Life Sciences Commons^™

A Comparison Of Phytoplankton Nutrient Limitation Between The Marsh And Beach Environments Of Waties Island, Sc, Raymond Sgambati, George Boneillo

Honors Theses

The aim of this study was to investigate the differences in nutrient limitation within the beach and marsh environments at Waties Island, SC. Conducting the experiment on Waties Island allowed most physical factors to be held as constant, meaning the marsh and beach environments would serve as the only variables. Experiments were performed in the winter, spring, summer and fall of 2018 to determine temporal changes in limitation to phytoplankton and cyanobacteria growth. Nutrient additions included dissolved inorganic nitrogen (nitrate, nitrite, and ammonium), dissolved organic nitrogen (urea), and phosphate. To test for co-limitation, a nitrate & phosphate treatment was also …

Evaluation Of Soybean Maturity Group And Planting Date In A Soybean-Rice Rotation On Overall Crop Productivity, Carrie Ortel

Graduate Theses and Dissertations

Little is known about the effects of soybean (Glycine max L.) management techniques on soil-nitrogen (N) credit development and its impact on the subsequent rice (Oryza sativa L.) crop’s success. This study was conducted to determine how soybean maturity group (MG) and planting date effect overall soybean productivity and its influence on the following rice crop. Various soybean planting dates (optimum and late) and MGs (3.5, 4.7, 5.4, and 5.6) were grown and followed in rotation with a rice crop. Six rates of pre-flood fertilizer-N (0, 44, 89, 134, 179, 224 kg N ha-1) were applied to the rice crop. …

A Multidecade Experiment Shows That Fertilization By Salmon Carcasses Enhanced Tree Growth In The Riparian Zone, Thomas P. Quinn, Helfield M. James, Catherine S. Austin, Rachel A. Hovel, Andrew Godard Bunn

Environmental Sciences Faculty and Staff Publications

As they return to spawn and die in their natal streams, anadromous, semelparous fishes such as Pacific salmon import marine‐derived nutrients to otherwise nutrient‐poor freshwater and riparian ecosystems. Diverse organisms exploit this resource, and previous studies have indicated that riparian tree growth may be enhanced by such marine‐derived nutrients. However, these studies were largely inferential and did not account for all factors affecting tree growth. As an experimental test of the contribution of carcasses to tree growth, for 20 yr, we systematically deposited all sockeye salmon (Oncorhynchus nerka) carcasses (217,055 individual salmon) in the riparian zone on one …

Forage News [2018-11], Department Of Plant And Soil Sciences, University Of Kentucky

Forage News

• Heart of America Conference - Jan. 22-23, 2019
• USDA Hay Markets - October 30, 2018
• Grazing Too Short in Fall and Winter Can Mean More Weeds in the Spring
• Forage Identification Book Now Available
• Utilizing Cost Share for Farm Improvements
• Late Fall Nitrogen Benefits Horse and Cattle Pastures

Ulva Spp. Bloom Dynamics In A Hyper-Eutrophic Estuary: Jamaica Bay, New York, Annesia Lamb

Dissertations, Theses, and Capstone Projects

In this dissertation, I present three studies that further our understanding of macroalgae identity, growth, and proliferation. Eutrophication is prevalent in shallow coastal ecosystems world-wide. One of the ecosystem consequences is the development of a bloom forming green marine macroalgae, Ulva spp. Ulva can have negative effects such as Zostera spp. degradation, fish, and shellfish declines. I performed assessments of (1) identity of the bloom-forming Ulva and other macroalgae assemblage, (2) physical, chemical, and biological drivers of Ulva bloom growth and proliferation, and (3) optimal irradiance and temperature requirements for early growth stages in Ulva linza.

The first study …

Effect Of Tannin-Containing Legume Hays On Enteric Methane Emissions And Nitrogen Partitioning In Beef Cattle, Elizabeth K. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cattle are responsible for greenhouse gas emissions such as carbon dioxide, methane and nitrous oxide. In particular, the cow-calf phase of production accounts for approximately 80 percent of the total beef production system greenhouse gas emissions. Tannins are chemical compounds found in certain forages and they have the potential to help reduce these negative environmental impacts. Thus, given that the cow-calf phase often relies on feeding hay, feeding tannin-containing hays may represent a significant mitigation practice.

