Diversity Enhance Grassland Ecosystem Functioning?, Mahtaab Bagherzadeh

Theses and Dissertations--Plant and Soil Sciences

The relationship between biodiversity and ecosystem functioning is important in maintaining agroecosystem sustainability. Plant-microbe symbioses, such as exists between the grass tall fescue (Schedonorus arundinaceum) and the asexual fungal endophyte Epichloë coenophiala, can be utilized to enhance agroecosystem functions, such as herbivore resistance. “Novel” E. coenophiala strains that vary in the production of mammal- and insect-toxic compounds have been identified, inserted into tall fescue cultivars, and are planted in pastures globally. Novel fungal endophyte-tall fescue associations may have divergent ecosystem function effects. This study assessed effects of different fescue-endophyte symbiotic combinations on pasture ecosystem function, including aboveground …

A Combined Field, Experimental And Modeling Approach To Understand The Impacts Of Flood Irrigation On Pedogenic Caco3 And Co2 Dynamics In Drylands, Anna Cristina Ortiz

Open Access Theses & Dissertations

Soil salinization is a global problem affecting 10% of agricultural soils, particularly in irrigated arid-lands. This study investigated salt loading through flood-irrigation, particularly of calcite (CaCO3) salt in the southwest of the United States. To evaluate the impact that flood-irrigation has on CaCO3 buildup and its effect on C-cycling, a natural soil and two agricultural soils were sampled: a pecan orchard and an alfalfa field in the El Paso, TX region. Agricultural soils in this study are flood irrigated by the Rio Grande river and by ground waters in its absence, both of which are oversaturated with calcite.

To trace …

Biologically Available Phosphorus In Biocrust-Dominated Soils Of The Chihuahuan Desert, Grace Margaret Crain

Open Access Theses & Dissertations

In desert soils, phosphorus (P) is an important limiting nutrient and its cycling characteristics are less understood compared to nitrogen and carbon. Phosphorus cycling is controlled by both geochemical and biological factors. Traditionally, P availability has been characterized via sequential extraction analyses such as Hedley fractionation, but newly developed extraction methods allow for the examination of more biologically relevant P fractions, providing insight on mechanisms of P acquisition by plants and microbes. We examined these P cycling features in the context of biological soil crusts (biocrusts), which have been found to be important drivers of nutrient cycling and have the …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

Delineation Of A Coal Combustion Residue Landfill And Underlying Karst Subsurface In Southwest Missouri Using Ert And Masw Surveys, Ruobai Zhao

Doctoral Dissertations

"The safe containment of coal combustion residual (CCR) in landfills was addressed by the U.S. Environment Protection Agency (EPA) CCR rule published in 2015. The new rule affects new and existing U.S. based CCR landfills in terms of implementing safeguard systems for safe disposal and contamination control. Electrical resistivity tomography (ERT) and multichannel analysis of surface waves (MASW) data were acquired across and in proximity to a CCR landfill in southwest Missouri, USA, with the intent to identify potential karst features and seepage pathways.

Electrical resistivity tomography data were acquired using an automated 8-channel resistivity meter and multichannel analysis of …

Strengths And Limitations Of Nitrogen Rate Recommendations For Corn And Opportunities For Improvement, Thomas F. Morris, T. Scott Murrell, Douglas B. Beegle, James J. Camberato, Richard B. Ferguson, John H. Grove, Quirine Ketterings, Peter M. Kyveryga, Carrie A.M. Laboski, Joshua M. Mcgrath, John J. Meisinger, Jeff Melkonian, Bianca N. Moebius-Clune, Emerson D. Nafziger, Deanna Osmond, John E. Sawyer, Peter C. Scharf, Walter Smith, John T. Spargo, Harold M. Van Es, Haishun Yang

Plant and Soil Sciences Faculty Publications

Nitrogen fi xation by the Haber–Bosch process has more than doubled the amount of fi xed N on Earth, significantly influencing the global N cycle. Much of this fi xed N is made into N fertilizer that is used to produce nearly half of the world’s food. Too much of the N fertilizer pollutes air and water when it is lost from agroecosystems through volatilization, denitrification, leaching, and runoff. Most of the N fertilizer used in the United States is applied to corn (Zea mays L.), and the profitability and environmental footprint of corn production is directly tied to N …

