Digital Commons Network^™

Mapping Nitrogen Fixing Shrubs In Dry Unimproved Tussock Grassland, C. C. Boswell, W. L. Lowther, P. D. Espie

IGC Proceedings (1977-2023)

Global Positioning System (GPS) was used to both map the positions of individual nitrogen-fixing shrub plants and record individual plant height and breadth dimensions, within a small catchment of dry sub-humid unimproved short tussock grassland. The distributions of different species of shrubs varied with different landscape units within the catchment. The information will provide the base data for a first approximation of the role of the shrubs in the nitrogen balance of the ecosystem, which is pivotal to the sustainability of pastoral farming in the tussock grasslands.

Repeated Measurement Analyses Of Forages In Cropping Systems, A. R. De Freitas, O. Primavesi, L. De A. Corrêa, A. C. Primavesi, E. B. Pott, A. Dos S. Mascioli

IGC Proceedings (1977-2023)

Repeated measurements (RM) are common in forage experiments. The data used in this study were accumulated ammonia losses by volatilization (N) and dry matter production (DM) of Cynodon dactylon cv. Coastcross pasture from an experiment in blocks with five levels of urea: 0, 25, 50, 100 and 200 kg of N ha^-1, applied in five periods (cuttings). For N, RM were the averages of cuttings and nine days of observation. The F test for the hypothesis of no effect for Period and Level x Period interaction (DM) and for Days and Level x Days interaction was not affected …

Farmwi$E: A Flexible Decision Support Tool For Grazing Systems Management, A. D. Moore

IGC Proceedings (1977-2023)

CSIRO's new FarmWi$e decision support tool provides a framework that permits pasture-livestock systems and management policies of any level of complexity to be simulated. An underlying "modelling protocol" permits other simulation models to be added, further extending its domain of applicability. Management policies are specified in FarmWi$e by means of rules that govern when, whether and how management events take place. An example of the use of FarmWi$e to study lamb production is given.

Sward Height; Visual Estimate Compared With Plate Meter Height, W. B. Bryan, E. C. Prigge, E. L. Nestor, O. J. Gekara, M. A. Schettini

IGC Proceedings (1977-2023)

Sward height (SH) is widely used in pasture research and farm practice to evaluate pasture conditions. Visual estimates can take less time than actual measurements. This study compared visually estimated SH, of continuously grazed cool-season permanent pasture with plate meter height. Weekly estimates, by five people, were made on 12, 0.75 to 1 ha fields, grazed at two intensities. Paired data (visual estimate and plate meter height) were subjected to variance and covariance analyses and prediction equations were developed. Average visual height accounted for 86% of the variability in plate meter height. Inclusion of other sources of variability in the …

Sources Of Error For Ultrasonic Measurements Of Steer Compositional Traits In Grazing Studies, Glen E. Aiken, F. M. Rouquette Jr., A. H. Brown Jr.

IGC Proceedings (1977-2023)

Real-time ultrasound technology has potential use for measuring compositional traits in grazing studies. Sources of error with this application must be identified for designing experiments with adequate precision to determine treatment effects. A study was conducted to evaluate breed type (Angus x Brahman, AB; Simmental x [Angus x Brahman], SAB; Simmental x [Brahman x Hereford], SBH), initial body weight, and initial ultrasonic measures as sources of experimental error in the analyses of external fat (EF) depths and longissimus dorsi (ribeye) areas (LDA). Steers were ultrasonically scanned at the initiation and conclusion of a grazing study that examined stocking rate effects …

Grassland Management And Animal Product Quality, G. W. Sheath, J. B. Coulon, Q. A. Young

IGC Proceedings (1977-2023)

The expectations of consumers ultimately determine the specification of product quality; and grassland systems produce a wide range of animal-based products. Therefore, to provide focus, this paper deals only with food products that are destined for markets that exhibit strong discretionary choice. Quality expectations of consumers have traditionally been based on product attributes such as taste, freshness, nutritional value and appearance, but customer expectations are expanding to encompass food safety, environmental care, animal welfare and biotechnologies.

