Open Access. Powered by Scholars. Published by Universities.®

Soil Science Commons

Open Access. Powered by Scholars. Published by Universities.®

2018

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 31 - 60 of 134

Full-Text Articles in Soil Science

A Novel Shortwave Infrared Proximal Sensing Approach To Quantify The Water Stability Of Soil Aggregates, Azadeh Gholoubi, Hojat Emami, Scott B. Jones, Markus Tuller Oct 2018

A Novel Shortwave Infrared Proximal Sensing Approach To Quantify The Water Stability Of Soil Aggregates, Azadeh Gholoubi, Hojat Emami, Scott B. Jones, Markus Tuller

Plants, Soils, and Climate Faculty Publications

Soil structure and aggregate stability (AS) are critical soil properties affecting water infiltration, root growth, and resistance to soil and wind erosion. Changes in AS may be early indicators of soil degradation, pointing to low organic matter (OM) content, reduced biological activity, or poor nutrient cycling. Hence, efficient and reliable AS measurement techniques are essential for detection, management, and remediation of degraded soil resources. Here we quantify soil AS by developing a novel proximal sensing technique based on shortwave infrared (SWIR) reflectance measurements. The novel approach is similar to the well-documented high energy moisture characteristic (HEMC) method, which yields a …


Nutrient Addition And Drought Interact To Change The Structure And Decrease The Functional Diversity Of A Mediterranean Grassland, Carla Nogueira, Alice Nunes, Miguel N. Bugalho, Cristina Branquinho, Rebecca L. Mcculley, Maria Conceição Caldeira Oct 2018

Nutrient Addition And Drought Interact To Change The Structure And Decrease The Functional Diversity Of A Mediterranean Grassland, Carla Nogueira, Alice Nunes, Miguel N. Bugalho, Cristina Branquinho, Rebecca L. Mcculley, Maria Conceição Caldeira

Plant and Soil Sciences Faculty Publications

Anthropogenic activities are increasing nutrient availability and altering precipitation regimes. This may lead to critical changes in grasslands functioning. This is particularly important for grasslands in the Mediterranean Basin that have evolved in nutrient poor soils, and where more frequent and prolonged droughts are projected to occur. However, there is limited knowledge regarding the interacting effects of multiple nutrient inputs and rainfall variability on the plant functional structure and diversity of Mediterranean grasslands. We conducted a nutrient addition experiment in a Mediterranean grassland during four contrasting precipitation years. We established four treatments that varied in the number of added nutrients, …


Influence Of Phosphate On Tungstate Sorption On Hematite: A Macroscopic And Spectroscopic Evaluation Of The Mechanism, Bryan Sallman, Sudipta Rakshit, Grégory Lefèvre Oct 2018

Influence Of Phosphate On Tungstate Sorption On Hematite: A Macroscopic And Spectroscopic Evaluation Of The Mechanism, Bryan Sallman, Sudipta Rakshit, Grégory Lefèvre

Agricultural and Environmental Sciences Faculty Research

The environmental fate of the tungstate (VI) oxyanion [ e.g. mono tungstate and several polytungstate, generally expressed by W (VI)] is largely controlled by sorption on soil minerals, especially on iron oxide minerals. Molecular scale evaluation of W (VI) retention on iron oxides in the presence of competing oxyanions is scarce in literature. Here we report surface interaction mechanisms of W (VI) on hematite in the presence of phosphate (P) using macroscopic and in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic experiments. Batch sorption experiments were conducted using 2 g L−1 hematite and 100 μM W (VI) and …


Growth, Yield Performance And Quality Parameters Of Three Early Flowering Chia (Salvia Hispanica L.) Genotypes Cultivated In Southwestern Germany, Samantha J. Grimes, Timothy D. Phillips, Volker Hahn, Filippo Capezzone, Simone Graeff-Hönninger Oct 2018

Growth, Yield Performance And Quality Parameters Of Three Early Flowering Chia (Salvia Hispanica L.) Genotypes Cultivated In Southwestern Germany, Samantha J. Grimes, Timothy D. Phillips, Volker Hahn, Filippo Capezzone, Simone Graeff-Hönninger