With my MS program, I sought to explore whether tannin-containing hays fed to mother cows and heifers influence methane and nitrogen emissions relative to …

Effects Of Drift Macroalgae On Sediment Nitrogen Cycling In Thalassia Testudinum Beds Of St. Joseph Bay, Fl, Erica Strope

Master of Science in Integrative Biology Theses

Anthropogenic nitrogen (N) loading and eutrophication can affect valuable ecosystem services and seagrass habitats by modifying structural and functional aspects of estuarine communities including increasing and prolonging macroalgae blooms. In some contexts, macroalgae may play a key role in N cycling pathways because they can alter sediment chemistry. Previous research has associated drift macroalgae blooms with elevated dissolved inorganic N concentrations in sediments as a result of increased remineralization of organic matter, but drift macroalgae effects on microbial N transformation pathways are not well understood. This study quantified the effects of macroalgae on estuarine N cycling in Thalassia testudinum seagrass …

Harvesting Invasive Plants To Reduce Nutrient Loads And Produce Bioenergy: An Assessment Of Great Lakes Coastal Wetlands, Brendan D. Carson, Shane C. Lishawa, Nancy C. Tuchman, Andrew M. Monks, Beth A. Lawrence, Dennis A. Albert

School of Environmental Sustainability: Faculty Publications and Other Works

In Laurentian Great Lakes coastal wetlands (GLCWs), dominant emergent invasive plants are expanding their ranges and compromising the unique habitat and ecosystem service values that these ecosystems provide. Herbiciding and burning to control invasive plants have not been effective in part because neither strategy addresses the most common root cause of invasion, nutrient enrichment. Mechanical harvesting is an alternative approach that removes tissue‐bound phosphorus and nitrogen and can increase wetland plant diversity and aquatic connectivity between wetland and lacustrine systems. In this study, we used data from three years of Great Lakes‐wide wetland plant surveys, published literature, and bioenergy analyses …

Clay Flocculation Effect On Microbial Community Composition In Water And Sediment, Chunyi Chen, Gang Pan, Wenqing Shi, Feng Xu, Stephen Techtmann, Susan M. Pfiffner, Terry Hazen

Michigan Tech Publications

Clay-based flocculation techniques have been developed to mitigate harmful algal blooms; however, the potential ecological impacts on the microbial community are poorly understood. In this study, chemical measurements were combined with 16S rRNA sequencing to characterize the microbial community response to different flocculation techniques, including controls, clay flocculation, clay flocculation with zeolite, and clay flocculation with O₂ added zeolite capping. Sediment bacterial biomass measured by PLFA were not significantly altered by the various flocculation techniques used. However, 16S rRNA sequencing revealed differences in water microbial community structure between treatments with and without zeolite capping. The differences were related to …

A Histological Assessment Of The Effects Of Elevated Temperature And Nitrogen On The Symbiodinium Of Palythoa Toxica (Walsh And Bowers 1971), Molly Westbrook

Honors College

Coral reefs around the world are suffering mass bleaching events caused by a combination of stressors, including rising ocean temperatures, acidity, pollution, increased suspended sediments, and increasing nitrogen levels. Corals harbor a complex microbial ecosystem consisting of bacteria, and algal symbionts known as Symbiodinium. This study examines the effects of elevated temperature, a known cause of bleaching, and elevated nitrogen, an increasingly important potential stressor for reefs, on the Symbiodinium of a zoanthid coral, Palythoa toxica. A total of 65 polyps were subjected to 5 different water treatments of 2 levels of elevated nitrogen, and 2 levels of …

Nutrient Dynamics And Ties To Environmental Conditions And Drivers In Central Puget Sound, Stephanie Jaeger, Ben Larson, Bob Kruger, Kimberle Stark

Salish Sea Ecosystem Conference

Real-time and near-continuous in-situ measurements can provide new insights into variability and patterns of a marine system that would otherwise be undetected by sampling at a lower temporal resolution. King County has a comprehensive long-term marine water quality monitoring program in the Central Basin of Puget Sound that currently includes: bi-monthly water column vertical profiles, discrete sampling, near-surface real-time moored sensors, and new quantitative phytoplankton and zooplankton components. These data can assist with identifying changes and linkages in biogeochemical and ecological processes as well as changes in climate patterns. Recently, new moored and profiling optical nitrate sensors were added to …

