Physical Sciences and Mathematics Commons^™

Development Of A Model Of Growth Of Grass/White Clover Swards For A Grassland Management Support System, A. Scott Laidlaw

IGC Proceedings (1997-2023)

No abstract provided.

In The Margins: Reconsidering The Range And Contribution Of Diazotrophs In Nearshore Environments, Corday R. Selden

OES Theses and Dissertations

Dinitrogen (N₂) fixation enables primary production and, consequently, carbon dioxide drawdown in nitrogen (N) limited marine systems, exerting a powerful influence over the coupled carbon and N cycles. Our understanding of the environmental factors regulating its distribution and magnitude are largely based on the range and sensitivity of one genus, Trichodesmium. However, recent work suggests that the niche preferences of distinct diazotrophic (N₂ fixing) clades differ due to their metabolic and ecological diversity, hampering efforts to close the N budget and model N₂ fixation accurately. Here, I explore the range of N₂ fixation …

Digitaria Eriantha Under Water Deficiency, H. Laborde, M. B. Toribio, M. N. Fioretti, R. E. Brevedan, S. S. Baioni

IGC Proceedings (1997-2023)

No abstract provided.

Monitoring Urine Distribution By Grazing Livestock, Keith Betteridge, Coby J. Hoogendoorn, Wendy Griffiths, Des A. Costall, Mark Carter, Patrick Laube

IGC Proceedings (1997-2023)

No abstract provided.

The Impact Of Stream-Groundwater Exchange On Seasonal Nitrate Loads In An Urban Stream, Julio I. Beltran

Theses - ALL

Urbanization negatively impacts water quality in streams by reducing stream-groundwater interactions, which reduces the stream’s ability to naturally attenuate nitrate. Meadowbrook Creek, a first order urban stream in Syracuse, New York, has a negative urbanization gradient that results in urbanized headwaters that are disconnected from the floodplain, and downstream reaches that have intact riparian floodplains and connection to riparian aquifers. This system allows us to assess how stream-aquifer interactions in urban streams impact the net sources and sinks of nitrate at the reach scale. We used continuous (15-minute) streamflow measurements, along with weekly grab samples at three gauging stations positioned …

Critical Plant And Leaf N Concentrations Of An Ageing Timothy Sward, Gilles Bélanger, Gaëtan F. Tremblay

IGC Proceedings (1997-2023)

No abstract provided.

Effects Of Yearly Simulated Temperature Rise And Nitrogen Deposition On Soil Nutrient In The Songnen Meadow Steppes Of Northeast China, L. J. Hu, D. L. Wang, W. W. Wang, J. X. Guo

IGC Proceedings (1997-2023)

No abstract provided.

Effects Of Nitrogen Fertilizers On Growth And Turf Quality Of Kentucky Bluegrass, Yuling Deng, Yan Peng, Yukuan Wang

IGC Proceedings (1997-2023)

No abstract provided.

The Impact Of Different Grassland Land‐Uses On Earthworm Populations In A New Zealand Fragi‐Pallic Soil, Todd A. White, Trevor L. Knight, C. L. Goulter, W. J. Clarke-Hill

IGC Proceedings (1997-2023)

No abstract provided.

Sources Of Nitrogen In A Napier Grass/Legume Mixture On Smallholder Dairy Farms In Central Kenya, David Miano Mwangi

IGC Proceedings (1997-2023)

No abstract provided.

Spatial And Temporal Variation Of Nutrients In The Great Lakes-St. Lawrence Basin: Implications For Primary Production In Stream Ecosystems, Nolan Pearce

Electronic Thesis and Dissertation Repository

Growing human populations and associated land use activities has increased the amount of nutrients delivered to surface waters. Eutrophication from the over-enrichment of nitrogen and phosphorus has degraded ecosystem conditions in streams, lakes, and coastal areas worldwide. Thus, the management of anthropogenic nutrient loading is a global concern. This thesis employed a combination of field and experimental research to provide watershed managers with information on the spatial and temporal patterns in stream nutrient enrichment, and the associated ecological effects of anthropogenic nutrient loading in the Great Lakes-St. Lawrence basin. Four studies were completed to address this research goal. First, I …

Production, Botanical Composition And Nutrient Status Of An Originally Lolium Perenne--Dominant Sward Receiving Long‐Term Manure Applications, Wenju Liu, Y. G. Zhu, P. Christie, A. Scott Laidlaw

IGC Proceedings (1997-2023)

No abstract provided.