Plant and Soil Sciences Faculty Publications

The combination of consumer’s ongoing demand for chia (Salvia hispanica L.) alongside the increased demand for regionally produced food products provided the impetus for this study. Its aim was to test if a regional cultivation of new chia genotypes, which were adapted to day lengths greater than 12 h, is feasible under Central European conditions. Therefore, three early flowering chia genotypes (Sahi Alba 914, W13.1, G8) were cultivated in a randomized block design at two experimental stations in Southwestern Germany (Ihinger Hof, Eckartsweier) over the course of two years (2015, 2016). Mean yields ranged from 100 to 1290 kg …


Iac Gene Expression In The Indole-3-Acetic Acid-Degrading Soil Bacterium Enterobacter Soli Lf7, Isaac V. Greenhut, Beryl L. Slezak, Johan H. J. Leveau Oct 2018

Iac Gene Expression In The Indole-3-Acetic Acid-Degrading Soil Bacterium Enterobacter Soli Lf7, Isaac V. Greenhut, Beryl L. Slezak, Johan H. J. Leveau

Plant and Soil Sciences Faculty Publications

We show for soil bacterium Enterobacter soli LF7 that the possession of an indole-3-acetic acid catabolic (iac) gene cluster is causatively linked to the ability to utilize the plant hormone indole-3-acetic acid (IAA) as a carbon and energy source. Genome-wide transcriptional profiling by mRNA sequencing revealed that these iac genes, chromosomally arranged as iacHABICDEFG and coding for the transformation of IAA to catechol, were the most highly induced (>29-fold) among the relatively few (iac cluster were genes for a major facilitator superfamily protein (mfs) and enzymes of the β-ketoadipate pathway (pcaIJD-catBCA), which channels …


New Insights Into Carboniferous Cyclothems. The Fourth Biennial Field Conference Of The American Association Of Petroleum Geologists (Aapg) Midcontinent Section Fourth Biennial Field Conference Abstracts And Guidebook, Robert Matthew Joeckel, Christopher R. Fielding Oct 2018

New Insights Into Carboniferous Cyclothems. The Fourth Biennial Field Conference Of The American Association Of Petroleum Geologists (Aapg) Midcontinent Section Fourth Biennial Field Conference Abstracts And Guidebook, Robert Matthew Joeckel, Christopher R. Fielding

Conservation and Survey Division: Faculty and Staff Publications

The term “cyclothem” was coined by Wanless & Weller (1932) to describe repetitive stratigraphic successions of Carboniferous age in Illinois. Nonetheless, comparable rhythmicity had been identified in Carboniferous rocks both in the central and eastern USA, and in Europe during the preceding century. Cyclothems were found to comprise repetitive vertical successions of sandstones, heterolithic (thinly interbedded) sandstones and mudrocks, mudrocks, limestones, and coals, in many cases with pedogenic overprinting of these lithologies. As usage of the term “cyclothem” increased, so did the diversity of successions to which the term was applied, to the point where many geologists advocated abandonment of …


Biomass Production Of Herbaceous Energy Crops In The United States: Field Trial Results And Yield Potential Maps From The Multiyear Regional Feedstock Partnership, Do Kyoung Lee, Ezra Aberle, Erik K. Anderson, William Anderson, Brian S. Baldwin, David Baltensperger, Michael Barrett, Jürg Blumenthal, Stacy Bonos, Joe Bouton, David I. Bransby, Charlie Brummer, Pane S. Burks, Chengci Chen, Christopher Daly, Josh Egenolf, Rodney L. Farris, John H. Fike, Roch Gaussoin, John R. Gill, Kenneth Gravois, Michael D. Halbleib, Anna Hale, Wayne Hanna, Keith Harmoney, Emily A. Heaton, Ron W. Heiniger, Lindsey Hoffman, Chang O. Hong, Gopal Kakani, David Williams, Linda Williams Oct 2018

