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2024

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Articles 1231 - 1260 of 3173

Full-Text Articles in Earth Sciences

Tectonic Geomorphology Of The South-Eastern Section Of The Burdur-Fethiye Shear Zone, Western Taurides: Morphotectonic Framework Of The Eşen Basin, İrem Eli̇tez, Cenk Yaltirak Jul 2024

Tectonic Geomorphology Of The South-Eastern Section Of The Burdur-Fethiye Shear Zone, Western Taurides: Morphotectonic Framework Of The Eşen Basin, İrem Eli̇tez, Cenk Yaltirak

Turkish Journal of Earth Sciences

The Eşen Basin is a transtensional basin located in the south-eastern section of the Burdur-Fethiye Shear Zone and includes a part of the Western Taurides to the east. This tectonically complex area is bounded by the back-arc region of the Hellenic Arc, the offshore Anaximander Mountains, the offshore Rhodes and Finike basins, the extensional Western Anatolian region, and the compressional regions of the Western Taurides. In this study, in order to characterise the recent tectonic activity of the Eşen Basin, 101 drainage basins and 41 mountain fronts were analysed in terms of the longitudinal river profiles and the application of …

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Eocene Magmatism Related To Postcollisional Extension In The Eastern Pontides (Ne Türkiye): 40ar-39ar Geochronology, Geochemistry, And Whole-Rock Sr-Nd-Pb-Hf Isotopes, Emre Aydinçakir, Cem Yücel, Abdullah Kaygusuz, Özgür Bi̇li̇ci̇, Si̇nan Yilmazer, Gilles Ruffet Jul 2024

Eocene Magmatism Related To Postcollisional Extension In The Eastern Pontides (Ne Türkiye): 40ar-39ar Geochronology, Geochemistry, And Whole-Rock Sr-Nd-Pb-Hf Isotopes, Emre Aydinçakir, Cem Yücel, Abdullah Kaygusuz, Özgür Bi̇li̇ci̇, Si̇nan Yilmazer, Gilles Ruffet

Turkish Journal of Earth Sciences

The mineral chemistry, whole-rock geochemistry, 40Ar / 39Ar dating and Sr-Nd-Pb-Hf isotopes of the Eocene Narman (Erzurum) Volcanic rocks in the southeast of the Eastern Pontides Orogenic Belt (EPOB, NE Türkiye) were investigated. The Narman Volcanites consist of basaltic dyke, basaltic lava, and basaltic volcanic breccia facies. Volcanites contain plagioclase (An34-80), clinopyroxene (Wo38-47En41-50Fs5-18), and olivine (Fo68-90) as phenocrystals with magnetite/titanomagnetite microphenocrysts. New 40Ar-39Ar ages suggest that these volcanic rocks erupted between 44.5 ± 0.1 and 43.4 ± 0.1 Ma, within the Middle Eocene (Lutetian). Narman Volcanites have calc-alkaline character, with medium-high K content. Volcanites are enriched in large ion lithophile …

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Evaluation Of Gis-Based Spatial Interpolation Methods For Groundwater Level: A Case Study Of Türkiye, Ni̇lüfer Ti̇rol Kirçi̇çek, Alper Baba, Ayhan Koçbay, Murat Mert Toklu Jul 2024

Evaluation Of Gis-Based Spatial Interpolation Methods For Groundwater Level: A Case Study Of Türkiye, Ni̇lüfer Ti̇rol Kirçi̇çek, Alper Baba, Ayhan Koçbay, Murat Mert Toklu

Turkish Journal of Earth Sciences

Groundwater is a valuable and universally distributed resource on Earth. Understanding the spatial and temporal dynamics of groundwater is of utmost importance for effective management. Normally, groundwater levels are recorded at arbitrary points, but groundwater modeling requires interpolating the measured values at specific grid nodes. The aim of this study was to identify and evaluate the geographical variations of groundwater levels in Türkiye using three geostatistical interpolation techniques. Data from 355 groundwater wells from 1970 to 2019 were used for this purpose. In addition, an investigation of changes in annual average temperature and precipitation was conducted for two different time …