Nitrogen In Puget Sound: A Story Map, Sheelagh Mccarthy, Teizeen Mohamedali, Paula Cracknell

Salish Sea Ecosystem Conference

“Nitrogen in Puget Sound” is an ArcGIS Online Story Map developed by scientists at the Washington State Department of Ecology (Ecology). The Story Map is an interactive communication tool that uses a combination of maps, graphics, and text showcasing the state of the science and available data and resources used to understand nitrogen in Puget Sound. It was created to appeal to a broad audience, explaining nitrogen pollution and its effects at a basic level, as well as providing more detailed information for researchers and organizations interested in exploring available data and resources. The Story Map begins with an overview …

Effects Of Application Timing And Soil Type On Optimal N Rate Requirement Of Sugarcane (Saccharum Spp.) And Changes In Soil Inorganic And Leaf N Concentrations, Joseph Martin Garrett

LSU Master's Theses

Research is limited on the effects of soil types and early nitrogen (N) fertilizer applications to N management strategies in sugarcane (Saccharum spp.) production in Louisiana. This study was established in 2015 at two locations in St. Gabriel, LA to 1) determine the effect of fertilizer application timing and soil type on the optimal N rate requirement and yield of sugarcane and 2) relate the relationship of soil and leaf N content to yield at different growth stages with sugarcane yield. Treatments were set in a randomized block design on a clay soil and in a complete randomized …

Watershed Assessment Modelling To Identify Critical Sources Of Pollution And Evaluate Effectiveness Of Conservation Management Practices, Nichole Embertson, Meagan Harris, Andrew Phay

Salish Sea Ecosystem Conference

Critical watershed assessments allow land managers to create strategic plans and prioritize funding and technical assistance when resources are limited. The Natural Resources Conservation Service (NRCS) National Water Quality Initiative (NWQI) provides a framework for watershed assessment to support long-term, strategic watershed planning and prioritize resources. The Tenmile Watershed in the Nooksack Basin in Whatcom County was selected as a pilot watershed for the NWQI assessment for Washington State in 2017. The primary objective of this assessment was to identify critical source areas (CSAs) within the watershed that were most susceptible to nutrient, sediment and bacteria export based on physical …

Effects Of Enhanced Efficiency Nitrogen Fertilizers On Agronomic Parameters And Loss Pathways In The Subtropical Mississippi Delta Region, Scott Michael Pensky

LSU Master's Theses

Minimizing nitrogen (N) loss is critical for improving N use efficiency (NUE) in crop production and reducing its effects on the environment. Management practices such as seasonal application timing of N fertilizers and the addition of enhanced efficiency N fertilizers (EENFs) were investigated for the high N requirement of the two most common cereal crops globally, corn (Zea mays L.) and wheat (Triticum aestivum L.), in the subtropical climate of Louisiana. Field research was established during the 2016 and 2017 seasons at the LSU Agricultural Center’s Dean Lee and Central research stations to examine the effect of different EENFs and …

Evaluation Of Controlled-Release Nitrogen And Potassium Fertilizer In Louisiana Sugarcane Production, Samuel Kwakye

LSU Master's Theses

Sugarcane (Saccharum spp) production is an integral part of Louisiana's economy. Proper fertilizer management, particularly nitrogen (N) and potassium (K), optimizes sugarcane production. An experiment was established in 2015 at the LSU AgCenter Sugar Research Station in St. Gabriel, Louisiana to: (1) assess the effect of N and K fertilizer sources on sugarcane yield and quality parameters, and (2) monitor the changes in inorganic N and K levels in the soil at different sugarcane growth stages. The experiment was arranged in a randomized complete block design on a Sharkey clay soil and complete randomized design on a Commerce …

Impact Of Sorghum Cultivar, Phenology, Nitrogen, And Silicon Fertilization On Melanaphis Sacchari Biology, Luna Lama

LSU Master's Theses

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an invasive pest of grain sorghum, Sorghum bicolor (L.) Moench. Since its first outbreak in sorghum in 2013, severe infestations have spread throughout the southern U.S. causing high economic losses. While insecticidal control has mitigated some of the impacts of this pest, a sustainable ecology-based management program is needed to reduce reliance on chemical control. We studied the effects of silicon (rates equivalent to 0 and 3360 kg Si/ha) and nitrogen (rates equivalent to 0, 110, and 220 kg N/ha) on M. sacchari growth and reproduction on resistant (DKS 37-07) and …

