Agriculture Commons^™

Nitrous Oxide Emissions From Smooth Bromegrass Pasture Under Nitrogen Fertilizer And Ruminant Urine Application In Eastern Nebraska, Laura K. Snell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrous oxide (N₂O) is a greenhouse gas primarily produced in soils by denitrifying and nitrifying organisms. Agricultural soils account for 70% of emissions in the United States, but little data is available for contributions from managed pasture ecosystems. This study focused on the production of N₂O in smooth bromegrass (Bromus inermis Leyss.) pastures established on silt loam soils in eastern Nebraska. Thirty smooth bromegrass plots (1.5m x 1.5m) were treated with five different fertilizer treatments (0, 45, 90, 135, and 180 kg N/ha) and two urine treatments (urine and no urine). Herbage sampling was taken …

Marketing Contracts, Overconfidence, And Timing In The Canadian Wheat Market, Fabio L. Mattos, Stefanie A. Fryza

Department of Agronomy and Horticulture: Faculty Publications

This paper investigates factors that impact marketing performance in the Canadian wheat market. Using data provided by the Canadian Wheat Board (CWB) for six crop years, results indicate that producers were not able to profitably use all marketing contracts offered by the CWB, earlier pricing tended to generate better performance, there was a negative relationship between activeness and performance (suggesting overconfidence in marketing skills), and performance was generally worse in volatile crop years. Further analysis reveals some of these findings differ when outperforming and underperforming producers are investigated separately, particularly with respect to activeness and volatility.

Do We Really Need New Policies? A Study On Soil Sealing In Egypt, Ahmed Harb Rabia

Ahmed Harb Rabia A.H. Rabia

Egypt has the lowest area of agricultural land per individual in Africa. The agricultural land stands for a total of approximately 3.5 million ha which characterized about 3.5% of the total area of Egypt in 2007. The urban encroachment over arable productive agricultural land in Egypt is common and is called (urban desertification). Therefore, the annual loss of arable land to urbanization is 1.2%. This indicates a serious situation to the agricultural area. the Academy of Scientific Research & Technology (1994) has reported that during the period from 1978 to 1984, the annual expansion rates of the dwelling area ranged …

Amelioration Of Root Disease Of Subterranean Clover (Trifolium Subterraneum) By Mineral Nutrients, Tim Scanlon, Tiernan A. O’Rourke, Megan H. Ryan, Martin J. Barbetti, Krishnapillai Sivasithamparam

Journal articles

Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, …

Cadmium Accumulation And Distribution In Lettuce And Barley, Fardausi Akhter

Electronic Thesis and Dissertation Repository

Cadmium (Cd) is a non-essential trace element and its environmental concentrations are increasing due to human activities. Edible plants can accumulate high concentrations of Cd, which could be toxic to humans. Understanding how and where Cd is stored in plants is important for ensuring lower concentration of Cd in the food. In this thesis, the accumulation and distribution of Cd in three agricultural plants, namely lettuce (Lactuca sativa L.), barley (Hordeum vulgare L.) and radish (Raphanus sativus L.), were investigated with a focus on the potential mechanisms involved in the localization of Cd in the root. The …

Protein Body Formation In Stable Transgenic Plants Of Nicotiana Tabacum Expressing Elastin-Like Polypeptide And Hydrophobin Fusion Proteins, Sonia P. Gutierrez

Electronic Thesis and Dissertation Repository

Plants are recognized as an efficient and inexpensive system to produce valuable recombinant proteins. However, the use of plants still faces two main limitations: the low accumulation levels of some recombinant proteins and the lack of efficient protein purification methods. Two fusion partners, elastin-like polypeptides (ELP) and hydrophobin I (HFBI) were found to increase the accumulation of recombinant proteins and induce the formation of protein bodies (PBs) when targeted to the ER in transient expression assays. In this study I examined the effect of these tags in stable transgenic plants of two Nicotiana tabacum cultivars when fused to green fluorescent …

What's In Your Nitrogen Budget?, Robert Mikkelsen

Robert Mikkelsen

No abstract provided.