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Facies Architecture And Depositional Evolution Of The Middle Eocene Mass Flow-Dominated Fan Delta Complex In The Multifeeder Areas: Elazığ Marine Basin (Eastern Türkiye), Onur Alkaç Jul 2024

Facies Architecture And Depositional Evolution Of The Middle Eocene Mass Flow-Dominated Fan Delta Complex In The Multifeeder Areas: Elazığ Marine Basin (Eastern Türkiye), Onur Alkaç

Turkish Journal of Earth Sciences

The mass flow-dominated fan delta complex is developed by the rapid deposition of coarse-grained materials in front of uplifted areas under the influence active tectonism. This is important for providing clues about the first opening stages of marine basins. The study aims to shed light on the fact that mass flow-dominated fan delta complexes play an active role in determining the characterization of tectonism controlling basin opening. In the study area, mass flow-dominated deposits of the Deliktaş Fan Delta Complex (DFDC) represent the first deposits of the southern part of the Middle Eocene Elazığ Marine Basin, whose development is controlled …

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Chemical And Physical Properties Of Fine Fractions From A Village Proximate To A Uranium Mine: Insights About Soil Health, Mary P. Haley Jul 2024

Chemical And Physical Properties Of Fine Fractions From A Village Proximate To A Uranium Mine: Insights About Soil Health, Mary P. Haley

Nanoscience and Microsystems ETDs

Thousands of abandoned uranium mines (AUM) in Native American tribal lands have not been fully remediated, leaving uranium mine wastes exposed and accessible for potential erosion and transport by wind. Analyzing the metal and organic content of the fine-grained fractions in soils could uncover the impact of mine legacy on the soil health in communities that live in proximity to AUM. This study investigates the physical and chemical properties of the fine-grained fraction (μm) of soils to quantify the effect of heavy metal-bearing particulates on the soil health in the village of Paguate and within the Jackpile-Paguate AUM located on …

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Sand, Ice, And X-Rays: Developing Xct Methods For Frozen Samples And Refining Siliciclastic Facies Models For Perennially Ice-Covered Lakes, Utilizing Cores From Lake Fryxell, Mcmurdo Dry Valleys, Antarctica, Holly M. Levett Jul 2024

Sand, Ice, And X-Rays: Developing Xct Methods For Frozen Samples And Refining Siliciclastic Facies Models For Perennially Ice-Covered Lakes, Utilizing Cores From Lake Fryxell, Mcmurdo Dry Valleys, Antarctica, Holly M. Levett

Earth and Planetary Sciences ETDs

Sedimentation in perennially ice-covered lakes (PICLs) is proposed to be bi-modal, with mud deposited by stream inflow and sand deposited on the ice cover by aeolian processes and then melting through by absorption of solar radiation. Here, we consider Lake Fryxell, a PICL in the McMurdo Dry Valleys, and several lake bed cores about 30 cm in length, to better understand PICL facies through time, using micro X-ray CT (XCT). Using XCT images along with sieve and laser granulometry data, we constrained the grain-size of PICL deposits to dominantly medium / fine sand with a coarse component. The presence of …

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Study The Global Earthquake Patterns That Follow The St. Patrick’S Day Geomagnetic Storms Of 2013 And 2015, Dimitar Ouzounov, Galina Khachikyan Jul 2024

Study The Global Earthquake Patterns That Follow The St. Patrick’S Day Geomagnetic Storms Of 2013 And 2015, Dimitar Ouzounov, Galina Khachikyan

Mathematics, Physics, and Computer Science Faculty Articles and Research

A response of global seismic activity to the geomagnetic storms of St. Patrick’s Day (March 17) in 2013 and 2015 is investigated. These two storms occurred during nearly identical storm sudden commencement times and similar solar flux levels. We have revealed a rather similar pattern of the most substantial earthquakes that have occurred since these storms. Two major crust continental earthquakes, in Iran (M = 7.7), 16 April 2013, and in Nepal (M = 7.8), 25 April 2015, have occurred with a time delay of ~30 and ~39 days after geomagnetic storm onsets in 2013 and 2015, respectively. After that, …

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Sampling Potential Hydrologic Impacts From An Underground Fire Lit By The Gray Road Fire, West Medical Lake, Isaac T. Dunmore Jul 2024

