Digital Commons Network^™

Residual Effects Of Crop Residues On Grain Production And Selected Soil Properties, James F. Power, Paul Koerner, John W. Doran, Wallace Wilhelm

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

Returning crop residue improves water conservation and storage, nutrient availability, and crop yields. We have little knowledge, however, of the residual impacts of crop residues on soil and crop production. We hypothesized that residual impacts of crop residues vary with the amount of residues used. A 10-yr study near Lincoln, NE, evaluated the residual effects of an earlier 8-yr study of various crop residue amounts on crop growth and selected soil properties. From 1978 through 1985, crop residues were returned at 0,50, 100, and 150% of the quantity produced by the previous crop (averaging 0 to =6 Mg ha^{-1 …}

Opportunities For Growing Short-Rotation Woody Crops In Agroforestry Practices, Gary A. Kuhn, W. J. Rietveld

Agroforestry Notes (USDA-NAC)

Technologies are readily available for growing hybrid poplars and willows in block plantings as short-rotation woody crops (SRWC) for fuel and fiber. SRWC species and technologies can also be incorporated into agricultural systems as agroforestry practices. Examples are windbreaks, living snowfences, “timberbelts”, riparian buffer strips, and wastewater treatment plantings. Fast growth, convenient propagation (see AF Note - 11), and compatibility with conventional farming methods make SRWC suitable for use in agroforestry practices to provide multiple benefits such as solid wood and wood fiber products, water quality improvement, crop and soil protection, wildlife habitat, and buffers for agricultural/community interfaces.

Establishment And Cultural Guidelines For Using Hybrid Tree Species In Agroforestry Plantings, Gary A. Kuhn, W. J. Rietveld, Don E. Riemenschneider

Agroforestry Notes (USDA-NAC)

Hybrid poplars (and willows) are well-suited for agroforestry applications in many parts of the United States (See AFN-10). Their convenient propagation and fast growth allow them to establish and provide conservation benefits more quickly. This note provides general establishment and cultural guidelines to consider when using hybrid poplar cuttings for agroforestry plantings.

Differentiation Of F18ab+ From F18ac+ Escherichia Coli By Single-Strand Conformational Polymorphism Analysis Of The Major Fimbrial Subunit Gene (Feda), Brad T. Bosworth, Evelyn A. Dean-Nystrom, Thomas A. Casey, Holly L. Neibergs

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

Toxin-producing Escherichia coli expressing F18 fimbriae colonizes the small intestines of weaned pigs and causes diarrhea, edema disease, or both. The F18 family is composed of two antigenic variants, F18ab and F18ac. Because many strains do not express F18 fimbriae in vitro, identification and differentiation of these two variants are difficult. Single-strand conformational polymorphism (SSCP) analysis is a rapid method for identifying genetic mutations and polymorphisms. The F18 major fimbrial subunit genes (fedA) of 138 strains were amplified by PCR, and genetic differences were detected by SSCP analysis. The SSCP analysis of the fedA gene differentiated F18ab^{+ …}

Development Of A Blocking Enzyme-Linked Immunosorbent Assay For Detection Of Serum Antibodies To O157 Antigen Of Escherichia Coli, William Laegreid, Mark Hoffman, James Keen, Robert Elder, Jimmy Kwang

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

The O157 antigen of Escherichia coli shares structural elements with lipopolysaccharide (LPS) antigens of other bacterial species, notably Brucella abortus and Yersinia enterocolitica O9, a fact that confounds the interpretation of assays for anti-O157 antibodies. To address this problem, a blocking enzyme-linked immunosorbent assay (bELISA) was designed with E. coli O157:H7 LPS as the antigen and a monoclonal antibody specific for E. coli O157, designated 13B3, as the competing antibody. The bELISA had equivalent sensitivity to, and significantly higher specificity than, the indirect ELISA (iELISA), detecting anti-O157 antibodies in sera from cattle experimentally inoculated with O157:H7. Only 13% of sera …

An Inventory And Condition Survey Of The Sandstone-Yalgoo-Paynes Find Area, Western Australia, A L. Payne, A M E Van Vreeswyk, K A. Leighton, H J. Pringle, P Hennig