Is Local Food In Your Future?: An Analysis Of The Viability Of The Local Food Movement, Jennifer A. Sliney

Pell Scholars and Senior Theses

The Local Food Movement has arisen in recent decades as a proposed solution to problems in the current food distribution system. Proponents of the movement look to solve problems such as unsustainable farming practices, greenhouse gas emissions, and unhealthy communities. Skeptics raise questions as to whether local food is truly capable of accomplishing any of those. The author proposes that as a solution, aspects of the Local Food Movement such as urban agriculture and attempts at community development should be taken more seriously in order to create a better future for the land and people alike.

Mapping Soil Erosion Risk Using Rusle, Gis And Remote Sensing Techniques, Ahmed Harb Rabia A.H. Rabia

Ahmed Harb Rabia A.H. Rabia

Soil erosion is one of the major causes of land degradation in arid and semi-arid areas like Ethiopia, including Tigray Highlands, which is highly affected by the risk of desertification. Tackling on-site effects of soil erosion requires understanding of the rates of soil loss as well as identification of the major controlling factors that accelerate or slow down these processes. The study aims to quantify the soil loss by erosion process and to specify the main factor affecting the Erosion development in the study area. The Study area was Kilte Awulaelo District which is situated in the eastern part of …

Dryland Soil Nitrogen Cycling Influenced By Tillage, Crop Rotation, And Cultural Practice, Upendra M. Sainju, Andrew W. Lenssen, Thecan Caesar-Tonthat, Jalal D. Jabro, Robert T. Lartey, Robert G. Evans, Brett L. Allen

Andrew W. Lenssen

Management practices may influence dryland soil N cycling. We evaluated the effects of tillage, crop rotation, and cultural practice on dryland crop biomass (stems and leaves) N, surface residue N, and soil N fractions at the 0–20 cm depth in a Williams loam from 2004 to 2008 in eastern Montana, USA. Treatments were two tillage practices (no-tillage [NT] and conventional tillage [CT]), two crop rotations (continuous spring wheat [Triticum aestivum L.] [CW] and spring wheat-barley [Hordeum vulgaris L.] hay-corn [Zea mays L.]-pea [Pisum sativum L.] [W-B-C-P]), and two cultural practices (regular [conventional seed rates and plant spacing, conventional planting date, …

A Gis Based Land Suitability Assessment For Agricultural Planning In Kilte Awulaelo District, Ethiopia, Ahmed Harb Rabia A.H. Rabia

Ahmed Harb Rabia A.H. Rabia

Land Suitability refers to the ability of a portion of land to tolerate the production of crops in a sustainable way. Such kind of analysis allows identifying the main limiting factors for the agricultural production and enables decision makers to develop crop managements able to increase the land productivity. Objectives of this study were to develop a GIS based approach for land use suitability assessment which will assist land managers and land use planners to identify areas with physical constraints for a range of nominated land uses. Also to help identify the management requirements that will ensure that a particular …

Composting Manure And Other Organic Materials, Charles S. Wortmann, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

The Composting Process

Composting is the aerobic decomposition of manure or other organic materials in the thermophilic temperature range (104-149oF). Composted material is odorless, fine-textured, and low-moisture. It can be bagged and sold for use in gardens or nurseries, or used as fertilizer on cropland with little odor or fly breeding potential. Composting improves the handling characteristics of any organic residue by reducing its volume and weight. Composting can kill pathogens and weed seeds.

Disadvantages of composting organic residues include loss of nitrogen and other nutrients, time for processing, cost for handling equipment, available land for composting, odors, marketing, diversion …

Escape From Preferential Retention Following Repeated Whole Genome Duplications In Plants, James C. Schnable, Xiaowu Wang, J. Chris Pires, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

The well supported gene dosage hypothesis predicts that genes encoding proteins engaged in dose–sensitive interactions cannot be reduced back to single copies once all interacting partners are simultaneously duplicated in a whole genome duplication. The genomes of extant flowering plants are the result of many sequential rounds of whole genome duplication, yet the fraction of genomes devoted to encoding complex molecular machines does not increase as fast as expected through multiple rounds of whole genome duplications. Using parallel interspecies genomic comparisons in the grasses and crucifers, we demonstrate that genes retained as duplicates following a whole genome duplication have only …

Modeling Of Soil Sealing By Urban Sprawl In Wukro, Ethiopia Using Remote Sensing And Gis Techniques, Ahmed Harb Rabia A.H. Rabia

