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Chapter 18. Daycent Simulated Effects Of Land Use And Climate On County Level N Loss Vectors In The Usa, S. J. Del Grosso, W. J. Parton, D. S. Ojima, C. A. Keough, T. H. Riley, A. R. Mosier

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

We describe the nitrogen (N) gas (NH₃, NO_x, N₂O, N₂) emission and NO₃ leaching submodels used in the DAYCENT ecosystem model and demonstrate the ability of DAYCENT to simulate observed N₂O emission and NO₃ leaching rates for various sites representing different climate regimes, soil types, and land uses. DAYCENT simulated seven major crops, grazing lands, and potential native vegetation at the county level for the United States. At the national scale, NO₃ leaching was the major loss vector, accounting for 86%, 66%, and 56% of total N …

Chapter 15. Proven Practices And Innovative Technologies For On-Farm Crop Nitrogen Management, N. R. Kitchen, K. W. T. Goulding, J.F. Shanahan

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

Nitrogen (N) from soil, fertilizer, and manure sources is generally inefficiently used (30-60%) in most crop production systems. As a consequence, unused inorganic N can move off crop fields and contaminate surface and groundwater resources. Local and national governments have responded with guidelines, standards, regulations, and in some cases fines when off-field losses of N have not been reduced. Along with these environmental pressures, soaring energy costs have resulted in commensurate increased costs for N fertilizers. These factors are real for crop producers and are compelling them to scrutinize their crop N management more closely than in previous decades. Numerous …

Chapter 4. Relationship Of Environmental Nitrogen Metabolism To Human Health, J. R. Follett, R. F. Follett

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

The need for humans to produce and consume food and other agricultural products is increasing. This need is directly related to increasing world populations, demands for goods and services, and expectations. Nitrogen (N) is contained in all of the amino acids and proteins in the foods consumed by humans. The use of N to produce food and other products is generally increasing as human needs increase. Proteins are an essential component of the human diet because, unlike plants, humans are unable to utilize more simple forms of N and rely on food sources for protein which can then be digested …

Initial Response Of Evapotranspiration From Tallgrass Prairie Vegetation To Co2 At Subambient To Elevated Concentrations, H. W. Polley, H. B. Johnson, P. A. Fay, J. Sanabria

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

A series of weighing lysimeters in which tallgrass prairie species had been planted were exposed to a subambient to elevated gradient in CO₂ in a field chamber. Lysimeters with intact monoliths of three soil types were represented along the CO₂ gradient. We used regression analysis to determine how CO₂ effects on evapotranspiration per unit of soil surface area (ET_soil) and per unit of leaf area (ET_la) depended on variation in leaf area index (LAI) and diurnal changes in environmental variables during the initial 6 weeks of CO₂ treatment.

Hydraulic Core Extraction: Cutting Device For Soil–Root Studies, T. S. Kornecki, S. A. Prior, G. B. Runion, H. H. Rogers, D. C. Erbach

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

A critical objective of belowground research is to collect and process representative soil samples. Mechanical devices have been developed to quickly take soil cores in the field; however, techniques to rapidly process large-diameter soil cores are lacking. Our objective was to design and construct a soil extraction–cutting system that could effectively reduce processing time. Soil cores were extracted from large diameter steel core tubes using a custom hydraulic cylinder device that vertically pushes the soil core to a desired depth increment before cutting in a horizontal direction with another hydraulically driven device. As many as eight large cores per hour …

Growth And Feed Efficiency Of Juvenile Channel Catfish Reared At Different Water Temperatures And Fed Diets Containing Various Levels Of Fish Meal, Menghe H. Li, Edwin H. Robinson, Brian C. Peterson, Terry D. Bates

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

Channel catfish Ictalurus punctatus do not feed well at low temperatures. It is generally thought that a diet containing fish meal enhances feed palatability at low temperatures since fish meal is highly palatable to fish. There is a lack of information on the effects of fish meal levels on the growth performance of channel catfish reared at low temperatures. Therefore, a study was conducted in a recirculating system to examine the effects of fish meal levels on the feed consumption, weight gain, and feed efficiency of juvenile channel catfish reared at various temperatures. Fish with an initial weight of 9.6 …