Technical Bulletins

The inventory and condition survey of the Sandstone-Yalgoo-Paynes Find area, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 1992 and 1993, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the area’s natural resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The area surveyed covers about …

Linking People, Purpose, And Place: An Ecological Approach To Agriculture, Heidi Carter, Richard Olson, Charles A. Francis

CARI Extension and Education Materials for Sustainable Agriculture

Linking Ecology and Agriculture

Whole Farm Planning

Soil Quality

Agroforestry

Grazing Systems

Weed and Insect Management

Farmer Groups

Farmland Conversion

Resources and Information Sources

Gas Chromatography/Mass Spectrometry Analysis Of The Cuticular Hydrocarbons From Parasitic Wasps Of The Genus Muscidifurax, Ulrich R. Bernier, David A. Carlson, Christopher J. Geden

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

Parasitic Hymenoptera can be difficult to identify by conventional taxonomic techniques. Examination of the cuticular hydrocarbons (CHCs) provides a basis for chemotaxonomic differentiation, which may lead to the discovery of pheromones, and can be a means of examining colonies for species cross-contamination. The parasitic wasps examined were Muscidifurax raptor, M. zaraptor, M. uniraptor, and the gregarious form of M. raptorellus. Species within the genus Muscidifurax, as well as the sex, can clearly be differentiated by examining the gas chromatograms of the CHCs. Identification of the alkanes by mass spectrometry shows uncommon dimethylalkanes and trimethylalkanes for members of the …

Elution Patterns From Capillary Gc For Methyl-Branched Alkanes, David A. Carlson, Ulrich R. Bernier, Bruce D. Sutton

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

A common and confusing problem in analyses of insect hydrocarbons is in making sense of complicated gas chromatograms and interpreting mass spectra since branched chain compounds differing by one or two carbons in backbone or chain length may elute from the column at nearly the same time. To address this confusing situation, relative gas chromatography (GC) retention times are presented for typical mono-, di-, tri-, and tetramethylalkanes comprising most of the commonly appearing series of homologous methyl-branched alkanes up to 53 carbons that are found in insect cuticular hydrocarbons. Typical insect-derived methylalkanes with backbones of 33 carbons were characterized by …

Black Flies, Simulium Spp. (Insecta: Diptera: Simuliidae), J. F. Butler, J. A. Hogsette

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

Introduction

Florida occasionally experiences outbreaks of black flies, though this is a rare occurance, and these large populations are caused by rainfall extremes. Common names for this pest include black flies and turkey gnats, as well as a number of new names applied by Floridians which are not repeatable here. Because of the hump visible behind their head when viewed in profile, black flies are also called buffalo gnats. Like eye gnats, they fly around people's heads, occasionally getting into eyes and ears as well as crawling in the hair. Because most of the specimens collected to date have been …

Spatial Pattern Of Gas Exchange For Montane Moist Meadow Species, Tony Svejcar, Gregg M. Riegel

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

Montane moist meadows of western North America are relatively unique in that they are characterized by annual cycles of spring inundation followed by summer drought. Thus, plants adapted to these ecosystems must cope with a wide range of environmental conditions. We compared gas exchange and water relations of upper canopy leaves and leaf area index (LAI) of three dominant montane meadow graminoids growing at both streamside and mid-meadow locations (2.5 and 20.0 m, respectively from the stream edge). The two locations were environmentally very different in spite of their close proximity. The water table at the streamside location was ca. …

Physiology And Reproduction: Gross Appearance Of The Turkey Blastoderm At Oviposition, M. R. Bakst, S. K. Gupta, W. Potts, V. Akuffo

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

The blastoderm (fertilized ovum) and unfertilized germinal disc (UGD) of fresh laid eggs and eggs stored prior to incubation exhibit subtle but definable morphological variations. Such variations may lead to difficulty when attempting to determine true flock fertility based on the appearance of the blastoderm/UGD. The objectives of this study were to define and categorize such morphological variations and to determine whether sperm influence the frequency distribution of the different categories. Eleven categories of blastoderms were defined based on the relative density and appearance of the area alba, area pellucida, area opaca, and the periblast. The majority of the blastoderms …

Northern Australia Quarantine Strategy. Weeds Target List, B. M. Waterhouse, A A. Mitchell

Biosecurity published reports

Second edition.