Ahmed Harb Rabia A.H. Rabia

Soil sealing is the covering of the soil surface with materials like concrete and stone, as a result of new buildings, roads, parking places but also other public and private space. Soil sealing by urban sprawl continues to increase all over the world where the area of urbanized land is increasing even more rapidly than the population. The degree of sealing is associated to the land use type and the density of population. Techniques of Remote Sensing and Geographical Information System (GIS) have been used widely to measure urban sprawl and to analyze the spatial features and unique mechanism of …

Gis Spatial Modeling For Land Degradation Assessment In Tigray, Ethiopia., Ahmed Harb Rabia A.H. Rabia

Ahmed Harb Rabia A.H. Rabia

Land degradation can be described as reduction in the present and prospective land quality and production, due to natural or anthropogenic dynamics. This phenomenon is one of the most important problems facing farmers and decision makers in several countries. This study aims to use GIS spatial modeling to quantify land (physically and chemically) degradation in the study area based on remotely sensed and field survey’s data. A GIS spatial model has been developed based on the LADA- FAO methodology to apply a land degradation assessment in the study area. Final land degradation map has been produced by combining the outputs …

Multifunctionality In U.S. Rice Production: A Logit Analysis In Farmers Participation, Juan Tur Cardona

Graduate Theses and Dissertations

Multifunctional agriculture is particularly fundamental to some working lands conservation policies and programs, such as the Environmental Quality Incentive Program (EQIP), Conservation Security Program (CSP) and Wildlife Habitat Incentive Program (WHIP). Farmers can also be engaged in providing recreational and agri-tourism services such as hunting, fishing, bird-watching, farm tours, petting zoos and hospitality services. Using the Agricultural Resource Management Survey (ARMS) we analyze factors associated with participation in conservation, recreation and agri-tourism activities as a function of farm structure, farm financial measures, production practices, and socio-demographic characteristics of the farm operator. To estimate the functional relationships we estimate a binary …

Chemical Responses Of Two Deciduous Trees After 10-Years Of Exposure To Free Air Co2 Enrichment, Keonhee Kim

Masters Theses

Globally, the mean atmospheric carbon dioxide level has risen steadily since pre-industrial times, which is largely attributable to human activities such as increased emissions from fossil fuel burning, and clearing of forests. Numerous research efforts have been made to understand responses of trees in higher atmospheric carbon dioxide levels in short term, small-scale experiments. To overcome the limitations of these experiments and understand the response of trees in a natural environment, the Free Air Carbon dioxide Enrichment (FACE) project was proposed. FACE is a global project that involves experimentally enriching carbon dioxide in the atmosphere of terrestrial ecosystems. The FACE …

Strawberry Growth, Yield, Fruit Nutrition, And Control Of Verticillium Wilt With Pre-Plant Soil Fumigants, Ozone, And Biological Control, Justin J. Scurich

Master's Theses

Verticillium wilt is a widespread soilborne disease of strawberry historically controlled by soil fumigation with methyl bromide (MB). MB was banned by the United Nations in 1995 and will be completely phased out by 2015. Research has concentrated on alternative methods of disease control without finding a single alternative able to replace MB in widespread disease control and yield increase. For the current study, strawberries were greenhouse grown in container pots filled with soil from both infested and non-infested areas of a commercial strawberry field in Watsonville, CA. Treatments included pre-plant soil fumigation with commercially available formulations of methyl bromide, …

Use Of Cti Grinders For Sorghum Flour Production And Utilization: Final Report, Vilma Ruth Calderón De Zacatares, Lily Marisol López, Kris Emillee Duville, Carla Elizabeth Bermúdez

INTSORMIL Scientific Publications

The use of sorghum for human consumption to add value to the crop and increase its profitability, especially for small and medium producers, has contributed to food security and nutrition in El Salvador. CENTA is promoting the cultivation of sorghum as an alternative to food production in rural and urban areas. Since 2010 when wheat prices lower again, sorghum was no more an alternative to replace wheat in certain types of food, but is being used in more stable markets, as people allergic to gluten, people with diabetes and to correct nutritional deficiencies such as iron deficiency anemia because of …

Proceedings Of The 39th Annual Meeting, Southern Soybean Disease Workers (March 7-8, 2012, Pensacola Beach, Florida), Tom Allen, Boyd Padgett, Danise Beadle, Stephen R. Koenning

