Agriculture Commons^™

Low Root Zone Temperature Limits Nutrient Effects On Cucumber Seedling Growth And Induces Adversity Physiological Response, Qiu-Yan Yan, Zeng-Qiang Duan, Jing-Dong Mao, Xun Li, Fei Dong

Chemistry & Biochemistry Faculty Publications

Effects of root-zone temperatures (RZT) (12°C-RZT and 20°C-RZT) and different N, P, and K nutrient regimes on the growth, reactive oxygen species (ROS), and antioxidant enzyme in cucumber seedlings were investigated in hydroponics. Strong interactions were observed between RZT and nutrient on the dry weight (P=0.001), root length (P=0.001) and leaf area (P=0.05). Plant dry weights were suppressed at low RZT of 12°C, while higher biomass and growth of cucumber seedlings were produced at elevated RZT of 20°C under each nutrient treatment. Growth indexes (plant height, internode length, root length, and leaf area) at 12°C-RZT had less difference among nutrient …

Understanding And Disrupting Institutional Settings : Using Networks Of Conversations To Re-Imagine Future Farming Lives, Robert Campbell

Theses: Doctorates and Masters

Farmers in Australia and elsewhere face the challenge of remaining profitable whilst dealing with adverse structural arrangements and public expectations to better manage environmental degradation. This thesis draws on arguments that dominant paradigms in agricultural science and environmental management have often been ineffective in addressing these apparently competing demands and appear poorly suited to ‘messy’ situations characterized by uncertainty and complexity, and in which diverse stakeholders are motivated by varying goals and values. Engaging with such situations requires a philosophy and methodology that accepts a multiplicity of perspectives and which seeks to learn about and reflect upon novel ways of …

Conservation Compliance Under The House And Senate Versions Of The 2013 Farm Bill: A Role For Empathy Nudging?, Hans J. Czap, Natalia Czap, Gary D. Lynne, Mark E. Burbach

Cornhusker Economics

Current and past farming practices have led to significant environmental degradation in the form of soil erosion (sediments), as well as fertilizer and chemical related water pollution. The United States Department of Agriculture (USDA) has long tried to implement policies to temper such negative effects on the environment. The 2008 Farm Bill which currently guides agricultural and related environmental/conservation policy is being revised on this front. The United States Senate and the House of Representatives are each currently proposing a version of the 2013 Farm Bill to change the existing system, making it more efficient in achieving environmental (and other …

Regional Broadband Plan Priorities Presented To The Nebraska Public Service Commissioners, Charlotte Narjes, Roger Terry, Connie Hancock, Rebecca J. Vogt, Jan Jackson Cejka

Cornhusker Economics

Nebraska Broadband Initiative regional plan priorities were presented to the Nebraska Public Service Commissioners in July. These priorities were created by extension led planning teams located across the state. The Departments of Agricultural Economics and Agricultural Leadership, Education and Communication (ALEC), along with Extension are collaboratively working on the broadband initiative.

Assessing Naturalistic Decision Making By Experienced And Inexperienced Interrogators In High Stakes Interviews, Amy Bethany Ross

Open Access Theses & Dissertations

The current thesis aimed to improve the ecological validity of human intelligence interrogation research. Although field practitioners and researchers have worked together to improve the scientific validity and practical execution of interrogation techniques, research has yet to understand how, when and why interrogators implement such techniques. This thesis investigated the active decision making processes of interrogators that occur during high value interrogations. The theory of Naturalistic Decision Making was used to capture the naturalistic characteristics of high value interrogations- ambiguity, time pressure and high stakes. To capture the decision-making processes that are associated with skilled performance, this research conducted in-depth …

Influence Of Riparian Buffer Management Strategies On Soil Properties, Amanda A. Gumbert

Theses and Dissertations--Plant and Soil Sciences

The Kentucky Division of Water indicates that agriculture is responsible for 55% of the Commonwealth’s assessed streams not supporting their designated uses. Riparian buffers reduce nonpoint source pollution in agroecosystems by storing and cycling nutrients, stabilizing streambanks, increasing infiltration, and storing water. Specific information regarding riparian buffer management is needed for land managers to maximize buffer effectiveness at reducing agricultural contaminants impairing water quality.