The Northern Australia Quarantine Strategy (NAQS) was established in 1989 as an outcome of a major evaluation of quarantine in Australia (AGPS 1987, 1988). NAQS activities include surveying for weeds,insect pests and diseases of plants; and pests and diseases of animals in northern Australia, Papua New Guinea and Indonesia. The primary goal is to provide early detection and warning of new quarantine threats or incursions.

A targetted approach was adopted for all pests, diseases and weeds. For each category of pest, experts in the discipline compiled lists of organisms not known from Australia but known to occur in …

Structure Of The Avian Oviduct With Emphasis On Sperm Storage In Poultry, Murray R. Bakst

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

The macroanatomy, histology, and fine structure of the avian oviduct is reviewed and related to its role in fertile egg production. The avian oviduct functions as a biological assembly line, beginning sequentially with the deposition of the albumen around the fertilized or unfertilized ovum, then the shell membrane, and lastly, the shell, all within 25 hr of ovulation. While in transit through the oviduct, the fertilized ovum progresses to the pre-gastrulation stage of development.

Biological Control: An Important Component In Integrated Management Of Musca Domestica (Diptera: Muscidae) In Caged-Layer Poultry Houses In Buenos Aires, Argentina, Diana C. Crespo, Roberto E. Lecuona, Jerome A. Hogsette

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

An Integrated Management program to control Musca domestica L. was developed by evaluating cultural + chemical control, cultural + biological control + granular bait (IMP 1), and cultural + chemical + biological control + granular bait (IMP 2) in poultry houses in Argentina. Adult fly density was estimated by a modified Scudder-grid method. Percentage of house fly parasitism was estimated by direct and indirect methods. Spalangia endius Walker and Muscidifurax raptor Girault & Sanders were released at a rate of 10 parasitoids/hen/week. Complete absence of control practices allowed a sustained growth of the fly population. When larvicides and adulticides were …

Purification And Characterization Of Intrauterine Folate-Binding Proteins From Swine, J.L. Vallet, R.K. Christenson, H.G. Klemcke

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

Folate-binding proteins (FBP) from Day 60 pseudopregnant uterine flushings and Day 60 allantoic fluid were purified by affinity chromatography on folate-Sepharose followed by G–100 Sephadex chromatography. FBP from uterine flushings had a molecular weight of 20 000; the N-terminal sequence was FNWDHXGKMEPAXKRHFXXXTXLYX, which is 72% identical to bovine milk FBP beginning at amino acid 64. Allantoic fluid FBP had a molecular weight of 30 000; and the N-terminal sequence ARAKTDMLNVXMDAKHHKPKPSXED, which is 68% identical to bovine milk FBP starting at amino acid 4. Scatchard analysis of purified allantoic fluid FBP using [³H]folic acid as ligand indicated a dissociation …

Selective And Organotypic Culture Of Intrahepatic Bile Duct Cells From Adult Pig Liver, Neil C. Talbot, Thomas J. Caperna

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

Secondary culture of nontransformed bile duct epithelium has been difficult to achieve. STO feeder cell-dependent secondary cultures of adult pig bile duct cells were established from primary cultures of adult pig liver cells. Adult pig hepatocytes exhibited limited or no replication and were lost from the secondary culture at Passage 3 or 4. In contrast, adult pig bile duct cells replicated and were carried for 4-8 passages in secondary culture. A simple method to produce nearly pure pig intrahepatic bile duct cultures was first to freeze a relatively crude liver cell preparation. Upon subsequent thawing, all hepatocytes and most macrophages …

Growth Traits Among Sorghum Genotypes In Response To Aluminum, J. H. Bernal, R. B. Clark

Department of Agronomy and Horticulture: Faculty Publications

Aluminum (Al) has many detrimental effects on plant growth, and shoots and roots are normally affected differently. A study was conducted to determine differences among sorghum [Sorghum bicolor (L.) Moench] genotypes with broad genetic backgrounds for growth traits of plants grown at 0,200,400,600, and 800 uM Al in nutrient solutions (pH 4.0). Genotypes were categorized into "Al-sensitive", "intermediate Al-tolerant", "Al-tolerant", and SC 283 (an Al-tolerant standard). As Al increased, shoot and root dry matter (DM), net main axis root length (NMARL), and total root length (TRL) became lower than controls (0 Al). Aluminum toxicity and/or nutrient deficiency symptoms become …