Biomass Production Of Herbaceous Energy Crops In The United States: Field Trial Results And Yield Potential Maps From The Multiyear Regional Feedstock Partnership, Do Kyoung Lee, Ezra Aberle, Erik K. Anderson, William Anderson, Brian S. Baldwin, David Baltensperger, Michael Barrett, Jürg Blumenthal, Stacy Bonos, Joe Bouton, David I. Bransby, Charlie Brummer, Pane S. Burks, Chengci Chen, Christopher Daly, Josh Egenolf, Rodney L. Farris, John H. Fike, Roch Gaussoin, John R. Gill, Kenneth Gravois, Michael D. Halbleib, Anna Hale, Wayne Hanna, Keith Harmoney, Emily A. Heaton, Ron W. Heiniger, Lindsey Hoffman, Chang O. Hong, Gopal Kakani, David Williams, Linda Williams

Plant and Soil Sciences Faculty Publications

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock …


Phosphorus And Potassium Fertilizer Application Strategies In Corn–Soybean Rotations, Timothy J. Boring, Kurt D. Thelen, James E. Board, Jason L. De Bruin, Chad D. Lee, Seth L. Naeve, William J. Ross, Wade A. Kent, Landon L. Ries Sep 2018

Phosphorus And Potassium Fertilizer Application Strategies In Corn–Soybean Rotations, Timothy J. Boring, Kurt D. Thelen, James E. Board, Jason L. De Bruin, Chad D. Lee, Seth L. Naeve, William J. Ross, Wade A. Kent, Landon L. Ries

Plant and Soil Sciences Faculty Publications

To determine if current university fertilizer rate and timing recommendations pose a limitation to high-yield corn (Zea mays subsp. mays) and soybean (Glycine max) production, this study compared annual Phosphorous (P) and Potassium (K) fertilizer applications to biennial fertilizer applications, applied at 1× and 2× recommended rates in corn–soybean rotations located in Minnesota (MN), Iowa (IA), Michigan (MI), Arkansas (AR), and Louisiana (LA). At locations with either soil test P or K in the sub-optimal range, corn grain yield was significantly increased with fertilizer application at five of sixteen site years, while soybean seed yield was significantly …


County-Wide Assessment Of Irrigation Expansion On Air Temperature, Humidity And Evapotranspiration Rates In Nebraska, 1979-2015, Jozsef Szilagyi Sep 2018

County-Wide Assessment Of Irrigation Expansion On Air Temperature, Humidity And Evapotranspiration Rates In Nebraska, 1979-2015, Jozsef Szilagyi

Conservation and Survey Division: Faculty and Staff Publications

Total irrigated land area has been expanding in Nebraska over the last 40 years, propelling the state into a leading position within the US in terms of irrigated acreages. Typically, those counties which display the largest degree of irrigation development had a significant portion of their land area already irrigated in 1978. Large-scale irrigation in Nebraska affects its atmospheric environment. During the typical irrigation season of May to August, counties with the largest rate of irrigation expansion have cooled by about 0.2 – 0.3 °F per decade in the summer months of June, July and August, while counties with the …


Engineered Nanoparticles Interact With Nutrients To Intensify Eutrophication In A Wetland Ecosystem Experiment, Marie Simonin, Benjamin P. Colman, Steven M. Anderson, Ryan S. King, Matthew T. Ruis, Astrid Avellan, Christina M. Bergemann, Brittany G. Perrotta, Nicholas K. Geitner, Mengchi Ho, Belen De La Barrera, Jason M. Unrine, Gregory V. Lowry, Curtis J. Richardson, Mark R. Wiesner, Emily S. Bernhardt Sep 2018

Engineered Nanoparticles Interact With Nutrients To Intensify Eutrophication In A Wetland Ecosystem Experiment, Marie Simonin, Benjamin P. Colman, Steven M. Anderson, Ryan S. King, Matthew T. Ruis, Astrid Avellan, Christina M. Bergemann, Brittany G. Perrotta, Nicholas K. Geitner, Mengchi Ho, Belen De La Barrera, Jason M. Unrine, Gregory V. Lowry, Curtis J. Richardson, Mark R. Wiesner, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

