Agricultural Science Commons^™

Food Webs And Food Sovereignty: Research Agenda For Sustainability, Charles A. Francis, Michelle Miller, Molly Anderson, Nancy Creamer, Michelle Wander, Jacob Park, Thomas Green, Brent Mccown

Department of Agronomy and Horticulture: Faculty Publications

Future food production will be constrained by the scarcity of fossil fuel and fresh water as well as increasing intensity and unpredictability of weather events and climate changes. The assurance of food security and equity for many consumers is complicated by concentration of ownership of land and other production resources, as well as a global corporate food systems model that is driven by profit at the expense of people and the environment. To assess potential alternatives to the contemporary global food chain, well focused research is needed on local food production and food webs where small- and midscale family farms …

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. …

Maternal Environment Effects On Phenolic Defenses In Abutilon Theophrasti Seeds, Brian J. Schutte, Sam E. Wortman, John L. Lindquist, Adam S. Davis

Department of Agronomy and Horticulture: Faculty Publications

A class of phenolic compounds, ortho-dihydroxyphenols (hereafter “o-DHP”), has been implicated with seed survival. Based on expectations of the growth-differentiation balance hypothesis, we predicted that seed o-DHP concentration exhibits a curvilinear response to increasing resource availability in the maternal environment, with maximum o-DHP occurring at moderate resource levels. To test this hypothesis, Abutilon theophrasti seeds were produced under field conditions at two locations. Each location included twelve maternal environments established through factorial combinations of soil compost (+/−), species assemblage (A. theophrasti with and without maize), and soil nitrogen fertilizer (0, 0.5× or 1× local …

Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Anita Dille, Frank Forcella, John Lindquist, Christy Sprague

Department of Agronomy and Horticulture: Faculty Publications

Robust predictions of weed seedling emergence from the soil seedbank are needed to aid weed management. A common seed accession (Illinois) of giant ragweed was buried in replicate experimental gardens over 18 site years in Illinois, Michigan, Kansas, Nebraska, Ohio, and South Dakota to examine the importance of site and climate variability by year on seedling emergence. In a nonlinear mixed-effects modeling approach, we used a flexible sigmoidal function (Weibull) to model giant ragweed cumulative seedling emergence in relation to hydrothermal time accumulated in each site-year. An iterative search method across a range of base temperature (T_b) …

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 ( …

Dna Fingerprinting And Anastomosis Grouping Reveal Similar Genetic Diversity In Rhizoctonia Species Infecting Turfgrasses In The Transition Zone Of Usa, B. S. Amaradasa, B. J. Horvath, D. K. Lakshman, S. E. Warnke

Department of Agronomy and Horticulture: Faculty Publications

Rhizoctonia blight is a common and serious disease of many turfgrass species. The most widespread causal agent, Thanatephorus cucumeris (anamorph: R. solani), consists of several genetically different subpopulations. In addition, Waitea circinata varieties zeae, oryzae and circinata (anamorph: Rhizoctonia spp.) also can cause the disease. Accurate identification of the causal pathogen is important for effective management of the disease. It is challenging to distinguish the specific causal pathogen based on disease symptoms or macroscopic and microscopic morphology. Traditional methods such as anastomosis reactions with tester isolates are time consuming and sometimes difficult to interpret. In the present study universally …

Distinguishing Between Yield Advances And Yield Plateaus In Historical Crop Production Trends, Patricio Grassini, Kent M. Eskridge, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Food security and land required for food production largely depend on rate of yield gain of major cereal crops. Previous projections of food security are often more optimistic than what historical yield trends would support. Many econometric projections of future food production assume compound rates of yield gain, which are not consistent with historical yield trends. Here we provide a framework to characterize past yield trends and show that linear trajectories adequately describe past yield trends, which means the relative rate of gain decreases over time. Furthermore, there is evidence of yield plateaus or abrupt decreases in rate of yield …

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 …

Ecology And Invasive Properties Of Musk Thistle (Carduus Nutans) In The Central Prairies Of Nebraska, Chengchou Han

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

Musk thistle (Carduus nutans) is an herbaceous monocarpic herb introduced to the U. S. from Eurasia. The invasion of musk thistle can reduce forage area, soil stability, and reduce recreation and open areas for humans and wildlife.

Resistance of warm season and cool season perennial grass communities to musk thistle invasion is important for land managers to consider, especially where disturbance has made an area particularly susceptible. Our results show that disturbances, such as overgrazing can open up niches in canopies of warm season grass communities and facilitate invasion but not in cool season grass communities. The mechanism …

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.