Effects Of Nitrogen Fertilizer Rate, Timing, And Herbicide Use On Industrial Hemp (Cannabis Sativa), Robert David Anderson

Masters Theses & Specialist Projects

Industrial hemp (Cannabis sativa) is an old crop being reintroduced into certain states; thus, very little information is known about growing the crop domestically. Two field experiments were established in Bowling Green, KY to evaluate various nitrogen fertilizer rates and timing applications to examine the effects on growth and yield of industrial hemp (Cannabis sativa). Each experiment was sprayed with 1.12 a.i. ha-1 pendimethalin on half of each plot as a pre – emergent herbicide. Hemp was planted at a rate of 43 kg/ ha into a conventionally tilled silt loam soil. Nitrogen rates studied were a control, 79, 157, …

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 …

Spatiotemporal Variation Of Nutrient Concentrations In The Upper Shule River Basin, The Qinghai-Tibetan Plateau, China, Hongzheng Pu, Yongjian Ding, Tianding Han, Fengjing Liu

Michigan Tech Publications

This study aimed to understand the spatiotemporal variation of nutrient concentrations in stream water, using analyses of total nitrogen (TN), NO₃⁻-N, NH₄⁺-N and total phosphorus (TP) concentrations from April to October in 2016 in the upper Shule River basin in the northeastern margin of the Qinghai-Tibetan Plateau. Dissolved inorganic nitrogen (DIN; NO₃⁻-N + NH₄⁺-N) concentrations in both groundwater and stream water were the predominant form of TN, accounting for about 88%. Median concentrations in stream water were 815 μg L⁻¹ for TN, 459 μg L⁻¹ for …

Ecosystem Function And Phenotypic Variation In Spartina Alterniflora Salt Marshes, Sandra E. Voors

USF Tampa Graduate Theses and Dissertations

Biodiversity is important to ecosystem function at many scales, and variation functional traits within a species can potentially influence ecosystem functioning by altering nutrient cycling dynamics. High population extinction rates are resulting in a rapid loss of within-species biodiversity, so there is a need to better understand the importance of intraspecific variation to ecosystem-level processes. Tidal salt marshes are ideal ecosystems for investigating intraspecific variation in plant-nutrient relationships because they are dominated by a monoculture of the foundation species Spartina alterniflora, with distinct phenotypes that correspond to environmental gradients across the marsh. We conducted a field survey of existing …

Investigation Of The Effects Of Mineral Fertilizers (Nitrogen) On The Development Of Mulberry Trees Growing And Productivity Of Their Leaves., M Ibragimov

Karakalpak Scientific Journal

The article is devoted to the study of influence of mineral fertilizers (nitric) on development and productivity mulberry leaves. It is the experimentally proved positive influence on growth and productivity of a mulberry.

Investigation Of The Effects Of Mineral Fertilizers (Nitrogen) On The Development Of Mulberry Trees Growing And Productivity Of Their Leaves., M Ibragimov

Karakalpak Scientific Journal

The article is devoted to the study of influence of mineral fertilizers (nitric) on development and productivity mulberry leaves. It is the experimentally proved positive influence on growth and productivity of a mulberry.

Assessing The Difference Between Soil And Water Assessment Tool (Swat) Simulated Pre-Development And Observed Developed Loading Regimes, Sean J. Zeiger, Jason A. Hubbart

Faculty & Staff Scholarship

The purpose of this research was to assess the difference between Soil and Water Assessment Tool (SWAT) simulated pre-development and contemporary developed loading regimes in a mixed-land-use watershed of the central United States (US). Native land cover based on soil characteristics was used to simulate pre-development loading regimes using The Soil and Water Assessment Tool (SWAT). Loading targets were calculated for each major element of a pre-development loading regime. Simulated pre-development conditions were associated with increased retention and decreased export of sediment and nutrients when compared to observed developed conditions. Differences between simulated pre-development and observed developed maximum daily yields …

Blooms Of Dinoflagellate Mixotrophs In A Lower Chesapeake Bay Tributary: Carbon And Nitrogen Uptake Over Diurnal, Seasonal, And Interannual Timescales, Margaret R. Mulholland, Ryan Morse, Todd Egerton, Peter W. Bernhardt, K. C. Filippino