Despite the rapid rise in diversity and quantities of engineered nanomaterials produced, the impacts of these emerging contaminants on the structure and function of ecosystems have received little attention from ecologists. Moreover, little is known about how manufactured nanomaterials may interact with nutrient pollution in altering ecosystem productivity, despite the recognition that eutrophication is the primary water quality issue in freshwater ecosystems worldwide. In this study, we asked two main questions: (1) To what extent do manufactured nanoparticles affect the biomass and productivity of primary producers in wetland ecosystems? (2) How are these impacts mediated by nutrient pollution? To address …


Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham Sep 2018

Investigation Of Biogeochemical Mechanisms Of Greenhouse Gas Production In The Urban Hudson River Estuary, Brian Alan Brigham

Dissertations, Theses, and Capstone Projects

Coastal megacities deposit significant amounts of carbon (C), nitrogen (N) and other pollutants into surrounding waters. These inputs, including wastewater and surface water runoff, may affect estuarine and adjacent wetland biogeochemical cycles, microbial production and ultimately greenhouse gas (GHG) efflux. In many megacities pollutant loading is typically greatest after periods of precipitation when the volume of wastewater and storm water runoff exceeds local sanitation capacity, resulting in the discharge of raw sewage into adjacent waters. These combined sewage overflow (CSO) events have received considerable attention primarily due to their potential impact on human health and eutrophication. However, whether these events …


Characterization Of Mrna Polyadenylation In The Apicomplexa, Ashley T. Stevens, Daniel K. Howe, Arthur G. Hunt Aug 2018

Characterization Of Mrna Polyadenylation In The Apicomplexa, Ashley T. Stevens, Daniel K. Howe, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Messenger RNA polyadenylation is a universal aspect of gene expression in eukaryotes. In well-established model organisms, this process is mediated by a conserved complex of 15–20 subunits. To better understand this process in apicomplexans, a group of unicellular parasites that causes serious disease in humans and livestock, a computational and high throughput sequencing study of the polyadenylation complex and poly(A) sites in several species was conducted. BLAST-based searches for orthologs of the human polyadenylation complex yielded clear matches to only two—poly(A) polymerase and CPSF73—of the 19 proteins used as queries in this analysis. As the human subunits that recognize the …


Invasive-Plant-Removal Frequency—Its Impact On Species Spread And Implications For Further Integration Of Forest-Management Practices, Bernabas Wolde, Pankaj Lal Aug 2018

Invasive-Plant-Removal Frequency—Its Impact On Species Spread And Implications For Further Integration Of Forest-Management Practices, Bernabas Wolde, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

For a given invasive plant species and control method, effective invasive plant eradication requires regular monitoring and management. While most previous studies characterize invasive plant species, develop appropriate control methods, or prioritize species for management using aggressiveness and other considerations, few study why some forestland owners are less likely than others to regularly remove invasive plant species. Such information is useful in prioritizing and targeting forestland owners who are at greater risk for invasion, with the stands threatening adjacent forestlands. Towards this end, we surveyed 1800 forestland owners in Virginia and Texas. We use data on forestland owners’ socioeconomics and …


Influence Of Collector-Drainage Waters On The Soil Properties Of The Desert Zone, G. Yuldashev,, M. Isagaliev,, D. Darmonov Aug 2018

Influence Of Collector-Drainage Waters On The Soil Properties Of The Desert Zone, G. Yuldashev,, M. Isagaliev,, D. Darmonov

Scientific journal of the Fergana State University

As a result of long-term research influence of the low-mineralized collector and drainage exhaust waters on properties irrigated sasa meadow soils of heavy loamy mechanical structure is established their negative influence on structure and amounts of water-soluble salts of soils and ground waters, on structure of the absorbed bases, ionic force, on quantity and quality of a humus and other properties of soils


Influence Of Cover Crop Species On Soil Physical Properties In A Corn-Soybean Rotation, Addison D. Jacobs Aug 2018

Influence Of Cover Crop Species On Soil Physical Properties In A Corn-Soybean Rotation, Addison D. Jacobs