Strong Spatial-Temporal Patterns In Maize Yield Response To Nutrient Additions In African Smallholder Farms, Samuel Njoroge, Antonius G.T. Schut, Ken E. Giller, Shamie Zingore

All Peer-Reviewed Publications

Large variability in crop responses to macronutrient application at various spatial scales present challenges for developing effective fertilizer recommendations for crop production in smallholder farming systems of sub-Saharan Africa. We assessed maize yield responses to nitrogen (N), phosphorus (P) and potassium (K) application and evaluated relationships between crop responses to N, P and K application and soil analysis data. Nutrient omission trials were conducted on 23 farms located in Sidindi, Western Kenya, selected to be representative of the main soil and management factors in maize based systems in Siaya County. Treatments included a control and PK, NK, NP and NPK …

Bacterial And Archaeal Nitrifier Communities After Seven Years Surface Ground Cover And Nutrient Management In An Orchard Soil, Mashael Albalawi

Graduate Theses and Dissertations

Nitrification is oxidation of ammonia to nitrite and subsequently to nitrate. The rate limiting step of nitrification, ammonia oxidation to nitrite, was thought for many years to be carried out primarily by ammonia oxidizing bacteria (AOB). However, using molecular techniques and investigating the amoA gene, ammonia-oxidizing archaea (AOA) were discovered. Understanding how long-term application of surface ground covers and organic fertilizers to perennial systems affect microbial communities is critical for sustainable soil management. An organically managed experimental apple orchard soil received seven years (2006 – 2013) of annual, surface applications of poultry litter or commercial fertilizer compared to no fertilizer …

The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond

Graduate Theses and Dissertations

Urea-N fertilizer is typically applied at the 5-leaf stage to rice (Oryza sativa L.) grown in a dry-seeded, delayed-flood production system. How long the preflood-N can be delayed without adverse effects on yield potential is poorly understood. The research objective was to determine the effects of preflood-N application and flood establishment timing on aboveground-N content, 50% heading, yield components, and grain yield. Trials were established on silt loam soils at the Pine Tree Research Station (PTRS) and Rice Research and Extension Center (RREC) during 2015 and 2016. Urea-N was applied at 0, 45, 90, 135, and 180 kg N ha-1 …

Assemblage Of The Emergent Plantation Museum Experience, Amy E. Potter, Candace Bright, Derek H. Alderman, David L. Butler, Perry L. Carter, Stephen P. Hanna, E. Arnold Modlin

Earth, Environment & Sustainability: Faculty Presentations (1988-2022)

This presentation was given during the Southeastern Division of the Association of American Geographers Annual Meeting.

How Useful Is Gsv As An Environmental Observation Tool? An Analysis Of The Evidence So Far., Katherine Nesse, Leah Airt

SPU Works

Researchers in many disciplines have turned to Google Street View to replace pedestrian- or carbased in-person observation of streetscapes. It is most prevalent within the research literature on the relationship between neighborhood environments and public health but has been used as diverse as disaster recovery, ecology and wildlife habitat, and urban design. Evaluations of the tool have found that the results of GSV-based observation are similar to the results from in-person observation although the similarity depends on the type of characteristic being observed. Larger, permanent and discrete features showed more consistency between the two methods and smaller, transient and judgmental …

The Impact Of Climate Change On Biodiversity In Nepal: Current Knowledge, Lacunae, And Opportunities, Aishwarya Bhattacharjee, Jose D. Anadon, David L. Lohnman, Tenzing Doleck, Tarendra Lakhankar, Bharat Babu Shrestha, Praseed Thapa, Durga Devkota, Sundar Tiwari, Ajay Jha, Mohan Siwakoti, Naba R. Devkota, Pramod K. Jha, Nir Y. Krakauer

Publications and Research

Nepal has an extreme altitudinal range from 60–8850m with heterogeneous topography and distinct climatic zones. The country is considered a biodiversity hotspot, with nearly a quarter of the land area located in protected areas. Nepal and the surrounding Himalayan region are particularly vulnerable to climate change because of their abrupt ecological and climatic transitions. Tens of millions of people rely on the region’s ecosystem services, and observed and modeled warming trends predict increased climate extremes in the Himalayas. To study the ecological impacts of climate change in Nepal and inform adaptation planning, we review the literature on past, present, and …