Grassland forages and their management influence the intrinsic sensory properties of food. A dairy products case study is presented, indicating that pasture species and …

Priority Setting And Funding Of Agricultural Research, M. Petit

IGC Proceedings (1977-2023)

Agricultural research funding amounts and modalities have been profoundly transformed in recent years in many countries. For instance, competitive funding has become the norm rather than the exception in most countries and funding sources have been greatly diversified. In addition, in some major countries, the private sector has become a major actor In agricultural research, both as a funder of research and as a provider research results. This poses a major challenge to public research institutions, which remain the major agricultural research actors and employers of researchers in most countries. With these changes in funding, formal procedures for research priority-setting …

Dilemma: Increase In Human Food Production Or Use Of Grasslands For Environmental And / Or Social Purposes, A. D. Meister

IGC Proceedings (1977-2023)

In the title for this paper we find three major objectives: to feed the world, sustain the environment and provide resources for social purposes, and a dilemma. Even though the word ‘dilemma’ usually implies choice between undesirable alternatives, it is obvious that the alternatives here are not undesirable. Is the dilemma then, that we can only do one at the time, or that the consequences of favouring one over the other can lead to undesirable outcomes? It is my opinion that we are talking about the latter interpretation. It is the foreclosing of options by allowing one objective to dominate …

The Development And Prospect Of Chinese Grassland Economic System, Fuzeng H.

IGC Proceedings (1977-2023)

China is a country with an old agriculture civilization of the world. The arrangement of the crop and pasture area had developed from Han and Tang dynasty. (From A.C 206.to AD 907). Chinese livestock economic had undergone the winding development for a thousand years of feudal society, however, It still belong to a phase of the loose private ownership. From 1949 when The People's Republic of China was founded, the pasture was nationalized and collective management. Since 1980s, the planned economic changed into the market economic gradually. The pasture was public ownership, but management by contract, paid utilization and unchanged …

Contextual Factors In The Management Of Common Grazing Lands: Lessons From Mongolia And Northwestern China, R. Mearns

IGC Proceedings (1977-2023)

Seen in a global perspective, pastoral development is now increasingly motivated by social and environmental objectives rather than by production- or output-orientated objectives. Attention is shifting towards a broader concern with sustainability, both of grasslands, and of the livelihoods of those who rely on them (de Haan et al, 1997, Fratkin and Mearns forthcoming). Quite how these twin sustainability objectives may be achieved in particular contexts, however, is an empirical question. Drawing on examples from a diverse range of natural grassland-based livestock production systems under economic transition in Mongolia and northwestern China, this summary paper aims to show how an …

De-Intensification Of Grasslands: Understanding The Processes To Find The Balance, K. C. Hodgkinson

IGC Proceedings (1977-2023)

There is a growing trend in Australia and other developed countries for deintensification of animal production from grasslands and for grasslands to be used for purposes other than livestock grazing. These shifts are occurring for a variety of reasons including unsustainable land management practices, environmental pollution, loss of conservation value, poor commodity prices and declining rural infra-structure and communities. In Australia, the shifts are under way in agricultural grasslands, where sown pastures occur in a matrix of semi-natural woodlands, but less so in the other three major natural grasslands that forms the arid and semi-arid rangelands.

The conversion of natural …

De-Intensification Of Grasslands: Current State And Trends, Michael Duru, Bernard Hubert

IGC Proceedings (1977-2023)

De-intensified use of grasslands, and more generally of the livestock systems they support, has been triggered by a growing sensitivity of citizens to environmental quality (nitrogen) and quality of animal products, and by the warnings addressed to political authorities by scientists about the environmental consequences of economic imbalances (decreasing biodiversity, drop in soil fertility, greenhouse effect), and in particular of food overproduction in Europe.

From an ecological standpoint, grassland de-intensification must be envisaged whenever the techniques implemented disrupt resource sustainability. The grassland resource itself may be at risk when a rate of vegetation offtake by herbivores that is incompatible with …

Arkansas Bulletin Of Water Research - Issue 2021-2022, Erin Grantz, Lillie Haddock, Brian E. Haggard

Arkansas Bulletin of Water Research

The Arkansas Bulletin of Water Research (Bulletin) is a publication of the Arkansas Water Resources Center (AWRC). We publish the Bulletin to communicate the major findings of research funded by the Water Resources Research Act Section 104(b) in Arkansas. This research is relevant to Arkansas water stakeholders, and the Bulletin provides an easily searchable and aesthetically engaging access option.

