Physical Sciences and Mathematics Commons^™

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …

Evaluating The Impacts Of Grassland Conversions To Experimental Forest On Groundwater Recharge In The Nebraska Sand Hills, Zablon A. Adane

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The Nebraska Sand Hills grasslands provide the greatest groundwater recharge rates in the High Plains Aquifer. However, the grasslands and their ecological services have become vulnerable to land use change and degradation. This study used a series of field data to investigate the effects of grassland conversions to forest on recharge rates in a century-old experimental forest in the Sand Hills. The results show that the impact of grassland conversion on recharge was dependent on the species and plantation density. Estimated recharge rates beneath the dense plantations represent reductions of 86–94% relative to the native grassland. Results of ¹H …

Accelerated Increase In The Arctic Tropospheric Warming Events Surpassing Stratospheric Warming Events During Winter, Shih-Yu (Simon) Wang, Yen-Heng Lin, Ming-Ying Lee, Jin-Ho Yoon, Jonathan D.D. Meyer, Philip J. Rasch

Plants, Soils, and Climate Faculty Publications

In January 2016, a robust reversal of the Arctic Oscillation (AO) took place associated with a rapid tropospheric warming in the Arctic region; this was followed by the occurrence of a classic sudden stratospheric warming in March-April. The succession of these two distinct Arctic warming events provides a stimulating opportunity to examine their characteristics in terms of similarities and differences. Historical cases of these two types of Arctic warming were identified and validated based upon tropical linkages with the Madden-Julian Oscillation and El Niño as well as those documented in previous studies. Our results indicate a recent and accelerated increase …

Alicyclic And Aromatic Carboxylic Acids In Soil Organic Matter: An Investigation Of Potential Origin And Association With Plutonium Using Advanced Analytical Techniques, Nicole Didonato

Chemistry & Biochemistry Theses & Dissertations

Carboxylic acids are a defining component of soil organic matter, responsible for many of the physical and chemical properties, including metal-organic matter interactions, which govern its role as an important constituent of soils. However, there is a shortage of detailed molecular level information regarding orientation and structural arrangement of carboxylic acids within soil organic matter. This dissertation utilizes electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) as well as solid-state and multi-dimensional nuclear magnetic resonance (NMR) to investigate the molecular formula composition within several organic matter sources and the primary structures that feature carboxylic acids. Soil organic matter …

Modeling The Movement Of Septic Water Chloride Through A Soil Profile, Shawkat Kochary, Tom Byl, Bahzad Noori

Civil and Architectural Engineering Faculty Research

The purpose of this study was to investigate the movement of chloride through a vadose zone located under failed and non-regulated septic tanks of Duhok city, Kurdistan of Iraq, potentially contaminating its groundwater. A physical vadose model (PVM) of a vertical flow direction was built in the laboratory to represent the city soil profile. The size of the PVM was 210 × 122 × 9.7 cm (height, width, and depth). Preliminary soil tests were conducted to better represent the lithology of study area. The PVM was then packed with regional silt clay soil, after modifying its texture, using an innovative …

Responses Of Terrestrial Ecosystem Phosphorus Cycling To Nitrogen Addition: A Meta-Analysis, Qi Deng, Dafeng Hui, Samuel Dennis, Chandra Reddy

Agricultural and Environmental Sciences Faculty Research

Aim

Anthropogenic additions of nitrogen (N) are expected to drive terrestrial ecosystems toward greater phosphorus (P) limitation. However, a comprehensive understanding of how an ecosystem's P cycle responds to external N inputs remains elusive, making model predictions of the anthropogenic P limitation and its impacts largely uncertain.

Location

Global.

Time period

1986-2015.

Major taxa studied

Terrestrial ecosystems.

Methods

We conducted a meta-analysis including 288 independent study sites from 192 articles to evaluate global patterns and controls of 10 variables associated with ecosystem P cycling under N addition.