Efficacy And Costs Of Controlling Eastern Redcedar, John Ortmann, James L. Stubbendieck, Robert A. Masters, George H. Pfeiffer, Thomas B. Bragg

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

(Juniperus virginiana L.) is reducing grassland productivity across much of the Great Plains. Control methods include broadcast prescribed fire, herbicides, cutting, and individual tree ignition. All methods have disadvantages when used alone. Fire can be ineffective against larger trees. Intensive methods can be too expensive for low-productivity grasslands. The objectives of this research were to determine the effects of broadcast prescribed fie alone as measured at 3 weeks after fire; to compare the effects of picloram herbicide application with or without fire, sawing with or without fire, and individual tree ignition with fire; and to compare all treatment costs. …

Productivity Of Well-Watered Panicum Virgatum Does Not Increase With Co2 Enrichment, Philip A. Fay, H. Wayne Polley, Virginia L. Jin, Michael J. Aspinwall

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

Aims Rising atmospheric CO₂ has been shown to increase aboveground net primary productivity (ANPP) in water-limited perennial grasslands, in part by reducing stomatal conductance and transpiration, thereby reducing depletion of soil moisture. However, the benefits of CO₂ enrichment for ANPP will vary with soil type and may be reduced if water limitation is low. Little is known about CO₂ effects on ANPP of Panicum virgatum, a perennial C₄ tallgrass and potential bioenergy crop. We hypothesized that if water limitation is minimized, (i) CO₂ enrichmentwould not increase P. virgatum ANPP because photosynthetic rates of this C …

High-Throughput Transcriptome Sequencing For Snp And Gene Discovery In A Moth, Nicholas J. Miller, Jing Sun, Thomas W. Sappington

Department of Entomology: Faculty Publications

The western bean cutworm, Striacosta albicosta (Smith) (Leptidoptera: Noctuidae) is a pest of corn (Zea mays L.) and dry beans that underwent a dramatic range expansion in North America during the first decade of the 21st century. Research into the population genetics of this species has been hindered by a lack of genetic markers. The transcriptome of adult male S. albicosta was partially sequenced using Illumina sequencing-by-synthesis. Assembly of the sequence reads yielded 16,847 transcript sequences, of which 6,631 could be assigned a putative function. A search for single nucleotide polymorphisms (SNPs) identified 2,487 candidate SNPs distributed among 1,265 …

Feed The Future Releases Two New Sorghum Varieties In Nicaragua, Kimberly Christiansen

INTSORMIL Impacts and Bulletins

de Tecnologia Agropecuaria (INTA), the Collaborative Research Support Program for Sorghum, Millet and Other Grains (INTSORMIL) has released two new varieties of sorghum in Nicaragua that will be used for forage (plant material eaten by grazing livestock).

These new varieties exhibit the “brown midrib” trait (bmr), which has been used for many years by sorghum producers in the United States. The bmr trait increases the digestibility of sorghum by reducing the amount of lignin, a chemical compound found in the cell walls of plants. The more digestible sorghum is for the livestock that consume it, the higher the quality of …

Chlorophyll-Based Approach For Remote Estimation Of Crop Gross Primary Production: From In Situ Measurements To Satellite Imagery, Yi Peng

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

The synoptic and accurate quantification of crop gross primary production (GPP) is essential for studying carbon budgets in croplands and monitoring crop status. The objective of this dissertation is to develop a quantitative technique to estimate crop GPP using remotely sensed data collected from close range to satellite altitudes. In this study, a model based on a recently developed paradigm, which relates crop GPP to a product of total crop chlorophyll content and incident radiation affecting vegetation photosynthesis, was justified for the remote estimation of GPP in crops. The model was tested with ground-observed incoming photosynthetically active radiation (PAR_{in …}

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 …

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 …

Cambio Climático Reduciría Cultivos: El País Vería Una Baja De Entre Un 20% Y 50% En El Rendimiento Del Frijol, Maíz Y Sorgo, Por El Incremento En Las Temperaturas, Según Un Informe De La Universidad Estatal De Kansas, Rosa María Pastrán

INTSORMIL Impacts and Bulletins

El aumento de la temperatura que se producirá en los próximos 50 años, a consecuencia del cambio climático, provocaría una reducción en la producción de granos básicos en El Salvador, según un estudio del Departamento de Agronomía de la Universidad Estatal de Kansas, Estados Unidos.

En el caso de El Salvador, la investigación encontró que la temperatura actual incrementará entre 3 y 5 grados centígrados (°C). Este aumento afectará, de manera progresiva, el rendimiento de cultivos como frijol, maíz y sorgo, de acuerdo con lo que explicó el profesor Vara Prasad, quien presentó el estudio en el país.

El cultivo …

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 …

Silvopastoreo: Una Práctica Agroforestal

Agroforestry Notes (USDA-NAC)

No abstract provided.

What Is Forest Farming?

Working Trees (USDA-NAC)

What is forest farming?

Forest farming, or multi-story cropping, is a distinctive approach to land management that combines management practices of conventional forestry with those of small-scale farming or gardening to attain an environmentally and economically sustainable land-use system.

Typically, a forest farming system is established by thinning an existing woodland or plantation to leave the best canopy trees for continued timber production and to create the appropriate conditions that favor the understory crop.

Using Agroforestry Practices To Reduce Pesticide Risks To

Agroforestry Notes (USDA-NAC)

No abstract provided.

Riparian Forest Buffers: An Agroforestry Practice

Agroforestry Notes (USDA-NAC)

No abstract provided.

Non-Timber Forest Products And Forest Stewardship Plans

Agroforestry Notes (USDA-NAC)

No abstract provided.

Indigenous Traditional Ecological Knowledge In

Agroforestry Notes (USDA-NAC)

No abstract provided.