Atrazine, Deethylatrazine, And Deisopropylatrazine Persistence Measured In Groundwater In Situ Under Low-Oxygen Conditions, Sharon Papiernik, Roy Spalding

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

The degradation of atrazine [2-chloro-4-(ethylamino)-6-isopropylamino-1,3,5-triazine], deethylatrazine [DEA; 2-amino-4-chloro-6-(isopropylamino)-1,3,5-triazine], and deisopropylatrazine [DIA; 2-amino-4-chloro-6-(ethylamino)-1,3,5-triazine] was assessed under limited oxygen conditions using in situ microcosms. Denitrification was induced in a shallow sand and gravel aquifer to measure the potential for degradation of atrazine, DEA, and DIA under low-O2 conditions. The dissolved oxygen content decreased from 7-8 mg/L to ≤1 mg/L within 4 days and remained ≤ mg/L for the remainder of the 45-day experiment. Atrazine, DEA, and DIA concentrations (normalized to the bromide concentration at each sampling time to account for dilution) did not show a significant decrease with time, indicating that these …

Inactivation Of Soybean Peroxidase During Sodium Azide Oxidation: A Comparative Study, Mohamed Yehia Zakaria Aboul Eish

Dissertations and Theses @ UNI

Azide ion is a mechanism-based inactivator of a number of peroxidases. However, there are often variations in the manner in which inactivation occurs. Soybean Peroxidase (SBP) is found in the plant's seed coat. Unlike many other peroxidases, a single enzyme rather than several isozymes are produced thus making more simple the purification and characterization of the enzyme. In this research it was shown that, as with other peroxidases, SBP is inactivated by azide during turnover. During azide oxidation SBP forms a ferrous-NO intermediate. In this respect, SBP is similar to the lignin peroxidases from Phanerochaete chrysosporium which also form ferrous-NO …

The Biology Of Silvopastoralism, Steven H. Sharrow

Agroforestry Notes (USDA-NAC)

Forestry and livestock grazing are common competing uses for non-irrigated lands around the world. Forest grazing is a traditional practice in most of North America. Approximately 25 percent of all US forest land is grazed by livestock. Young forests and mature open-canopied forests can provide considerable amounts of forage for livestock. Prescription grazing makes beneficial use of ground vegetation that would otherwise compete with trees for soil moisture and nutrients, harbor gnawing rodents, and pose a fire hazard. Pasture grasses and legumes are sometimes seeded into newly harvested forest areas to reduce erosion, to provide high-quality food for deer and …

Growing Degree-Days: One Equation, Two Interpretations, Gregory S. Mcmaster, Wallace Wilhelm

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

Heat units, expressed in growing degree-days (GDD), are frequently used to describe the timing of biological processes. The basic equation used is GDD = [(T_MAX + T_MIN)/2] - T_BASE where T_MAX and T_MIN are daily maximum and minimum air temperature, respectively, and T_BASE is the base temperature. Two methods of interpreting this equation for calculating GDD are: (1) if the daily mean temperature is less than the base, it is set equal to the base temperature, or (2) if T_MAX or T_MIN < T_BASE they are reset equal to T …

The Prospect For An Asparagus Industry In Northern Western Australia, John Bonnardeaux

Horticulture published reports

Asparagus grown in temperate regions of southern Australia is available, fresh, between August and March. For the remainder of the year, asparagus is not grown in Australia on a significant scale.

Recent work in Thailand, Peru, Kununurra (northern-western Australia) and Katherine (Northern Territory) has indicated that good quality asparagus can be produced in tropical and subtropical climates. Furthermore, research has shown the timing of the harvest can be manipulated by withholding irrigation and fern cutting. In an environment such as the Ord River Irrigation Area (ORIA) it is possible to harvest asparagus at any time of the year.