Baseline soil properties (texture, pH, C and nutrients) of the riparian buffer surrounding a tributary of Cane Run Creek in Fayette County, KY were characterized prior to imposing three mowing regimes (intense, moderate, and no mow …

A Linear Programming Model And Partial Budget Analysis To Optimize Management Strategies Of Western Flower Thrips In Greenhouse Impatiens Production, Xiaohua Yue

LSU Master's Theses

The research problem of this thesis was to compare strategies and costs of protecting impatiens in greenhouse culture from western flower thrips that would provide a plant of acceptable quality to the market and would address the issue of development of resistance to commonly used pesticides by evaluating biopesticides. Partial budgets based on alternative strategies were identified. Six control strategies were identified from a combination of commercial growers, research experts and biopesticide recommendations from product distributors. The research-recommended strategy 6 had the highest total production cost ($197.44), while one of the grower strategies based on conventional pesticides had the lowest …

Assessing The Efficiency Of Alternative Best Management Practices To Reduce Nonpoint Source Pollution In The Broiler Production Region Of Louisiana, Bryan Gottshall

LSU Master's Theses

The Louisiana broiler production region is located in North Central and Northwestern Louisiana. The region consists of twelve parishes in Northwestern and North Central Louisiana. The broiler production region is a significant contributor of nonpoint source (NPS) pollution to nearby waterways. This pollution is a consequence of sediment, nitrogen and phosphorus runoff caused by agricultural production. NPS pollution is difficult to mitigate due to uncertainties in its point of origin as well as a host of other factors ranging from rainfall to topographical parameters. Best Management Practices (BMPS) have been shown to be a reliable method for reducing nonpoint source …

Quality Of Care: Analyzing The Relationship Between Hospital Quality Score And Total Hospital Costs, Jordan Andrew Newell

LSU Master's Theses

As healthcare costs and premiums have increased in the recent past, hospitals are forced to try to provide healthcare on tight budgets. In many cases, quality is often sacrificed in an effort to manage patient wait-times and costs. This research attempted to add to the existing body of knowledge of quality of care by defining a relationship between quality of care provided and total hospital costs. This study used the 2006 American Hospital Association’s Annual Survey Database and the 2006 Hospital Compare dataset to meet the data requirements for the study. A log-log, as well as a translog, cost function …

An Analysis Of Consumer Preferences For Grass-Fed Versus Grain-Fed Beef, Bo Lin

LSU Master's Theses

As a consequence of the growing concerns about human health and the environment, consumers are becoming more interested in grass-fed beef than conventional grain-fed beef. Therefore, the study of consumers’ preference towards grass-fed versus grain-fed beef steak is the focus of research. In this paper, 2,000 respondents who indicate they have eaten grass fed beef in the past years and 2,000 respondents that complete a nationally representative sample is the general population. Conjoint analysis is utilized to analyze the preference of consumers. Participants are presented ten hypothetical beef steaks to rate. All steaks are identical excluding their product type, source …

No Holes Barred: Invasion Of The Intestinal Mucosa By Mycobacterium Avium Subsp. Paratuberculosis, John Bannantine, Luiz E. Bermudez

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The infection biology of Mycobacterium avium subsp. paratuberculosis has recently crystallized, with added details surrounding intestinal invasion. The involvement of pathogen-derived effector proteins such as the major membrane protein, oxidoreductase, and fibronectin attachment proteins have been uncovered. Mutations constructed in this pathogen have also shed light on genes needed for invasion. The host cell types that are susceptible to invasion have been defined, along with their transcriptional response. Recent details have given a new appreciation for the dynamic interplay between the host and bacterium that occurs at the outset of infection. An initial look at the global expression pathways of …

Effect Of Anaerobic Dairy Manure Co-Digestion And Effluent Solid Separation On Volatile Fatty Acids During Manure Storage, Laura Page

Open Access Theses

Volatile fatty acids (VFA) are among the most abundant organic compounds found in animal manure and act as important intermediates in the production of methane under anaerobic digestion (AD). However, VFA also contribute to odor emissions from manure. Anaerobic digestion and separation of solids may help to reduce odor pollution during manure storage and subsequent land application by reducing VFA concentrations.