This is the fourth publication of the Bulletin. This issue contains final reports from research projects that were funded by the 104(b) program in fiscal years 2019 and 2020. The articles in this issue can be cited as an AWRC publication. …

A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska

Adam Liska Papers

Mitigation of climate change requires the systematic identification and cataloging of emissions sources at city, state, and national levels. In this study, an inventory of annual greenhouse gas emissions from the state of Nebraska was created based on industry data, and emissions inventories were completed each year from 1990 to 2016. Nebraska’s net emissions were found to increase from 56.2 million metric tons of carbon dioxide equivalents (MMtCO₂e) in 1990 to 87.4 MMtCO₂e in 2016. Agriculture was found to be the sector with the most emissions (36 MMtCO₂e) followed by electricity generation (21 MMtCO …

Guidebook For Omaha's Urban Geology And Anthropocene Nebraska Well Drillers 2022 Field Trip, Harmon Maher, Ashlee L. Dere, Melina Luethje

Geography and Geology Faculty Books and Monographs

This geologic field trip focus is somewhat atypical but arguably reflects an ongoing evolution within the geosciences. Instead of traveling out into rural settings to look at outcrops and the stratigraphy exposed, or rural landforms and their geologic history, this field trip is focused on built and engineered environments in the Omaha area and the ‘modified’ associated geologic processes such as surface and groundwater flow, weathering, and soil formation. The ongoing evolution includes an increase in a multidisciplinary system science approach and is driven by a need to address environmental and resource management challenges using new tools and conceptual frameworks. …

Dynamics And Turnover Of Lipid And Protein Domains In Cells And Supported Bilayers, Alan Weisgerber

Electronic Theses and Dissertations

Protein and lipid clustering is an important mechanism for cell processes such as exo- and endo-cytosis and creating functional signaling complexes. It has been seen that both lipids and proteins are involved with the formation of cluster domains on cell membranes, yet little is known about the interplay between the two. In this work I began with visualizing lipid sorting to artificially induced curvature in supported lipid bilayers, with lipid tails affecting the sorting differently to curvature. These results demonstrate that lipids sort to curvature on curved, supported lipid bilayers. The sorting depends on the number of lipids in the …

Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Improvement of nutrient use efficiency and limiting trace elements such as arsenic and uranium bioavailability is critical for sustainable agriculture and food safety. Arsenic and uranium possess different properties and mobility in soils, which complicates the effort to reduce their uptake by plants. Here, we postulate that unsaturated soil amended with ferrihydrite nanominerals leads to improved nutrient retention and helps reduce uptake of these geogenic contaminants. Unsaturated soil is primarily oxic and can provide a stable environment for ferrihydrite nanominerals. To demonstrate the utility of ferrihydrite soil amendment, maize was grown in an unsaturated agricultural soil that is known to …

Great South Bay, Long Island, New York Summer Water Quality Monitoring Program, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli

CERCOM Reports

The Center for Environmental Research and Coastal Oceans Monitoring (CERCOM) visits 11 locations in the Great South Bay from Memorial Day – Labor Day to monitor dissolved oxygen (DO), pH, salinity, clarity and temperature. Students are trained to assist in CERCOM’s water quality data collection by research assistant Mr. Kyle Maurelli. This monitoring program has been conducted for the past 17 years. These parameters are critical in determining long term water quality conditions in Long Island estuaries

Mercury Methylation In Oxic Sub-Polar Marine Regions Linked With Nitrification, Marissa Collins Despins

Browse all Theses and Dissertations

Methylmercury (MeHg) is a neurotoxin that bioaccumulates to potentially harmful concentrations in Arctic marine wildlife and in those that consume them. Monitoring and modeling MeHg bioaccumulation and biogeochemical cycling in the ocean requires understanding of the mechanisms behind net mercury (Hg) methylation. The key functional gene for Hg methylation, hgcAB, is widely distributed throughout ocean basins and spans multiple microbial phyla. While multiple microbially-mediated anaerobic pathways for Hg methylation are known, in the ocean, the majority of hgcA homologs have been found in oxic subsurface waters, in contrast to other ecosystems. In particular, microaerophilic Nitrospina, a genera of nitrite-oxidizing bacteria …

Species Effect On The Ecohydrology Of A Floodplain Forest In The Upper Mississippi, Claire Mchenry

Geology Honors Projects

The primary objective of this study is to understand how soil moisture is depleted underneath native and non-native Minnesotan tree species following a rain event. It is hypothesized that soil moisture will deplete more significantly and faster underneath drought intolerant, shallow rooted species native to Minnesota. This study also focuses on utilizing remote sensing techniques to calculate the soil moisture availability across a floodplain forest using Landsat 8 images to compare satellite-derived and field-recorded soil moisture values to assess the potential of these images to remotely estimate soil moisture in floodplains.

