Digital Commons Network^™

Changes In Nitrogen Use Efficiency And Soil Quality After Five Years Of Managing For High Yield Corn And Soybean, Timothy J. Arkebauer, Achim R. Dobermann, Kenneth G. Cassman, Rhae A. Drijber, J. Lindquist, James E. Specht, Daniel T. Walters, Haishun Yang

Department of Agronomy and Horticulture: Faculty Publications

Average corn grain yields in the USA have increased linearly at a rate of 1.7 bu/acre over the past 35 years with a national yield average of 140 bu/acre. Corn yield contest winners and simulation models, however, indicate there is ~100 bu/a in exploitable corn yield gap. Four years (1999-2002) of plant development, grain yield and nutrient uptake were compared in intensive irrigated maize systems representing (a) recommended best management practices for a yield goal of 200 bu/acre (M1) and (b) intensive management aiming at a yield goal of 300 bu/acre (M2). For each management level, three levels of plant …

Common Lambsquarters (Chenopodium Album) Interference With Corn Across The North-Central United States, David W. Fischer, R. Gordon Harvey, Thomas T. Bauman, Sam Phillips, Stephen E. Hart, Gregg A. Johnson, James J. Kells, Philip Westra, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Variation in crop–weed interference relationships has been shown for a number of crop–weed mixtures and may have an important influence on weed management decision-making. Field experiments were conducted at seven locations over 2 yr to evaluate variation in common lambsquarters interference in field corn and whether a single set of model parameters could be used to estimate corn grain yield loss throughout the north-central United States.

Factors Affecting The Realized Niche Of Common Sunflower (Helianthus Annuus) In Ridge-Tillage Corn, Michael G. Burton, David A. Mortensen, David B. Marx, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Because soil characteristics and weed densities vary within agricultural landscapes, determining which subfield areas are most favorable to weed species may aid in their management. Field and greenhouse studies were conducted to determine whether subfield environments characterized by higher soil organic carbon (SOC), or ridge vs. furrow microsites, affect common sunflower seed germination after winter burial, seedling emergence, or the control afforded by a preemergence herbicide in a ridge-tillage corn production system. Among seeds buried in situ during winter months and germinated in the laboratory, no differences in common sunflower seed germination or mortality were detected between high-SOC (1.8% mean) …

Glyphosate Efficacy On Velvetleaf Varies With Application Time Of Day, Aaron L. Waltz, Alex R. Martin, Fred W. Roeth, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Field and growth chamber experiments determined the efficacy of temporal glyphosate applications on velvetleaf. Glyphosate was applied post-emergence to velvetleaf periodically before and during light and after dark. In 1999, glyphosate at 840 g ae/ha applied before sunrise and after midday provided 54 and 100% velvetleaf control, respectively. In 2000, glyphosate at 840 g/ha applied before sunrise, midday, and after sunset provided 69, 100, and 37% velvetleaf control, respectively. In the growth chamber, glyphosate at 840 g/ha applied before or after light reduced velvetleaf biomass 15 to 20% or 32 to 47%, respectively, and reduced velvetleaf height 24% or 45 …

Windbreaks, Robert J. Rouse, Laurie Hodges

Department of Agronomy and Horticulture: Faculty Publications

Windbreaks are an important and often overlooked component of a plasticulture system. They provide benefits regardless of where you farm or what crops you are raising. When wind protection is included in a plasticulture production system, crops benefit from less wind stress and an improved microclimate for growth and development. There is less crop injury due to soil abrasion or wind-whipping of plants, less extreme soil temperature fluctuations, and improved soil warming. Wind protection often results in earlier yields of higher-quality crops.