Nationally Coordinated Evaluation Of Soil Nitrogen Mineralization Rate Using A Standardized Aerobic Incubation Protocol, T. S. Griffin, C. W. Honeycutt, S. L. Albrecht, K. R. Sistani, H. A. Torbert, B. J. Wienhold, B. L. Woodbury, R. K. Hubbard, J. M. Powell

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

Aerobic incubation methods have been widely used to assess soil nitrogen (N) mineralization, but standardized protocols are lacking. A single silt loam soil (Catlin silt loam; fine-silty, mixed, superactive, mesic, Oxyaquic Arguidoll) was subjected to aerobic incubation at six USDA-ARS locations using a standardized protocol. Incubations were conducted at multiple temperatures, which were combined based on degree days (DD). Soil water was maintained at 60% waterfilled pore space (WFPS; constant) or allowed to fluctuate between 60 and 30% WFPS (cycle). Soil subsamples were removed periodically and extracted in 2 M potassium chloride (KCl); nitrate (NO₃) and ammonium (NH …

Areawide Suppression Of Fire Ants, M. D. Aubuchon, R. K. Vander Meer

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

The imported fire ants, Solenopsis invicta and S. richteri, were inadvertently introduced into the USA in the early 1900s and currently inhabit over 129 million ha in Puerto Rico and 12 southern states, from Texas to Virginia (Callcott and Collins, 1996; USDA-APHIS map). Imported fire ants have also become established in isolated sites in California, Arizona, New Mexico and Maryland. Strict quarantine procedures have limited the spread of this pest (Lockley and Collins, 1990), but eventually populations will expand westward in increasing numbers in New Mexico, Arizona and California. They will also move upward along the Pacific coast, southward …

The Hawaii Fruit Fly Areawide Pest Management Programme, Roger I. Vargas, Ronald F. L. Mau, Eric B. Jang, Robert M. Faust, Lyle Wong

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

Fruit flies (Diptera: Tephritidae) are among the most economically important pests attacking soft fruits worldwide (White and Elson-Harris, 1992). Four invasive species Mediterranean fruit fly or medfly (Ceratitis capitata), melon fly (Bactrocera cucurbitae), oriental fruit fly (Bactrocera dorsalis) and the so-called Malaysian fruit fly or solanaceous fruit fly (Bactrocera latifrons) - have been devastating to Hawaiian agriculture for over 100 years by infesting more than 400 different host plants. These fruit flies:

• Jeopardize development of a diversified tropical fruit and vegetable industry.

• Require that commercial fruits undergo quarantine treatment prior …

Short Communication- An Update On The Diversity Of Wolbachia In Spalangia Spp. (Hymenoptera: Pteromalidae), K.D. Floate, P.C. Coghlin, D. B. Taylor

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

Results from 13 additional host populations improves resolution on the diversity of Wolbachia bacteria in Spalangia spp. (Hymenoptera: Pteromalidae). These bacteria are of interest because they can profoundly affect their host’s reproduction. Manipulating Wolbachia infections may provide a method to improve the efficacy of biocontrol agents including Spalangia spp.

Parasitoid wasps (Pteromalidae: Hymenoptera) are of interest as biocontrol agents for pest flies (Diptera: Muscidae) of livestock confinements; e.g. dairies, cattle feedlots, poultry houses, swine barns. Many of these wasps are infected with Wolbachia bacteria that can profoundly affect their host’s reproduction. Wolbachia induce parthenogenesis in Muscidifurax uniraptor Kogan & Legner …

Volatile Compounds From The Integument Of White Leghorn Chickens (Gallus Gallus Domesticus L.): Candidate Attractants Of Ornithophilic Mosquito Species, Ulrich R. Bernier, Sandra A. Allan, Brian Quinn, Daniel Kline, Donald Barnard, Gary Clark

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

Candidate kairomones of ornithophilic mosquito species are reported from GC/MS analysis of compounds from the skin on the back, the feet, and feathers from the back of White Leghorn chickens (Gallus gallus domesticus). Hexane and ether extracts of chicken feathers differ significantly in attractiveness of Culex spp. mosquitoes. The active (hexane) extracts contained an abundance of alcohols, ketones, and diones. The inactive (ether) extracts contained aldehydes, which also were in the hexane extracts. Analysis of hexane extracts from chicken feet, skin, and feathers demonstrated the qualitative similarity in the compounds collected with subtle differences observed in the quantitative …