Results

Overall, N addition increased biomass in plants (+34%) and litter (+15%) as …

Wait Until Soil Temps Drop Before Applying Anhydrous Ammonia, John E. Sawyer, Barbara Stewart, William Ehm

John E. Sawyer

With the early harvest, Iowa’s conservation leaders are encouraging farmers to wait until soil temperatures lower before applying anhydrous ammonia (NH3) this fall. Anhydrous ammonia applied before daily soil temperatures remain below 50 degrees Fahrenheit and continue trending lower can result in the nitrogen loss that can impact crop development and have negative environmental impacts, such as enhanced leaching into groundwater and streams once converted to nitrate.

Wet Conditions And Change In Soil Profile Nitrate, John E. Sawyer

John E. Sawyer

I wrote an ICM News article February 21, 2013, that provided a summary of fall soil profile nitrate sampling results following the 2012 corn harvest. As I cautioned in that and other articles, the amount of nitrate-N that might remain for a 2013 corn crop depends on springtime rainfall. Unfortunately, much of Iowa has received considerable precipitation since soils thawed, especially the eastern two-thirds of Iowa. The two maps of the Midwest region show the total precipitation and deviation from normal since March 7, 2013. Tile lines are flowing again, and nitrate in the profile will move with percolating water. …

Sulfur Emerges As A Nutritional Issue In Iowa Alfalfa Production, John E. Sawyer, Brian J. Lang, Daniel W. Barker

John E. Sawyer

Sulfur is often classified as a “secondary” essential element, mainly due to a smaller plant requirement, but also because it is less frequently applied as a fertilizer compared to N, P, and K. This has certainly been the case in Iowa, where research had not documented S deficiency or fertilization need for optimal crop production. However, if deficient, S can have a dramatic effect on plant growth and crop productivity – more than the classification “secondary” would imply.

Carbon Sequestration By Australian Tidal Marshes, Peter I. Macreadie, Q. R. Oliver, J. J. Kelleway, Oscar Serrano, P. E. Carnell, C. J. Ewers Lewis, T. B. Atwood, J. Sanderman, J. Baldock, R. M. Connolly, C. M. Duarte, Paul Lavery, A. Steven, C. E, Lovelock

Research outputs 2014 to 2021

Australia’s tidal marshes have suffered significant losses but their recently recognised importance in CO2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia’s tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha − 1 (range 14 – 963 Mg OC ha − 1). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha − 1 yr − 1. Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC …

Results Of Test-Hole Drilling For Observation Well Planning In The Upper Loup Natural Resources District, Fall 2016, Douglas Hallum, Sue Olafsen Lackey

Conservation and Survey Division

The High Plains Aquifer underlies much of Nebraska (Figure 1). It is the primary source of groundwater within the Upper Loup Natural Resources District (ULNRD) of central Nebraska (Figure 2). Water derived from the aquifer is an important natural resource for the area and supplies water for recreation, wildlife and agriculture, as well as domestic, municipal, and industrial uses. A general lack of water level observations in the region (Figure 3), recently developed groundwater irrigated acres along the upper Calamus River (Figure 4), falling spring water levels measured in existing irrigation wells (Figure 5), and a stable to falling stream …

Quantifying The Short-Term Dynamics Of Soil Organic Carbon Decomposition Using A Power Function Model, Weiping Zhou, Jinhong He, Dafeng Hui, Weijun Shen

Biology Faculty Research

Introduction

Soil heterotrophic respiration (R _h, an indicator of soil organic carbon decomposition) is an important carbon efflux of terrestrial ecosystems. However, the dynamics of soil R _h and its empirical relations with climatic factors have not been well understood.