Little information about the characteristics and concentrations of VFA in dairy manure related to AD is available. This thesis presents the results of VFA production during two three-month storage studies of dairy manure collected from four different sources on …

Analysis Of Sources Of Variation And Relationships Among Sow Productivity Traits, Richard L. Cutshaw

Open Access Theses

The swine industry has witnessed major changes in the past three decades in terms of selection tools and implementation of effective selection. As the pork industry continues to consolidate, it is increasingly important to be able to accurately predict and direct future performance toward increased overall profitability. Overall, sow productivity greatly affects a pork producer's ability to be profitable in the industry and have sufficient knowledge of production levels to improve the likelihood of remaining profitable into the future.

The relationships among sow productivity traits including total number born, litter birth weight, number weaned, preweaning survival, mean piglet birth weight, …

Swat Model Simulation Of Bioenergy Crop Impacts In A Tile-Drained Watershed, Chelsie Marie Werling Boles

Open Access Theses

Tile drains are an important component of agricultural production in the Midwest, and their inclusion in modeling studies is important in watersheds where they are a principal hydrologic pathway. The new tile drainage simulation method in the Soil Water Assessment Tool (SWAT) was parameterized and tile flow results were compared with reviewed literature. Streamflow, sediment, and nutrient outputs were compared to measured values and simulated crop yields were examined with respect to average county yields. Plant growth stressors were examined to account for differences between simulated and published yields. The bioenergy crop switchgrass (Panicum virgatum) was applied over …

Estimation Of Watershed Nitrate Loads On Drained Agricultural Lands, Yan Jiang

Open Access Theses

Estimation of nutrient load is critical for many applications in water quality management; however, infrequent data monitoring and measurement error could raise considerable uncertainty in the load estimations. The objectives of this study were to quantify the overall uncertainty in annual nitrate-N load estimates, and develop a statistical model to predict nitrate loads based on subsurface drainage characteristics in Indiana watersheds. Nitrate was selected as the study object because of the high loads common in Midwestern streams, and its important influence on hypoxia in the Gulf of Mexico.

A standard error propagation method was used to quantify the uncertainty from …

Specific Salt Effects On The Formation And Thermal Transitions Among Β-Lactoglobulin And Pectin Electrostatic Complexes, Stacey Ann Hirt

Open Access Theses

Factors of ion specificity and ionic strength (I~0-100) were studied in the electrostatic complex formation and protein particle formation by thermal treatment for a β-lactoglobulin and pectin system. ζ-potential showed β-lactoglobulin and pectin began to interact near pH 5.50 and interactions were strengthened with decrease in pH. Visible light turbidimetry and light scattering at 90° revealed a trend in critical pH transitions for electrostatic complex formation based on both the ionic strength and the anion of the salt species, while effects of the monovalent cation was insignificant. Critical pH values for complex formation and separation (pHc and pHΦ) decreased with …

How Population Density Influences Agricultural Intensification And Productivity: Evidence From Ethiopia, Anna Leigh Josephson

Open Access Theses

We use household-level panel data to estimate how population density impacts agricultural intensification and farm income in Ethiopia. We hypothesize that increases in population density affect agricultural intensification and farm income directly through information flows, institutional development, and reduction in transactions costs. Increases in population density also affect agricultural intensification and farm income indirectly through farm size, agricultural wage rates, and staple crop prices. We find that increases in population density lead to lower farm sizes, which has major implications for agricultural intensification and household well-being. Our analysis indicates that increases in population density cause farmers to purchase more inorganic …

Effects Of Housing And Calcium-Deficient Diet On Health And Egg Production In Bovans Brown Hens., Jiaying Hu

Open Access Theses

Public concern about the welfare of hens kept in conventional cages has become an important issue worldwide. The conventional cage system has been banned by the European Union since 2012. Several housing systems, including free range, have been developed as welfare friendly alternatives to the conventional cage system. Experiment 1, the study examined the effects of housing environment, conventional cages vs. floor pens, on hens' health and egg production. A total of 84 19-wk-old Bovans Brown hens were randomly assigned into 2-bird cage with 12 replications (n=12), providing 968 cm2 floor space per hen or 10-bird floor pen with 6 …

A Land Data Assimilation System (Ldas) Based Dataset For Regional Agro-Climatic Assessments, Xing Liu

Open Access Theses

This study is part of a USDA sponsored project ----Useful to Usable (U2U): "Transforming Climate Variability and Change Information for Cereal Crop Producers". The broader objective includes improving farm resilience and profitability in the U.S. Corn Belt region by transforming existing climate/weather data into usable knowledge and tools for the agricultural community.

