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2021

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Articles 91 - 120 of 16206

Full-Text Articles in Earth Sciences

Linking Migration To Community Resilience In The Receiving Basin Of A Large-Scale Water Transfer Project, Anna Erwin, Zhao Ma, Ruxandra Popovici, Emma Patricia Salas O’Brien, Laura Zanotti, Chelsea A. Silva, Eliseo Zeballos Zeballos, Jonathan Bauchet, Nelly Ramírez Calderón, Glenn Roberto Arce Larreah Dec 2021

Linking Migration To Community Resilience In The Receiving Basin Of A Large-Scale Water Transfer Project, Anna Erwin, Zhao Ma, Ruxandra Popovici, Emma Patricia Salas O’Brien, Laura Zanotti, Chelsea A. Silva, Eliseo Zeballos Zeballos, Jonathan Bauchet, Nelly Ramírez Calderón, Glenn Roberto Arce Larreah

School of Earth, Environmental, & Marine Sciences Faculty Publications

Large-scale water transfer projects (LWTPs) transfer water to urban and agricultural areas. The Majes-Siguas canal, established in 1983, is an LWTP that created a thriving agricultural area through irrigating the Majes district in the Atacama Desert of Peru. Like other LWTP receiving basins, the project has attracted an influx of migrants who work on the farms. At the same time, the Majes LWTP is the district’s only source of water and has an aging infrastructure which presents significant risks. While many studies critically analyze the consequences of LWTPs in water supply basins, few evaluate the resilience of communities living in …


Progressive Destabilization And Triggering Mechanism Analysis Using Multiple Data For Chamoli Rockslide Of 7 February 2021, Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li Dec 2021

Progressive Destabilization And Triggering Mechanism Analysis Using Multiple Data For Chamoli Rockslide Of 7 February 2021, Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A catastrophic rockslide occurred on 7 February 2021 in Chamoli area in the high Himalaya. In the absence of field data, multiple satellites data of decade span have been used to investigate and understand the progressive destabilization of rockslide body. A 3D geometric model was developed using geospatial information about geology, terrain, and ice cover to understand the triggering mechanism. Several causes are uncovered as: the pronounced long-term change of land surface temperature facilitated local permafrost degradation and led to ice cover shrinking since 2010; the occurrence of ice avalanche nearby in 2016 accompanying with sidewall-to-bedrock fracturing enhanced the ice …


Sheep Performance In Italian Ryegrass Swards At Contrasting Sward Heights, Paulo C. De F. Carvalho, L. S. Pontes, E. O. Silveira, C. H. E. C. Poli, Carlos Nabinger, O. A. Pereira Neto, G. E. Maraschin Dec 2021

Sheep Performance In Italian Ryegrass Swards At Contrasting Sward Heights, Paulo C. De F. Carvalho, L. S. Pontes, E. O. Silveira, C. H. E. C. Poli, Carlos Nabinger, O. A. Pereira Neto, G. E. Maraschin

IGC Proceedings (1977-2023)

The objective of this study was to assess the effect of Italian ryegrass (Lolium multiflorum Lam.) sward height on lamb performance. The experiment was carried out at the Research Station of UFRGS, Eldorado do Sul, Brazil. Yearling no-castrated male lambs were assessed in terms of individual animal performance and gain per hectare. The experiment was carried out in a randomised block design with three replications of four treatments: 5, 10, 15 and 20 cm of sward surface height (SSH), which were maintained using continuous variable stocking, and monitored by a sward stick. Samples of 0.25 m2 were cut …


Animal Performance In Pastures Of Panicum Maximum Cv. Ipr 86 Fertilized With Nitrogen, S. M. B. Lugão, L. R. De A. Rodrigues, E. B. Malheiros, J. J. Dos S. Abrahão, A. De Morais Dec 2021

Animal Performance In Pastures Of Panicum Maximum Cv. Ipr 86 Fertilized With Nitrogen, S. M. B. Lugão, L. R. De A. Rodrigues, E. B. Malheiros, J. J. Dos S. Abrahão, A. De Morais