In-Season Prediction Of Attainable Maize Yield Using The Hybrid-Maize Model, Achim R. Dobermann, Haishun Yang, Kenneth G. Cassman, Daniel T. Walters

Department of Agronomy and Horticulture: Faculty Publications

The Hybrid-Maize Model

Real-time Simulation and Yield Forecasting

Case Study 1: Irrigated Maize, Lincoln, Nebraska

Case Study 2: Rainfed Maize, Oliveros, Argentina

Case Study 3: Rainfed Maize, Mead, Nebraska

Conclusions

References

Test Of The Hybrid-Maize Model For Simulation Of Soil Moisture Dynamics And Maize Response To Water Deficit, Haishun S. Yang, Achim R. Dobermann, Kenneth G. Cassman, Kenneth G. Hubbard, Timothy J. Arkebauer, Shashi Verma, Daniel T. Walters

Department of Agronomy and Horticulture: Faculty Publications

The Hybrid-Maize model (Yang et al, 2004), which has been validated under optimal water conditions, was evaluated for its ability to simulate soil moisture dynamics in the root zone and effects of water deficits on maize development and final yields (Fig. 1). The experimental data for this evaluation were obtained from ongoing field studies of the Carbon Sequestration Program (CSP) at the University of Nebraska. The studies include three cropping systems, each located in a quarter-section field (57 ha), two of which are irrigated by central-pivots and the third is rainfed. One irrigated field is in continuous maize and the …

Plant Population And Fertilization Impacts On Irrigated Corn In Nebraska, Daniel T. Walters, Achim R. Dobermann

Department of Agronomy and Horticulture: Faculty Publications

Since 1999, a team of researchers at the University of Nebraska has been conducting studies to understand the yield potential of corn and soybeans and how management affects it. The crop model discussed in the previous article was a product of this team. The research compares continuous corn to a corn-soybean rotation and evaluates how plant population and nutrient management impact yield. In addition to determining productivity, the research involves an integrated assessment of profitability, input use efficiency, energy balance, and environmental consequences.

Emergence And Survival Of Legumes Seeded Into Pastures Varying In Landscape Position, John A. Guretzky, Kenneth J. Moore, Allen D. Knapp, E. Charles Brummer

Department of Agronomy and Horticulture: Faculty Publications

Landscape position affects legume establishment in pastures. We conducted this study to (i) determine the role of emergence and survival on establishment of legumes on summit and backslope positions and (ii) examine how competition, as influenced by sward-cutting height and N fertilization, affects legume emergence and survival across these positions. We no-till drilled a mixture composed of red clover (Trifolium pratense L.), alfalfa (Medicago sativa L.), and birdsfoot trefoil (Lotus corniculatus L.) into an existing cool-season grass pasture at Rhodes, IA, in 1998 and 1999. Treatments consisted of landscape positions (summit and backslope), N fertilizer rates (0, …

Genotypic And Environmental Modification Of Asian Noodle Quality Of Hard Winter Wheats, Robert A. Graybosch, N. Ames, P. Stephen Baenziger, C. J. Peterson

Department of Agronomy and Horticulture: Faculty Publications

The relative effects of environment, genotype, and their interactions on the modification of Asian noodle quality attributes were assessed using 38 winter wheat (Triticum aestivum L.) cultivars and breeding lines grown in replicated trials at three Nebraska locations in harvest year 2000. Noodle color was determined in both white salted and yellow alkaline procedures, and noodle textural features were investigated by producing white salted noodles. Significant environmental, genotypic, and genotype-by-environment variation was observed for nearly all initial and 24-hr noodle color traits in both types of noodles. Significant genotypic effects were observed for several textural traits, while significant environmental …

Registration Of Npm-4, A Dwarf White Grain Pearl Millet Germplasm, J.F. Rajewski, D.J. Andrews, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Dwarf grain pearl millet [Pennisetum glucum (L.) R. Br.] germplasm NPM-4 (Reg. no. GP-37, PI 634545) was released in September 2003 by the Institute of Agriculture and Natural Resources, University of Nebraska, Lincoln, NE.