Sampling Potential Hydrologic Impacts From An Underground Fire Lit By The Gray Road Fire, West Medical Lake, Isaac T. Dunmore

2024 Symposium

Eastern State Hospital (ESH) dumped and buried construction related material along the south west shores of West Medical Lake. Based on aerial photos from 1957, the dump was established with pine trees growing on the landfill. The dump is approximately 400 feet long, 50 ft wide and about 30 ft deep or about 6000,00 cubic feet of material. On August 18, 2023, during the Gray Road Fire, the buried site was ignited and has since continued to burn underground. Department of Health Services hired a consultant to analyze soils from the dump using the TCLP method for standard RCRA metals …

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Pfas Variation Through A Wastewater Treatment Facility Process, Aaron A. Fuzak, Chad J. Pritchard Jul 2024

Pfas Variation Through A Wastewater Treatment Facility Process, Aaron A. Fuzak, Chad J. Pritchard

2024 Symposium

PFAS concentrations were measured at a wastewater treatment facility to see the effect the treatment process had on PFAS levels. Samples were collected following an initial clarifier, second clarifier, sand filtration system, ultraviolet light purification system, and then from the effluent produced by the facility and analyzed using EPA Method 533. The effluent from the treatment facility flows from a pipe that enters a wetland, where it evaporates or infiltrates the groundwater. Municipal and septic treated systems are considered possible point sources for PFAS contamination in groundwater. Sampling levels of PFAS after treatment will give insight into the concentrations and …

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Historical Structural Analysis Of The Rileyville Quadrangle, Page County, Virginia, Sydney Fergen Jul 2024

Historical Structural Analysis Of The Rileyville Quadrangle, Page County, Virginia, Sydney Fergen

2024 Symposium

The Northwest corner of Virginia, within the Appalachian Mountains, formed during a collision of continents called the Alleghenian Orogeny roughly 250 million years ago(Ma). This event caused tectonic plates to collide, reforming the fractured continental crust back into a new supercontinent, Pangaea. This process took over 100 Ma and closed the Rheic Ocean. These large-scale compressional tectonics had several effects including formation of the Allegheny Plateau and Taconic Mountain range, which has gradually eroded exposing a series of plunging folds and imbricated thrust faults. This poster presents a structural analysis of the Rileyville quadrangle to help decipher regional geologic history …

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U/Pb Zircon Ages Of Saltese Upland Conservation Area, Priest River Core Complex, Jessica M. Lawrence, Natalie Potter, Chad Pritchard Jul 2024

U/Pb Zircon Ages Of Saltese Upland Conservation Area, Priest River Core Complex, Jessica M. Lawrence, Natalie Potter, Chad Pritchard

2024 Symposium

The Saltese Upland Conservation Area provides a window into the Priest River Core Complex with Lake Hauser gneiss grading to migmatite, garnet-baring amphibolite juxtaposed with felsite to orthogneiss rocks. U/Pb ages from LA-ICP-MS of separated zircon grains show trends very similar to detrital 207Pb/206Pb ages of the Belt Supergroup. The amphibolite displays a much stronger peak at 1.4 to 1.5 Ga , possibly related to the emplacement of Mesoproterozoic dikes. The amphibolite and granitic rocks also contain a number of grains with 238U/206Pb around 60 Ma preserving events from the uplift of the Priest River Complex in the Spokane area. …

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Paleohydraulic Analysis Of Megaripples From Outburst Floods In Omak, Washington, Jessica M. Lawrence Jul 2024

Paleohydraulic Analysis Of Megaripples From Outburst Floods In Omak, Washington, Jessica M. Lawrence

2024 Symposium

Located in Omak, Washington atop what is observed to be a gravel point bar are giant current ripples associated with outburst floods that took place during the Pleistocene (O’Connor et al. 2020 and Minard 1985). Thorough breakdown of these giant current ripples was conducted using their geomorphologies associated with stream flow mechanisms for gravel bedforms such as hydraulic radius of cross- sectional area and velocity using Manning’s equation to determine Froude’s Number (USDA 2007). Ripple index associated with ripple wavelength and height was then compared to additional megaripples located throughout Scablands of Washington that have been correlated to the Great …