The specific tasks of this research are: (1) Build a high-resolution (4 km, daily) agro-climatic dataset using a Land Data Assimilation System (LDAS). (2) Estimate regional corn yield across the Corn Belt with crop models and the agro-climatic dataset. (3) Evaluate the impacts of climate variability due to …

Impacts Of Insecticide Treatments On Platytetranychus Multidigituli (Acari:Tetranychidae) And Predatory Mites On Gleditsia Triacanthos Var. Inermis (Honeylocust), Adam Robert Witte

Open Access Theses

Spider mite outbreaks can occur in urban forests after insecticides are applied to control early season pests. We used thornless honeylocust (Gleditsia triacanthos var. inermis) and honeylocust spider mite (Platytetranychus multidigituli) as a model to investigate this phenomenon by applying both topical and systemic insecticides to treat early season pests of honeylocust. Impacts of these applications on populations of P. multidigituli and its associated predatory mites were assessed. Early season applications of bifenthrin caused outbreaks of honeylocust spider mite and drastically reduced phytoseiids but not the stigmaeid mite, Zetzellia mali. In contrast later season applications suppressed populations of P. multidigituli. …

Rheological Properties Of Gluten Free Dough Systems, Stephany Aurea Tandazo

Open Access Theses

Bread is the one of the oldest processed foods and a major wheat based product. The basic process involves mixing of ingredients until the flour is converted into dough, followed by baking the dough into a loaf. A very important step in breadmaking is to know how to make good quality dough. However, the increasing knowledge of people being diagnosed with celiac disease (gluten intolerance) has encouraged scientists to develop healthier and better quality gluten-free products that would greatly improve the quality of life of celiac patients. The main objective of this study was to create a dough system composed …

A Spatially Explicit Watershed Scale Optimization Of Cellulosic Biofuels Production, Jingyu Song

Open Access Theses

Producing biofuels from energy crops is one such alternative. They can result in relatively lower greenhouse gas emissions compared to traditional energy sources. Up to now, corn grain is the most researched energy crop. Cellulosic perennial crops such as switchgrass, miscanthus and fast growing trees are also promising energy crops and are expected to help with the energy supply. The 2007 Renewable Fuel Standard requires 16 billion gallons of a total of 36 billion gallons of renewable fuels to be cellulosic biofuels by 2022. Many studies are being done to evaluate costs and feasibility of different potential feedstocks and the …

Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr

Open Access Dissertations

The shift to concentrated animal production facilities and increasing rural-urban migration has increased the localized land application of nearly 1 billion tons of manure and biosolids annually. Although these applications provide nutrients and contribute to soil tilth, they also serve as a source for an estimated 49 tons of the natural manure-borne estrogens, 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estrone (E1). While these estrogens are critical to endocrine systems, the low concentrations observed in the environment can disrupt endocrine function in non-target organisms, e.g., altering secondary sex characteristics which can lead to changes in wildlife communities.

Research presented here focuses on …

Evaluating Food Safety Systems Development And Implementation By Quantifying Haccp Training Durability, Marienne A. Anandappa

Theses and Dissertations--Animal and Food Sciences

HACCP-based food safety programs have been widely acclaimed, accepted and implemented as an effective means of managing food safety risks. While HACCP training is a cornerstone of managing HACCP programs, there is little information about the effectiveness of HACCP training and the durability of HACCP knowledge. Findings reveal a link between involvement level in HACCP activities and the accuracy of HACCP knowledge over time. Opportunities for peer training in HACCP, irrespective of overall experience in the food industry provide favorable circumstances for maintaining accuracy of HACCP knowledge. The optimal window for engaging employees in HACCP is directly following the completion …

Planning Ahead - A Guide For Your Cropping Program, Janet Paterson

Farm Systems and Economics published reports

It is difficult to think logically and make rational choices when under extreme pressure.

