Soil Science Commons^™

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 …

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 …

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

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.

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.

Differential Responses Of Carbon-Degrading Enzyme Activities To Warming: Implications For Soil Respiration, Ji Chen, Yiqi Luo, Pablo García-Palacios, Junji Cao, Marina Dacal, Xuhui Zhou, Jianwei Li, Jianyang Xia, Shuli Niu, Huiyi Yang, Shelby Shelton, Wei Guo, Kees Jan Van Groenigen

Agricultural and Environmental Sciences Faculty Research

Extracellular enzymes catalyze rate-limiting steps in soil organic matter decomposition, and their activities (EEAs) play a key role in determining soil respiration (SR). Both EEAs and SR are highly sensitive to temperature, but their responses to climate warming remain poorly understood. Here, we present a meta-analysis on the response of soil cellulase and ligninase activities and SR to warming, synthesizing data from 56 studies. We found that warming significantly enhanced ligninase activity by 21.4% but had no effect on cellulase activity. Increases in ligninase activity were positively correlated with changes in SR, while no such relationship was found for cellulase. …

Using Geological Facies To Estimate Chromate Sorption To Soils, Victoria Smith, Daja Scurlock, Chauntilena Butler, Eddie Hollins, Kennedy Smith, Tim Spearman, Christina Fulghum, John Dickson, Daniel I. Kaplan, Miles Denham, Garriet Smith

Journal of the South Carolina Academy of Science

Quantifying the extent to which contaminant metals bind to subsurface soils is important for risk assessment, the tendency for a contaminant to migrate, and developing environmental remediation strategies. Unfortunately, subsurface soils vary widely in their composition, which in turn affect their tendency to bind metals. The hypothesis of this study was predicated on how a better understanding of geological facies would reduce uncertainty associated with predicting contaminant metal sorption. Facies are layers of sediment deposited in the subsurface due to similar depositional conditions, including energy of an overlying waterway. As such, facies are expected to have similar assemblages of minerals, …

Distribution Of Classified Soils In South-West Western Australia, Dennis Van Gool, Angela Stuart-Street, Peter Tille

Resource management technical reports

This report provides areas, locations and properties of the main soil classifications identified in south-west Western Australia using current conventional soil map data. It is a reference point for classified soils in the south-west. It provides a way of communicating how soil properties or productivity are likely to relate to soils with similar classifications found elsewhere so that soil research or knowledge can be effectively shared around the state and across Australia.

This is a high-level summary of the relationships between the main soil classifications currently used in Western Australia. These are: • Western Australian Soil Groups, WASG (Schoknecht & …

Integrated Soil Fertility Management Sequences For Reducing Climate Risk In Smallholder Crop Production Systems In Southern Africa, Hatirarami Nezomba, Florence Mtambanengwe, Jairos Rurinda, Paul Mapfumo

All Peer-Reviewed Publications

Climate change, increased climate variability and poor soil fertility are major bio-physical constraints to cropping on smallholder farms in southern Africa. We used the Agricultural Production Systems sIMulator (APSIM) to assess maize yield response to integrated soil fertility management (ISFM) rotational sequences of low-quality organic resources, nitrogen-fixing green manure and grain legumes, and mineral fertilizers under baseline (1960–2005) and projected (2040–2069) climates. APSIM was also employed to evaluate the response of maize yield to the ISFM sequences under a combination of a changing climate, and typical sowing dates and mineral fertilizer application rates for smallholder households of varying resource endowment. …

Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Wildfires are a major ecological disturbance in Southern California and often lead to great destruction along the Wildland-Urban Interface. Live fuel moisture has been used as an important indicator of wildfire risk in measurements of vegetation water content. However, the limited field measurements of live fuel moisture in both time and space have affected the accuracy of wildfire risk estimations. Traditional estimation of live fuel moisture using remote sensing data was based on vegetation indices, indirect proxies of vegetation water content and subject to influence from weather conditions. In this study, we investigated the feasibility of estimating live fuel moisture …

A Broad Spectrum Racemase In Pseudomonas Putida Kt2440 Plays A Key Role In Amino Acid Catabolism, Atanas D. Radkov, Luke A. Moe

Plant and Soil Sciences Faculty Publications

The broad-spectrum amino acid racemase (Alr) of Pseudomonas putida KT2440 preferentially interconverts the L- and D-stereoisomers of Lys and Arg. Despite conservation of broad-spectrum racemases among bacteria, little is known regarding their physiological role. Here we explore potential functional roles for Alr in P. putida KT2440. We demonstrate through cellular fractionation that Alr enzymatic activity is found in the periplasm, consistent with its putative periplasm targeting sequence. Specific activity of Alr is highest during exponential growth, and this activity corresponds with an increased accumulation of D-Lys in the growth medium. An alr gene knockout strain (Δalr) was generated …

Soil Conservation Efforts Affecting And Implementations To Help Tree Growth In Iceland, Justin Lawlor

