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Integration Of An Extended Octagonal Ring Transducer And Soil Coulterometer For Identifying Soil Compaction, Santosh K. Pitla, Larry G. Wells, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

The soil coulterometer is an "on-the-go" electro-mechanical system which collects impedance force data at multiple depths using an oscillating coulter. During the initial testing (summer 2006), only vertical soil impedance force data was collected using a pressure sensor. To improve the performance of the coulterometer, an extended octagonal ring transducer was integrated into the system to collect both the horizontal and vertical impedance forces given by the soil. In the summer of 2007, data was collected using the revised sensor from a typical central Kentucky field setting in a 0.8-ha (2-acre) plot. Four passes were made with the coulterometer. Seventy …

Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

In south-western United States, soil moisture data is important for drought studies in the region which is experiencing a drought for many years, whereas in South Florida, water stage data is required by hydrologists to monitor the hydrological flow in wetlands. Soil moisture data and water stage data are not sufficiently available due to sparse monitoring stations. Installation of dense measuring stations over an extended area is costly and labor intensive. Therefore, there is a need to develop an alternative method of measuring soil moisture and water stage. Microwave remote sensing has proven to be a useful tool in the …

Effects Of Plant Uptake And Micro-Topography On Chloride Transport In Arid Soils, Wenming Nie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chloride concentration profiles to depths of 1 m were evaluated on a young alluvial fan in Eldorado Valley, NV. It was found that chloride beneath plant canopies were 11 to 222 times higher than adjacent (1 - 2 m away) bare soil locations. Two-dimensional numerical simulations using HYDRUS 2D/3D model were used to further explore the impact of plants on chloride transport. The simulation results indicated that lateral flow driven by root uptake concentrated chloride toward root zones, leading to the accumulation of chloride under plant canopies. Results also suggest that locally micro-topography can have a substantial impact on chloride …

Mineralogy And Micromorphology Of An Atacama Desert Soil, Chile: A Model For Hyperarid Pedogenesis, Michael S. Howell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Atacama Desert is the oldest and driest desert on Earth. Hyperarid soils in this desert are dominated by rare (or exclusive) salt minerals and assemblages. Previous research details salt origins and abundance, however pedogenic processes involved in salt distribution are not adequately explained. Therefore, the main goal of this investigation was to identify and document evidence for hyperarid pedogenesis (via salt mineralogy and soil micromorphology) at a field site, Oficina Ercilla, located ~80 km northeast of Antofagasta, Chile within the Central Depression and hyperarid core of the Atacama Desert. This study presents an interpretational model for hyperarid pedogenesis, which …

Analytical Method Development For Determination Of Volatile Organic Compounds In Calcareous Desert Soil, Mary F. Turner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soil sample preservation for volatile organic compound analysis generally requires short sample holding times or preservation of the sample's chemical constituents with sodium bisulfate (NaHSO 4 ). Calcareous soils cannot be preserved using NaHSO4 because effervescence will promote the loss of analytes, and short holding times before analysis are not practical for remote sampling locations. An experimental approach was developed for determination of volatile organic compounds (VOCs) in soil that utilizes solid sorbents for sample preservation and solid-phase microextraction (SPME) sample preparation technique coupled with gas chromatography/mass spectrometry (GC/MS) for analysis. Solid sorbents are used to sequester readily extractable (vapor …

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota, Jennifer Borgo

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Solarization Effects On Chemical Properties Of Soils Under Kudu (Pueraria Montana) Invasion, Nicole Gilbert

All Theses

Solarization is an effective method for managing small areas with kudzu (Pueraria montana) invasions that may alter soil chemical properties. Conducted from 2005 to 2007 at the Clemson University Experimental Forest in Clemson, South Carolina on a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludult), this study compares soil chemical properties under thermally-treated and non-treated plots at different depths invaded by Kudzu.
The experimental factors of treatment and depth were arranged in a factorial treatment design with 15 treatments arranged in a split plot design. The five thermal treatments were the whole plot factors which were arranged in a randomized …

Identification Of Subsoil Compaction Using Electrical Conductivity And Spectral Data Across Varying Soil Moisture Regimes In Utah, Jay Murray Payne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Subsoil compaction is a major yield limiting factor for most agricultural crops. Tillage is the most efficient method to quickly treat compacted subsoil, but it is also expensive, increases erosion, and accelerates nutrient cycling.