Nitrous Oxide Emission And Methane Oxidation Potential In The Pastoral Soil Under Intensive Dairy Farm Management, Z. Li, F. M. Kelliher

IGC Proceedings (1997-2023)

No abstract provided.

Response Of Natural And Cultivated Hay Meadows To Fertilizer Applied By Small Scale Livestock Farmers In The Mountainous Sandzak Region Of Serbia, Ian R. Lane, M. V. Stosic, G. Topisirovic, S. Reynolds

IGC Proceedings (1997-2023)

No abstract provided.

Nitrogen Fertilizer Needs Of First-Year Small Grains Following Alfalfa, Collin Pound

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wheat, barley, triticale, and oats, are small grains commonly grown as hay and grain following alfalfa in Utah and the Intermountain West, especially during drought years as they require less irrigation than corn. Several studies in many parts of the world have shown that first-year corn following alfalfa rarely needs nitrogen (N) fertilizer, yet relatively few have evaluated the N needs of small grains, especially small grains grown for hay. Objectives of this research were to determine whether N fertilizer is needed to economically optimize the yield and quality of first-year small grains following alfalfa, develop N guidelines, and whether …

Effect Of Plant Derived Tannins On Nitrogen And Carbon Cycling In Pasture Soils, Kathryn A. Slebodnik

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pasture-finished beef has become increasingly popular, but nitrogen losses from these pastures are of concern. Legumes containing condensed tannins such as birdsfoot trefoil (Lotus corniculatus) and sainfoin (Onobrychis viciifolia) may serve as environmentally and economically viable alternative forages in pasture finishing systems while reducing soil nitrogen loss. The goal of this project was to understand how tannin type and concentration affects soil nitrogen cycling both in the lab and the field. This thesis: 1) compared the physical, chemical, and biological characteristics of soil samples obtained from grazed grass and tannin and non-tannin containing legume pastures, 2) …

Resources Use Efficiency In Tall Fescue And Annual Ryegrass Pastures With Different Nitrogen Nutrition (Humid Pampa, Argentina), Mónica G. Agnusdei, M. A. Marino, F. Lattanz

IGC Proceedings (1997-2023)

No abstract provided.

Nitrogen Cycling In Intensively Grazed Pastures And Practices To Reduce Whole‐Farm Nitrogen Losses, Sterwart F. Ledgard, J. Luo

IGC Proceedings (1997-2023)

No abstract provided.

Pattern Of Nitrogen Integration And Its Ecological Implications In Clonal Plant Zoysia Japonica, Dezhi Li, Changai Wang

IGC Proceedings (1997-2023)

No abstract provided.

Evaluation Of Nitrogen And Phosphorus Removal From A Denitrifyingwoodchip Bioreactor Treatment System Receiving Silage Bunker Runoff, Jillian C. Sarazen, Joshua W. Faulkner, Stephanie E. Hurley

College of Agriculture and Life Sciences Faculty Publications

Leachate and storm-driven runoff from silage storage bunkers can degrade receiving water bodies if left untreated. This study evaluated a novel treatment system consisting of three treatment tanks with a moving-bed biofilm reactor and paired side-by-side denitrifying woodchip bioreactors for the ability to reduce influent nutrient mass loads. Flow-based samples were taken at four locations throughout the system, at the inflow to the first tank, outflow from the tanks prior to entering the woodchip bioreactors, and from the outflows of both bioreactors. Samples were analyzed for concentrations of nitrogen (N) and phosphorus (P) species. Inflow concentrations were reduced from the …