Southern Soybean Disease Workers: Conference Proceedings

Contents

Symposium: Soybean Nematodes: Their Status, Impact and Management

The Current Status of Nematodes of Soybean in Louisiana and Arkansas. Charles Overstreet, Edward C McGawley, Melea Martin, and Terry Kirkpatrick

A Molecular Analysis of Resistance of Soybean to the Soybean Cyst Nematode. Vincent Klink

Racism in Nematology. Terry Niblack

SCN-resistant Soybeans, HG types, Yield, and SCN Reproduction: How It All Comes Together in the Field in Iowa. Gregory Tylka

Soybean Lines Evaluated for Resistance to Reniform Nematode. Sally Stetina

Graduate student presentations (Boyd Padgett, moderator)

Fungicide Resistance in Cercospora kikuchii, a Major Pathogen of Louisiana Soybean. Trey Price

Variation …

2011 Vadose Zone Nitrate Study At Hastings, Ne (Revised), Roy F. Spalding, Martin Toavs

Department of Agronomy and Horticulture: Faculty Publications

In an effort to assist Hastings Utilities in the management of their well-head protection area (WHP A) and to protect the groundwater from the impact of nitrate loading from potential nonpoint and point sources, Hastings Utilities subcontracted with the Department of Agronomy and Horticulture at the University of Nebraska for deep vadose zone coring. Continuous 60-ft soil cores were obtained at 36 sites within the apparent WHP A (Figure 1). The sites were selected by Marty Stange on the basis of availability for sampling, management, landuse , cropping history, and location within the WHPA. Nitrogen analyses of these deep soil …

Genome-Wide Analysis Of Syntenic Gene Deletion In The Grasses, James C. Schnable, Michael Freeling, Eric Lyons

Department of Agronomy and Horticulture: Faculty Publications

The grasses, Poaceae, are one of the largest and most successful angiosperm families. Like many radiations of flowering plants, the divergence of the major grass lineages was preceded by a whole-genome duplication (WGD), although these events are not rare for flowering plants. By combining identification of syntenic gene blocks with measures of gene pair divergence and different frequencies of ancient gene loss, we have separated the two subgenomes present in modern grasses. Reciprocal loss of duplicated genes or genomic regions has been hypothesized to reproductively isolate populations and, thus, speciation. However, in contrast to previous studies in yeast and teleost …

Varietal Release History (2006-2012) Of Intsormil-Supported Nars Breeding Programs, Intsormil

INTSORMIL Scientific Publications

Spreadsheet of varietal release history for sorghum and pearl millet, by year, of INTSORMIL-supported national agricultural research systems breeding programs. Includes country, name of variety, on-farm yield, yield of local check variety, amount of seed produced (including breeder and whether Basic/Foundation certified), qualities other than yield (such as drought tolerance, forage quality, food type, etc.), and additional comments, such as whether birds will attack the crop at a particular time during the growing process, etc.

Country data for: Ethiopia, Mali, Mozambique, Niger, Uganda, Zambia, El Salvador, Guatemala, Honduras, and Nicaragua.

Sorgo Sureño Normal: El Sorgo Tradicional De Honduras De Doble Proposito, Alberto Morán Araujo, Miriam Villeda

INTSORMIL Scientific Publications

Origen: En Honduras, el Sorgo Sureño Normal ingresó a la estación experimental La Lujosa, en Choluteca, en el año de 1982, por medio del vivero de resistencia a l a i n t e m p e r i e , d o n d e s e seleccionó por su rendimiento, adaptación y calidad tortillera.

El Sorgo Sureño Normal fue liberado por la Secretaría de Recursos Naturales (SRN) y el Programa Internacional de Sorgo y Mijo (INTSORMIL) en 1985.

Adaptación: Sureño Normal se adapta a climas secos y calientes, suelos pobres, en condiciones de sequía y exceso de humedad …

Igrow Wheat: Best Management Practices For Wheat Production, David C. Clay, C. Gregg Carlson, Kevin Dalsted

Agronomy, Horticulture, and Plant Science Books

No abstract provided.

