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2015

Nitrogen

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Full-Text Articles in Life Sciences

Elevated Co2 Induced Changes In The Chemistry Of Quaking Aspen (Populus Tremuloides Michaux) Leaf Litter: Subsequent Mass Loss And Microbial Response In A Stream Ecosystem, Steven Rier, Nancy Tuchman, Robert Wetzel, James Teeri Dec 2015

Elevated Co2 Induced Changes In The Chemistry Of Quaking Aspen (Populus Tremuloides Michaux) Leaf Litter: Subsequent Mass Loss And Microbial Response In A Stream Ecosystem, Steven Rier, Nancy Tuchman, Robert Wetzel, James Teeri

Nancy Tuchman

No abstract provided.


Nonnative Phragmites Australis Invasion Into Utah Wetlands, Andrew Kulmatiski, Karen H. Beard, Laura A. Meyerson, Jacob R. Gibson, Karen E. Mock Dec 2015

Nonnative Phragmites Australis Invasion Into Utah Wetlands, Andrew Kulmatiski, Karen H. Beard, Laura A. Meyerson, Jacob R. Gibson, Karen E. Mock

Laura A. Meyerson

Phragmites australis (Cav.) Trin. ex Steud. (common reed), already one of the world’s most widespread plant species, has realized rapid range expansion in coastal wetlands of North America in the past century, but little is known about P. australis range expansion in inland wetland systems. We used genetic analyses, aerial photographs, field surveys, and a greenhouse experiment to study the extent and mechanism of nonnative P. australis invasion of Utah wetlands. We collected and genetically analyzed 39 herbarium samples across the state and 225 present-day samples from northern Utah’s major wetland complexes. All samples collected before 1993 and all samples …


Nonnative Phragmites Australis Invasion Into Utah Wetlands, Andrew Kulmatiski, Karen H. Beard, Laura A. Meyerson, Jacob R. Gibson, Karen E. Mock Dec 2015

Nonnative Phragmites Australis Invasion Into Utah Wetlands, Andrew Kulmatiski, Karen H. Beard, Laura A. Meyerson, Jacob R. Gibson, Karen E. Mock

Laura A. Meyerson

Phragmites australis (Cav.) Trin. ex Steud. (common reed), already one of the world’s most widespread plant species, has realized rapid range expansion in coastal wetlands of North America in the past century, but little is known about P. australis range expansion in inland wetland systems. We used genetic analyses, aerial photographs, field surveys, and a greenhouse experiment to study the extent and mechanism of nonnative P. australis invasion of Utah wetlands. We collected and genetically analyzed 39 herbarium samples across the state and 225 present-day samples from northern Utah’s major wetland complexes. All samples collected before 1993 and all samples …


Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford Dec 2015

Available Nitrogen And Denitrification In Soil Altered By Ground Cover And Nutrient Source In An Organic Apple Orchard, Jade Nicole Ford

Graduate Theses and Dissertations

A shift in public demand towards more organic and locally produced fruit and vegetables has been occurring across the United States in recent years. A common practice in organic fruit production is the application of organic ground covers to supply nutrients while enhancing other soil properties. A need for research exists in the southern region of the U.S. examining the effects of regionally applicable ground cover and nutrient management on nitrogen availability and the microbial community to provide information to organic farmers in the region. Two studies were conducted to determine how 12 treatment combinations of four ground covers (compost, …


A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary Oct 2015

A Bat-Guano-Derived Δ15N And Δ13C Record Of Paleoenvironmental Change: Zidită Cave, Romania, Daniel Martin Cleary

USF Tampa Graduate Theses and Dissertations

Because nitrogen isotopes are fractionated along the soil-plant-insect-bat-guano pathway, it may be possible to reconstruct environmental and climatic changes reflected in the nitrogen isotopic composition of guano. A 1.5-m core of bat guano from Zidită Cave (western Romania) provides a record of climatic and anthropogenic influence on the regional nitrogen cycle and paleoenvironmental controls on nitrogen transforming processes. Increasing and decreasing trends of nitrogen isotopic composition (δ15N values) correspond well with changes in the influence of farming practices, deforestation, and forest expansion. These influences likely had a significant effect on the openness of the nitrogen cycle, resulting in …


Molybdenum And Iron Interactions As Micronutrients For Growth Of A Freshwater Cyanobacterium, Microcystis Aeruginosa, Yan Xu Sep 2015

Molybdenum And Iron Interactions As Micronutrients For Growth Of A Freshwater Cyanobacterium, Microcystis Aeruginosa, Yan Xu