The use of real-time electrical conductivity (EC) and near-infrared (NIR) reflectance values to differentiate compacted areas from uncompacted areas was studied. This method has potential to reduce monetary and time investments inherent in traditional grid sampling and the resultant deep tillage of an entire field. EC and NIR reflectance are both very sensitive to spatial variability of soil attributes.

The objective of this research was to …

Measurement Of Fine Spatial Scale Ecohydrologic Gradients In A Pinyon-Juniper Ecosystem, Matthew David Madsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, …

Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m³/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m).

To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase …

Variations In Stomatal Traits Of 14 Bornean Tree Species Growing On Soils With Different Moisture Contents In Lambir Hills National Park, Whitney Logan Cannon

Department of Environmental Studies: Undergraduate Student Theses

The goal of this study was to look at variations in stomatal traits of tree species on soils with different moisture contents and fertility at Lambir Hills National Park. Stomates are important structures on the surface of leaves that mediate conduction of moisture and gassesin and out of the leaf. If stomatalt raits are important for regulation, then there should be variation in stomatal traits in regards to their soil specialization. The 14 Borneant ree speciess ampledi ncluded6 sandyl oam specialists6, clay specialistsa nd 2 generalistsfo und growing with equald istributionso n both sandyl oam and clay. Confocal microscopy was …

Optlime, A Bioecenomic Model Of Soil Acidity Management In Agricultural Systems, Chris Gazey

All other publications

Optlime is a model that represents the essential biological, physical and economic factors related to soil acidity management in Western Australia. The model allows users to define site and soil characteristics for an acidic scenario and then simultaneously assess likely outcomes for 2 different lime sources and application strategies. With and without liming scenarios are examined over a 20 year simulation so as to capture the long-term impacts of soil acidity management. Output provided allows you to examine the likely effect of liming on pH, exchangeable aluminium, yields, and profits. An investment appraisal is provided to show you how liming …

Lime For High Rainfall Pastures: Above 800mm Average Annual Rainfall, Mike Bolland, Bill Russell

Bulletins 4000 -

Conventional agriculture acidifies soil. As your soil becomes more acid, productive pasture species disappear and are replaced by species of low agricultural value. It is a waste of money to apply expensive fertiliser to pastures which are inherently poorly productive because they are growing in an acid soil.

The paper examines the types of lime available, how to select lime for quality and when and how much lime to apply. Maganese toxity and aluminum toxicity are examine, how to test your soil, and affect of soil acidity on bacteria and other microorgansims.

Estimating Soil Seed Bank Characteristics In Ponderosa Pine Forests Using Vegetation And Forest-Floor Data, Scott R. Abella, Judith D. Springer

Public Policy and Leadership Faculty Research

Soil seed banks are important for vegetation management because they contain propagules of species that may be considered desirable or undesirable for site colonization after management and disturbance events. Knowledge of seed bank size and composition before planning management activities facilitates proactive management by providing early alerts of exotic species presence and of abilities of seed banks to promote colonization by desirable species. We developed models in ponderosa pine (Pinus ponderosa) forests in northern Arizona to estimate the size and richness of mineral soil seed banks using readily observable vegetation and forestfloor characteristics. Regression models using three or fewer predictors …

Stereospecificity In Glucose Consumption: A New Approach To Martian Life Detection, Vienna R. Saccomanno, Henry J. Sun

Undergraduate Research Opportunities Program (UROP)

In 1976, the Viking mission made a remarkable discovery: Martian soil was capable of decomposing an organic nutrient broth to carbon dioxide as if it contained live microorganisms. However, a biological interpretation of this finding is in apparent contradiction with the gas chromatograph-mass spectrometer aboard the Viking landers, which showed Martian soil to be devoid of indigenous organics. To reconcile these findings, it has been hypothesized that unknown abiotic oxidants, such as peroxide and superoxide, are present on Mars and that they were responsible for its soil reactivity. The objective of this research is to develop a life detection method …

Potential Antimicrobial Properties Of The Cyanobacterium Microcoleus Vaginatus In Relationship To The Moss Bryum Argenteum, Crystal Erickson, Lloyd Stark

Undergraduate Research Opportunities Program (UROP)