IGC Proceedings (1977-2023)

The experiment was carried out at the Experimental Station of the IAPAR in Paranavaí– PR, Brazil, from October 1998 to May 1999 to evaluate the response of crossbred steers grazing pastures of Panicum maximum cv. IPR 86 fertilized with four doses of N (0; 150; 300 and 450 kg.ha-1.year). The grass was grazed according to a rotational grazing system with grazing cycles (GCs) of 40 days (grazing period of 5 days and rest period of 35 days). It was used a randomized complete block design, with split-plots, and two replications per treatment, being the N-doses studied in the …


Dairy Cow Performance On Pasture-Based Feeding Systems And In Confinement, Renato S. Fontaneli, Lynn E. Sollenberger, C. R. Staples Dec 2021

Dairy Cow Performance On Pasture-Based Feeding Systems And In Confinement, Renato S. Fontaneli, Lynn E. Sollenberger, C. R. Staples

IGC Proceedings (1977-2023)

Interest in grazing systems is growing among farmers in the USA as a means of reducing feed costs for lactating dairy cows. An experiment was conducted near Gainesville, FL to compare milk production and composition and milk income minus feed costs from two pasture-based systems with those of a conventional confinement housing system over a 276-d period. System 1 was based on a mixture of rye (Secale cereale L.), annual ryegrass (Lolium multiflorum Lam.), crimson clover (Trifolium incarnatum L.), and red clover (Trifolium pratense L.) during the winter-spring seasons and pearl millet (Pennisetum glaucum [L.] …


Weather And Climate Research At The Kentucky Climate Center Based On Mesonet Observations, Brittany Pekara, Eric Rappin Dec 2021

Weather And Climate Research At The Kentucky Climate Center Based On Mesonet Observations, Brittany Pekara, Eric Rappin

Posters-at-the-Capitol

The Kentucky Mesonet is a great asset for the Commonwealth of Kentucky in a multitude of ways, from real-time storm monitoring to building a detailed climate record. A detailed climate record is essential as causality between observations and extreme weather can be identified, making it a great tool in an evolving climate system. The climate record being developed at the 75+ Kentucky Mesonet observation stations consists of approximately 75 indices that reflect frequency, extremes, range, duration, trends of precipitation, droughts, and extreme temperatures. Calculations are done for daily, weekly, monthly, seasonal, bi-annual, and annual aggregation periods. Tools will also be …


Characterization And Interpretation Of Feldspathic Chromite Assemblages (Fcas) In Four Ordinary Chondrites: An Electron Backscatter Diffraction (Ebsd) Study, Kimberly Louisa Maccini Dec 2021

Characterization And Interpretation Of Feldspathic Chromite Assemblages (Fcas) In Four Ordinary Chondrites: An Electron Backscatter Diffraction (Ebsd) Study, Kimberly Louisa Maccini

Dissertations and Theses

Feldspathic Chromite Assemblages (FCAs) are chemically distinctive assemblages rich in Na, Al, and Cr that are found in a variety of chondrites. They consist of concentrations of chromite associated mainly with feldspathic material, either feldspar or the glassy material known as maskelynite. Professor Alan Rubin (2003) has proposed that some FCAs formed by shock melting, but the origin of different types of feldspathic chromite assemblages are unclear and have not been studied with more modern techniques such as Electron Backscatter Electron Diffraction (EBSD).

Here EBSD was used to study FCAs in four metamorphosed ordinary chondrites of different shock stages, including …


Cuny York College–Hosted Nasa Stem Outreach Program Graduates Over 30,000 Students – The Legacy Continues Amidst The Covid-19 Pandemic, Nazrul I. Khandaker Dec 2021

Cuny York College–Hosted Nasa Stem Outreach Program Graduates Over 30,000 Students – The Legacy Continues Amidst The Covid-19 Pandemic, Nazrul I. Khandaker

