Agriculture Commons^™

Soil And Crop Response To Stover Removal From Rainfed And Irrigated Corn, Ian Kenney, Humberto Blanco-Canqui, Deann R. Presley, Charles W. Rice, Keith Janssen, Brian Olson

Department of Agronomy and Horticulture: Faculty Publications

Excessive corn (Zea mays L.) stover removal for biofuel and other uses may adversely impact soil and crop production. We assessed the effects of stover removal at 0, 25, 50, 75, and 100% from continuous corn on water erosion, corn yield, and related soil properties during a 3-year study under irrigated and no-tillage management practice on a Ulysses silt loam at Colby, irrigated and strip till management practice on a Hugoton loam at Hugoton, and rainfed and no-tillage management practice on a Woodson silt loam at Ottawa in Kansas, USA. The slope of each soil was <1%. One year after removal, complete (100%) stover removal resulted in increased losses of sediment by 0.36–0.47 Mg ha-1 at the irrigated sites, but, at the rainfed site, removal at rates as low as 50% resulted in increased sediment loss by 0.30 Mg ha-1 and sediment-associated carbon (C) by 0.29 kg ha-1. Complete stover removal reduced wet aggregate stability of the soil at the irrigated sites in the first year after removal, but, at the rainfed site, wet aggregate stability was reduced in all years. Stover removal at rates ≥ 50%resulted in reduced soil water content, increased soil temperature in summer by 3.5–6.8 °C, and reduced tem-perature in winter by about 0.5 °C. Soil C pool tended to decrease and crop yields tended to increase with an increase in stover removal, but 3 years after removal, differences were not significant. Overall, stover removal at rates ≥50% may enhance grain yield but may increase risks of water erosion and negatively affect soil water and temperature regimes in this region.

High Tunnel Design, Site Development, And Construction, Stacy A. Adams, Kim Todd

Department of Agronomy and Horticulture: Faculty Publications

High tunnels are low technology plant growing structures that provide opportunity for season extension, severe weather protection, and modified environments to increase productivity and visual quality of harvested plant products. This publication describes high tunnel components, site selection, development, covering materials, installation, and operation.

Experienced specialty plant growers can increase the quality of their products and the duration of their marketing of high- value crops through the use of high tunnels. High tunnels give growers the opportunity to plant earlier and include more sequential planting dates. This can result in early- season, high- dollar returns and the ability to offer …

Generation Of An Attenuated, Cross-Protective Pepino Mosaic Virus Variant Through Alignment-Guided Mutagenesis Of The Viral Capsid Protein, Godwill M. Chewachong, Sally A. Miller, Joshua J. Blakeslee, David M. Francis, Thomas Jack Morris, Feng Qu

School of Biological Sciences: Faculty Publications

Mild variants of many viruses are able to protect infected plants from subsequent invasion by more severe variants of the same viruses through a process known as cross-protection. In the past, the cross-protective viral variants were commonly derived from mild field isolates that were sometimes genetically heterogeneous, providing variable levels of crossprotection. Here, we report a novel approach to rapidly generate crossprotective variants of the tomato-infecting Pepino mosaic virus (PepMV) independently of the availability of mild field isolates. Our approach sought to attenuate PepMV by mutating less conserved amino acid residues of the abundantly produced capsid protein (CP). These less-conserved …

Characterization Of The Inflammatory Phenotype Of Mycobacterium Avium Subspecies Paratuberculosis Using A Novel Cell Culture Passage Model, Jamie L. Everman, Torsten M. Eckstein, Jonathan Roussey, Paul M. Coussens, John Bannantine, Luiz E. Bermudez

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

Understanding the pathogenic mechanisms of Mycobacterium avium subspecies paratuberculosis (MAP) and the host responses to Johne’s disease is complicated by the multi-faceted disease progression, late-onset host reaction and the lack of available ex vivo infection models. We describe a novel cell culture passage model that mimics the course of infection in vivo. The developed model simulates the interaction of MAP with the intestinal epithelial cells, followed by infection of macrophages and return to the intestinal epithelium. MAP internalization triggers a minimal inflammatory response. After passage through a macrophage phase, bacterial reinfection of MDBK epithelial cells, representing the late phase of …

Rural Year-Round Growing To Ameliorate A Possible Negative Effect From Climate Change, Kimberlie A. Brussa

Walden Dissertations and Doctoral Studies

The Intergovernmental Panel on Climate Change (IPCC) suggested that, as the world population grows, food and water shortages will become even more serious issues (IPPC's 2014 predictions about the future effects of climate change (CC), Year-round growing (YRG) may provide a way for communities to extend growing seasons, expand local farm systems, and provide food year round. This case study included a detailed analysis of responses from representatives of all sectors of rural Mesa County, Colorado, regarding YRG and a local food and farm plan due to CC. The case was bounded by time (6 months of data collection) which …