NPM-4 was derived from open-pollinated outcrosses of white grain inbred line 57028R1w grown in a 1998 Puerto Vallarta winter nursery. The source of the outcross pollen was from primarily genetically diverse, dwarf, early maturing, gray seeded lines being developed as parents for grain yield. Line 57028R₁w was derived from 89C57028R₁/3*90PV0121. Line 89C57028R₁ is gray-seeded, and line 90PV0121 has white seed. …

Application Of Sequence-Related Amplified Polymorphism Markers For Characterization Of Turfgrass Species, Hikmet Budak, Bob Shearman, Roch E. Gaussoin, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

A simple marker technique called sequence-related amplified polymorphism (SRAP) provides a useful tool for estimation of genetic diversity and phenetic relationships in natural and domesticated populations. Previous studies and our initial screen show SRAP is highly polymorphic and more informative when compared to AFLP, RAPD and SSR markers. In this study, applicability of the SRAP markers to obtain an overview of genetic diversity and phenetic relationships resent among cool-season (C3) and warm-season (C4) turfgrass species and their relationship with other Gramineae species were tested. Phenetic trees based on genetic similarities (UPGMA, N-J) were consistent with known taxonomic relationships. In some …

Random Amplified Polymorphic Dna (Rapd) Analysis Of Long-Term Cultured Hybrid Hazelnut, Mehmet Nuri Nas, Nedim Mutle, Paul Read

Department of Agronomy and Horticulture: Faculty Publications

RAPD and phenotypic analysis were conducted to assess clonal stability of hazelnuts generated from axillary buds cultured in vitro for long-term. The nuts produced on in vitro-propagated plants were indistinguishable from those of donor plants. With the exception of rare horizontal (plagiotropic) growth, all in vitro-propagated plants exhibited phenotypes similar to those of donor plants. RAPD analysis did not reveal any somaclonal variation between donor plants from which in vitro cultures were initiated and micropropogated plants (6-year cultures), and no somaclonal variation was detected among in vitro propogated plants. However, polymorphism (15.6%) was detected between the parent plant and its …

Selective Primary Hepatocyte Adhesion On Polyelectrolyte Multilayer : Template For Patterned Cell Co-Culture, Srivatsan Kidambi, Ilsoon Lee, Christina Chan

Department of Chemical and Biomolecular Engineering: Faculty Publications

The ability of surfaces to modulate cellular behavior such as adhesion, migration, proliferation and differentiation is an important facet of tissue and organ formation and in the eventual realization of functional biomaterials. The presence of micro or nanostructures on a surface permits the manipulation of cell-substrate and cell-cell interactions to better control cellular function and behavior. Commonly, proteins and cells indiscriminately attach onto medically implantable surfaces, which may ultimately lead to undesired fibrous encapsulation, detrimental clinical complications, increased risk of infection, and poor device performance. ^{1, 2} Consequently, by generating so-called bioinert materials, one may attempt to first reduce any …

The State Department Of Education's Role In Creating Safe Schools, Marilyn Grady, Jean Haar, Mary Ann Losh

Department of Educational Administration: Faculty Publications

The authority for public education in the United States does not stem from the Constitution, but rather is a "reserved" power remaining with the states. It originates from the Tenth Amendment, which reserves to the states those powers neither expressly given to the national govennnent nor denied to the state governments. However, most states have not exercised their authority for public education directly until recent decades. Education is a state function that is largely locally administered (Aikin, Linden, Noel, & Ray, 1992). Each state exercises its education function completely or in part through a state department of education that has …

You've Got To Talk Him Out Of It, Nicholas J. Pace

Department of Educational Administration: Faculty Publications

When a student makes his sexual identity public in a small rural community, worst-case scenarios occupy the principal's thoughts. Prepare for problems but don't underestimate your students and school community. Be ready to live up to your school's mission statement that promises to care for every student.

Molecular Mapping And Identification Of Soybean Fatty Acid Modifier Quantitative Trait Loci, D. L. Hyten Jr., Vincent R. Pantalone, Arnold M. Saxton, Michael E. Schmidt, Carl E. Sams

Department of Agronomy and Horticulture: Faculty Publications

Altering FA content in soybean [Glycine max (L.) Merr.] oil for improved functionality is a research goal of many soybean breeders. Several of the genes that alter palmitic, stearic, oleic, linoleic, and linolenic acids are modifier genes with small effects, causing these FA traits to act as quantitative traits. The objective of this study was to identify modifier FA quantitative trait loci (QTL) in soybean. A recombinant inbred line population was created from two prominent ancestors of currently avail-able U.S. cultivars (Essex and Williams) and grown in five environments. One hundred simple se-quence repeat markers spaced throughout the genome …

Implementation Of A Mitochondrial Mutator, Sally Mackenzie, Ricardo Vilela Abdelnoor

Department of Agronomy and Horticulture: Faculty Publications

Plant MSH1 polynucleotides and polypeptides are described. Also described are methods for the use and modulation of such MSH1 polynucleotides and polypeptides.