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Geotechnical Analysis Of Soil Sample Pp-7 From The Ewu Palouse Prairie Restoration Site, Cheney, Wa, Jessica M. Lawrence, Sydney Fergen, Kai L. Valentine, Annika Smith Jul 2024

Geotechnical Analysis Of Soil Sample Pp-7 From The Ewu Palouse Prairie Restoration Site, Cheney, Wa, Jessica M. Lawrence, Sydney Fergen, Kai L. Valentine, Annika Smith

2024 Symposium

The Eastern Washington University Palouse Prairie Restoration Project is a program set to restore 120 acres of Palouse prairie back to its native habitat. The land is currently leased as a no till annual wheat field. The soil lies atop Pleistocene loess from the Cordilleran Ice Sheet and glaciofluvial deposits from the Great Missoula Floods. There were 9 different soil samples collected from the Palouse prairie restoration project area. Group 7 analyzed soil sample PP-7 collected at 47.492747°N, -117.593442°W, on September 21st, 2023, and over 10 weeks, tested the specific gravity (ASTM D854), particle size distribution (ASTM D422, D7928), soil …

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A Seasonal Decomposition Comparison Between Forest And Turf Habitats: Implications For Climate Change, Amanda Shirmer Jul 2024

A Seasonal Decomposition Comparison Between Forest And Turf Habitats: Implications For Climate Change, Amanda Shirmer

DePaul Discoveries

Decomposition is an essential ecosystem service in which microorganisms breakdown organic matter. This process improves soil health and acts as a vital step in global carbon cycles. In this study, we examined decomposition rates and associated soil properties in turf and forest habitats across summer and fall seasons in order to determine how land management practices and climate change may be altering local decomposition regimes. Our study determined that there was a statistically significant difference between decomposition rates in turf and forest ecosystems (P=0.003) and a significant difference in decomposition rate across season (P

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Gnss And Insar Observations Of Vertical Motion In The Valles Caldera, Nm, Savannah Chase Devine Jul 2024

Gnss And Insar Observations Of Vertical Motion In The Valles Caldera, Nm, Savannah Chase Devine

Earth and Planetary Sciences ETDs

The Valles caldera is a rhyolitic “supervolcano” formed 1.231 Ma. An understanding of whether Valles caldera is currently deforming is needed to inform volcanic hazard estimates for northern New Mexico and will allow for a better understanding of the hazards presented by other rhyolitic caldera systems. Here, we present an InSAR time series of the Valles Caldera using 37 interferograms, spanning 2014 to 2022, which show a small but consistent signal of broad pattern subsidence/yr. We also present GNSS observations from a survey conducted in October 2022 and compare the results to surveys in 2002 and 2003 to estimate the …

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Data Requirements For Whole-Farm Economic Analysis Of Grazing Alternatives, R O. Burton Jr Jul 2024

Data Requirements For Whole-Farm Economic Analysis Of Grazing Alternatives, R O. Burton Jr

IGC Proceedings (1977-2023)

The purpose of this paper is to contribute to better communications among the agronomists, animal scientists, and agricultural economists on interdisciplinary teams, that wish to provide useful information to forage producers. This is accomplished by discussing major issues and data requirements for whole-farm economic analysis.

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Native Grasslands Of Yugoslavia As A Potential For "Biologically High Quality Food" Production - To Be Preserved And Used For The Benefit Of All, Djordjevic-Milosevic Suzana, Negovanovic Dragan, Zakonovic Miodrag Jul 2024

Native Grasslands Of Yugoslavia As A Potential For "Biologically High Quality Food" Production - To Be Preserved And Used For The Benefit Of All, Djordjevic-Milosevic Suzana, Negovanovic Dragan, Zakonovic Miodrag

IGC Proceedings (1977-2023)

Natural grasslands are the base of the livestock production in the hilly-mountainous regions of Yugoslavia. Poor economic power of the owners of these areas brought about a complete dying out of agricultural production in these regions in the last few years. In the same time, the lack of financial resources made it impossible for the farmers to use the fertilisers, protective and other chemical agents which result in a high degree of environmental preservation. Due to current economic policy at this time the population has moved out and there is no industrialisation. The revival of agriculture on the hilly-mountainous regions …