Publications and Research

The NASA MUREP (Minority University Research and Education Project) and SEMAA (Science, Engineering, Mathematics and Aerospace Academy) at York College CUNY (City University of New York), borough of Queens, New York City, recently earned a distinction by graduating over 30,000 underrepresented minority students since 1999 with the culmination of the fall 2021 session! African American students are leading the graduates, followed by Hispanic and Asian students being almost equal in proportion. The primary objective of both MAA (MUREP Aerospace Academy) and SEMAA is getting underrepresented minority students exposure to innovative STEM content and prepare many of them to enter higher …


2021 Grand River Water Quality, Allison Romanski, Madeleine Lang Dec 2021

2021 Grand River Water Quality, Allison Romanski, Madeleine Lang

Student Summer Scholars Manuscripts

2021 Grand River Water Quality Sampling

The goals of this research project were to collect repeat samples at designated reaches and under different flow conditions along the Grand River, sample the entire Grand River over a short period of time, collaborate with wastewater treatment plant labs and technicians to analyze water samples, and to calculate a Water Quality Index (WQI) for samples collected.

Seven different reaches were sampled and over 120 samples were collected between May 7th and August 12th of 2021. Water samples were collected and analyzed for nitrate, total phosphate, ammonium, chloride, dissolved oxygen, biological oxygen demand , …


Principal Component Analysis In Paspalum Germplasm Characterization, A. Regitano Neto, L. A. R. Batista Dec 2021

Principal Component Analysis In Paspalum Germplasm Characterization, A. Regitano Neto, L. A. R. Batista

IGC Proceedings (1977-2023)

In a survey, through principal component analyses, for the most representative descriptors to be used in Paspalum germplasm characterization, 16 agronomic traits, 16 reproductive traits and 21 vegetative traits were evaluated in 32 accessions comprising Paspalum plicatulum (19) and Paspalum compressifolium (13) from the institutional germplasm collection. ANOVA for agronomic descriptors showed significant differences among accessions, except for percentage of dry matter in winter (DMW) which was not significant. Principal component analyses allowed reduction of 69%, 69% and 62%, respectively, in the initial number of descriptors, and the election of the most important for agronomic traits: DMYS, DMYW, RGS, CPPW …


Production And Quality Of Paspalum Forage In State Of São Paulo, L. A. R. Batista, A. Regitano Neto, Rodolfo Godoy Dec 2021

Production And Quality Of Paspalum Forage In State Of São Paulo, L. A. R. Batista, A. Regitano Neto, Rodolfo Godoy

IGC Proceedings (1977-2023)

Biomass produced by accessions of 26 species, belonging to 12 botanical groups of the genus Paspalum, collected in the south and central regions of Brazil, were evaluated during the first year of establishment for quantitative characteristics: production of dry biomass (DMY), percentage of dry matter (PDM) and regrowth score and qualitative traits: concentration of neutral detergent fiber (NDF), “in vitro” dry matter digestibility (IVDMD) and crude protein percentage in dry matter (CPPDM) -, in the central area of the state of São Paulo, in a completely randomized block design with two replications. The largest averages of DMY were obtained …


Study Of The Diversity Of Soil Animals Community In The Songnen Plain Grassland Of China, Xiuqin Yin, Tingcheng Zhu Dec 2021

Study Of The Diversity Of Soil Animals Community In The Songnen Plain Grassland Of China, Xiuqin Yin, Tingcheng Zhu

IGC Proceedings (1977-2023)

This paper dealt with the diversity in eight habitat soil animals communities in Songnen plain grassland. The results showed the better habitat condition the higher diversity index of soil animals, and vice-versa. The diversity of soil animals communities correlated positively with soil organic matter, total nitrogen, and negatively with soil pH; there was a poor correlation with soil water content and total soil phosphorus. The diversity of soil animals communities decreased with increasing depth of soil layer and has surface-collection.