Susceptibility Of Cry1ab Maize-Resistant And -Susceptible Strains Of Sugarcane Borer (Lepidoptera: Crambidae) To Four Individual Cry Proteins, Liping Zhang, Fangneng Huang, B. Rogers Leonard, Mao Chen, Thomas Clark, Yu Cheng Zhu, David S. Wangila, Fei Yang, Ying Niu

Department of Entomology: Faculty Publications

Sugarcane borer, Diatraea saccharalis (F.), is a major target of Bt maize in South America and many areas of the US mid-south region. Six laboratory strains of D. saccharalis were established from six single-pair F2 families possessing major resistance alleles to Cry1Ab maize hybrids. Susceptibility of the six strains was evaluated on diet treated with each of four purified trypsin-activated Bt proteins, Cry1Ab, Cry1Aa, Cry1Ac, and Cry1F. Bt susceptibility of the six strains was compared with that of known Cry1Ab-susceptible and -resistant strains of D. saccharalis. At least two of the six strains demonstrated a similar level (>526-fold) …

Identification And Characterization Of Four Missense Mutations In Brown Midrib 12 (Bmr12), The Caffeic O-Methyltranferase (Comt) Of Sorghum, Scott E. Sattler, Nathan A. Palmer, Ana Saballos, Ann M. Greene, Zhanguo Xin, Gautam Sarath, Wilfred Vermerris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Modifying lignin content and composition are targets to improve bioenergy crops for cellulosic conversion to biofuels. In sorghum and other C4 grasses, the brown midrib mutants have been shown to reduce lignin content and alter its composition. Bmr12 encodes the sorghum caffeic O-methyltransferase, which catalyzes the penultimate step in monolignol biosynthesis. From an EMS-mutagenized TILLING population, four bmr12 mutants were isolated. DNA sequencing identified the four missense mutations in the Bmr12 coding region, which changed evolutionarily conserved amino acids Ala71Val, Pro150Leu, Gly225Asp, and Gly325Ser. The previously characterized bmr12 mutants all contain premature stop codons. These newly identified mutants, along …

Superweeds And Suspect Seeds: Does The Genetically-Engineered Crop Deregulation Process Put American Agriculture At Risk, Margaret Sova Mccabe

Law Faculty Scholarship

The federal government’s regulatory approach to genetically engineered (GE) crops, known as “The Framework”, is now twenty-five years old. Despite two and half decades of a consistent regulatory regime, GE crop and food regulation remains controversial. This article suggests that regulatory science and its tenets of independence, transparency, and public science should guide reforms of The Framework so that it is an efficient and reliable regulatory system. The article has four parts: 1) it provides a brief overview of the history of GE crop regulation; 2)it describes the key attributes of The Framework and related regulatory documents, with particular focus …

High-Resolution Mapping Of Open Chromatin In The Rice Genome, Wenli Zhang, Yufeng Wu, James C. Schnable, Zixian Zeng, Michael Freeling, Gregory E. Crawford, Jiming Jiang

Department of Agronomy and Horticulture: Faculty Publications

Gene expression is controlled by the complex interaction of transcription factors binding to promoters and other regulatory DNA elements. One common characteristic of the genomic regions associated with regulatory proteins is a pronounced sensitivity to DNase I digestion. We generated genome-wide high-resolution maps of DNase I hypersensitive (DH) sites from both seedling and callus tissues of rice (Oryza sativa). Approximately 25% of the DH sites from both tissues were found in putative promoters, indicating that the vast majority of the gene regulatory elements in rice are not located in promoter regions. We found 58% more DH sites in …

Brown Midrib2 (Bmr2) Encodes The Major 4-Coumarate: Coenzyme A Ligase Involved In Lignin Biosynthesis In Sorghum (Sorghum Bicolor (L.) Moench), Ana Saballos, Scott Sattler, Emiliano Sanchez, Timothy P. Foster, Zhanguo Xin, Chulhee Kang, Jeffrey F. Pedersen, Wilfred Vermerris

Department of Agronomy and Horticulture: Faculty Publications

Successful modification of plant cell-wall composition without compromising plant integrity is dependent on being able to modify the expression of specific genes, but this can be very challenging when the target genes are members of multigene families. 4-coumarate:CoA ligase (4CL) catalyzes the formation of 4-coumaroyl CoA, a precursor of both flavonoids and monolignols, and is an attractive target for transgenic down-regulation aimed at improving agro-industrial properties. Inconsistent phenotypes of transgenic plants have been attributed to variable levels of down-regulation of multiple 4CL genes. Phylogenetic analysis of the sorghum genome revealed 24 4CL(-like) proteins, five of which cluster with bona fide …