Biological soil crusts play important ecological roles in arid desert regions. These crusts cycle nutrients, prevent wind/water erosion, and form the basis of food chains and soil formation in desert communities. Primary components of these structures include two desert moss species Bryum argenteum and Syntrichia caninervis, and Microcoleus vaginatus, a cyanobacterium. Our Phase I experiment strongly suggests that in an environment of intense light, a condition of stress to Syntrichia caninervis, there is an increase in shoot regeneration when cyanobacteria are present compared to when they are absent. Microcoleus is a highly motile species and our lab observations of fewer …

Compost Production And Use In Horticulture, Bob Paulin, Peter O'Malley

Bulletins 4000 -

Maintaining and improving soil organic carbon levels is becoming an increasingly important aspect of modern farming. Compost provides potentially one of the most effective ways of applying organic matter to soils and improving organic carbon levels.

Improving soil organic carbon is directly related to soil quality and performance. Increased quality reflects improved biological function (soil health), fertility and physical attributes that include better drainage, reduced compaction and erosion, and improved moisture-holding capability, at least for lighter soils.

Compost is not the only option available. Others include the use of cover or break crops, reducing the use of cultivations, selecting safe …

Land Use Influences The Spatiotemporal Controls On Nitrification And Denitrification In Headwater Streams, Clay P. Arango, J. L. Tank

All Faculty Scholarship for the College of the Sciences

N and C cycles in headwater streams are coupled, and land use can modify these cycles by increasing N availability and removing riparian vegetation. To increase our understanding of how land use modifies the controls on N cycling, we quantified rates of 2 microbial N transformations in a total of 18 agricultural and urban streams (with and without riparian buffers) for 3 y to examine how riparian vegetation and land use influence sediment nitrification and denitrification. Nitrification rates were highest in agricultural streams in late spring. Nitrification was not related to streamwater NH₄⁺ concentrations but was positively related …

Economics Of Soil Conservation Adoption In High-Rainfall Areas Of The Ethiopian Highlands, Menale Kassie, Stein Holden, Gunnar Köhlin, Randall Bluffstone

Economics Faculty Publications and Presentations

This study measures the impact of fanya juu bunds (an important soil and water conservation technology and the most popular type of contour bund in east Africa) on the value of crop production in a high-rainfall area in the Ethiopian highlands using cross-sectional multiple plot observations. We applied switching regression, stochastic dominance analysis (SDA), and decomposition and propensity score matching methods to ensure robustness. The switching regression, SDA, and decomposition analyses relied on matched observations, which was important because regression and SDA often do not ensure that comparable plots with conservation technology (conserved) and plots without (unconserved) actually exist in …

Alfalfa: Forage Crop Of The Future, Neal P. Martin, David Mertens, Ronald Hatfield, Hans Jung

Kentucky Alfalfa and Stored Forage Conference

In 2007, U.S. farmers harvested 23.6 million acres of alfalfa. Alfalfa harvested as hay and haylage produced 82.8 million tons valued at approximately $9.4 billion, ranking behind only corn and soybeans. Alfalfa hay supports dairy, beef, sheep, and horse production in the U.S. as well as a growing export market.

From Debate To Design: Issues In Clean Energy And Climate Change Law And Policy, Leslie Parker, Jennifer Ronk, Rachel Maxwell, Bradford Gentry, Marijn Wilder, James Cameron

Yale School of the Environment Publications Series

A report on the work of the REIL Network 2007-2008

Mullewa Research Annexe Spring Field Day Future Farming Systems For North-Eastern Districts 21 August 2008, Department Of Agriculture, Western Australia

Grain and other field crops research reports

Papers:

• Mullewa Research Annexe activities 2008

• Wheat for today and the future

• Consequences of strongly acidic and alkaline soils

• Break crop influence on low rainfall heavy soil

• Chemical fallow options for the north-east agricultural region

• Herbicide tolerance of new wheat varieties

• Lowrainfall oilseed crops for food and biofuel

• Utilising stock to reduce business risk in Binnu! A case study

Radiocarbon Evidence For The Importance Of Surface Vegetation On Fermentation And Methanogenesis In Contrasting Types Of Boreal Peatlands, J. P. Chanton, P. H. Glaser, L. S. Chasar, David J. Burdige, M. E. Hines, D. I. Seigel, L. B. Tremblay, W. T. Cooper