Student Theses and Dissertations

As crop land decreases and population increases, soil quality is becoming a concern. Utilizing cover crops in cropping systems could improve soil quality. This study examined 16 treatments of single-species cover crops, cover crop mixes, and two control treatments on a silt-loam soil, in a corn (Zea mays L.) - soybean (Glycine max L. Merr.) crop rotation under no-tillage, to determine their effect on soil physical properties. Cover crop biomass differed (p<0.10) among treatments and produced a maximum of 15.6 Mg ha-1 of biomass in the crimson clover treatment. Water infiltration rates increased as much as 282% in the complete-mix treatment compared to the fallow control. Differences in infiltration rates due to cover crop species were shown in two-years. However, these results suggest that it may take more time for cover crops to affect change in bulk density and aggregate stability.


The Evaluation Of Two Different Harvesting 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) Leaves From Plants Grown In A Wiregrass Tunnel House, Edward Sparks, Raymon Shange, Jacquelyn Jackson, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore Aug 2018

The Evaluation Of Two Different Harvesting 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) Leaves From Plants Grown In A Wiregrass Tunnel House, Edward Sparks, Raymon Shange, Jacquelyn Jackson, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore

Professional Agricultural Workers Journal

A study was conducted to determine if a 100% or 50% harvest intensity of ‘Topbunch’ collards leaves could be a recommended practice for Tunnel House producers. The experiment was conducted as a split-plot design with harvest dates as main plots, and harvesting intensity of 100% or 50% of leaves as sub-plots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between harvest methods and dates for number and weight of leaves harvested. There were also significant differences for the weight of leaves harvested and numbers. The leaf recovery rates …


The Effect Of Two Different Harvesting Methods On The Yield Of 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) When Grown In A Wiregrass Tunnel House, Veronica E. Walton, Raymon Shange, Melissa Johnson, Edward Sparks, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore Aug 2018

The Effect Of Two Different Harvesting Methods On The Yield Of 'Topbunch' And 'Hi-Crop' Collards (Brassica Oleracea (L)) When Grown In A Wiregrass Tunnel House, Veronica E. Walton, Raymon Shange, Melissa Johnson, Edward Sparks, Victor Khan, James E. Currington, Ramble Ankumah, Nathaniel Ellison, George X. Hunter Jr., Jeffery L. Moore

Professional Agricultural Workers Journal

A study was conducted to determine if 100% or 50% harvesting of collard leaves was a suitable recommendation for Tunnel House producers. The experiment was conducted as a split-split plot design with varieties as the main plots, harvesting 100% or 50% of leaves as the sub-plots, and days after transplanting as the subplots. All treatments were replicated three times, drip irrigated, and fertilized according to soil test recommendations. The results showed significant interactions between varieties and method of harvest, for leaf numbers and weight. Conversely, the varieties showed significant differences for yield but not leaf numbers. Both varieties showed significant …


Quantifying Plant Soluble Protein And Digestible Carbohydrate Content, Using Corn (Zea Mays) As An Exemplar, Carrie A. Deans, Gregory A. Sword, Paul A. Lenhart, Eric Burkness, William D. Hutchison, Spencer T. Behmer Aug 2018

Quantifying Plant Soluble Protein And Digestible Carbohydrate Content, Using Corn (Zea Mays) As An Exemplar, Carrie A. Deans, Gregory A. Sword, Paul A. Lenhart, Eric Burkness, William D. Hutchison, Spencer T. Behmer

Entomology Faculty Publications

Elemental data are commonly used to infer plant quality as a resource to herbivores. However, the ubiquity of carbon in biomolecules, the presence of nitrogen-containing plant defensive compounds, and variation in species-specific correlations between nitrogen and plant protein content all limit the accuracy of these inferences. Additionally, research focused on plant and/or herbivore physiology require a level of accuracy that is not achieved using generalized correlations. The methods presented here offer researchers a clear and rapid protocol for directly measuring plant soluble proteins and digestible carbohydrates, the two plant macronutrients most closely tied to animal physiological performance. The protocols combine …


Spatio-Temporal Variations Of Soil Active Layer Thickness In Chinese Boreal Forests From 2000 To 2015, Xiongxiong Bai, Jian Yang, Bo Tao, Wei Ren Aug 2018