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Some Economics Problems Of Range Resource Analysis In Free And Open Access Environment, E Tedonkeng Pamo Jul 2024

Some Economics Problems Of Range Resource Analysis In Free And Open Access Environment, E Tedonkeng Pamo

IGC Proceedings (1977-2023)

Economic analysis has been the traditional means by which the costs and benefits of rangeland conservation and sustained development have been identified. Conventional analysis has proved inadequate for dealing with the following realities : (1) open access in circumstances of poorly defined common-resource ownership tends to encourage over exploitation; (2) many costs of rangeland degradation involve externalities that will occur in the future; (3) the values of preservation and sustained management are substantial and can be translated into financial assistance; and (4) benefits from rangeland are not often appreciated because of lack of knowledge from rangeland. Recent approaches to economic …

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Studies On The Distribution And Formation Of The Meadows In China, Feng Guojun, Zhang Xiujun, Zhu Libuo, Wei Shaocheng, Zhang Yongliang Jul 2024

Studies On The Distribution And Formation Of The Meadows In China, Feng Guojun, Zhang Xiujun, Zhu Libuo, Wei Shaocheng, Zhang Yongliang

IGC Proceedings (1977-2023)

The lowland meadows are distributed on the Northeast Plains in the temperate zone in China, and its area became less and less with an increase of longitude. There are some regularities for the distribution of montane meadows, sub-montane meadows and cold-alpinal meadows. And the distribution and formation for meadows are independent upon the zonal climate and their environmental soil moisture.

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Sward Structure Under Continuous And Rotation Grazing, V Pavlu, J Velich Jul 2024

Sward Structure Under Continuous And Rotation Grazing, V Pavlu, J Velich

IGC Proceedings (1977-2023)

Sward structure under continuous (CG) and rotational (RG) grazing system was studied at an experimental pasture in the Jizerské hory mountains. Herbage mass and vertical distribution was assessed by cutting ten quadrats (0.1 x 0.5 m) and separated into grass, white clover, dandelion, other forbs and dead material. The proportions of grasses was higher at RG (on average 51% of the pasture mass) than at CG (41%). In the years with normal amount and distribution of precipitation the proportion of white clover was higher at CG (17%) than at RG (9%). The lack of summer precipitation damaged more significantly the …

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Beef Cattle Production On Renovated Grass Pastures In Savannas Of Brazil, V.P B. Euclides, M.C M. Macedo, M P. Oliveira Jul 2024

Beef Cattle Production On Renovated Grass Pastures In Savannas Of Brazil, V.P B. Euclides, M.C M. Macedo, M P. Oliveira

IGC Proceedings (1977-2023)

A 3-year grazing trial was conducted, to study animal production on degraded grass pastures, renovated by two levels of fertilization. All paddocks were divided into halves: one received 1.5 t/ha of dolomitic limestone, 400 kg/ha of a fertilizer formula 0-16-18 and 50 kg/ha of microelements (FL1); and the other 3.0 t/ha , 800 kg/ha and 50 kg/ ha of the same fertilizers (FL2). Productivity on FL2 pastures was greater than that on FL1 pastures, averaging 565 and 395 kg of liveweight gain (LWG)/ha/year, respectively. For all grasses the productivity in both fertilizer treatments decreased linearly from the first to the …

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Pasture Attributes And Live-Weight Gain Of Lambs Grazing With Different Supplementation Levels, P A. Martinez-Hernandez, M Meza-Nieto, J Perez-Perez, R Barcena, J G. Herrera Jul 2024

Pasture Attributes And Live-Weight Gain Of Lambs Grazing With Different Supplementation Levels, P A. Martinez-Hernandez, M Meza-Nieto, J Perez-Perez, R Barcena, J G. Herrera

IGC Proceedings (1977-2023)

The purpose of this study was to determine pasture attributes, liveweight gain and stocking rate from a mixed pasture grazed by lambs recieving different supplementation levels. There were four treatments: in two, lambs grazed at 4 or 8% herbage allowance, no supplement; in the other two, lambs grazed at 4% herbage allowance plus a concentrate to cover 25 and 30 or 50 and 60% of estimated daily needs of metabolizable energy and crude protein. Pasture was of perennial and annual ryegrass, orchard grass and red clover. Pre and postgrazing forage mass, crude protein and dead material were not different (P …