The seasonal break between harvest and preparation for seeding is a good time to get some rest and take some time to consider the position of your enterprise.

This is your best opportunity to assess risks and make important decisions when the demands on your time are few.

Most people, farm managers included, struggle to make sound decisions if they are extremely stressed-this is only natural. If you feel that you are struggling to make decisions, counselling services are a valuable resource to help you plan …

Influence Of Two Herbicides On Soybean Cyst Nematode (Heterodera Glycines) Reproduction On Henbit (Lamium Amplexicaule) Roots, Rodrigo Werle, Mark L. Bernards, Loren J. Giesler, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Soybean cyst nematode (SCN) is the most yield-limiting pathogen of soybean in the United States. Henbit is a prevalent winter annual weed species in no-till fields and is reported to be an alternative host of SCN. A greenhouse study was conducted to evaluate how the development of SCN on henbit roots was affected by herbicide mode of action and time of herbicide application. Henbit plants were grown in watertight pots placed in a water bath bench that kept soil temperature constant (27 6 1 C) during the study. Ten d after transplanting, pots were inoculated with approximately 1,000 SCN eggs. …

Development And Evaluation Of Soysnp50k, A High-Density Genotyping Array For Soybean, Qijian Song, D. L. Hyten, Gaofeng Jia, Charles V. Quigley, Edward W. Fickus, Randall L. Nelson, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

The objective of this research was to identify single nucleotide polymorphisms (SNPs) and to develop an Illumina Infinium BeadChip that contained over 50,000 SNPs from soybean (Glycine max L. Merr.). A total of 498,921,777 reads 35–45 bp in length were obtained from DNA sequence analysis of reduced representation libraries from several soybean accessions which included six cultivated and two wild soybean (G. soja Sieb. et Zucc.) genotypes. These reads were mapped to the soybean whole genome sequence and 209,903 SNPs were identified. After applying several filters, a total of 146,161 of the 209,903 SNPs were determined to be …

Soil Sorptivity Enhancement With Crop Residue Accumulation In Semiarid Dryland No-Till Agroecosystems, T.M. Shaver, G. A. Peterson, Laj R. Ahuja, D.G. Westfall

Department of Agronomy and Horticulture: Faculty Publications

Water capture and precipitation use efficiency are of great importance in dryland cropping systems because the world's dependence on food produced in dryland areas continues to increase. Growing season evapotranspiration potential greatly exceeds growing season precipitation rates in dryland areas, creating a water deficit for crops. Management practices that positively impact soil physical properties increase the potential for soils to capture water. One way to assess the ability of soils to capture water is through the measurement of sorptivity. Sorptivity is defined as the cumulative infiltration proportionality constant and is governed by surface soil physical properties such as texture, degree …

Transcriptome Analysis Of Two Buffalograss Cultivars, Michael Wachholtz, Tiffany Heng-Moss, Paul Twigg, Lisa Baird, Guoqing Lu, Keenan Amundsen

Department of Agronomy and Horticulture: Faculty Publications

Background: Buffalograss [Buchloë dactyloides (Nutt.) Engel. syn. Bouteloua dactyloides (Nutt.) Columbus] is a United States native turfgrass species that requires less irrigation, fungicides and pesticides compared to more commonly used turfgrass species. In areas where water is limited, interest in this grass species for lawns is increasing. While several buffalograss cultivars have been developed through buffalograss breeding, the timeframe for new cultivar development is long and is limited by a lack of useful genetic resources. Two high throughput next-generation sequencing techniques were used to increase the genomic resources available for buffalograss.

Results: Total RNA was extracted and …

Genetic Dissection Of Yield And Its Component Traits Using High-Density Composite Map Of Wheat Chromosome 3a: Bridging Gaps Between Qtls And Underlying Genes, Sachin Rustgi, Mustafa N. Shafqat, Neeraj Kumar, P. Stephen Baenziger, M. Liakat Ali, Ismail M. Dweikat, B. Todd Campbell, Kulvinder Singh Gill

Department of Agronomy and Horticulture: Faculty Publications

Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed and were localized to narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366), total biomass (wPt2740-Xcfa2076), kernels/spike (KPS) (Xwmc664-Xbarc67), and Pseudocercosporella induced lodging ( …