Digital Commons Network^™

Evaluation Of Algorithm Thresholds For Crop Canopy Sensor-Based In-Season Nitrogen Application In Corn, Brian Theodore Krienke

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

Nitrogen fertilizer is frequently the most limiting nutrient in corn production. Typically most nitrogen is applied before planting. Since nitrogen can leave the soil system fairly easily, the result can be an inefficient use of nitrogen fertilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regulated spatially through the use of active crop canopy sensors. This study evaluated the potential for N cutoff thresholds using a sufficiency index as the threshold value for areas with poor stand or an unrecoverable N deficiency. …

Mojave Applied Ecology Notes Summer 2011, Scott R. Abella, Charles W. Denton, David G. Brewer, Rory W. Steinke, Wayne A. Robbie, W. Wallace Covington, E. Cayenne Engel, Ross Guida

Mojave Applied Ecology Notes

Thoughts on fire possibilities on Mount Charleston, estimating historical densities of Ponderosa pine in northern AZ, over-understory changes in the Spring Mountains, seeding effectiveness in Red Rock Canyon, workshop announcements.

Prairie Restoration And Species Diversity: A Comparison Of Propagation Success Between Seeded And Planted Forbs, Julie A. Widinski

All Student Theses and Dissertations

Prairie ecosystems used to dominate Illinois’ landscapes, providing some of the most organically rich soils in the world, supplying homes to hundreds of native species, and conserving soil and water. The deep rooted forbs prevent water runoff and soil erosion. Economically the prairies have provided medicines, commercial forbs, and aesthetically pleasing landscapes for humans. Society is dependent on the rich soils these prairies have provided for agriculture and for prevention of erosion and water runoff. With less than one tenth of one percent of Illinois prairies still remaining, successful prairie restoration is of the utmost importance. In order to achieve …

Soil Test And Phosphorus Rate For High Rainfall Clover Pastures, Robert Summers, David Weaver

Bulletins 4000 -

Essential information for soil testing to determine the phosphorus fertiliser requirements for clover pastures in high rainfall coastal areas of Western Australia. Includes procedures for soil sampling, tissue testing, liming, when to apply fertiliser, how to decide on the target production level, how much fertiliser is required and type of fertiliser.

Effects Of Species, Water, And Nitrogen On Competition Among Three Prairie Grasses, Jerry L. Weatherford, Randall W. Myster

The Prairie Naturalist

We conducted an experiment to investigate effects of species, water (W), and nitrogen (N) on competition among little bluestem (Schizachyrium scoparium), sideoats grama (Bouteloua curtipendula), and indiangrass (Sorghastrum nutans). All biomass parameters and the root:shoot ratio of little bluestem were reduced by the presence off 1 of 2 other species, and its shoot biomass and total biomass were both increased by addition of N. Root and shoot biomass of sideoats grama were reduced by the presence of indiangrass and its total biomass was reduced by the presence of itself, whereas its shoot biomass was increased by addition of W at …

Assessing The Role Of Conspecific Attraction In Habitat Restoration For Henslow’S Sparrows In Iowa, Jennifer A. Vogel, Rolf R. Koford, David L. Otis

The Prairie Naturalist

The presence of conspecific individuals may provide important cues about habitat quality for territorial songbirds. We tested the ability of a conspecific song playback system to attract Henslow’s sparrows to previously unoccupied restored habitat. We successfully attracted Heslow’s sparrows to 3 of 7 treatment plots using conspecific song playbacks and we found no Henslow’s sparrows in control plots. The addition of social cues using playback systems in restored grassland habitats may aid conservation efforts of Henslow’s sparrows to available habitat.