Evaluating Varieties Of Alfalfa And Tall Fescue For Tolerance To Over-Grazing By Cattle, Robert F. Spitaleri, Jimmy C. Henning, Charles T. Dougherty, Garry D. Lacefield, B. T. Larson Dec 2021

Evaluating Varieties Of Alfalfa And Tall Fescue For Tolerance To Over-Grazing By Cattle, Robert F. Spitaleri, Jimmy C. Henning, Charles T. Dougherty, Garry D. Lacefield, B. T. Larson

IGC Proceedings (1977-2023)

Cultivars of alfalfa (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb.) were seeded in small (1.5 m x 4.6 m) plots and harvested for estimating yield the following spring. Plots were then grazed by cattle continuously for the remainder of the season so as to keep stand heights at 7.5 cm or less. This procedure was repeated for one or two more grazing seasons, depending on stand survival. Stands were visually rated for stand in the fall and spring. Marked differences in grazing tolerance were observed among alfalfa cultivars, following closely the commercial designations as grazing-type or …


The Role Of Cattle Dung In Seed Dispersal Of Major Species In A Zoysia Japonica Pasture In Japan, K. Shimoda, S. Sakanoue Dec 2021

The Role Of Cattle Dung In Seed Dispersal Of Major Species In A Zoysia Japonica Pasture In Japan, K. Shimoda, S. Sakanoue

IGC Proceedings (1977-2023)

To evaluate the role of cattle dung in seed dispersal of major species in Zoysia japonica pasture in Japan, we investigated the species composition and density of seeds in cattle dung by means of a germination test. Of 20 major species which had a mean coverage of more than 0.1%, 90% were detected as seeds in cattle dung. In addition, the species composition and density of seeds in cattle dung differed among three sampling seasons. Seeds of the six most prevalent species in terms of coverage were detected from cattle dung during the growing season. Hence, we conclude that it …


Geochemical And Sensor-Based Monitoring Of Fault-Associated Carbonic Springs In Grand Canyon And Northern New Mexico: Identifying Hydrologic Pathways And Establishing Baselines, Chris Mcgibbon Dec 2021

Geochemical And Sensor-Based Monitoring Of Fault-Associated Carbonic Springs In Grand Canyon And Northern New Mexico: Identifying Hydrologic Pathways And Establishing Baselines, Chris Mcgibbon

Earth and Planetary Sciences ETDs

This dissertation examines the interaction of spring systems and faulting. When springs discharge within a fault zone the interaction is often complex, and multiple methods are required to understand the flow, mixing and evolution of groundwater. In karst aquifer systems fracture networks can range from sub-millimeter to meters and only adds to the complexities involved in examining spring hydrology. The Interest in springs and faulting is not only driven by science, but also has applied applications. Faulting and fluid flow are of interest to the oil and gas industry, and potential CO2 sequestration. In the southwestern US, water quantity …


Stimulation Of Ammonia Oxidizer And Denitrifier Abundances By Nitrogen Loading: Poor Predictability For Increased Soil N2o Emission, Yong Zhang, Feng Zhang, Diego Abalos, Yiqi Luo, Dafeng Hui, Bruce A. Hungate, Pablo García-Palacios, Yakov Kuzyakov, Jørgen Eivind Olesen, Uffe Jørgensen, Ji Chen Dec 2021

Stimulation Of Ammonia Oxidizer And Denitrifier Abundances By Nitrogen Loading: Poor Predictability For Increased Soil N2o Emission, Yong Zhang, Feng Zhang, Diego Abalos, Yiqi Luo, Dafeng Hui, Bruce A. Hungate, Pablo García-Palacios, Yakov Kuzyakov, Jørgen Eivind Olesen, Uffe Jørgensen, Ji Chen

Biology Faculty Research

Unprecedented nitrogen (N) inputs into terrestrial ecosystems have profoundly altered soil N cycling. Ammonia oxidizers and denitrifiers are the main producers of nitrous oxide (N2O), but it remains unclear how ammonia oxidizer and denitrifier abundances will respond to N loading and whether their responses can predict N-induced changes in soil N2O emission. By synthesizing 101 field studies worldwide, we showed that N loading significantly increased ammonia oxidizer abundance by 107% and denitrifier abundance by 45%. The increases in both ammonia oxidizer and denitrifier abundances were primarily explained by N loading form, and more specifically, organic N …