Residual Effects Of Manure And Compost Applications On Corn Production And Soil Properties, Bahman Eghball, Daniel Ginting, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Residual effects of manure or compost application on crop production and soil properties can last for several years. This study was conducted to evaluate residual effects of annual or biennial applications of N- and P-based composted and non-composted beef cattle (Bos Taurus) feedlot manure, chemical fertilizer, and no-treatment check on corn (Zea mays L.) production and soil properties. Manure and compost were applied from 1992 to 1995, and the residual effects were determined from 1997 to 1999. Residual effects of N- and P-based manure and compost applications on corn grain yield and N uptake lasted for at …

Changes In Composition And Thermal Transition Temperatures Of Grain Sorghum Wax During Storage, Keum Taek Hwang, Curtis L. Weller, Susan L. Cuppett, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain sorghum (Sorghum bicolor) wax is composed mainly of aldehydes, alcohols, and acids. Aldehydes, comprising about one-half of the wax, are readily converted to acids in presence of air. In this study, whole sorghum wax and an aldehyde fraction from sorghum wax were subjected to oxidative conditions. Changes in the major components and thermal transition temperatures were determined using HPLC and differential scanning calorimeter (DSC), respectively. The aldehyde fraction was oxidized markedly to acids over 4 months in storage at room temperature. Acid content, in the fraction, was initially 5–7% and increased to 42–51% after 135 days in …

Controlled Release Systems For Dna Delivery, Angela K. Pannier, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Adapting controlled release technologies to the delivery of DNA has the potential to overcome extracellular barriers that limit gene therapy. Controlled release systems can enhance gene delivery and increase the extent and duration of transgene expression relative to more traditional delivery methods (e.g., injection). These systems typically deliver vectors locally, which can avoid distribution to distant tissues, decrease toxicity to nontarget cells, and reduce the immune response to the vector. Delivery vehicles for controlled release are fabricated from natural and synthetic polymers, which function either by releasing the vector into the local tissue environment or by maintaining the vector at …

Development Of An Instrumented Deep−Tillage Implement For Sensing Of Soil Mechanical Resistance, Viacheslav I. Adamchuk, Andrey V. Skotnikov, Justin D. Speichinger, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Variable−depth tillage has the potential for economic and environmental benefits to modern crop production. Varying tillage depth according to local soil conditions prevents the waste of energy and preserves soil ecology. A prototype instrumentation system was developed based on a conventional implement for deep tillage. It was equipped with two load cells and two sets of strain gauges for sensing the load applied to the implement during tillage. Two linear pressure distribution models (full and redundant) were used to describe the change of soil mechanical resistance with depth. These models were then used to compare estimates of soil mechanical resistance …

Predicting Tractor Fuel Consumption, Robert D. Grisso, Michael F. Kocher, David H. Vaughan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reports from the Nebraska Tractor Test Laboratory (NTTL) show improved fuel efficiency during the past 20 years. A 4.8% decrease in average annual specific volumetric fuel consumption for the data used in the ASAE Standards was shown. Using fuel consumption and power data from the NTTL reports, new equations for fuel consumption were established that predict fuel consumption for diesel engines during full and partial loads and under conditions when engine speeds are reduced from full throttle.