Discovery Of Diurnal Resting Sites Of Phlebotomine Sand Flies In A Village In Southern Egypt, Jerome Hogsette, Hanafi A. Hanafi, Ulrich R. Bernier, Daniel L. Kline, Emad Y. Fawaz, Barry D. Furman, David F. Hoel

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

In an attempt to find diurnal resting sites of adult phlebotomine sand flies, potential phlebotomine adult habitats were aspirated in the village of Bahrif in Aswan, Egypt. During this survey, sand flies were aspirated from low (30–45 cm high) irregular piles of mud bricks found under high date palm canopies between the village and the Nile River. There were 5 ♂♂and 7 ♀♀ of Phlebotomus papatasi and 3♂♂ of Sergentomyia schwetzi. Six of the 7 aspirated females were engorged with blood. A total of 78 sand flies was captured on 3 glue boards placed overnight on the ground next …

Enteric Bacteria Of Field-Collected Colorado Potato Beetle Larvae Inhibit Growth Of The Entomopathogens Photorhabdus Temperata And Beauveria Bassiana, Michael B. Blackburn, Dawn E. Gundersen-Rindal, Donald C. Weber, Phyllis A. W. Martin, Robert R. Farrar Jr.

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

The nematode Heterorhabditis marelatus fails to reproduce in the Colorado potato beetle, Leptinotarsa decemlineata, possibly due to interference from the enteric bacteria of the beetle. Specifically, the enteric bacteria inhibit the growth of Photorhabdus temperata, the enteric symbiont of the nematode, in vitro. However, previous work was based on a laboratory culture of L. decemlineata, and we wished to determine if similar bacteria were present in the field. Therefore, we cultured the enteric bacteria of fourth-instar larvae collected from the field at two locations in Maryland and Virginia. Representatives of the genera Pantoea, Enterobacter, Pseudomonas …

The Genetic Diversity, Relationships, And Potential For Biological Control Of The Lobate Lac Scale, Paratachardina Pseudolobata Kondo & Gullan (Hemiptera: Coccoidea: Kerriidae), S. Schroer, R. W. Pemberton, L. G. Cook, T. Kondo, P. J. Gullan

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

The lobate lac scale Paratachardina pseudolobata Kondo & Gullan (Kerriidae) is a polyphagous pest of woody plants in Florida (U.S.A.) the Bahamas, Christmas Island (Australia) and it has been reported from Cuba. Its recent appearance as a pest in these places indicates that this scale is introduced; however, its native range is unknown. Until 2006, this pest species was identified mistakenly as Paratachardina lobata (Chamberlin) [now P. silvestri (Mahdihassan)], which is native to India and Sri Lanka. Quarantine laboratory acceptance trials with Indian P. silvestri parasitoids indicated a strong immune response from P. pseudolobata. Gregarious development of encyrtid wasps …

A Core Set Of Microsatellite Markers For Western Corn Rootworm (Coleoptera: Chrysomelidae) Population Genetics Studies, Kyung Seok Kim, Uwe Stolz, Nicholas J. Miller, Miller R. Waits, Thomas Guillermaud, Douglas V. Sumerford, Thomas W. Sappington

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

Interest in the ecological and population genetics of the western corn rootworm, Diabrotica virgifera virgifera LeConte, has grown rapidly in the last few years in North America and Europe. This interest is a result of a number of converging issues related to the increasing difficulty in managing this pest and the need to characterize and understand gene ßow in the context of insect resistance management. One of the key components needed for successful population genetics studies is the availability of suitable molecular markers. Using a standard group of microsatellite markers enables researchers from different laboratories to directly compare and share …

Entomopathogenic Fungal Endophytes, Fernando E. Vega, Francisco Posada, M. Catherine Aime, Monica Pava-Ripoll, Francisco Infante, Stephen A. Rehner

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

Fungal endophytes are quite common in nature and some of them have been shown to have adverse effects against insects, nematodes, and plant pathogens.
Our research program is aimed at using fungal endophytes-mediated plant defense as a novel biological control mechanism against the coffee berry borer, the most devastating pest of coffee throughout the world. A survey of fungal endophytes in coffee plants from Hawaii, Colombia, Mexico, and Puerto Rico has revealed the presence of various genera of fungal entomopathogens, including Acremonium, Beauveria, Cladosporium, Clonostachys, and Paecilomyces. Two of these, B. bassiana and Clonostachys rosea …

Seeding Effectiveness And Natural Regeneration Of Mojave Desert Plant Communities After 2005-2006 Wildland Fires, E. Cayenne Engel, Scott R. Abella, Christina L. Lund

Fire Science Presentations

1) Assessment of BLM seeding effectiveness in mid-elevation burn where pre-burn plant communities were dominated by blackbrush, Joshua trees, and creosote.