This report …

Herbicide Evaluation In Arkansas Rice, 1996, Eric Webster, Ron Talbert, Ford Baldwin, David Gealy, Tomilea Dillon, Jason Norsworthy, Lance Schmidt, Dwayne Beaty

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Proceedings Of The Global Conference On Ergot Of Sorghum, Carlos R. Casela, Jeffery A. Dahlberg

INTSORMIL Impacts and Bulletins

In June 1996, several of us had the opportunity to see sorghum ergot in Brazil and the damage that the disease can do. We saw severe damage in seed production plots and witnessed the pain that seed producers had to go through to deal with this new problem. There was a wide spread scare in the sorghum community in the Americas because of the infamous reputation of the disease in causing damage in seed production fields. As a silver lining, we also observed first hand, the excellent research program that the Brazilians had in place. It became apparent that all …

A Comparative Study Of The Benthic Population In Weir Ponds Draining Watersheds Of The Fernow Experimental Forest, Parsons, West Virginia, Kevin Dwayne Brittingham

Theses, Dissertations and Capstones

A study of the benthos of weir ponds draining watersheds of the Fernow Experimental Forest (FEF) was conducted in 1994-1995. The objectives of this study were: (1) to relate differences in weir pond faunas to watershed treatments on the FEF, and (2) to compare current weir pond faunas to those described in 1973 by Steve Harris. In 1971-1972, there were fewer invertebrates but greater taxa richness than in 1994-1995. Total density varied among weir pond and between studies with numbers in the 1971- 1972 study ranging from 26,168 to 79,259 individuals collected, while numbers in the 1994-1995 study raged from …

Molecular And Functional Characterization Of A Novel Low-Affinity Cation Transporter (Lct1) In Higher Plants, Daniel P. Schachtman, Raman Kumar, Julian I. Schroeder, Ellen L. Marsh

Department of Agronomy and Horticulture: Faculty Publications

The transport of cations across membranes in higher plants plays an essential role in many physiological processes including mineral nutrition, cell expansion, and the transduction of environmental signals. In higher plants the coordinated expression of transport mechanisms is essential for specialized cellular processes and for adaptation to variable environmental conditions. To understand the molecular basis of cation transport in plant roots, a Triticum aestivum cDNA library was used to complement a yeast mutant deficient in potassium (K⁺) uptake. Two genes were cloned that complemented the mutant: HKT1 and a novel cDNA described in this report encoding a cation …

Effects On White Leghorn Hens Of Constant Exposure To Ultraviolet Light From Insect Traps, Jerome Hogsette, Henry Wilson, Susan Semple-Rowland

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

Constant exposure of Hy-Line^® W-36 White Leghorn hens to ultraviolet light from insect traps resulted in no significant differences in egg production, fertility, hatchability of fertile eggs, or total hatchability. Also, there were no apparent effects on the eyes of the birds. Results were the same when either blacklight or blacklight blue tubes were used. The need for additional testing of light traps for nuisance fly control in commercial caged layer houses is discussed.

Selenium Speciation Of Soil/ Sediment Determined With Sequential Extractions And Hydride Generation Atomic Absorption Spectrophotometry, Dean A. Martens, Donald L. Suarez

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

Understanding the speciation of the multioxidation states of selenium is vital to predicting the mineralization, mobilization, and toxicity of the trace element in natural systems. Asequential extraction scheme (SES) was developed for identification of Se oxidation states that first employed 0.1 M (pH 7.0) K₂HPO₄-KH₂PO₄ (P-buffer) to release soluble selenate (Se^+VI) and selenide (Se^-II) and ligand-exchangeable selenite (Se^+IV). The second step involved oxidation of organic materials with 0.1 M K₂S₂O₈ (90 °C) to release Se^-II and Se^+IV associated or occluded …

Resource Management Decision Support Tools - Brief Model Descriptions, Campbell White & Associates Pty Ltd

Farm Systems and Economics published reports

During the past 10 years, a number of financial models have been developed within Agriculture Western Australia to assist decision making in resource management. Various approaches have been taken including whole farm, development and partial budgets.

Natural resource managers within Agriculture Western Australia, have identified a need to preserve these decision support systems in a central library. The models should be readily accessible to new staff, and the library should provide an 'engine' through which the models can be promoted, and information relating their application distributed. Recent technology such as the development and mainstream adoption of the World Wide Web …