Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, 2018 University of Arkansas, Fayetteville
Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern
Biological Sciences Undergraduate Honors Theses
Methanogens, some of Earth’s most primitive prokaryotic organisms, are candidates for possible life forms capable of inhabiting Mars. Specifically, four different species (Methanobacterium formicicum, Methanococcus maripaludis, Methanosarcina barkeri, Methanothermobacter wolfeii) were analyzed for their tolerance to the presence of illite clay. Illite is a crystalline mineral that has been identified from regions of Mars’s surface. Results indicated that all four species grew with some success in the illite at different concentrations. This experimentation with methanogens’ abilities to survive and reproduce in the presence of illite allows for a more accurate understanding of the potential capability of microbial growth ...
Observing Soil Changes Under Common Cropping Practices In Kentucky, 2018 Murray State University, Hutson School of Agriculture
Observing Soil Changes Under Common Cropping Practices In Kentucky, Samantha Peterson, Iin Handayani, Alyx Shultz Dr, Brian Parr
Cropping production and tillage systems lead to loss of soil organic matter (SOM), lowering soil pH, and soil compaction in Kentucky. However, the magnitude of the changes varied among the soil properties. Therefore, the objective of this research was to evaluate the changes in SOM, soil pH, and soil compaction under different cropping systems like corn-soybean-tobacco rotation (Field #1), continuous corn field (Field #2), hemp field (Field #3), wheat field (Field #4), pasture with animal grazing (Field #5), and canola field (Field #6). The prominent soil textures in all fields are silt loam and silty clay loam. Disturbed soil samples ...
Microbial Community Structure And Functions Differ Between Native And Novel (Exotic-Dominated) Grassland Ecosystems In An 8-Year Experiment, Aleksandra Checinska Sielaff, Racheal N. Upton, Kirsten S. Hofmockel, Xia Xu, H. Wayne Polley, Brian J. Wilsey
Ecology, Evolution and Organismal Biology Publications
A Grasslands dominated by non-native (exotic) spe- cies have replaced purely native-dominated areas in many parts of the world forming ‘novel’ ecosystems. Altered precipitation patterns are predicted to exacerbate this trend. It is still poorly understood how soil microbial communities and their functions differ between high diversity native- and low diversity exotic-dominated sites and how altered precipitation will impact this difference.
Methods We sampled 64 experimental grassland plots in central Texas with plant species mixtures of either all native or all exotic species; half with summer irrigation. We tested how native vs. exotic plant species mixtures and summer irrigation affected ...
Perennial Biomass Crop Establishment, Community Characteristics, And Productivity In The Upper Us Midwest: Effects Of Cropping Systems Seed Mixtures And Biochar Applications, 2018 Iowa State University
Perennial Biomass Crop Establishment, Community Characteristics, And Productivity In The Upper Us Midwest: Effects Of Cropping Systems Seed Mixtures And Biochar Applications, Catherine L. Bonin, Rivka B. Fidel, Chumki Banik, David A. Laird, Robert Mitchell, Emily A. Heaton
Native perennial plants have potential as bioenergy feedstocks, but their use is currently limited by relatively long establishment times and low biomass yields. Some research suggests that incorporating plant species diversity and applying biochar as a soil amendment might alleviate these limitations by creating a more resilient crop and soil system. The objective of this research was to investigate how 1) seeded plant diversity and 2) biochar soil amendments interact to affect the establishment, yield, and plant species composition of biomass cropping systems during the first four years of growth on productive soils. We measured species emergence, cover, peak and ...
Turning Grass Into Cash With Small Ruminants, 2018 Kentucky State University
Turning Grass Into Cash With Small Ruminants, Kenneth Andries
Kentucky Grazing Conference
As agriculture continues to change, it is important to consider sustainability before starting or expanding any enterprise. One critical factor in any animal agriculture enterprise is controlling feeding costs. Most research indicates feeding is the largest expenses in any livestock enterprise. However, nutrition is critical to overall productivity and the income of the enterprise. Because of this, producers need to find ways to improve nutrient availability while minimizing costs to optimize production and profitability for their livestock enterprise.