Engineering Triterpene Metabolism In Tobacco, Zuodong Jiang

Theses and Dissertations--Plant and Soil Sciences

Terpenes comprise a large diverse class of natural products and many of them attract interest because of their physiological function, therapeutic and industrial values. Triterpene oils including squalene (C30), botrycococcene (C30) and their methylated derivatives (C31-C37) generated by the green algae Botryococcus braunii race B, which have recently received significant attention because of their utility for advanced biofuels. However, the slow growth habit of B. braunii makes it impractical as a robust biofuel production system. In this thesis, we firstly evaluated the potential of generating high levels of triterpene (C30) production in tobacco plants by diverting carbon flux from cytosolic …

Urea Formulations On The Productivity Of Bermudagrass And Bermudagrass-White Clover Pastures, Caitlin Timberlake

Theses and Dissertations--Plant and Soil Sciences

Bermudagrass (Cynodon dactylon L.) is a perennial warm-season grass that is very responsive to nitrogen (N) fertilization. Excessive N applications have negative environmental consequences and make maintaining mixed swards difficult. This study determined the effects of enhanced efficiency (EE) N fertilizers and fertilizer rate on bermudagrass yields, nutritive values, and white clover persistence. Nitrogen sources included urea, urea formulated with Agrotain^® (U+A), urea with Agrotain^® and dicyandiamide (SuperU), a polymer-coated urea (ESN), ESN+urea (75% ESN, 25% urea), and methylene urea (MU). In the urea formulation trial, SuperU and U+A maximized forage yields at lower N rates. The …

Effects Of Refuges On The Evolution Of Resistance To Transgenic Corn By The Western Corn Rootworm, Diabrotica Virgifera Virgifera Leconte, Jennifer Deitloff, Mike W. Dunbar, David A. Ingber, Bruce E. Hibbard, Aaron J. Gassmann

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

BACKGROUND: Diabrotica virgifera virgifera LeConte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. Corn producing toxins derived from Bacillus thuringiensis (Bt) has been developed to help manageD. v. virgifera.However, previous studies have demonstrated the ability of this species to evolve resistance to Bt toxins in both laboratory and field settings.

RESULTS: We used an experimental evolution approach to test the refuge strategies for delaying resistance of D. v. virgifera to corn producing Bt toxin Cry34/35Ab1. In the absence of refuges, D. v. virgifera developed resistance to …

Efficacy Of Ultraviolet Radiation To Control Lactic Acid Bacteria In Wine Must, Brian D. Williams

All Master's Theses

The use of shortwave ultraviolet (UV_c) radiation to control lactic acid bacteria (LAB) in wine production was studied. A simulated wine sterilizer was built using a commercially sourced ultraviolet (UV) sterilizer commonly used in aquariums and ponds. After growing cultures in test tubes, samples of five different species of LAB were introduced into white grape juice adjusted for brix and pH to match that of wine must commonly found in the Yakima Valley American Viticultural Area. The mixture was then agitated and allowed time to evenly distribute the bacteria throughout the juice. The juice was sent through the …

National Agri-Marketing Association Annual Conference Professional Growth Opportunities For Unl Students, Caleb Nuehring, Rosalee A. Swartz

Cornhusker Economics

The National Agri-Marketing Association (NAMA) annual conference in April of each year is a highlight for Nebraska NAMA students. The students look forward to opportunities to network with professionals and attend sessions and workshops presented by internationally known speakers and experts.

NAMA is comprised of 23 professional chapters in six regions nationwide and has more than 3,500 professional and student members. NAMA members include professionals in agribusinesses, commodity associations, advertising and public relations agencies, as well as faculty, staff, and students from universities across the u.s. and Canada. At the state level, Nebraska's professional Cornhusker Chapter has nearly 70 members. …

Focus Paddocks Trial Report - Benchmarked Result Summary 2010 - 14, Martin Harries, Geoff Anderson

Grain and other field crops published reports

This report was co-funded by GRDC through project no. DAW00213 - Putting the Focus on Profitable Crop and Pasture Sequences in WA.

Crop and pasture sequences in south-western Australia have changed in the past decade. These survey results from the Focus Paddock project provide data to help growers employ profitable and sustainable crop and pasture sequences. The project compiled information on the nature, suitability and productivity of crop and pasture sequences from 184 paddocks over five years. The results of the analyses of chemical and physical attributes of the soil, weed counts and disease management are presented here.