Primary Versus Secondary Gravity Wave Responses At F-Region Heights Generated By A Convective Source, C. J. Heale, P. A. Inchin, J. B. Snively Dec 2021

Primary Versus Secondary Gravity Wave Responses At F-Region Heights Generated By A Convective Source, C. J. Heale, P. A. Inchin, J. B. Snively

Publications

A 2D nonlinear, compressible model is used to simulate the acoustic-gravity wave (AGW, i.e., encompassing the spectrum of acoustic and gravity waves) response to a thunderstorm squall-line type source. We investigate the primary and secondary neutral AGW response in the thermosphere, consistent with waves that can couple to the F-region ionospheric plasma, and manifest as Traveling Ionospheric Disturbances (TIDs). We find that primary waves at z = 240 km altitude have wavelengths and phase speeds in the range 170–270 km, and 180–320 m/s, respectively. The secondary waves generated have wavelengths ranging from ∼100 to 600 km, and phase speeds from …


Soil Moisture Dependent Runoff In A Dryland Region: An Investigation Of The Role Of Antecedent Conditions, Monitoring, And Modeling Strategies, Gerhard Schoener Dec 2021

Soil Moisture Dependent Runoff In A Dryland Region: An Investigation Of The Role Of Antecedent Conditions, Monitoring, And Modeling Strategies, Gerhard Schoener

Civil Engineering ETDs

Approximately 30% of the Earth’s land surface is characterized as arid or semiarid, including much of the western United States. Accurate runoff predictions are important for informed watershed management, particularly in rapidly urbanizing areas. Infiltration excess overland flow is the dominant mechanism for runoff generation in many dryland basins, and event-based infiltration or loss models are commonly used to estimate runoff. However, predictions are associated with considerable uncertainty due to the role antecedent soil moisture, an initial condition that must be set by the modeler. The objectives of my research were to (1) evaluate the impact of antecedent soil moisture …


Biodiversity And Spatial Heterogeneity In Semi-Natural Grasslands In A Mountain Area In Slovakia, Masae Shiyomi, N. Gáborèík, H. Koizumi, A. Javorkova, E. Uhliarova, O. Jezikova Dec 2021

Biodiversity And Spatial Heterogeneity In Semi-Natural Grasslands In A Mountain Area In Slovakia, Masae Shiyomi, N. Gáborèík, H. Koizumi, A. Javorkova, E. Uhliarova, O. Jezikova

IGC Proceedings (1977-2023)

The spatial pattern of vegetation in the following 3 semi-natural grasslands in Banska Bystrica, Slovakia, was observed in August, 1998: (1) a grassland sown with improved herbage plants after plowing in 1991, (2) a grassland oversown with improved herbage plants in 1991, and (3) a natural grassland without any treatment at the time of establishment. A new method of measuring vegetation was adopted: in each grassland, 50 quadrats 50 cm × 50 cm, composed of 4 smaller cells 25 cm × 25 cm, were set up, and all the species in each cell were recorded. The sown grassland displayed the …


Optimum Area Of Semi-Natural Grassland To Maintain Maximum Butterfly And Avian Species Richness In Japan, A. Shoji, K. Kohyama, H. Sasaki Dec 2021

Optimum Area Of Semi-Natural Grassland To Maintain Maximum Butterfly And Avian Species Richness In Japan, A. Shoji, K. Kohyama, H. Sasaki

IGC Proceedings (1977-2023)

To evaluate the optimum area of semi-natural grassland to maintain maximum butterfly and avian species richness in Japan, digitalized grid data of butterfly and avian distribution, as well as vegetation distribution, throughout the country were used. After obtaining logistic regression models explaining the probabilities of occurrence of each species with semi-natural grassland area and latitude as variables, the optimum value was calculated. The expected maximum species richness of butterflies in the country was the highest in the case of about 40 square kilometers of semi-natural grassland per 100 square kilometers, though the value varied somewhat with latitude. The expected maximum …