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Characteristics Of Grass Species In Pasture For High Producing Cows In Northern Japan, K Sudo, K Ochiai, T Ikeda Jul 2024

Characteristics Of Grass Species In Pasture For High Producing Cows In Northern Japan, K Sudo, K Ochiai, T Ikeda

IGC Proceedings (1977-2023)

The prupose of this research was to investigate characteristics of grass species under different conditions appropriate to the intensive grazing system for high producing cows (8000 kg for a 305-day lactation) in northern Japan. Meadow fescue (Festuca elatior L.), timothy (Phleum pratense L.) and perennial ryegrass (Lolium perene L.) white clover (Trifolium repens L.) pastures were established and divided into two plots by difference of regulated plant height (meadow fescue and timothy) or of stocking intensity (perennial ryegrass). Each plot was 60m2 and was grazed when plant height reached 20cm or 30cm. Meadow fescue and perennial …

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Agenda De Investigación Para El Manejo Sustentable Del Manglar En Tamaulipas, México [Research Agenda For The Sustainable Management Of Mangroves In Tamaulipas, Mexico], Carlos Zamora-Tovar, Alejandro Fierro-Cabo, Glenda Nelly Requena-Lara Jul 2024

Agenda De Investigación Para El Manejo Sustentable Del Manglar En Tamaulipas, México [Research Agenda For The Sustainable Management Of Mangroves In Tamaulipas, Mexico], Carlos Zamora-Tovar, Alejandro Fierro-Cabo, Glenda Nelly Requena-Lara

School of Earth, Environmental, & Marine Sciences Faculty Publications

Se presenta un análisis de la información ecológica disponible sobre los manglares de Tamaulipas, México. El objetivo fue establecer una línea base de conocimiento que defina el estado del arte a partir de la información publicada; actualizar la estructura forestal con datos propios observados en el año 2018; y determinar una agenda de investigación prioritaria para el manejo sostenible del ecosistema de man-glar, ecosistema de vital importancia por la gran variedad de recursos y servicios ambientales que aporta a la sociedad. La investigación bibliográfica recopiló 32 trabajos relevantes: 16 publicaciones formales, siete ediciones institucionales y nueve consideradas literaturas gris; recopilación …

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Preliminary Analysis Of Per-And Polyfluoroalkyl Substances (Pfas) In Surface Waters Of The West Plains Region Of Spokane County, Jerusha Hampson Jul 2024

Preliminary Analysis Of Per-And Polyfluoroalkyl Substances (Pfas) In Surface Waters Of The West Plains Region Of Spokane County, Jerusha Hampson

2024 Symposium

Per-and Polyfluoroalkyl Substances (PFAS) have become a national issue as regulatory limits for these toxins have just recently been put into the Clean Water Act. The West Plains has been significantly impacted by PFAS contamination due to the decades-long use of aqueous film-forming foam (AFFF) for firefighting training at both Fairchild Airforce Base and the Spokane International Airport. Though research is still underway, it is known that PFAS contamination in West Plains groundwater is significant and widespread. This study focuses on West Plains surface waters, as there is currently less information about how these water bodies are impacted by PFAS. …

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Live-Weight Gain Of Steers Grazing African Star Grass Four Herbage Allowances, J Perez-Perez, J O. Hernandez-Velez, J G. Herrera-Haro, R Barcena-Gama Jul 2024

Live-Weight Gain Of Steers Grazing African Star Grass Four Herbage Allowances, J Perez-Perez, J O. Hernandez-Velez, J G. Herrera-Haro, R Barcena-Gama

IGC Proceedings (1977-2023)

The objective was to determine weight changes of steers grazing African star grass (Cynodon plectostachyus) at four herbage allowances (2.0, 2.5, 3.0 and 3.5 kg of dry matter/100 kg of live weight day-1). A rotational grazing system with 10 grazing days and 30 days rest was followed. A Split Plot Design with four replications was used. Response variables were: daily gain per steer (DGS) and per hectare (DGH), dry matter forage yield (FY), % of utilization (% U) and in vitro dry matter digestibility (DMIVD). DGS and DGH were not different (P >0.05) among allowances and grazing periods. …