Grazing Dairies: Challenges And Opportunities, 2018 Michigan State University
Grazing Dairies: Challenges And Opportunities, Howard Straub Iii
Kentucky Grazing Conference
No abstract provided.
Considerations For Making A Profit With Stocker Cattle, 2018 University of Kentucky
Considerations For Making A Profit With Stocker Cattle, Jeff Lehmkuhler
Kentucky Grazing Conference
The southeast is home to more than 7.3 million beef cows (USDA 2018). At an estimated 80% weaning rate and 20% heifer retention, the southeast region would be expected to produce more than 4.6 million feeder calves that would go to market in 2018. The cow-calf industry in the region provides an opportunity for the stocker and backgrounding operations to co-exist. Much of the land in the region is best suited for forage and pasture production, which at the current moment, provides a low cost feed for adding pounds to light weight feeder cattle. Yet, the stocker and ...
Measuring Profitability In Grazing Operations, 2018 University of Kentucky
Measuring Profitability In Grazing Operations, Kenneth H. Burdine
Kentucky Grazing Conference
When producers make investments in extending their grazing season, they do so in order to obtain an economic benefit. These benefits usually include a reduction in the number of days that stored feed (typically hay) is fed, an increase in carry capacity or stocking rate, or an increase in production level (rates of gain, weaning weights, etc). While all of these are potential benefits of improved grazing systems, a reduction in winter feeding days is often the simplest way to start. When the grazing season is extended, winter feeding days are reduced, and this cost savings can be weighed against ...
Foreword And Conference Information , 2018 University of Kentucky
Foreword And Conference Information , S. Ray Smith, Christopher D. Teutsch
Kentucky Grazing Conference
No abstract provided.
Spatial Structuring Of Cellulase Gene Abundance And Activity In Soil, 2018 Iowa State University
Spatial Structuring Of Cellulase Gene Abundance And Activity In Soil, Jinlyung Choi, Elizabeth Bach, Jaejin Lee, Jared Flater, Shane Dooley, Adina Howe, Kirsten S. Hofmockel
Agricultural and Biosystems Engineering Publications
Microbial mechanisms controlling cellulose degradation in soil habitats remains a critical knowledge gap in understanding and modeling terrestrial carbon-cycling. We investigated land management and soil micro-habitat influences on soil bacterial communities and distribution of cellulose-degrading enzyme genes in three bioenergy cropping systems (corn, prairie, and fertilized prairie). Within the soil, aggregates have been examined as potential micro- habitats with specific characteristics influencing resource partitioning and regulation, thus we also investigated genes associated with cellulose degradation within soil aggregate fractions from the fertilized prairie system. Soil bacterial communities and carbon-cycling gene presence varied across land management and soil microhabitats. Examination of ...
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, 2018 University of Nebraska - Lincoln
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
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 the ...
Legacy Effects Of Long-Term Nitrogen Fertilizer Application On The Fate Of Nitrogen Fertilizer Inputs In Continuous Maize, Hanna J. Poffenbarger, John E. Sawyer, Daniel W. Barker, Daniel C. Olk, Johan Six, Michael J. Castellano
Nitrogen fertilizer management can impact soil organic C (SOC) stocks in cereal-based cropping systems by regulating crop residue inputs and decomposition rates. However, the impact of long-term N fertilizer management, and associated changes in SOC quantity and quality, on the fate of N fertilizer inputs is uncertain. Using two 15-year N fertilizer rate experiments on continuous maize (Zea mays L.) in Iowa, which have generated gradients of SOC, we evaluated the legacy effects of N fertilizer inputs on the fate of added N. Across the historical N fertilizer rates, which ranged from 0 to 269 kg N ha−1 yr ...