Managing Grassy Woodlands: Balancing Production And Conservation Of Resources, John G. Mcivor, Neil D. Macleod, S. Mcintyre Dec 2021

Managing Grassy Woodlands: Balancing Production And Conservation Of Resources, John G. Mcivor, Neil D. Macleod, S. Mcintyre

IGC Proceedings (1977-2023)

Eastern Australian eucalypt woodlands are important agricultural areas that have been widely modified during two centuries of European-style use. Despite this they contain important natural resources including significant biodiversity. Long term sustainability of production depends on maintaining resources and management must be for both production and conservation. A research program on four properties in south east Queensland showed the properties were in generally good condition although all had some problems, and has highlighted a number of significant costs and barriers to adopting a more balanced approach to production and conservation.


Species Segregation And Functional Groups In The Hill Country Of New Zealand, I. López, I. Valentine, D. Hedderley, M. G. Lambert Dec 2021

Species Segregation And Functional Groups In The Hill Country Of New Zealand, I. López, I. Valentine, D. Hedderley, M. G. Lambert

IGC Proceedings (1977-2023)

In the hill country of New Zealand, the soil-sward relationship on hill microrelief was studied. Three categories of slope or microsites were distinguished: low, medium and high. The hypothesis was that soil variables of neighbouring microsites differ, and because of this, there is a segregation of species or functional groups of species between the microsites. Soil features, botanical composition and total annual yield were measured in the slope categories in two similar paddocks; one of which had received long-term phosphorus fertilisation and a non-fertilised paddock. ANOVA, cluster analysis and canonical variate analysis were performed on the data. Unsaturated hydraulic conductivity, …


Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin Dec 2021

Poor Acclimation To Experimental Field Drought In Subalpine Forest Tree Seedlings, Alex Goke, Patrick H. Martin

Biological Sciences: Faculty Scholarship

The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought …


Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring Dec 2021

Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring

IGC Proceedings (1977-2023)

The objectives of this study were to test the possibilities of using different farm animals for landscape care on extensive pasture, taking into account their particular performance, and to analyse alterations of the flora in consequence of grazing by different animals and various pasture management. Salers had the highest (836g/d) and Galloways (584g/d) the lowest live weight gain as compared with the other breeds (771g/d). Lambs had higher live weight when grazing together with cattle and horses (mixed grazing) than under one species grazing. The number of legume increased and that of grass decreased. Following 3 years the grazing animals …


Animal Production From Tropical Pastures Renovated By Subsoiling And Fertilization In The Cerrados Of Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, M. P. Oliveira Dec 2021

Animal Production From Tropical Pastures Renovated By Subsoiling And Fertilization In The Cerrados Of Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, M. P. Oliveira

IGC Proceedings (1977-2023)

A grazing trial was conducted, to study the effects of fertilization on the maintenance of the productivity of four tropical grasses. The paddocks were subsoiled, and dived into halves: one (LF1) received 400 kg/ha of a fertilizer formula 0-20-20.and the other (LF2) 800 kg/ha of the same fertilizers, in January 1995. Annually, 50 kg/ha of N was applied. The productivity on LF2 pastures was greater than that on FL1 pastures, averaging 520 and 410 kg of liveweight gain/ha/year. A double strategy should be followed to sustain animal production in the savanna: maintain soil P over a critical value of 3.0 …


Performance Of Nellore Cattle Under Two Grazing Management Systems, L. De A. Corrêa, Maurício M. De Alencar, Rogério T. Barbosa, P. F. Barbosa, Geraldo M. Da Cruz, I. U. Packer, C. A. Cordeiro Dec 2021

Performance Of Nellore Cattle Under Two Grazing Management Systems, L. De A. Corrêa, Maurício M. De Alencar, Rogério T. Barbosa, P. F. Barbosa, Geraldo M. Da Cruz, I. U. Packer, C. A. Cordeiro

IGC Proceedings (1977-2023)