Electronic Thesis and Dissertation Repository

The cyanobacterium M. aeruginosa is an important bloom former in freshwater environments. We investigated the growth, photosynthesis and toxin contents of two toxic strains of M. aeruginosa, CPCC 299 and CPCC 300, under a combination of nitrogen supply (nitrate or ammonium) and depleted or replete Molybdenum (Mo) and/or Iron (Fe) concentrations. When Mo and Fe were supplied at growth-replete levels, M. aeruginosa grew equally well on nitrate and ammonium. Reducing Fe dramatically reduced growth rate efficiency when the cells were supplied with nitrate, but not with ammonium. In contrast, the removal of Mo from the medium did not impair …


Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard Aug 2015

Evidence Of Late Quaternary Fires From Charcoal And Siliceous Aggregates In Lake Sediments In The Eastern U.S.A., Joanne P. Ballard

Doctoral Dissertations

The late-glacial transition to the Holocene, 15,000–11,600 cal yr BP, is an enigmatic period of dynamic global changes and a major extinction event in North America. Fire is an agent of disturbance that transforms the environment physically and chemically, and affects plant community composition. To improve understanding of the linkages between fire, vegetation, and climate over the late glacial and Holocene in the eastern U.S., I analyzed lake-sediment cores for charcoal and indicators of wood ash, and compared results to existing pollen records. A new microscopic charcoal record from Anderson Pond, Tennessee revealed high fire activity from 23,000–15,000 cal yr …


Nitrogen And Water Effects On Canopy Sensor Measurements For Site-Specific Management Of Crops, Nicholas C. Ward Jul 2015

Nitrogen And Water Effects On Canopy Sensor Measurements For Site-Specific Management Of Crops, Nicholas C. Ward

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Water and nitrogen (N) are undoubtedly the two largest agricultural inputs globally. Coupled with advances in site-specific management technology their integration into production agriculture will allow for the most efficient use these crop input resources. Active canopy sensors offer the ability to measure biophysical plant traits rapidly and make assessments about plant status. Specifically, optical sensor measurements of light reflectance assess plant N status allowing for in-season and on-the-go N recommendations and applications; while infrared thermometers (IRT) measurement of canopy temperature can be used a tool for irrigation management. To evaluate how these technologies work among different plant stress environments …


Rice Grain Yield And Nitrogen Uptake And Ammonia Volatilization From Urea As Affected By Urea Amendment And Simulated Rainfall, Randy Dempsey May 2015

Rice Grain Yield And Nitrogen Uptake And Ammonia Volatilization From Urea As Affected By Urea Amendment And Simulated Rainfall, Randy Dempsey

Graduate Theses and Dissertations

The effect of rainfall between urea application and flood establishment on N loss and grain yield of rice (Oryza sativa L.) has not been studied. The first research objective was to compare the effects of simulated rainfall amounts and N-(n-butyl) thiophosphoric triamide (NBPT) urease inhibitor rate on NH3 volatilization and rice growth. Three field experiments were conducted and NH3 volatilization was measured in two experiments for 11 days after urea application (DAU) in semi-open chambers. Urea or NBPT-treated urea (NBPT-Urea) was subjected to six simulated rainfall amounts (0-25 mm) applied 5 to 15 h after urea application and flooded 7 …


Evaluación Nutricional Y Económica De Diferentes Planes De Fertilización En Remolacha Forrajera Beta Vulgaris, L. Para Alimentación De Bovinos, Paula Andrea Alvarez Moreno Jan 2015

Evaluación Nutricional Y Económica De Diferentes Planes De Fertilización En Remolacha Forrajera Beta Vulgaris, L. Para Alimentación De Bovinos, Paula Andrea Alvarez Moreno

Zootecnia

El objetivo de este estudio fue analizar nutricional y económicamente diferentes tratamientos de fertilización en remolacha forrajera (Beta vulgaris, L) Partiendo de una fertilización base que es el tratamiento control y una serie de tratamientos que consiste en 50% más nitrógeno, 50% más fosforo y 50% más potasio, con el fin de conocer y establecer cuál es el tratamiento con mejor valor nutricional, mejor rendimiento por hectárea y con el mejor costo de producción. El proyecto se realizó en una explotación productora de leche que cuenta con desarrollos agrícolas para la nutrición animal, en el municipio de Guasca (Cundinamarca) en …


Biogeochemical Cycling In Lake Superior Tributaries: Seasonality, Quantity And Quality Of Export, Ashley Anne Coble Jan 2015

Biogeochemical Cycling In Lake Superior Tributaries: Seasonality, Quantity And Quality Of Export, Ashley Anne Coble