Floodplain Monitoring – Plaster Creek Segment At Shadyside Park, Alin Stoica, Julie Wildschut

Summer Research

• High stream velocity and flow rate during precipitation events endanger the urban areas through bank erosion and potential of flooding due to steep entrenchment of streambeds. An urban creek, Plaster Creek was impacted by this phenomenon throughout its watershed.
• Plaster Creek Stewards restored the segment of Plaster Creek located within Dutton Shadyside Park, Mi in 2018 by receding the walls of the tall banks that were entrenching the stream.
• The restored floodplains provide improved distribution of overflow water onto the plain, lowering bank erosion and sediment transportation. Native riparian vegetation planted along the plain improves biodiversity, strengthening the creek banks, …

Soil Resilience And Arbuscular Mycorrhizal Fungi: How Fungi Can Inform Climate Change Mitigation And Adaptation In Maya Milpa Management, Courtney Mathers

Electronic Theses and Dissertations

In Mexico’s state of Yucatán, climate change impacts like prolonged and less predictable dry season length are manifesting as threats to agricultural production and food security. Nearly two thirds of Yucatán’s population is indigenous, many of whom live in rural communities that rely on rainfed subsistence agriculture (INEGI 2015). Ensuring sufficient food production in the face of climate change relies on the quality of agricultural soils. With both mismanagement of agricultural soils and climate change posing as threats to food production in Mexico, soil management practices that increase a soil quality should be identified and promoted. The primary objective of …

Accuracy And Practical Considerations For Doubly Labeled Water Analysis In Nutrition Studies Using A Laser-Based Isotope Instrument (Off-Axis Integrated Cavity Output Spectroscopy), Linda M. Reynard, William W. Wong, Noreen Tuross

Geosciences Faculty Publications and Presentations

Background: Given the utility of the doubly labeled water (DLW) method for determination of energy expenditure, additional techniques for isotope analysis of the samples are welcome. Laser-based instruments are one such new analytical tool, but their accuracy and feasibility for DLW studies are grossly understudied.

Objectives: We assessed the accuracy of laser-based isotope ratio measurements as part of the DLW method for estimation of carbon dioxide production rate (rCO₂) and total energy expenditure (TEE), in between-group comparison study designs.

Methods: Urine samples from a previous study were analyzed with a laser-based instrument [off-axis integrated cavity output spectroscopy (OA-ICOS)]. …

Review Of The Effects Of Asphalt Fume Emission (Vocs And Pahs) In Vitro, In Vivo And Human Studies, Omran Taqi, Nastassja Lewinski, Elham Fini, Eran Rozewski, Judith Klein-Seetharaman

UROP Posters

Review of the effects of Asphalt fume emission (VOCs and PAHs) in vitro, in vivo and human studies

Omran Taqi, Nastassja Lewinski¹

1) Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA

Background

Asphalt is abundantly available around human operations including road paving and roofing sites. However, their emissions and fumes (specifically volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs)) have been found to have adverse effects on health. Asphalt fumes are a class 2A carcinogen and exposure can increase the risk of lung cancer, asthma, headache, fatigue, and other cardiovascular diseases.