2) Patterns driving fire recovery at the landscape scale:

• Link initial vegetation, environment, and soils
• Are there patterns that can be gleaned that can then be applied to management prescriptions?

Management Techniques For The Control Of Sahara Mustard (Brassica Tournefortii) In The Mojave Desert, Dianne N. Bangle, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

In the southwestern United States, Brassica tournefortii(Sahara mustard) is a highly invasive plant that colonizes roadsides, beaches, sand dunes, and open desert threatening native annuals. Sahara mustard is believed to contribute to fuel loads in the Mojave Desert in areas where Schismussp. and Bromussp. occur. Sahara mustard may act as ladder fuel, thereby facilitating the spread of fire throughout the landscape. Manpower limitations and insufficient funding limits the abilities of managers to effectively control Sahara mustard. We tested seed germinability in Sahara mustard after fruiting plants were treated with either 2%, 5%, or 12% triclopyr. Sahara mustard seed pods were …

Exotic Annual Plant Invasions And Their Relationships To Roads And Native Perennial Species In The Mojave Desert, Southwestern Usa, Donovan J. Craig, Jill Pacovsky Craig, Scott R. Abella

Vegetation Monitoring Presentations

For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a site’s shrub composition could influence exotic invasive plant distributions.

Implications For Management Prioritization Of Exotic Annual Weed Monitoring Near Roadsides In The Eastern Mojave Desert, Usa, Donovan J. Craig, Jill E. Craig, Scott R. Abella, Public Lands Institute,

Vegetation Monitoring Presentations

Invasive exotic plants provide an unnatural conduit for fires in the Mojave Desert. For the last five years, roadside monitoring for exotic invasive species has been a common practice for documenting distributions in Clark County, Nevada (Abella et al., in press). Yet, studies have shown that weed relationships to road corridors differ depending upon the natural system (Hansen and Clevenger, 2005). In the Mojave Desert, it is unknown whether exotic species are limited to or even predominant along roadsides.

Compounding this uncertainty, fertile islands under shrubs are known to enhance conditions for many annuals (Thompson et al., 2005). Thus, a …

Response Of Sahara Mustard (Brassica Tournefortii) To Water Addition And Soil Disturbance, Alexis Suazo, Jessica E. Spencer, Scott R. Abella

Vegetation Monitoring Presentations

Invasive exotic species can have a significant impact on the structure, function, and diversity of ecological communities. Sahara mustard (Brassica tournefortii) is one of the top exotic invasive species spreading through the southwestern deserts of North America. In arid environments, it is well documented that species abundance is sensitive to rainfall (Beatly 1974, Ernest et al. 2000). In the Mojave Desert, winter precipitation can trigger massive germination events (Beatly 1974). As a winter annual, Sahara mustard may have a positive response to winter precipitation by germinating, growing, and reproducing before native annuals, monopolizing soil moisture and nutrients, and potentially changing …

Mojave Applied Ecology Notes Winter 2008, Scott R. Abella, E. Cayenne Engel, Jill E. Craig

Mojave Applied Ecology Notes

Mojave Desert collaborative projects, fire history in Spring Mountains, Northshore Road rehabilitation, wildfires and invasive plants in American deserts conference, weed sentry surveys

Reestablishing The Juneberry On The Fort Berthold Indian Reservation: Cultural, Horticultural, And Educational Connections, Kerry E. Hartman

Electronic Theses and Dissertations

Tribal people of the Northern Great Plains have utilized plants for centuries. Amelanchier anifolia (Juneberries/Serviceberries) historically played an important part in the diet and culture of the Mandan, Hidatsa, and Arikara (MHA) Tribal Nations. Research conducted as part of this study into historical and contemporary uses of the Juneberry by MHA Tribal Members indicated extensive historical use and a high interest in Juneberry reestablishment for cultural, nutritional, and economic reasons. Previous research on Juneberries has investigated factors including state of dormancy, propagation method, transplant type, and mulch type. Another purpose of this study was to elucidate the impact of presence …