OES Faculty Publications

We found a consistent distribution pattern for radiocarbon in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and methane replicated across spatial and temporal scales in northern peatlands from Minnesota to Alaska. The ¹⁴C content of DOC is relatively modern throughout the peat column, to depths of 3 m. In sedge-dominated peatlands, the ¹⁴C contents of the products of respiration, CH₄ and DIC, are essentially the same and are similar to that of DOC. In Sphagnum- and woody plant-dominated peatlands with few sedges, however, the respiration products are similar but intermediate between the ¹⁴C contents of …

Using Biosolids To Enhance Phytoremediation Of Oil-Contaminated Soil, Heather N. Markway, Duane C. Wolf, Kaaron J. Davis, Edward E. Gbur

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

While the plant rhizosphere and associated microbial processes have been shown to amplify the degradation rate of chemical residues in soils, phytoremediation can be a slow process. The objective of this greenhouse study was to determine if the addition of biosolids as an organic soil amendment would enhance growth of plants in oil-contaminated soil and thus potentially increase effectiveness of phytoremediation. Pearl millet (Pennisetum glaucum (L.) R. Br.) or sudangrass (Sorghum sudanense (Piper) Stapf (Piper)) was grown in a Captina silt loam (finesilty, siliceous, mesic Typic Fragiudults) contaminated with 5% crude oil (v/w) and amended with 24 g biosolids/kg soil. …

The Balancing Act, David Weaver

Conference papers and presentations

Nutrient management is as much a global issue as a local one with a balance required between economics and environment, inherent biological limitations and expectations of nutrient use efficiency, and traditional fertiliser practices and actual enterprise nutrient requirements. The concept of nutrient balance depends on context and scale. Nutrient balance can be considered at a global scale, where issues of nutrient stocks, cycles, depletion and transfer of a particular element are important. For a single farm enterprise, nutrient balance might be considered in terms of phosphorus (P) inputs into and outputs from the enterprise. This is commonly known as a …

Reclamation Of Saline Soils Through Revegetation In Australia: Plants, Processes And People, Edward G. Barrett-Lennard

Conference papers and presentations

Secondary salinity (salinity induced by human activity) is a major world problem. Hydrological imbalances in landscapes cause watertables to rise, drawing salt from deeper in the soil profile to the soil surface, where the combined stresses of salinity and waterlogging threaten the growth of crops and pastures. The reversal of salinity by the broad‐scale reintroduction of perennial plants back into landscapes may not be economically feasible, but watertables may be at least partly directly drawn‐down by the grow th of salt tolerant plants (halophytes) on saltland . This review summarises data from Australia in which the water use by perennial …

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …

Geogram 2007, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

A Simple Array Platform For Microrna Analysis And Its Application In Mouse Tissues, Xiaoqing Tang, Jozsef Gal, Xun Zhuang, Wang-Xia Wang, Haining Zhu, Guiliang Tang

Plant and Soil Sciences Faculty Publications

MicroRNAs (miRNAs) are a novel class of small noncoding RNAs that regulate gene expression at the post-transcriptional level and play a critical role in many important biological processes. Most miRNAs are conserved between humans and mice, which makes it possible to analyze their expressions with a set of selected array probes. Here, we report a simple array platform that can detect 553 nonredundant miRNAs encompassing the entire set of miRNAs for humans and mice. The platform features carefully selected and designed probes with optimized hybridization parameters. Potential cross-reaction between mature miRNAs and their precursors was investigated. The array platform was …

Microbial Nitrogen Limitation Increases Decomposition, Joseph M. Craine, Carl Morrow, Noah Fierer

Dartmouth Scholarship

With anthropogenic nutrient inputs to ecosystems increasing globally, there are long-standing, fundamental questions about the role of nutrients in the decomposition of organic matter. We tested the effects of exogenous nitrogen and phosphorus inputs on litter decomposition across a broad suite of litter and soil types. In one experiment, C mineralization was compared across a wide array of plants individually added to a single soil, while in the second, C mineralization from a single substrate was compared across 50 soils. Counter to basic stoichiometric decomposition theory, low N availability can increase litter decomposition as microbes use labile substrates to acquire …