Dissertations, Master's Theses and Master's Reports - Open

Seasonal and spatial variability in environmental factors may affect dissolved organic matter composition and nutrient transformation and retention in streams. The objective of this research was to quantify and describe seasonality, quantity, and quality of nutrient processing and export of ammonium (NH4), soluble reactive phosphate (SRP), and dissolved organic carbon (DOC) into Lake Superior through intensive study in a small 1st order watershed coupled with snapshot measurements across 12 tributaries that varied in size, location, and wetland coverage. Our results suggest biodegradable C is exported from a small headwater stream year-round and that DOC mineralization rates can be …


Reductions Of Wheat Yield And Yield Components And Nitrogen Loss Following Frozen Soil Nitrogen Applications, Carrie Ann Knott, Edwin L. Ritchey, Lloyd W. Murdock Jan 2015

Reductions Of Wheat Yield And Yield Components And Nitrogen Loss Following Frozen Soil Nitrogen Applications, Carrie Ann Knott, Edwin L. Ritchey, Lloyd W. Murdock

Plant and Soil Sciences Research Report

Most wheat producers in Kentucky apply nitrogen (N) as a split application. The first N increment is applied when wheat plants begin actively growing (green-up) in late winter, which is typically in mid- February between growth stages Feekes 2 to 3. The second N increment typically occurs in March when wheat is between Feekes 5 to 6. Many producers in Kentucky, especially Western Kentucky, have become accustomed to beginning first N applications in late January when the ground is frozen and the wheat is still dormant. This practice allows them to apply N to large acreages of wheat while avoiding …


Ectomycorrhizal Fungal Communities And Enzymatic Activities Vary Across An Ecotone Between A Forest And Field, Megan A. Rúa, Becky Moore, Nicole Hergott, Lily Van, Colin R. Jackson, Jason D. Hoeksema Jan 2015

Ectomycorrhizal Fungal Communities And Enzymatic Activities Vary Across An Ecotone Between A Forest And Field, Megan A. Rúa, Becky Moore, Nicole Hergott, Lily Van, Colin R. Jackson, Jason D. Hoeksema

Biological Sciences Faculty Publications

Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing …


Investigating The Role Of Polyploidy In The Response Of Chamerion Angustifolium To Increased Soil Nitrogen Availability And Insect Herbivory, Alex Bales Jan 2015

Investigating The Role Of Polyploidy In The Response Of Chamerion Angustifolium To Increased Soil Nitrogen Availability And Insect Herbivory, Alex Bales

Dissertations, Master's Theses and Master's Reports

Human activities have more than doubled the input rate of nitrogen to terrestrial ecosystems. Increased soil nitrogen availability is associated with increased plant productivity, changes in plant resource allocation strategies, and changes in interactions between plants and their associated insect herbivores. For example, nitrogen-rich conditions can alter the physiological and chemical properties of plants in ways that increase their ability to deter herbivore attack (resistance) and maintain fitness following herbivore attack (tolerance). The ecological tolerance of plants to such abiotic and biotic environments is thought to be influenced by autopolyploidy, a commonly occurring phenomenon in plants in which individuals have …


Detrital Stoichiometry As A Critical Nexus For The Effects Of Streamwater Nutrients On Leaf Litter Breakdown Rates, David W. P. Manning, Amy D. Rosemond, John S. Kominoski, Vladislav Gulis, Jonathan P. Benstead, John C. Maerz Jan 2015

Detrital Stoichiometry As A Critical Nexus For The Effects Of Streamwater Nutrients On Leaf Litter Breakdown Rates, David W. P. Manning, Amy D. Rosemond, John S. Kominoski, Vladislav Gulis, Jonathan P. Benstead, John C. Maerz

Biology Faculty Publications

Nitrogen (N) and phosphorus (P) concentrations are elevated in many freshwater systems, stimulating breakdown rates of terrestrially derived plant litter; however, the relative importance of N and P in driving litter breakdown via microbial and detritivore processing are not fully understood. Here, we determined breakdown rates of two litter species, Acer rubrum (maple) and Rhododendron maximum (rhododendron), before (PRE) and during two years (YR1, YR2) of experimental N and P additions to five streams, and quantified the relative importance of hypothesized factors contributing to breakdown. Treatment streams received a gradient of P additions (low to high soluble reactive phosphorus [SRP]; …


Influence Of Simulated Golf Cart Traffic And Nitrogen Rate On Buffalograss Quality, E. Alderman, J. Hoyle, J. Fry, S. Keeley Jan 2015

Influence Of Simulated Golf Cart Traffic And Nitrogen Rate On Buffalograss Quality, E. Alderman, J. Hoyle, J. Fry, S. Keeley

Kansas Agricultural Experiment Station Research Reports

Application of 2 and 3 lb N/1,000 ft2resulted in acceptable buffalograss quality when subjected to simulated golf cart traffic. Across all fertilizer treatments, traffic rates of 8 and 16 passes per week resulted in unacceptable quality ratings for the study duration.