Calodium Hepaticum In White-Tailed Jackrabbits In South Dakota, Dustin J. Schaible, Charles D. Dieter, Regg D. Neiger, Michael B. Hildreth

The Prairie Naturalist

White-tailed jackrabbits (Lepus townsendii) are common on the prairie, and an important species in prairie food webs (Lim 1987). Although it has been suggested that jackrabbits have cyclic populations (Donoho 1972, Gross et al. 1974, Anderson and Shumar 1986), there is concern that a general downward trend exists in populations in the Northern Great Plains (Feldhamer et al. 2003). Disease incidence in white-tailed jackrabbits is poorly known (Feldhamer et al. 2003), but may be an important factor in population changes. Tularemia, a disease caused by bacteria (Francisella tularensis), occurs throughout the Northern Hemisphere and can affect many mammals including hares, …

Multiple Bats Entangled On Cactus, Jon C. Pigage, Richard L. Bunn

The Prairie Naturalist

Accidental deaths of bats by entanglement on plants and barbed wire are common (McNicholl 1988, Norquay et al. 2010). It has been hypothesized these incidents involve miscalculations by bats on how close they fly to plants or barbed wire or when chasing insects highly concentrated around vegetation (Norquay et al. 2010). Once the bats hit the plants or barbed wire, they become entangled and or impaled while struggling to free themselves. The earliest reports involved little brown bats (Myotis lucifugus) and unidentified bats entangled on burdock, Arctium sp. (Lyon 1925, Little 1925). Additional reports of bats becoming entangled in plants …

First Record Of The Least Weasel In The Black Hills Of South Dakota, Tim R. Mullican

The Prairie Naturalist

The least weasel (Mustela nivalis) is a circumboreal species, occurring in North America from Alaska to the Appalachian Mountains (Jones et al. 1983). In the Great Plains, the least weasel recently expanded its range southward through Nebraska (Benedict et al. 2000) and Kansas (Choate et al. 1979, Bailey and Terman 1986) into Oklahoma (Clark and Clark 1988). Also, in recent decades, the least weasel has expanded from eastern and central Nebraska into western Nebraska (Benedict et al. 2000). In South Dakota, least weasels have been previously reported from the eastern 3/4 of the state (Jones et al. 1983, Higgins et …

Crustaceous Zooplankton Transfer Between A Floodplain Wetland And The Missouri River, Shannon J. Fisher

The Prairie Naturalist

Floodplain interactions are a critical riverine ecosystem function, including zooplankton transfer. Floodplain alternations have had an assumed impact on zooplankton productivity. I assessed floodplain wetland and main channel densities of crustaceous zooplankton, alluding to organism transfer in the Missouri River, North Dakota. Significant t-test differences (P < 0.05) were present between backwater and channel habitat zooplankton densities in 83, 75, 83, and 50% of the sample periods for cyclopoid copepods, copepod nauplii, Daphnia spp., and Bosmina spp. respectively, suggesting the presence of uncoupled zooplankton dynamics during portions of each annual cycle. Two relationships with increased flows were found, including a biologically significant decrease (P = 0.09) of backwater copepod nauplii numbers and a significant increase (P = 0.02) in the channel density of Daphnia spp. During the highest flow periods, fewer significant differences in zooplankton densities were present between the backwater and channel habitats, indicating moderate homogenization.

Distribution Of Crayfish Species In Select North Dakota Streams, Cari-Ann Hayer, Terrance L. Velazquez, Mclain S. Johnson, Brian Graeb

The Prairie Naturalist

Crayfish have an integral role in aquatic ecosystems, serving as herbivores, predators, detritivores, and prey for fishes and other aquatic and terrestrial animals (Momot 1995, Taylor et al. 1996, Martin 1997). Many crayfish populations are currently declining as a result of habitat alteration (Taylor et al. 1996) and invasive predators (e.g., rusty crayfish Orconectes rusticus [Girard; Lodge et al. 2000]). Knowledge of crayfish distribution and biology in North America and specifically North Dakota is sparse or lacking (Taylor et al. 1996) and baseline information is necessary to identify effects of anthropogenic alterations. Early inventories documented 3 crayfish species in North …

Notes: River Otters Use Agricultural Field Along The Turtle Riveri In Eastern North Dakota As Crossover And Latrine Area, Maggie D. Triska, Steven C. Loughry, Thomas L. Sergass