Student Works

The purpose of this research was to understand and project the opinions of the public in Iceland on soil conservation and current efforts. The issue of soil erosion dates back to settlement around 1,100 years ago. The loss of vegetation from deforestation and grazing exposes the land to the effects of wind, water, and other devastating elements, leading it to erode away. The Soil Conservation Service of Iceland (SCSI) was developed to combat this issue over 100 years ago with efforts including planting trees, promoting safe farming practices, and replenishing the land. Interviews were conducted with various individuals, including a …

On The Way To Create A New Exchange Dealer With The Vekua-Erdei-Loundes, Sh. Karimov,, L. Rakhimova

Scientific journal of the Fergana State University

In this article the composition of the transformation operator Vekua-Erdey-Loundes with Bessel function in the nucleus and the fractional order operator Reeman-Zuivill is studied. As a result a new prevention with a degenerated hypergeometric function Gumbert in the nucleus is recieved.

On The Way To Create A New Exchange Dealer With The Vekua-Erdei-Loundes, Sh. Karimov,, L. Rakhimova

Scientific journal of the Fergana State University

In this article the composition of the transformation operator Vekua-Erdey-Loundes with Bessel function in the nucleus and the fractional order operator Reeman-Zuivill is studied. As a result a new prevention with a degenerated hypergeometric function Gumbert in the nucleus is recieved.

On The Way To Create A New Exchange Dealer With The Vekua-Erdei-Loundes, Sh. Karimov,, L. Rakhimova

Scientific journal of the Fergana State University

In this article the composition of the transformation operator Vekua-Erdey-Loundes with Bessel function in the nucleus and the fractional order operator Reeman-Zuivill is studied. As a result a new prevention with a degenerated hypergeometric function Gumbert in the nucleus is recieved.

Glyphosate In Soils: Retention, Transport, And Effect Of Phosphate, Joshua Padilla

LSU Master's Theses

Glyphosate [N-(phosphonomethyl) glycine)] (GPS) is currently the most commonly used herbicide worldwide, and is generally considered as immobile in soils. However, numerous reports of the environmental occurrence of the herbicide coupled with recent evidence of human toxicity require further investigation as to the behavior of GPS in the soil environment. The objectives of this study were to quantify GPS sorption and mobility in two Louisiana agricultural soils with varying physiochemical properties; Commerce silt loam and Sharkey clay. Results of batch sorption studies indicated a high affinity of both soils for solvated GPS, with 24-hour Freundlich partitioning coefficients of 158 and …

Column Tests Of Nitrate Breakthrough Behavior In Subsurface Sediments To Understand Transport In The Root-Zone, Rebecca Sally Haworth, Emma Rose Goodwin

Natural Resources Management and Environmental Sciences

Nitrate has become an increasingly ubiquitous pollutant in surface and groundwater, posing a threat to hu- man health and ecosystems. Nitrogen is a necessary nutrient for plant growth and is limiting in many soils. As a result, farmers often add nitrogen to soil in a usable form such as nitrate, nitrite, or ammonia through the addition of fertilizer.

Groundwater Prospectivity In The Midlands Area, L J. Baddock, S Johnson

Natural resources commissioned reports

As part of the Water For Food Midlands project, Department of Primary Industry and Regional Development (DPIRD) is undertaking mapping of high-quality agricultural land (HQAL) to identify areas of agricultural value. This mapping utilises data relating to soils, land capability and rainfall, that is being integrated into a GIS-format that is easy to comprehend and can be incorporated into planning processes. This report details the development and results of a GIS-based product that represents groundwater resource prospectivity for irrigated agriculture in the Midlands project area. The output maps will be useful for landowners and developers highlighting the opportunities and risks …

A Quantitative Analysis Of The Effects Of Urbanization, Mesophication And Prescribed Burns On Oak Woodlands In The Chicago Metropolitan Area, Chad Populorum

Celebration of Learning

Urban expansion has had devastating impacts on forest ecosystems, especially within the past century. Human attempts to dominate nature have diminished natural disturbance regimes, which have maintained the biodiversity and historic composition of these ecosystems. Fires have been a prominent force in maintaining the structure of oak, hickory and other heliophytic (sun loving and fire-adapted) forest systems. Human induced fire suppression has led to mesophication across North America. Mesophication is the transition from drier conditions with open canopies to wetter conditions with closed canopies. These new conditions decrease the survival rates of these important species and begin to favor mesophytic …

Results Of Test-Hole Drilling For Observation Well Planning In The Lower Loup Natural Resources District, Spring 2017, Douglas R. Hallum P.G., Sue Olafsen Lackey, Steven S. Sibray

Conservation and Survey Division: Faculty and Staff Publications

The High Plains Aquifer underlies much of Nebraska. It is the primary source of groundwater within the Lower Loup Natural Resources District (LLNRD) of central Nebraska. 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. Falling spring water levels measured in existing observation and irrigation wells have raised concerns about possible changes in water availability, groundwater-surface water relationships and water quality in the area, prompting the LLNRD to propose test holes and the collection of additional groundwater data in the …