Sex-Specific Feeding Rates And Provisioning Of Fruit To Nestling Bell's Vireo, Greg H. Farley

The Prairie Naturalist

Provisioning of fruit to nestlings and possible sex-specific differences in feeding rate have not been reported for Bell's vireo (Vireo bellii; Brown 1993). While studying nesting ecology of Bell's vireo on Konza Prairie Biological Station, Geary and Riley counties, Kansas, I quantified feeding rate by sex and food type delivered to nestlings. Sex was determined by capturing adults with mist-nets and inspecting for a cloacal protuberance, as well as conducting behavioral observations of uniquely-marked individuals. Males sing regularly while moving around territories, as well as during incubation (Nolan 1960). I assigned "female" to the individual in these socially …

Combination Of Natural Variability Estimation With Real Time Measurement For Mushroom Shelf Life Assessment., Leixuri Aguirre

Doctoral

The shelf life of mushrooms (Agaricus bisporus) is affected by the natural variability of the produce which influences the perishable vegetable quality. One of the main causes of this variability is non-homogeneity in the product maturity at harvest, resulting in each vegetable batch being at a different stage of senescence. The present work aims to study a new approach to improve the assessment of the shelf life of mushrooms (Agaricus bisporus) taking into account this variability. The study of variability involved the: i) study of the shelf life, quality parameters and variability of the mushrooms and modelling these experimental laboratory …

Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano

Publications

The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant-1 s-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO2 uptake. Diurnal cycles in ethylene synthesis were present in all crops studied. These …

Lignin Degradation In Wood-Feeding Insects, Scott M. Geib, Timothy R. Filley, Patrick G. Hatcher, Kelli Hoover, John E. Carlson, Maria Del Mar Jimenez-Gasco, Akiko Nakagawa-Izumi, Rachel L. Sleighter, Ming Tien

Chemistry & Biochemistry Faculty Publications

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut …

New Strategy For The Search Of Natural Biologically Active Substances., Vyacheslav Dushenkov, Ilya Raskin

Publications and Research

The modern pharmaceutics actively screens an immense diversity of substances occurring in plants and other natural resources in the search for new effective medicinal agents. The Global Institute for Bioexploration (GIBEX) established by joint efforts of Rutgers University and the University of Illinois (United States) represents the organizational core of international scientific community whose activity is directed towards the search and development of new medicinal preparations from natural raw materials. The basis of GIBEX activity is the transfer of modern screening technologies to countries and geographical regions characterized by remarkable biodiversity. The GIBEX goals are to encourage the search for …

Assessment Of Terrain Attribute Models For The Identification Of Erosion Prone Areas Suitable For The Establishment Of Grassed Waterways In An Agricultural Field Setting In The Out Bluegrass Region Of Kentucky, Adam Clellon Pike

University of Kentucky Master's Theses

The speed and accuracy of conservation planning could be improved if maps indicating areas where grassed waterways should be placed to reduce erosion could be easily created. For five central Kentucky fields, elevation data were obtained with real time kinematic (RTK) global positioning system (GPS) and from US Geological Survey (USGS) digital elevation models (DEMs). Terrain attributes were calculated from these datasets which were used as predictor variables for neural network and logistic regression analyses. Grassed waterway prediction models were developed with these analyses. The type of activation function, type of standardization procedure, number of neurons, number of preliminary runs, …

Systematic Revision Of Elaphoglossum (Dryopteridaceae) In French Polynesia, With The Description Of Three New Species, Germinal Rouhan, David H. Lorence, Timothy J. Motley, Judith Garrison Hanks, Robbin C. Moran

Biological Sciences Faculty Publications

Species descriptions and a key for the nine species of Elaphoglossum (Dryopteridaceae) in French Polynesia are provided. Three new species are described: E. austromarquesense from the southern Marquesas Islands, E. florencei from Raiatea and Moorea, and E. meyeri from Rapa. Each species is illustrated by a line drawing of the habit, and spore images using a scanning electron microscope. Images of scales, one of the most important diagnostic characters in the genus, are also included. © 2008 The Linnean Society of London.