Methods

We used …

Long Island Horseshoe Crab Network Annual Inventory Report, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli

CERCOM Reports

CERCOM monitors 115 beach locations from Brooklyn – Montauk during the optimal Limulus Polyphemus breeding season. These beach surveys take place for approximately 15 weeks, ranging from May - August. These beach locations are marked specifically using GPS coordinates, to assure the same location is visited each year. Students and volunteers are required to attend a HSC Survey training orientation led by CERCOM’s research assistant, Mr. Kyle Maurelli. Surveying is done around tide and moon cycles (New/Full Moon). Each site takes about 1-2 hours and data is recorded along an approximate 1 mile distance. Walking along the water’s edge the …

Reconstructing Regional Paleoenvironments And Geomorphic History Of High Plains Playa-Lunette Systems, Alyssa E. Sims

All Graduate Theses, Dissertations, and Other Capstone Projects

Playas are ephemeral upland-embedded wetlands found in semiarid and arid regions worldwide. Lunettes are isolated dunes that form along the downwind margin of playas. The paleoclimatic and geomorphic history of High Plains playa-lunette systems (PLSs) are poorly understood. To address this, we characterize the stratigraphy of four PLSs in southwest Kansas, USA. Methods include: 1) collect soil-sediment cores from playa centers and windward slopes of lunettes; 2) describe cores using USDA techniques; 3) estimate age of stratigraphic units using radiocarbon (14C); and 4) reconstruct paleoenvironmental conditions using stable carbon isotopes (13C) and particle size analysis. Playa stratigraphy is relatively simple …

Mining-Contaminated Sediment And Metal Storage In Channel Deposits In Turkey Creek, Tri-State Mining District, Missouri And Kansas, Max Quinn Hillermann

Graduate Theses/Dissertations

The Joplin subdistrict, within the Tri-State Mining District (TSMD), was a major producer of lead (Pb) and zinc (Zn) ore between the 1880s to 1920s. Metalliferous mining wastes are still stored in the channel deposits of local streams raising environmental and health concerns. This study quantifies the volume, sediment size, and metal concentrations in channel bed, bar, bench, and chute deposits to quantify the spatial variability of contaminated sediment storage in Turkey Creek (119 km²). Sample reaches (n=14) contained metal concentrations elevated above the Tri-State Mining District specific probable effects concentration at every site with mean concentrations in …

Power In Numbers: An Abundance Of Small Corals Responsible For Storing Over Half Of The Carbon Stored By All Alaskan Primnoa Pacifica Deep-Sea Corals, Sylvie Alexander

Scripps Senior Theses

Gorgonian deep-sea corals (DSCs) are biologically linked to ocean carbon cycling converting ocean carbon to gorgonin and calcite in their skeletons. As such, gorgonian DSCs likely accumulate and store carbon in their skeleton throughout their lifespans, acting as carbon sinks on historic timescales. Yet, DSC carbon storage hasn’t been investigated to date. This study evaluates gorgonian DSC carbon storage capacity through an evaluation of the carbon stored by Alaskan Primnoa pacifica corals. The development of a model relating coral height to biomass in specimens with this data available was used to determine biomass values in a suite of Alaskan P. …

Satellite Evidence Of Canopy-Height Dependence Of Forest Drought Resistance In Southwestern China, Peipei Xu, Wei Fang, Tao Zhou, Hu Li, Xiang Zhao, Spencer Berman, Ting Zhang, Chuixiang Yi

Publications and Research

The frequency and intensity of drought events are increasing with warming climate, which has resulted in worldwide forest mortality. Previous studies have reached a general consensus on the size-dependency of forest resistance to drought, but further understanding at a local scale remains ambiguous with conflicting evidence. In this study, we assessed the impact of canopy height on forest drought resistance in the broadleaf deciduous forest of southwestern China for the 2010 extreme drought event using linear regression and a random forest (RF) model. Drought condition was quantified with standardized precipitation evapotranspiration index (SPEI) and drought resistance was measured with the …

Phototrophy And Carbon Fixation In Chlorobi Postdate The Rise Of Oxygen, L. M. Ward, Patrick M. Shih

Geosciences: Faculty Publications

While most productivity on the surface of the Earth today is fueled by oxygenic photosynthesis, for much of Earth history it is thought that anoxygenic photosynthesis—using compounds like ferrous iron or sulfide as electron donors—drove most global carbon fixation. Anoxygenic photosynthesis is still performed by diverse bacteria in niche environments today. Of these, the Chlorobi (formerly green sulfur bacteria) are often interpreted as being particularly ancient and are frequently proposed to have fueled the biosphere during late Archean and early Paleoproterozoic time before the rise of oxygenic photosynthesis. Here, we perform comparative genomic, phylogenetic, and molecular clock analyses to determine …