Methods

We incubated soils of three subtropical forests at five temperatures (10, 17, 24, 31, and 38 °C) and five moistures (20, 40, 60, 80, and 100% water holding capacity (WHC)) over 90 days. R _h was measured throughout the course of the incubation. Three types of models (log-linear, exponential, and power model) were fitted to the measurements …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2016, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Photo Highlights Of The 36th Kentucky Alfalfa And Stored Forages Conference, Kentucky Alfalfa And Stored Forages Conference

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

Alfalfa Conference Speakers From The Beginning, Kentucky Alfalfa And Stored Forages Conference

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

Kentucky Alfalfa Awards History, Kentucky Alfalfa And Stored Forages Conference

Kentucky Alfalfa and Stored Forage Conference

The Kentucky Alfalfa Awards Program was initiated in 2000 at the 20th Anniversary of the Kentucky Alfalfa Conference. The Awards Program is funded annually from revenues generated each year for the Silent Auction during the Annual Conference.

Save The Date! [Announcement], S. Ray Smith, Krista Lea

Kentucky Alfalfa and Stored Forage Conference

This is an announcement of upcoming events.

Selecting Summer Annual Varieties Using Yield And Digestibility, Christopher D. Teutsch

Kentucky Alfalfa and Stored Forage Conference

Although cool-season grasses can provide ample and high quality forage for grazing livestock in the spring and fall, forage growth during the summer months is often restricted by high temperatures (Figure 1). In contrast warm-season annual grasses are most productive during the summer months and do not reach peak growth until temperatures approach 90 degrees Fahrenheit. Summer annual grasses such as forage sorghum (Sorghum bicolor (L.) Moench), sudangrass (Sorghum bicolor (L.) Moench), sorghum-sudangrass hybrids, and pearl millet (Pennisetum americanum (L.) Leeke) can provide high quality summer grazing for ruminant livestock in many regions of the United States.

The Economics Of Hay Quality, Madeline L. Dant, Kenneth H. Burdine, Brandon Sears

Kentucky Alfalfa and Stored Forage Conference

Hay quality is often discussed when one considers the viability of cash hay operations. A great deal is known about how production impacts quality and how quality impacts animal performance. This knowledge certainly has economic implications, but the economics of hay quality has primarily been evaluated from the animal performance perspective. Analyzing the economics of hay quality from the cash hay producer’s prospective becomes more difficult due to data limitations.

There are approximately 2.5 million acres of hay produced in Kentucky annually. The vast majority of this hay is grass type hay that is produced and fed on beef cattle …

What Is New In Seed Coatings, Bill Talley

Kentucky Alfalfa and Stored Forage Conference

Seed Coatings started many centuries ago when the Chinese wrapped their rice seed in a mud ball when planting their rice fields. The ball would keep the seed from floating to the top when they flooded their fields. Seed treatment of Alfalfa first began with preinoculation of the seed to make it more convenient to plant. The farmer did not have to go through the process of inoculating the seed himself, and this was a great improvement at the time. In 1975 Ramsey Seed in California acquired technology from a New Zealand company to begin coating seed with a buildup …

Western Hay Production Vs. Eastern Hay Production, Tom Keene

Kentucky Alfalfa and Stored Forage Conference

Early in the history of mankind, man was nomadic and moved from location to location in order to gather and find sustenance for themselves as well as their livestock. At some point in time, man decided that rather than keep moving, they would establish a community in one location, usually near running water (or fresh water of some kind), and would begin to sustain themselves with production agricultural practices.

Planting and harvesting soon took the place of packing up and moving every time the current resources had been depleted. Each year a new crop would be planted; livestock also became …

Why Is Intake Reduced When Cattle Are Fed Tall Fescue?, James L. Klotz

Kentucky Alfalfa and Stored Forage Conference

A major problem for the cattle producer that utilizes tall fescue forage is the unrealized or reduced gains in body weight in growing animals. This result has been reproduced across numerous studies evaluating cattle performance on tall fescue (Hoveland et al., 1983; Boling, 1985; Schmidt et al., 1986; Goetsch et al., 1987). Cattle have gained from 30 to 100% less consuming toxic endophyte-infected tall fescue compared to consumption of an endophyte-free tall fescue (Paterson et al., 1995). This effect of reduced gain is a consequence of a fungal endophyte present within the grass that produces toxins called ergot alkaloids. Fungal …