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Strategic Use Of Brachiaria Decumbens Pasture To Beef Heifers During Dry Season, E G. Cardoso, N F. Seiffert, J Marques Da Silva, V.P. B. Euclides, J M. Vieira Jul 2024

Strategic Use Of Brachiaria Decumbens Pasture To Beef Heifers During Dry Season, E G. Cardoso, N F. Seiffert, J Marques Da Silva, V.P. B. Euclides, J M. Vieira

IGC Proceedings (1977-2023)

The main objective of this study was to evaluate a Brachiaria decumbens pasture, instead of a common rangeland, for zebu beef heifers during the dry season of the year as a means of anticipating the first calving age from four to three years of age, and so improve the production rate of the herd. Daily liveweight gains (DLWG) were analyzed for the effects of year and three stocking rates during the dry season (SR1=1.5; SR2=2.0 and SR3=2.5 head/ha). The main effect on heifers DLWG was the year (P<0.01), but SR was also important (P<0.05), mainly during the last half of the dry season when pastures are under severe constraints such as soil moisture deficit and low temperatures. The lowest SR presented the highest DLWG (0.204a, 0.174ab and 0.145b kg/head, respectively for SR1, SR2 and SR3), during the dry season. If climatic conditions are not exceptionally bad, heifer first calving occurs at 37 months of age when reared on B. decumbens.

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Quality Grassland For Dairy Production In North-West Spain, A Gonzalez-Rodriguez Jul 2024

Quality Grassland For Dairy Production In North-West Spain, A Gonzalez-Rodriguez

IGC Proceedings (1977-2023)

An experiment with two groups of 15 Friesian cows grazing independent areas, with no N and 240 kg N ha-1, was run during two years to see the levels of milk production based on a grass/white clover pasture, maintaining high levels of herbage quality. N application decrease clover content from 55% to 42%. The total DM response to N was low. Herbage utilization was maintained similar in both treatments. Moderate levels of milk production can be reached, more than 4000 litres cow-1 and 9000 litres ha-1, with low use of concentrates, only 400 kg cow-1. Crude protein levels were high …

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Sward Height On The Performance Of Cow-Calf Units And Yearling Steers Grazing Cool Season Pasture, E C. Prigge, W B. Bryan, E L. Nestor Jul 2024

Sward Height On The Performance Of Cow-Calf Units And Yearling Steers Grazing Cool Season Pasture, E C. Prigge, W B. Bryan, E L. Nestor

IGC Proceedings (1977-2023)

Performance and grazing time of cow-calf units and yearling steers were determined over four years on naturalized cool season pastures maintained at a sward height of 4-6, 6-8, 8-10, or 10-12 cm. Daily gains of cows and steers responded quadratically (P<0.05) to increasing sward heights, with gains maximized at 8-10 cm. Milk production of the cows and gain of the calves were not affected (P>0.10) by sward height. Grazing days (cow-calf unit/hectare) decreased linearly (P<0.01) with increasing sward height. The proportion of the day spent grazing for cows and steers decreased in a linear manner (P<0.05) as pasture height increased. Cows spent less time grazing than steers (P<0.05) at all but the low pasture height.

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Buffer Grazing For A Twelve Month Cow-Calf Production System, W B. Bryan, E C. Prigge, D J. Flaherty, G E. D'Souza Jul 2024

Buffer Grazing For A Twelve Month Cow-Calf Production System, W B. Bryan, E C. Prigge, D J. Flaherty, G E. D'Souza

IGC Proceedings (1977-2023)

Set stocking is a widely used grazing management for beef cow-calf production on Appalachian hill land pastures of the USA. A replicated study was conducted to compare a conventional (set stocking) and buffer grazing management. For the buffer system, grazing area was restricted in the spring and hay was harvested from the ungrazed area. In summer, a portion of this area (buffer) was grazed and a second cutting of hay removed from the remaining area. For the conventional treatment a fixed area was set stocked and hay was harvested on an area designated for hay only. Land areas and fertilizer …

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