A Study Of The Anthropogenic Impact In Farmington Bay Through Isotopic And Elemental Analysis, Nathan Vaun Gunnell

Theses and Dissertations

The influence of human activity on surrounding environments is an important field of research. With respect to aquatic settings, lacustrine deposits provide excellent proxies of environmental change since the sediment accumulates at a relatively constant rate, recording environmental change. This study employs isotopic, mineral, and chemical records from Farmington Bay freeze cores, in particular δ13C, δ15N, and 210Pb isotopes as well as phosphorus level fluctuation and trace metal analysis. In particular, 210Pb isotopes permit estimation of the age of sediment with depth and δ15N, δ13C, and concentration of P provides a record of changing nutrient sources and level of eutrophication. …

In Situ Plant Uptake Of Excess Nutrients And Consequential Alteration Of Rhizosphere Dynamics, Srusti Maddala

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The use of phytoremediation in ecological remediation projects has numerous benefits including soil stabilization and nutrient uptake. Recently, microdialysis, a diffusion-based sampling technique commonly used in biomedical research, has been recognized as a candidate for monitoring chemical changes in the rhizosphere. The real-time, in situ data it provides about nutrient diffusion may improve the management and success of restoration projects. Therefore, the objective of this study was to employ the technique of microdialysis in the novel application of quantifying the diffusive flux of inorganic nitrogen compounds in the rhizosphere of native plants of Arkansas. The microdialysis technique was first optimized …

Biomass Of Grasses And Other Herbaceous Plants For Bioenergy Use, Žydrė Kadžiulienė, Lina Šarūnaitė, Vita Tilvikienė, Jonas Šlepetys, Zenonas Dabkevičius

IGC Proceedings (1997-2023)

Biomass supply for different uses, especially for bioenergy production, is becoming increasingly important. Independently of the purposes of biomass use, high yields per unit area and best possible quality need to be achieved. As a result, the selection of appropriate plant species is an important aspect. Cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and reed canary grass (Phalaris arundinacea L.) were investigated on a light loam (Cambisol) with a view to assessing the impact of nitrogen (N) and harvest time on biomass yield used for biogas. The biomass yield was influenced by cutting …

Forage Production Potential And Nitrate Nitrogen In Napier Bajra Hybrid As Influenced By Nitrogen Dose Under Shaded And Un-Shaded Environments, U. S. Tiwana, Sukhpreet Singh, Meenakshi Goyal, P. K. Kingra, Awtar Singh

IGC Proceedings (1997-2023)

Dairy farming is an important and prevalent subsidiary occupation along with agriculture in the state of Punjab. But because of declining land holding, the pressure on land is so high that there is little scope of expanding the area under forage crops. Crop intensification either in space (intercropping) or in time (sequential cropping) or both is the feasible option left to the farmers for enhancing the fodder production. The green fodder is deficit by about 25% in the state and there is around 65,000 ha area under Agroforestry. There is a need to explore possibility of growing fodder crops under …

Effect Of Nitrogen And Phosphorus Application On Productivity, Nutrient Uptake And Quality Of Teosinte (Zea Mexicana L.) Fodder, Magan Singh, A. S. Harika, P. S. Oberoi, Rakesh Kumar

IGC Proceedings (1997-2023)

Teosinte (Zea mexicana L.) is popularly known as Makchari being a close relative of maize. It provides succulent, palatable and nutritive fodder during Kharif season for feeding the animals as green fodder or conserved fodder in the form of silage. Teosinte is an excellent multicut fodder which gives high yield of nutritious green lush fodder in 65-70 days with less inputs as compared to maize. Nitrogen is an essential component of proteins, nucleic acid, enzymes, coenzymes, chlorophyll and cell wall. Phosphorus plays a vital role in crop production as it is involved in CO₂ fixation, sugar metabolism, energy …

Field And Numerical Evaluation Of Nitrogen Transport From Septic Systems In Surfical Aquifer Systems To Charlotte Harbor, Florida, Tanten T. Buszka