The objective of this study was to evaluate the effects of grazing intensification on birth weight (BW), weaning weight (WW, standartized to 205 days), average daily gain from birth to weaning (ADG), and gestation length (GL) of calves, cow weight at calving (CWC) and at weaning (CWW), cow condition score at calving (CCC) and at weaning (CCW), and BW/CWC (BWR), WW/CWC (WWRC) and WW/CWW (WWRW) ratios. One hundred and sixty eight Nellore calves born in 1998 and 1999, out of dams maintained in two grazing management systems were evaluated: an extensive 1.0 animal unity (AU). ha-1 system on unfertilized …


Orchardgrass Pastures For Early-Weaned Beef Calves, J. C. Waller, H. A. Fribourg, C. Dixon, A. E. Fisher, B. V. Conger Dec 2021

Orchardgrass Pastures For Early-Weaned Beef Calves, J. C. Waller, H. A. Fribourg, C. Dixon, A. E. Fisher, B. V. Conger

IGC Proceedings (1977-2023)

Orchardgrass (Dactylis glomerata) grown alone or with ladino white (Trifolium repens) and red (T. pratense) clovers, provides a high quality March to June pasture. However, many beef producers have their cows calving in January-March, thus producing offspring that are too young to utilize spring forage well. As an alternative, some producers have their cows bred so that calves are born in autumn (September-November). By spring, these calves are old enough to consume pasture forage. The few earlier studies on early weaning of fall-born calves consist of drylot feeding of high quality hay or concentrates. …


Paleoindian Response To Climate Change In The Northern Jornada Del Muerto, Christopher Wayne Merriman Dec 2021

Paleoindian Response To Climate Change In The Northern Jornada Del Muerto, Christopher Wayne Merriman

Anthropology ETDs

Human-environment interaction is a long-standing and productive line of inquiry that includes the study of cultural responses to climate change. However, demonstrating a causal relationship between climate change and the consequent culture change is rarely straightforward for numerous reasons. In this dissertation I develop an optimality model to predict how Paleoindians should have responded to changes in precipitation across the Late Pleistocene-Early Holocene. The water supply model (WSM) ranks water supplies much like the diet breadth model ranks food resources. To adjust the WSM for climate change, paleoclimate records from playas in the northern Jornada del Muerto were used in …


Salt Marshes As Groundwater Buffers For Development: A Survey Of South Carolina Salt Marsh Basins, Alicia M. Wilson, Meghan Shanahan, Erik M. Smith Dec 2021

Salt Marshes As Groundwater Buffers For Development: A Survey Of South Carolina Salt Marsh Basins, Alicia M. Wilson, Meghan Shanahan, Erik M. Smith

Faculty Publications

Salt marshes serve as zones of intense groundwater mixing and reaction between freshwater uplands and estuaries. This raises the question of whether the impacts of upland development on nutrient and carbon species can be transmitted through salt marshes via groundwater, or whether salt marshes can buffer estuarine waters from coastal development. We sampled groundwater from fifteen tidal creek basins in South Carolina to test for compositional differences associated with development and marsh width. Groundwater samples from near creekbanks and below freshwater uplands were analyzed for salinity, total dissolved nitrogen and phosphorus, and dissolved organic carbon. Analyses revealed significantly higher TDN …


Management Of Meadow Fescue Pasture For High-Producing Dairy Cows In Northern Japan, K. Sudo, K. Ochiai, T. Ikeda Dec 2021

Management Of Meadow Fescue Pasture For High-Producing Dairy Cows In Northern Japan, K. Sudo, K. Ochiai, T. Ikeda

IGC Proceedings (1977-2023)

The objective of this study was to establish an intensive grazing system of meadow fescue (Festuca elatior L.) pasture for high-producing dairy cows in some areas of Japan where soil freezes in winter. Plant succession of meadow fescue pastures that had been grazed at different plant heights and milk production from cows grazed on meadow fescue pasture compared to that from cows grazed on perennial ryegrass pasture were surveyed over a five year period. Succession of meadow fescue pasture depended on the management of plant height before grazing use. Milk production from cows grazed on meadow fescue pasture was …