Spatio-Temporal Variations Of Soil Active Layer Thickness In Chinese Boreal Forests From 2000 To 2015, Xiongxiong Bai, Jian Yang, Bo Tao, Wei Ren

Forestry and Natural Resources Faculty Publications

The soil active layer in boreal forests is sensitive to climate warming. Climate-induced changes in the active layer may greatly affect the global carbon budget and planetary climatic system by releasing large quantities of greenhouse gases that currently are stored in permafrost. Ground surface temperature is an immediate driver of active layer thickness (ALT) dynamics. In this study, we mapped ALT distribution in Chinese boreal larch forests from 2000 to 2015 by integrating remote sensing data with the Stefan equation. We then examined the changes of the ALT in response to changes in ground surface temperature and identified drivers of …


Remote Sensing Using I-Band And S-Band Signals Of Opportunity, Kadir Efecik, Benjamin R. Nold, James L. Garrison Aug 2018

Remote Sensing Using I-Band And S-Band Signals Of Opportunity, Kadir Efecik, Benjamin R. Nold, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Measurement of soil moisture, especially the root zone soil moisture, is important in agriculture, meteorology, and hydrology. Root zone soil moisture is concerned with the first meter down the soil. Active and passive remote sensing methods used today utilizing L-band(1-2GHz) are physically limited to a sensing depth of about 5 cm or less. To remotely sense the soil moisture in the deeper parts of the soil, the frequency should be lowered. Lower frequencies cannot be used in active spaceborne instruments because of their need for larger antennas, radio frequency interference (RFI), and frequency spectrum allocations. Ground-based passive remote sensing using …


Geophysical Assessment Of Subsurface Soil Conditions Using Capacitively Coupled Resistivity, Folaseye Coker Aug 2018

Geophysical Assessment Of Subsurface Soil Conditions Using Capacitively Coupled Resistivity, Folaseye Coker

Graduate Theses and Dissertations

The purpose of this research is to explore the applicability of Capacitively-Coupled Resistivity (CCR) as an improvement on traditional drilling and sampling methods for subsurface soil investigations. The CCR method could be used to identify critical locations for drilling and sampling such as expansive clay layers and anomalies (sinkholes, unknown landfills, etc.) rather than uniformly sampling across a site. CCR surveys were performed at Alpena, Arkansas along a highway expansion project changing US 62 from a two lane to four lane highway, and at Alton, Illinois along the Mel Price Levee, a 5.2 mile levee along a portion of the …


Proposed Astm Standard For The Stokoe-Type Resonant Column Torsional Shear Device, Anh Tuan Tran Aug 2018

Proposed Astm Standard For The Stokoe-Type Resonant Column Torsional Shear Device, Anh Tuan Tran

Graduate Theses and Dissertations

Resonant Column Torsional Shear (RCTS) testing has become one of the most commonly used methods for determining laboratory soil stiffness and soil damping. The RCTS test has been accepted and is commonly utilized during the permitting of new nuclear facilities. However, there is still no available public standard for performing RCTS tests using the Stokoe-type device. Therefore, an ASTM standard for calibration and performance of RCTS tests using the Stokoe-type RCTS device is presented herein. Data collected using the Stokoe-type RCTS devices at the University of Arkansas (UofA) and at the Norwegian Geotechnical Institute (NGI) also aided in the development …


Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd Aug 2018

Flow Regime Influences On Stream And Riparian Soil Carbon Dynamics In The Ozark Highlands And Boston Mountains Of Arkansas, Allyn Dodd

Graduate Theses and Dissertations

The natural flow regime exerts primacy over lotic ecosystem patterns and processes. However, little work has examined the influence of flow regime on instream and riparian carbon (C) dynamics in minimally-impacted, temperate forested systems. To date, most research efforts have focused on characterizing C movement and transformations across biomes and land use categories; however, flow regime represents an overlooked, finer level of detail that may drive differences in ecosystem function. My dissertation objective was to measure C fixation and movement within and across multiple environmental spheres (e.g. within stream channels, between stream surfaces and the atmosphere, and from riparian soils …