OES Faculty Publications

A multi-year study was conducted in the eutrophic Lafayette River, a sub-tributary of the lower Chesapeake Bay during which uptake of inorganic and organic nitrogen (N) and C compounds was measured during multiple seasons and years when different dinoflagellate species were dominant. Seasonal dinoflagellate blooms included a variety of mixotrophic dinoflagellates including Heterocapsa triquetra in the late winter, Prorocentrum minimum in the spring, Akashiwo sanguinea in the early summer, and Scrippsiella trochoidea and Cochlodinium polykrikoides in late summer and fall. Results showed that no single N source fueled algal growth, rather rates of N and C uptake varied on seasonal …

Timing Of Side-Dress Applications Of Nitrogen For Corn In Conventional And No-Till Systems, D. W. Sweeney, D. E. Shoup, Dorivar Ruiz Diaz

Kansas Agricultural Experiment Station Research Reports

Environmental conditions vary widely in the spring in southeastern Kansas. As a result, much of the N applied prior to corn planting may be lost before the time of maximum plant N uptake. Side-dress or split applications to provide N during rapid growth periods may improve N use efficiency while reducing potential losses to the environment. The objective of this study was to determine the effect of timing of side-dress N fertilization compared with pre-plant N applications for corn grown on a claypan soil.

Nitrogen, Phosphorus, And Potassium Fertilization For Newly Established Tall Fescue, D. W. Sweeney, J. L. Moyer, J. K. Farney

Kansas Agricultural Experiment Station Research Reports

Tall fescue is the major cool-season grass in southeastern Kansas. Perennial grass crops, as with annual row crops, rely on proper fertilization for optimum production; however, meadows and pastures are often under-fertilized and produce low quantities of low-quality forage. Even when new stands are established, this is often true. The objective of this study was to determine whether N, P, and K fertilization improves yields during the early years of a stand.

Including Legumes In Bermudagrass Pastures, J. L. Moyer, L. W. Lomas

Kansas Agricultural Experiment Station Research Reports

Bermudagrass is a productive forage species when intensively managed. However, it has periods of dormancy and requires proper management to maintain forage quality. Legumes in the bermudagrass sward could improve forage quality and reduce fertilizer usage; however, legumes are difficult to establish and maintain with the competitive grass. Clovers can maintain survival once established in bermudagrass sod and may be productive enough to substitute for some N fertilization. This study was designed to compare dry cow performance on a bermudagrass pasture system that included ladino and crimson clovers (Legume) vs. bermudagrass alone (Nitrogen).

Microorganisms Facilitate Uptake Of Dissolved Organic Nitrogen By Seagrass Leaves [Dataset], Flavia Tarquinio, Jeremy Bourgoure, Annette Koenders, Bonnie Laverock, Christin Säwström, Glenn A. Hyndes

Research Datasets

The database compiles data (used in Tarquinio et al. 2018, ISME Journal, accepted for publication) obtained from nitrogen stable isotope analysis (IRMS) and Nanoscale secondary ion mass spectrometry (NanoSIMS) of seagrass (Posidonia sinuosa) leaves and associated microorganisms. Row data (IRMS) are presented for bulk tissue ¹⁵N enrichment of P. sinuosa leaves at different times of incubation (plotted as bar chart in the manuscript), as well as the enrichment detected through the drawing of regions of interest (ROI) from NanoSIMS image analysis and plotted as box plots in the manuscript.

Air-Propelled Organic Fertilizer Grits Can Be Used To Control Weeds And Provide Nitrogen, Michael Carlson

Electronic Theses and Dissertations

Weeds are one of the biggest challenges for organic growers because of the alternative weed control methods. Air-propelled abrasive grit management has been reported to control weed seedlings in corn and soybeans while maintaining yield. This research examined the weed control, corn and soybean yields, nitrogen mineralization, and nitrogen yield responses from grits. The grits used in this research included: Phytaboost Plant Food 7-1-2 (soybean meal), Sustane 8-2-4 and 4-6-4 (turkey litters), and two non-fertilizer grits: Agra Grit (walnut shells) and corn cob meal. Field studies were conducted from 2015 to 2017 in Aurora, SD, Beresford, SD and Morris, MN. …