Field Efficiency Determination Using Traffic Pattern Indices, Robert D. Grisso, Michael F. Kocher, Viacheslav I. Adamchuk, Paul J. Jasa, Mark A. Schroeder

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Field efficiency is an important criterion for determining field capacity during field operations and, indirectly, for making important machinery management decisions. Geographic location data gathered with a yield monitor during harvest and a data logger during planting were used to provide time−motion studies of equipment and operator productivity. This study used these spatial and temporal data to quantify field performance of a combine and a planter. Seven Nebraska fields were used to compare results from soybean and corn production systems. Fields that were relatively flat with straight rows were contrasted with contoured fields with slopes of 3% to 5%. Two …

Measurement And Analyses Of Growth And Stress Parameters Of Viburnum Odoratissimum (Ker-Gawl) Grown In A Multi-Pot Box System, Suat Irmak, Dorota Z. Haman, Ayse Kilic, James W. Jones, Kenneth L. Campbell, Thomas L. Crisman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Two colors (white and black) of a recently introduced irrigation-plant production system [multi-pot box system (MPBS)] for container-grown nurseries were researched and results were compared with those obtained from the sprinkler-irrigated conventional (control) system (CS). Experiments were carried out in summer and fall of 2001 in Gainesville, Fla. Plant growth [growth index (GI), growth rate (GR), and dry matter] and stress parameters[stomatal resistance (r_s), crop water stress index (CWSI), plant water potential (PWP), and substrate temperature (ST)] were measured and analyzed for Viburnum odoratissimum (Ker-gawl). In both seasons, plants grown in the white MPBS has significantly higher GI …

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

Reconsidering The Evolution Of Eukaryotic Selenoproteins: A Novel Nonmammalian Family With Scattered Phylogenetic Distribution, Sergi Castellano, Sergey V. Novoselov, Gregory V. Kryukov, Alain Lescure, Enrique Blanco, Alain Krol, Vadim N. Gladyshev, Roderic Guigo

Vadim Gladyshev Publications

While the genome sequence and gene content are available for an increasing number of organisms, eukaryotic selenoproteins remain poorly characterized. The dual role of the UGA codon confounds the identification of novel selenoprotein genes. Here, we describe a comparative genomics approach that relies on the genome-wide prediction of genes with in-frame TGA codons, and the subsequent comparison of predictions from different genomes, wherein conservation in regions flanking the TGA codon suggests selenocysteine coding function. Application of this method to human and fugu genomes identified a novel selenoprotein family, named SelU, in the puffer fish. The selenocysteinecontaining form also occurred in …

Clark’S Nutcrackers (Nucifraga Columbiana) And The Effects Of Goal-Landmark Distance On Overshadowing, Aleida J. Goodyear, Alan Kamil

Papers in Behavior in Biological Sciences

Three groups of Clark’s nutcrackers (Nucifraga columbiana) were trained to find a goal location defined by an array of 4 landmarks that varied in goal–landmark distance. The arrays for each group differed in the distance of the closest landmark and contained goal–landmark distances that were common across groups, allowing for the examination of the effects of both relative and absolute goal–landmark distance on encoding of a landmark array. All 3 groups readily learned the task and were subsequently tested in probe tests with only single landmarks from the array available. Search error in tests with single landmarks was …

Social Play In Kaka (Nestor Meridionalis) With Comparisons To Kea (Nestor Notabilis), Judy Diamond, Alan B. Bond

Papers in Behavior in Biological Sciences

Social play in the kaka (Nestor meridionalis), a New Zealand parrot, is described and contrasted with that of its closest relative, the kea (Nestor notabilis), in one of the first comparative studies of social play in closely related birds. Most play action patterns were clearly homologous in these two species, though some contrasts in the form of specific play behaviors, such as kicking or biting, could be attributed to morphological differences. Social play in kakas is briefer, more predictable, and less sequentially diverse than that shown by keas. Kaka play also appears to be restricted to …

Sociality And The Evolution Of Intelligence, Alan Kamil

Papers in Behavior in Biological Sciences

Two recently published studies provide important new data relevant to the evolution of human intelligence. Both studies of social behavior in baboons, Bergman et al. demonstrated that baboons use two criteria simultaneously to classify other troop members, and Silk et al. showed that highly social female baboons have higher reproductive success than less social females. Taken together, these studies provide strong evidence for the importance of social context in cognitive evolution.