Managing Herbicide Resistance: Listening To The Perspectives Of Practitioners. Procedures For Conducting Listening Sessions And An Evaluation Of The Process, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Micheal D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel Aug 2018

Managing Herbicide Resistance: Listening To The Perspectives Of Practitioners. Procedures For Conducting Listening Sessions And An Evaluation Of The Process, Jill Schroeder, Michael Barrett, David R. Shaw, Amy B. Asmus, Harold Coble, David Ervin, Raymond A. Jussaume Jr., Micheal D. K. Owen, Ian Burke, Cody F. Creech, A. Stanley Culpepper, William S. Curran, Darrin M. Dodds, Todd A. Gaines, Jeffrey L. Gunsolus, Bradley D. Hanson, Prashant Jha, Annie E. Klodd, Andrew R. Kniss, Ramon G. Leon, Sandra Mcdonald, Don W. Morishita, Brian J. Schutte, Christy L. Sprague, Phillip W. Stahlman, Larry E. Steckel, Mark J. Vangessel

Plant and Soil Sciences Faculty Publications

Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting …


Testing An Improved Method For Estimating The Unsaturated Hydraulic Conductivity Of Moderately Dry Soils, Sara Gedo Aug 2018

Testing An Improved Method For Estimating The Unsaturated Hydraulic Conductivity Of Moderately Dry Soils, Sara Gedo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Prediction of water movement in the vadose zone requires knowledge of either the unsaturated hydraulic conductivity, K(θ), or the hydraulic diffusivity, D(θ), of the soil as a function of the moisture content. However, both K(θ) and D(θ) are difficult to obtain for moderately dry soils because the tests are time consuming and expensive. In order to address this issue, Globus and Gee (1995) developed a “heat pipe” method that allowed for the direct estimation of D(θ) and K(θ) for moderately dry soils on relatively short time scales. They proposed that exposing a sealed horizontal soil column to a steady thermal …


Dissolution Rates Of Allophane, Fe-Allophane, And Hisingerite And Implications For Aqueous Alteration On Mars And In Potential Returned Martian Samples, S. J. Ralston Aug 2018

Dissolution Rates Of Allophane, Fe-Allophane, And Hisingerite And Implications For Aqueous Alteration On Mars And In Potential Returned Martian Samples, S. J. Ralston

UNLV Theses, Dissertations, Professional Papers, and Capstones

Recent measurements from Mars document X-ray amorphous/nano-crystalline materials in multiple locations across the planet. However, despite their prevalence, little is known about these materials or what their presence implies for the history of Mars. The amorphous component of the martian soil in Gale Crater has an X-ray diffraction pattern that can be partially fit with allophane (approximately Al2O3•(SiO2)1.3-2•(H2O)2.5-3), as well as low-temperature water release consistent with allophane. The chemical data from Gale Crater suggest that other silicate phases similar to allophane, such as Fe-substituted allophane (here, approximately (Fe2O3)0.01(Al2O3)0.99(SiO2)2•3H2O) and hisingerite (approximately Fe3+2Si2O5(OH)4•(H2O)), may also be present. In order to investigate …


Improvement Of Soil Structure Through Organic Crop Management, Conservation Tillage And Grass-Clover Ley, Viviana Loaiza Puerta, Engil Isadora Pujol Pereira, Raphaël Wittwer, Marcel G. A. Van Der Heijden, Johan Six Aug 2018

Improvement Of Soil Structure Through Organic Crop Management, Conservation Tillage And Grass-Clover Ley, Viviana Loaiza Puerta, Engil Isadora Pujol Pereira, Raphaël Wittwer, Marcel G. A. Van Der Heijden, Johan Six

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

  • Organic crop management combined with reduced tillage improved soil structure.
  • The ley period improved soil structure for conventional intensive tillage.
  • The ley period increased total carbon in organic crop management at 0–6 cm soil depth.