Masters Theses

Shallow water tables in coastal surficial aquifers limit effective treatment of septic effluent which can result in excess nutrient loading into nearby surface water bodies. Approximately 45,000 septic systems in Charlotte County, Florida transmit effluent into an under studied surficial aquifer and contribute to harmful algal blooms and outbreaks of E. coli. An undeveloped field site was characterized using standard hydrogeologic methods, including a one-year duration natural gradient tracer test, to obtain representative lithology of the sandy surficial aquifer and estimates of groundwater velocity, flow directions, effective porosity and dispersion. These data were used to support the development of a …

Impacts Of Human Recreation On Nutrient Availability And Periphyton Abundance On The Niobrara River, Matthew Chen, Jessica Corman, Sydney Kimnach, Kayla Vondracek

UCARE Research Products

In freshwater ecosystems, eutrophication can create many problems. Excess nutrients, like nitrogen or phosphorus, promote algal or cyanobacterial growth. This growth also leads to increased organic matter production and decomposition, a process that can reduce oxygen concentration in the water. When this happens, species diversity declines, transparency of the water declines, and anoxia may lead to fish kills . Of particular concern is the possibility of cyanobacteria blooms that create compounds toxic for humans. Many of the waters across Nebraska receive excessive nutrients from human activities, largely related to agriculture (Dickey 1982). However, there is one river, the Niobrara River, …

Management Effect On Rainfall Use Efficiency And Growth Rate Of Spineless Cactus Cv. Miúda In Northeast Brazil, Toni Carvalho De Souza, Mércia V. F. Dos Santos, Márcio V. Da Cunha, Felipe M. Saraiva, Alexandre C. L. De Mello, Mário De Andrade Lira, Ivan Ferraz, José C. B. Dubeux Jr.

IGC Proceedings (1997-2023)

Spineless cactus has a high rainfall use efficiency. Under water deficit, they open their stomata during the night to capture atmospheric carbon dioxide when the air temperature is lower and relative humidity higher (Taiz and Zeiger, 2009), losing less water to the atmosphere. The rainfall use efficiency (RUE) can be expressed as the amount of water used by the crop to produce dry matter (Han and Felker, 1997). The RUE showed by spineless cactus, a CAM plant, is three to five times greater than the one observed in C₃ and C₄ plants (Felker and Russel, 1988; Nobel, 1991). …

Tall Fescue (Festuca Arundinacea) Stockpiling Response To N Fertilizer In Southern Virginia As Affected By Biological Soil Quality, Christopher D. Teutsch, Robert Shoemaker, Alan J. Franzluebbers

IGC Proceedings (1997-2023)

Cattlemen in the eastern USA profitably utilize endophyte-infected tall fescue (Festuca arundinacea) for fall-stockpiled winter grazing. Ergot alkaloid concentration in fescue tends to decline in winter. This improves the quality of fescue for grazing when the supply of other forage becomes limited on most farms. Tall fescue dry matter yields generally respond favorably to nitrogen (N) inputs, but response can be limited with summer application due to accumulation of biologically available N in soil. Research is needed to characterize a diversity of pastures for response to N fertilizer during fall stockpiling.

Biological soil quality can be estimated with …

The Design Of A Continuous Wave Molecular Nitrogen Stimulated Raman Laser In The Visible Spectrum, Timothy J. Bate

Theses and Dissertations

Hollow-core photonic crystal fibers (HCPCFs) shows promise as a hybrid laser with higher nonlinear process limits and small beam size over long gain lengths. This work focuses on the design of a CW molecular nitrogen (N₂) stimulated Raman laser. N₂ offers Raman gains scaling up to 900 amg, scaling higher than H₂. The cavity experiment showed the need to include Rayleigh scattering in the high pressure required for N₂ Raman lasing. Even at relatively low pressure ssuch as 1,500 psi, high conversion percentages should be found if the fiber length is chosen based on …