The survey …

Evaluating A Satellite-Based Seasonal Evapotranspiration Product And Identifying Its Relationship With Other Satellite-Derived Products And Crop Yield: A Case Study For Ethiopia, Tsegaye Tadesse, Gabriel B. Senay, Getachew Berhan, Teshome Regassa, Shimelis Beyene

Department of Agronomy and Horticulture: Faculty Publications

Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy …

Msym 109: Physical Principles In Agriculture And Life Sciences—A Peer Review Of Teaching Project Benchmark Portfolio, David Mabie

UNL Faculty Course Portfolios

This benchmark course portfolio was developed for MSYM 109 - Physical Principles in Agriculture and Life Sciences. The class is a general service course taken by majors as a prerequisite for future coursework along with several other CASNR majors to fulfill their physics course requirement. MSYM 109 is a high enrollment course, with 115 students in lecture, along with four separate 30 person recitation sections. This portfolio was developed to assess the following objectives: 1. Identify, evaluate, and justify the course objectives 2. Assess and evaluate the course pedagogy and assessment methodology 3. Analyze the historical students assessment results against …

Precision Agriculture Usage And Big Agriculture Data, Mike Castle, Bradley D. Lubben, Joe Luck

Cornhusker Economics

Agricultural producers have quickly adopted precision agriculture technologies in recent years. With the availability of global positioning system (GPS) signals and other technology, producers can track yields, steer and control equipment, monitor field conditions, and manage inputs at very precise levels across a field, offering the potential to substantially increase productivity and profitability.

Increasing Student Interest In Poultry Science Careers Through 4-H, Peggy Lynn Armstrong

Walden Dissertations and Doctoral Studies

The demand for poultry science graduates to fill available positions in the poultry industry continues to increase. At the same time, there are not enough graduates to fill the positions. The purpose of this study was to investigate the implementation of the poultry curriculum in the 4-H program and student recruitment through the 4-H program into the Poultry Science Department. The targeted populations were 4-H leaders who implement the poultry curriculum and university students who were currently studying poultry. Career development theories suggest that previous experiences during adolescence can be a major influence in future vocation choice. A mixed methods …

Germplasm Enhancement For Resistance To Pyrenophora Tritici-Repentis In Wheat, Manisha Shankar, Diane E. Mather, Dorthe Jorgensen, Hossein Golzar, Ken J. Chalmers, Grant J. Hollaway, Mark S. Mclean, Stephen M. Neate, Rob Loughman

Conference papers and presentations

Yellow spot (syn. tan spot), caused by Pyrenophora tritici-repentis, is an important foliar disease of wheat in Australia that causes losses exceeding 50 % when conditions are favourable for disease development. Although good progress has been made internationally to understand yellow spot resistance, relatively few resistance genes have been identified and mapped in Australian germplasm and only one (tsn1 on chromosome 5BL) is in general and known use in Australian breeding programs. Although tsn1 is an important yellow spot resistance gene, it doesn’t explain the full spectrum of resistance and there is a significant opportunity to enhance expression …

2015 Weed Science Research Report –Blue Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document reports on field research conducted in 2015. It includes work on corn, soybean and the management of several weeds in North Dakota.

2015 Weed Science Research Report – White Section, Ndsu Weed Science, Dept. Of Plant Sciences

Plant Sciences Weed Science Reports

The Weed Science team at North Dakota State University conduct field research in the State of North Dakota. This specific document provides environmental, indexes, abbreviations and collaborators in 2015.

Characterization Of Suspected Cyclic Di-Gmp Metabolizing Genes In Streptomyces Scabies, Bridget N. Bickers

Undergraduate Honors Thesis Projects

Streptomyces scabies is a bacterial plant pathogen responsible for a condition known as common scab in potatoes and other tuber crops. Aerial hyphae and spore development have been shown to be regulated by cyclic di-GMP (c-di-GMP) signaling in the non-pathogenic species Streptomyces coelicolor and Streptomyces venezuelae. The second messenger c-di-GMP is ubiquitous among bacteria and is connected to many functions such as: motility, virulence, and biofilm formation, but the effects of c-di-GMP signaling in other streptomycetes are unknown. The purpose of this study is to elucidate the function of the suspected S. scabies c-di-GMP phosphodiesterase genes SCAB11501 and SCAB27241 …

Expanding Eco-Visualization: Sculpting Corn Production, Jennifer E. Figg

Theses and Dissertations

This dissertation expands upon the definition of eco-visualization artwork. EV was originally defined in 2006 by Tiffany Holmes as a way to display the real time consumption statistics of key environmental resources for the goal of promoting ecological literacy. I assert that the final forms of EV artworks are not necessarily dependent on technology, and can differ in terms of media used, in that they can be sculptural, video-based, or static two-dimensional forms that communicate interpreted environmental information. There are two main categories of EV: one that is predominantly screen-based and another that employs a variety of modes of representation …