Abstract

Conventional intensive tillage is a widespread soil management practice that controls weeds and promotes nutrient mineralization at the expense of a degraded soil structure and soil carbon (C) loss. Alternative soil management practices such as no tillage, reduced tillage and temporary leys, however, can minimize the negative effects of intensive tillage on soil structure. To improve understanding of these management practices on …


Plant And Microbial Responses To Repeated Cu(Oh)2 Nanopesticide Exposures Under Different Fertilization Levels In An Agro-Ecosystem, Marie Simonin, Benjamin P. Colman, Weiyi Tang, Jonathan D. Judy, Steven M. Anderson, Christina M. Bergemann, Jennifer D. Rocca, Jason M. Unrine, Nicolas Cassar, Emily S. Bernhardt Jul 2018

Plant And Microbial Responses To Repeated Cu(Oh)2 Nanopesticide Exposures Under Different Fertilization Levels In An Agro-Ecosystem, Marie Simonin, Benjamin P. Colman, Weiyi Tang, Jonathan D. Judy, Steven M. Anderson, Christina M. Bergemann, Jennifer D. Rocca, Jason M. Unrine, Nicolas Cassar, Emily S. Bernhardt

Plant and Soil Sciences Faculty Publications

The environmental fate and potential impacts of nanopesticides on agroecosystems under realistic agricultural conditions are poorly understood. As a result, the benefits and risks of these novel formulations compared to the conventional products are currently unclear. Here, we examined the effects of repeated realistic exposures of the Cu(OH)2 nanopesticide, Kocide 3000, on simulated agricultural pastureland in an outdoor mesocosm experiment over 1 year. The Kocide applications were performed alongside three different mineral fertilization levels (Ambient, Low, and High) to assess the environmental impacts of this nanopesticide under low-input or conventional farming scenarios. The effects of Kocide over time were …


Genome-Wide Atlas Of Alternative Polyadenylation In The Forage Legume Red Clover, Manohar Chakrabarti, Randy D. Dinkins, Arthur G. Hunt Jul 2018

Genome-Wide Atlas Of Alternative Polyadenylation In The Forage Legume Red Clover, Manohar Chakrabarti, Randy D. Dinkins, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Studies on prevalence and significance of alternative polyadenylation (APA) in plants have been so far limited mostly to the model plants. Here, a genome-wide analysis of APA was carried out in different tissue types in the non-model forage legume red clover (Trifolium pratense L). A profile of poly(A) sites in different tissue types was generated using so-called ‘poly(A)-tag sequencing’ (PATseq) approach. Our analysis revealed tissue-wise dynamics of usage of poly(A) sites located at different genomic locations. We also identified poly(A) sites and underlying genes displaying APA in different tissues. Functional categories enriched in groups of genes manifesting APA between …


El Niño-Southern Oscillation Complexity, Axel Timmermann, Soon-Il An, Jong-Seong Kug, Fei-Fei Jin, Wenju Cai, Antonietta Capotondi, Kim Cobb, Matthieu Lengaigne, Michal J. Mcphaden, Malte F. Stuecker, Karl Stein, Andrew T. Wittenberg, Kyung-Sook Yun, Tobias Bayr, Han-Ching Chen, Yoshimitsu Chikamoto, Et Al. Jul 2018

El Niño-Southern Oscillation Complexity, Axel Timmermann, Soon-Il An, Jong-Seong Kug, Fei-Fei Jin, Wenju Cai, Antonietta Capotondi, Kim Cobb, Matthieu Lengaigne, Michal J. Mcphaden, Malte F. Stuecker, Karl Stein, Andrew T. Wittenberg, Kyung-Sook Yun, Tobias Bayr, Han-Ching Chen, Yoshimitsu Chikamoto, Et Al.

Plants, Soils, and Climate Faculty Publications

El Niño events are characterized by surface warming of the tropical Pacific Ocean and weakening of equatorial trade winds that occur every few years. Such conditions are accompanied by changes in atmospheric and oceanic circulation, affecting global climate, marine and terrestrial ecosystems, fisheries and human activities. The alternation of warm El Niño and cold La Niña conditions, referred to as the El Niño–Southern Oscillation (ENSO), represents the strongest year-to-year fluctuation of the global climate system. Here we provide a synopsis of our current understanding of the spatio-temporal complexity of this important climate mode and its influence on the Earth system.