Soil Science Commons^™

Microbial Ecology, Nitrogen, And Nitrous Oxide Trends In Marginal Soils Used For Cellulosic Biofuel Production In Eastern Nebraska, Carla M. Ahlschwede

School of Natural Resources: Dissertations, Theses, and Student Research

There is a growing demand for diverse biofuels in the United States. Potential feedstocks for cellulosic ethanol include corn (Zea mays, L.) stover and switchgrass (Panicum virgatum, L). Lands used to provide for corn production can provide some cellulosic feedstock through corn stover, but crop residue removal can have negative impacts on soil quality. Furthermore, arable land must supply both fuel and food. To meet both demands, lands considered marginal for row-crop production will likely be used to produce dedicated bioenergy crops such as switchgrass. Marginal lands are typically placed in conservation programs because they are prone …

Accelerated Thermokarst Formation In The Mcmurdo Dry Valleys, Antarctica, Joseph S. Levy, Andrew G. Fountain, James L. Dickson, James W. Head, Marianne Okal, David R. Marchant, Jaclyn Watters

Geology Faculty Publications and Presentations

Thermokarst is a land surface lowered and disrupted by melting ground ice. Thermokarst is a major driver of landscape change in the Arctic, but has been considered to be a minor process in Antarctica. Here, we use ground-based and airborne LiDAR coupled with timelapse imaging and meteorological data to show that 1) thermokarst formation has accelerated in Garwood Valley, Antarctica; 2) the rate of thermokarst erosion is presently,10 times the average Holocene rate; and 3) the increased rate of thermokarst formation is driven most strongly by increasing insolation and sediment/albedo feedbacks. This suggests that sediment enhancement of insolation-driven melting may …

Water Track Modification Of Soil Ecosystems In The Lake Hoare Basin, Taylor Valley, Antarctica, Joseph S. Levy, Andrew G. Fountain, Michael N. Gooseff, John E. Barrett, Robert Vantreese, Kathleen A. Welch, W. Berry Lyons, Uffe N. Nielsen, Diana H. Wall

Geology Faculty Publications and Presentations

Water tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Will Hubbard Brook Soils Be A Source Or Sink Of Carbon In A Changing Climate?, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

No abstract provided.

Soil Peels: Their Preparation And Presentation, Tim D. Overheu

All other publications

Soil peels are an exciting and inexpensive technique for collecting an exact reproduction of soil profiles. They are an excellent product for displays and soil extension activities. Introduced in the mid-1960s, the soil peel (lackfilm) technique was initially developed using a flexible glue product in combination with a cloth base, and was used to preserve soil stratigraphy at geo-archaeological excavations (Voight & Gittins 1977). The method described in this update introduces refinements to the technique for heavy and consolidated clay or duplex soils in Western Australia. Applying and removingtechnique was initially developed using a flexible glue product in combination with …

Responses Of Soil Respiration And Its Temperature/Moisture Sensitivity To Precipitation In Three Subtropical Forests In Southern China, H. Jiang, Qi Deng, Guoyi Zhou, Dafeng Hui, Deqiang Zhang, S. Liu, Guowei Chu, J. Li

Biology Faculty Research

Both long-term observation data and model simulations suggest an increasing chance of serious drought in the dry season and extreme flood in the wet season in southern China, yet little is known about how changes in precipitation pattern will affect soil respiration in the region. We conducted a field experiment to study the responses of soil respiration to precipitation manipulations – precipitation exclusion to mimic drought, double precipitation to simulate flood, and ambient precipitation as control (abbr. EP, DP and AP, respectively) – in three subtropical forests in southern China. The three forest sites include Masson pine forest (PF), coniferous …

Lower San Luis Obispo Creek Stewardship Plan, Raven Lukehart, Daniel Bohlman

Natural Resources Management and Environmental Sciences

No abstract provided.

Decomposition And Nutrient Release Of Different Cover Crops In Organic Farm Systems, Jianru Shi

School of Natural Resources: Dissertations, Theses, and Student Research

Cover crops act as green manure adding organic matter to agricultural-soils. For legume green manures to be an effective nitrogen (N) source for organic farming systems, their N release must be in synchrony with crop N demand. The objectives of this study were 1) determine the decomposition rates of three common cover crops (white clover, (Trifolium repens,L ) red clover (Trifolium pratense L.) and soybean (Glycine max L) in order to determine when most N was released and its synchrony with subsequent corn crop uptake; 2) we focused on the effect of cover crops on soil …

Mechanisms Of Nutrient Limitation And Nutrient Acquisition In Managed And Unmanaged Forest Ecosystems, Matthew A. Vadeboncoeur

Doctoral Dissertations

Understanding the interactions between global change, human and natural disturbances, and other factors on biogeochemical processes in forests is necessary to ensure the sustainability of forest management. Here I report the results of several investigations into nutrient acquisition processes in the forests of New Hampshire. I begin with a meta-analysis of fertilization studies showing that phosphorus (P) and calcium (Ca) as well as nitrogen (N) may limit primary production in deciduous forests of the region. Because these limiting nutrients are all removed from the ecosystem when trees are harvested, I compared nutrient budgets under a range of harvesting scenarios with …

Variability In The Hydraulic Conductivity Of A Test Pad Liner System Using Different Testing Techniques, Matthew Jonathan Nanak

Graduate Theses and Dissertations

Historic methods (the time lag approach, the velocity approach, and the Z-t approach), utilized to reduce two stage borehole test data, were evaluated. Two of the historic methods provided viable results and were used for this research project. Additionally, these two methods are recommended for reducing two stage borehole test data in the future.