Understanding And Improving Fermentation In Alfalfa And Grass Baleage, Dennis Hancock

Kentucky Alfalfa and Stored Forage Conference

The ancient Egyptian and Carthaginians are believed to be the first conserve forage by ensiling it in the absence of oxygen. Though the technique has been refined in the 3500 years since, the basic fermentation process has not changed. Populations of naturally-occurring bacteria on the plant surface can consume some of the readily available carbohydrates and produce organic acids. These organic acids lower the pH of the forage material and prevent fungal deterioration of the product. Fermentation has been used for millennia as a natural method for preserving food. Similar bacterial fermentation occurs when one makes yogurt, sour cream, or …

Hay Making Weather In Kentucky: How To Get Good Information, Matthew Dixon, Tom Priddy

Kentucky Alfalfa and Stored Forage Conference

The UK Agricultural Weather Center, housed within the Department of Biosystems and Agricultural Engineering, was developed in 1978. As part of the Cooperative Extension Service, the goal of the Ag Weather Center is to minimize weather and climate related surprise for Kentucky residents and their agricultural needs, ultimately for profitable and sustainable production. In doing so, numerous tools and models have been developed throughout the years to further help farmers and producers in management and production related decisions.

Foreword Of Kentucky Alfalfa And Stored Forages Conference [2017], S. Ray Smith, Krista Lea

Kentucky Alfalfa and Stored Forage Conference

This is the front matter of the proceedings.

Rapid Surface-Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph Michael Wheaton, Carol A. Johnston, Angela Bedard-Haughn

Watershed Sciences Faculty Publications

Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range …

Effect Of Seed Position On Parental Plant On Proportion Of Seeds Produced With Nondeep And Intermediate Physiological Dormancy, Juan J. Lu, Dun Y. Tan, Carol C. Baskin, Jerry M. Baskin

Biology Faculty Publications

The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 …

High Prevalence Of Toxigenic Clostridium Difficile In Public Space Lawns In Western Australia, Peter Moono, Su Chen Lim, Thomas V. Riley

Research outputs 2014 to 2021

Clostridium difficile is a well-established hospital pathogen. Recently, it has been detected increasingly in patients without hospital contact. Given this rise in community associated infections with C. difficile, we hypothesized that the environment could play an important role in transmission of spores outside the hospital. Lawn samples (311) collected in public spaces in the metropolitan area of Perth, Western Australia, from February to June 2016 were cultured for C. difficile. C. difficile was isolated from the samples by direct and enrichment culture, and characterized by standard molecular methods using toxin gene PCR and ribotyping. The overall prevalence of …

Ergot And Loline Alkaloid Concentrations In Endophyte-Infected Tall Fescue Tillers, Rebecca L. Mcculley

Forage Climate Change Experiment Research Data

Approximately 40 tall fescue tillers were randomly collected and frozen from each of the 20 treatment plots.

Tillers were cut at 7.6 cm above ground level and tested for the presence of the Epichloe endophyte using an enzyme-linked immunosorbent assay.

Tillers from each plot were sorted into 'infected' vs 'uninfected' groups, lyophilized, and ground through a 1mm screen using a Cyclotec 1093 mill.

Ground material from the endophyte infected tillers was analyzed for ergot and loline alkaloids in the lab of Lowell Bush at the University of Kentucky, Plant and Soil Sciences Dept.

For details on alkaloid analyses see: McCulley …

Basic Meteorological Data Derived 30-Year Normas (1981-2010) Of Actual Evapotranspiration Rates In Nebraska, Usa, Jozsef Szilagyi

Conservation and Survey Division

No abstract provided.