Conservation Agriculture Practices Increase Potentially Mineralizable Nitrogen: A Meta-Analysis, 2018 Iowa State University
Conservation Agriculture Practices Increase Potentially Mineralizable Nitrogen: A Meta-Analysis, Navreet K. Mahal, Michael J. Castellano, Fernando E. Miguez
Potentially mineralizable nitrogen (PMN) is considered an important indicator of soil health. Cropping systems management can affect PMN. However, the effect size and relationship with crop yield across specific management practices remain uncertain. We conducted a quantitative review to understand how conservation agriculture management practices affect PMN including N fertilizer application, cropping system diversity, and tillage system as well as the relationship of crop yield with PMN. Data were extracted from 43 studies published in peer-reviewed journals, providing 494 paired comparisons of PMN and 26 paired comparisons of PMN and yield across selected crop management practices. In our meta-analysis, 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
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 ...
Pedology At Four Representative Sites Of Southern Highland Zone Of Tanzania, 2018 Tanzania Agricultural Research Institute: TARI
Pedology At Four Representative Sites Of Southern Highland Zone Of Tanzania, Johnson Godlove Mtama, Balthazar Michael Msanya, Charles Lee Burras
To study the soils of Southern Highland Zone of Tanzania, four representative pedons of some landscapes were characterized. Their names and identifiers are Seatondale, Mbimba, Inyala, and Uyole, respectively TzSea 01, TzMb 02, TzIny 03, and TzUy04. The pedons were formed from the weathering of among other materials, colluvial igneous rocks, alluvium, eluvial soils, laterite, lacustrine sands and silts, andesite, pumice, aeolian deposits, and metamorphic rocks including coarse grained and strongly foliated biotite gneisses. Twenty soil samples were taken for laboratory characterization. In addition to classical horizon by horizon descriptions and laboratory analyses, 12 core samples were taken for soil-water ...
County-Wide Assessment Of Irrigation Expansion On Air Temperature, Humidity And Evapotranspiration Rates In Nebraska, 1979-2015, 2018 Conservation and Survey Division, School of Natural Resources
County-Wide Assessment Of Irrigation Expansion On Air Temperature, Humidity And Evapotranspiration Rates In Nebraska, 1979-2015, Jozsef Szilagyi
Conservation and Survey Division
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 Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, 2018 The University of Western Ontario
The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina
Electronic Thesis and Dissertation Repository
Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering ...
Development And Application Of The Heat Pulse Method For Soil Physical Measurements, 2018 Northwest A&F University
Development And Application Of The Heat Pulse Method For Soil Physical Measurements, Hailong He, Miles F. Dyck, Robert Horton, Tusheng Ren, Keith L. Bristow, Jialong Lv, Bingcheng Si
Accurate and continuous measurements of soil thermal and hydraulic propertiesare required for environmental, Earth and planetary science, and engineering applications, but they are not practicallyobtained by steady-state methods. The heat pulse (HP) method is a transient method for determinationof soil thermal properties and a wide range of other physical properties in laboratory and field conditions. The HP method is based on the line-heat source solution of the radial heat flow equation. This literature review begins with a discussion of the evolution of the HP method and related applications, followed by the principal theories, data interpretation methods and their differences. Important ...
Nitrogen Cycling During A Period Of Environmental Change, 2018 University of Maine
Nitrogen Cycling During A Period Of Environmental Change, Kaizad Patel
Electronic Theses and Dissertations
Natural and anthropogenic disturbances have altered the N cycle on the regional to global scale. Although numerous studies have examined the effects of chronic atmospheric N deposition on ecosystem processes, less is known about intra-annual variability of these processes, or how these responses might be altered under conditions of changing climate. The work described in this dissertation focuses on the effects of a changing chemical and physical climate, particularly terrestrial N processes (a) during Maine’s changing winters, and (b) in response to chronic elevated N additions.
Subnivean winter soil processes were examined at the Dwight B. DeMerritt Forest (DBDF ...
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 ...