Tillage And Nitrogen Placement Effects On Yields In A Short-Season Corn/Wheat/Double-Crop Soybean Rotation, D. W. Sweeney Jan 2015

Tillage And Nitrogen Placement Effects On Yields In A Short-Season Corn/Wheat/Double-Crop Soybean Rotation, D. W. Sweeney

Kansas Agricultural Experiment Station Research Reports

Overall in 2014, adding nitrogen (N) improved average wheat yields, but different N placement methods resulted in similar yields. Double-crop soybean yields were unaffected by tillage or the residual from N treatments that were applied to the previous wheat crop.


An Examination Of El Niño's And Agricultural Runoff's Effect On Harmful Algal Blooms And California Sea Lion (Zalophus Californianus) Health In Monterey Bay, Nadine Lafeber Jan 2015

An Examination Of El Niño's And Agricultural Runoff's Effect On Harmful Algal Blooms And California Sea Lion (Zalophus Californianus) Health In Monterey Bay, Nadine Lafeber

Scripps Senior Theses

An increase in marine mammal stranding and die-off events has been observed along the California coast. The exact cause to explain for these recent events is unknown, but El Niño and harmful algal blooms are established sources for temporary decreases in marine mammal health. To determine whether El Niño could be causing and amplifying harmful algal blooms, particularly in Monterey Bay where they occur frequently, data was analyzed from the Marine Mammal Center in Sausalito, California. Data analysis focused on California sea lions (Zalophus californianus), because they have the largest data set and are directly affected by harmful …


The Effects Of Phosphorus And Nitrogen Fertilization On Tall Fescue Nutrient Content, Yield And Baleage Quality, Cheyenne Adele Arthur Jan 2015

The Effects Of Phosphorus And Nitrogen Fertilization On Tall Fescue Nutrient Content, Yield And Baleage Quality, Cheyenne Adele Arthur

MSU Graduate Theses

Tall fescue (Festuca arundinacea Schreb.) is a cool season perennial grass commonly used in year-round forage production systems. Producers often wrap large round bales of tall fescue in plastic. The fermented product of this practice, termed baleage, allows the forage to be stored for later feeding. During periods of rapid growth in the spring and the fall, the nutrient content of tall fescue can be imbalanced and cause nutritional disorders in grazing animals. To improve the nutrition of tall fescue, it is known that fertilization of phosphorus (P) can help improve leaf nutrient content of P, magnesium (Mg), and calcium …


Grassland Renovation And Consequences For Nutrient Management, Johannes Isselstein, Manfred Kayser Jan 2015

Grassland Renovation And Consequences For Nutrient Management, Johannes Isselstein, Manfred Kayser

IGC Proceedings (1997-2023)

Sward degradation is a serious threat to the functioning of grassland and the provision of ecosystem services. Renovation measures are frequently applied in order to restore degraded swards. However, the success is highly variable and substantial tradeoffs are often found following renovation such as among agronomic and environmental services. Starting from a general classification of renovation measures the paper investigates the processes induced by renovation that lead to a change of the vegetation and that affect carbon and nitrogen fluxes. These processes are strongly interrelated and dependent on site, climate and management condition as well as on the time scale. …


Nitrogen And Sulfur Fertilization Effects On Camelina Sativa In West Central Kansas, E. Obeng, A. Obour Jan 2015

Nitrogen And Sulfur Fertilization Effects On Camelina Sativa In West Central Kansas, E. Obeng, A. Obour

Kansas Agricultural Experiment Station Research Reports

Camelina sativais early maturing and possesses characteristics that make it a good fit as a rotation crop in dryland wheat cropping systems. Nitrogen (N) and sulfur (S) play very important roles in oilseed production, including camelina. This study was undertaken in 2013 and 2014 to determine N and S rates necessary for optimum camelina production in West Central Kansas. The experiment was set up as randomized complete blocks with four replications in a split-plot arrangement. Treatments were two S rates (0 and 18 lb/a) as the main plots, and N rates (0, 20, 40, and 80 lb/a) were the …


Nitrogen, Phosphorus, And Potassium Fertilization For Newly Established Tall Fescue, D. W. Sweeney, J. L. Moyer Jan 2015

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

Kansas Agricultural Experiment Station Research Reports

First-year production of tall fescue (Site 1 in 2013 and Site 2 in 2014) was affected by nitrogen (N) and phosphorus (P) but not potassium (K) fertilization. Environmental conditions likely influenced the growth of the fescue and the response to fertilizer N and P in the first year of production at the two sites.