Flexible wall permeameter and soil index laboratory testing were conducted on the soil used to construct three environmentally controlled compacted clay liners (test pads) to develop a zone of acceptance (placement window). Using the results from the laboratory testing, two acceptance criterions were evaluated, while one …

Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker

Graduate Theses and Dissertations

For every ten kilograms of biodiesel that is produced from the transesterification of vegetable oil, approximately 1 kg of glycerol is produced as a byproduct. Also known as glycerin, it is a chemical used in many products including cosmetics, foods, and desiccants. However, the crude glycerol created during biodiesel production is tainted with potassium hydroxide and methanol making it unsuitable for commercial use without costly refinement. With increase in production of biodiesel driven by rising fuel prices, the market has become glutted with glycerol and it is on the threshold of becoming a waste product. Common methods for disposing glycerol …

Subsurface Stratigraphy And Characterization Of Mississippian (Osagean To Meramecian) Carbonate Reservoirs Of The Northern Anadarko Shelf, North-Central Oklahoma, Brett Robert Wittman

Graduate Theses and Dissertations

Mississippian carbonate strata of the midcontinent contain prolific oil and gas reservoirs. Production from these carbonates has been primarily from two reservoir types, the Mississippi "chat" and recently denser chert-rich mudstone intervals. The"chat" interval is a high porosity chert residuum associated with the both the Osagean and basal Pennsylvanian unconformity. The distribution of the "chat" reservoir is discontinuous and heterogeneous. Recent horizontal drilling successes have reinvigorated academic and industry interest in the Lower Mississippian. Much of the activity is now targeting lower porosity, cherty, mudstone intervals of the Reeds Spring and Cowley Formations, which were previously considered to be non-economic. …

Initial Elastic Modulus Degradation Using Pressuremeter And Standard Penetration Test Results At Two Sites, Dustin Robbins

UNLV Theses, Dissertations, Professional Papers, and Capstones

In-situ testing was performed at two sites consisting of pre-bored pressuremeter testing, seismic surface wave testing to develop a shear wave velocity profile, and Standard Penetration testing during the soil boring phase in order to evaluate the feasibility of using large shallow foundations for a project. This study focuses on a comparison of the in-situ direct measurements of soil stiffness obtained from this testing program. The small strain modulus obtained from the seismic surface wave test results is compared to the intermediate strain modulus obtained from both the initial loading pressuremeter modulus and reload pressuremeter modulus. The modulus calculated from …

Soil Moisture Recognition And The Spatial Distribution Of Storm Activity In The Mojave Desert Using High-Resolution Aster And Modis Imagery For Thermophysical Mapping, Russell J. Skuse

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate models suggest that the Mojave Desert ecoregion is vulnerable to becoming drier in the future, and as the human population grows and development increases, environmental stresses will likely increase. Determining the spatial distribution and variation of soil moisture on a regional scale is an essential component to climate change, hydrologic, and habitat analyses. Soil permeability and sediment stability are characteristics that have been shown to be measurable from remote sensing observations. The primary objective of this project is to map the mechanical composition of the surface materials in the Mojave Desert ecoregion with implications for soil permeability, sediment stability, …

Adaptation Of Regional Representative Soil Project And Soil Judging For Cameroon, Celestine Che

All Dissertations

Representative regional soils have agricultural, cultural, economic, environmental, and historical importance to Cameroon. Twenty seven regional representative soils have been identified in Cameroon. A set of laboratory exercises, assignments and exam questions have been developed utilizing the Regional Representative Soil Project (RRSP) that gives students an opportunity to practice interpretation of soil series descriptions, taxonomic classes, soil forming factors, and soil physical and chemical properties. The RRSP can be further enhanced and complemented with Soil Judging. Conventional soil judging as practiced in the United States has been adapted for Cameroon by a graduate student from that country using an undergraduate-level …

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Graduate Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same …

Researching Soil Hydrogen Dynamics In Subarctic Sweden, Victoria Lynn Ward

Inquiry Journal 2013

No abstract provided.

Preliminary Groundwater Level Changes At Selected Sites In Nebraska Following The Drought Of 2012, Aaron R. Young, Mark E. Burbach, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Adsorption Of Hexavalent Chromium On Hydrous Manganese Oxide, Andrew K. Macleod

Masters Theses

Hexavalent chromium is a very common contaminant most often associated with industrial processes, it is quite mobile in the subsurface and a better understanding of its mobility and interactions with soil constituents will help ongoing remediation efforts.

Hydrous manganese oxides (HMO) are a very common soil constituent and thus would be likely to interact with Cr(VI) in contaminated shallow subsurface environments. The goal of this study is to develop a working model that can improve predictions of Cr(VI) mobility in natural systems. A diffuse double layer surface complexation model (DLM) was developed by deriving reaction stoichiometries and stability constants for …

Alluvial Sediment Or Playas: What Is The Dominant Source Of Sand And Silt In Desert Soil Vesicular A Horizons, Southwest Usa, Mark R. Sweeney, Eric V. Mcdonald, Christohper E. Markley

All Faculty Scholarship for the College of the Sciences

Vesicular A (Av) soil horizons form beneath desert pavements from the accretion of aeolian sediment (dust) commonly thought to be derived primarily from desiccating pluvial lakes and playas, with contributions from ephemeral washes and alluvial fans. Particle size distributions of Av horizons are typically bimodal with primary modes of very fine silt and fine sand, suggesting that the horizon matrix is derived from multiple sources. Here we conduct detailed chemical and physical analysis of both Av horizon soil samples and potential sources of aeolian sediment to better constrain the relative contributions of dust associated with the development of Av horizons. …

Map-Based Probabilistic Infinite Slope Analysis Of The Stephens Creek Watershed, Portland, Oregon, Ryan Andrew Cole

Dissertations and Theses

The Stephens Creek Watershed in southwest Portland, Oregon was chosen by the city as a pilot project for urban stream restoration efforts, and the infiltration of stormwater was identified as a potential restoration strategy. The Stephens Creek Watershed has historically been known to be unstable during high precipitation events (Burns, 1996), and the need to address the response of slope stability to anthropogenically-driven changing groundwater conditions is the focus of this study. Airborne light detection and ranging (LiDAR) and geotechnical data from the City of Portland were employed to create a high resolution (0.84 m2) physics-based probabilistic slope stability model …

Soil Groups Of Western Australia: A Simple Guide To The Main Soils Of Western Australia (4th Edn) - Superseded, Noel R. Schoknecht, Shahab Pathan

Resource management technical reports

No abstract provided.

A Review Of The Broome Sandstone Aquifer In The La Grange Area, Robert J. Paul, Richard J. George Dr, Peter Gardiner

Resource management technical reports

Land use in the West Kimberley near Broome, Western Australia, is dominated by cattle grazing on pastoral stations, dispersed mining activity and tourism. Irrigated agriculture has developed but is at a small scale. There is interest from pastoralists and horticultural companies to expand irrigated agriculture, and pastoral diversification and mosaic irrigation systems have been proposed. However, if irrigated agriculture is to expand, it must be viable and meet community and regulatory requirements. Developing secure and sustainable water resources is critical

This review is focussed on the La Grange groundwater subareas (La Grange area). Its purpose is to summarise the existing …

Arsenic In The Soils Of Northwest Oregon, Tracy Ryan Ricker

Dissertations and Theses

One hundred and eighty-six soil samples from Northwest Oregon were tested for arsenic content. The highest values measured were 13.9 ppm in the A horizon (site C4) and 20.4 ppm in the B horizon (Site P4). Arsenic was not detected in 28 A horizon samples and 23 B horizon samples. Data are grouped based on the age and rock type of underlying bedrock. Lithologic groups with six or more data points were compared statistically to ascertain if groups are distinct. Analysis of Variance (ANOVA) multiple comparison tests indicate that the arsenic content of the Marine Sediments and Sedimentary Rocks group …

Photo Highlights From The 33rd Kentucky Alfalfa Conference, Krista Cotton

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

Finishing Beef On Alfalfa, Todd Powell

Kentucky Alfalfa and Stored Forage Conference

Powell Farms started in 1996 with 15 acres of Alfalfa hay intended for cow/calf feed. A neighbor and his friends bought every bale that year. Over the next 14 years the only alfalfa hay our cows got to eat was when a cutting got wet and was rolled. As with any business when the economy starts to take a downward trend, it is wise to start looking for new and innovative ways to market your product.

Making And Marketing Hay For The Horse Industry, Todd Clark

Kentucky Alfalfa and Stored Forage Conference

No abstract provided.

Fertilizer: How Much Is In Each Bale?, Dennis Hancock

Kentucky Alfalfa and Stored Forage Conference

What do you see when you look at a bale? Certainly, many would say it is a source of feed for our livestock. Others see a commodity that is sold to their customers. These are the most important aspects of any forage. But, there is one other intrinsic value worth noting… its nutrient content. In a sense, it is a bale of fertilizer.

Our Experience With Roundup Ready Alfalfa, Clayton Geralds

Kentucky Alfalfa and Stored Forage Conference

We raise approximately 500 acres of alfalfa with approximately 175 seeded to Roundup Ready varieties. We established our first field in 2006 and a second in 2007. Roundup Ready alfalfa was not available for additional seedings until 2011. We have seeded over 100 additional acres in 2011 and 2012.