The Prairie Naturalist

Recently, the Nearctic river otter (Lontra canadensis) has been re-colonizing portions of eastern North Dakota. The landscape in eastern North Dakota is dominated by agricultural fields and pastures, habitats which have received little research attention related to otter habitat use. During 2008, we searched shorelines to detect otter latrines, which is a common method for determining otter presence. Generally, latrines are locations along bodies of water where otters deposit scats, urine, and glandular secretions for olfactory communication, and groom, wrestle, and play, which may mat vegetation. In the northeastern United States, inland riverine system studies have shown latrines …

Resource Selection By Elk At Two Spatial Scales In The Black Hills, South Dakota, Mark A. Rumble, R. Scott Gamo

The Prairie Naturalist

Understanding resource selection by elk (Cervus elaphus) at multiple spatial scales may provide information that will help resolve the increasing number of resource conflicts involving elk. We quantified vegetation at 412 sites where the precise location of elk was known by direct observation and 509 random sites in the Black Hills of South Dakota during 1998– 2001. We obtained stand level variables from geographic information system coverages for a 250 m buffer around elk and random sites. We used classification and regression trees to simultaneously evaluate environmental thresholds of resources selected by feeding and bedded elk at the site and …

Habitat Selection By Female Swift Foxes (Vulpes Velox) During The Pup- Rearing Season, Indrani Sasmal, Jonathan A. Jenks, Troy W. Grovenburg, Shubham Datta, Greg. M. Schroeder, Robert W. Klaver, Kevin M. Honness

The Prairie Naturalist

The swift fox (Vulpes velox) was historically distributed in western South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1800s, largely due to habitat loss and poisoning targeted at wolves (Canis lupis) and coyotes (C. latrans). Only a small population of swift foxes near Ardmore, South Dakota persisted. In 2003, an introduction program was initiated at BNP with swift foxes translocated from Colorado and Wyoming. We report on habitat use by female swift foxes during the pup-rearing season (May–July) in 2009. Analyses of location data from 13 radiomarked female foxes indicated disproportional use (P < 0.001) of some habitats relative to their availability within swift fox home ranges. Swift foxes used grassland (ŵ = 1.01), sparse vegetation (ŵ = 1.43) and prairie dog towns (ŵ = 1.18) in proportion to their availability, whereas they were less likely to use woodland (ŵ = 0.00), shrubland (ŵ = 0.14), pasture/agricultural-land (ŵ = 0.25) and development (ŵ = 0.16) relative to availability. Swift foxes typically are located in habitats that provide greater visibility, such as shortgrass prairie and areas with sparse vegetation; which allow detection of approaching coyotes (e.g., primary predator of swift foxes).

Phragmites Australis In South Dakota: Historical Distribution And Environment, Carol A. Johnston, Kayla L. Miller

The Prairie Naturalist

Common reed, Phragmites australis, has long been a component of Northern Plains wetlands, but impending invasion by the non-native P. australis haplotype M may displace native haplotypes in the future. To increase understanding of historical Phragmites occurrence, we developed a geographic information system (GIS) protocol to improve the georeferencing of specimens from South Dakota herbaria, and mapped the distribution of Phragmites relative to geology, physiographic regions, and water bodies. There were 91 Phragmites herbarium specimens from South Dakota and adjacent Wyoming. Phragmites collections occurred in nearly all physiographic regions of the state, with concentrations occurring in the Prairie Coteau of …

The Transfer Of Agricultural Water To Municipal And Industrial Usages, Dallin Paul Stephens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The water that is available for beneficial use in Utah is quickly approaching full appropriation; water that has been claimed is nearing the amount that is available for use. The Division of Water Resources of the State of Utah has organized a three-part plan to "Plan, Conserve, Develop and Protect Utah's Water Resources." One of these three elements has a focus to "provide comprehensive water planning." Such planning is best achieved when current and accurate data on the uses of the state's water are available.

The primary purpose of this thesis was to provide an evaluation, from data collected on …

Spatiotemporal Modeling Of Threats To Big Sagebrush Ecological Sites In Northern Utah, Alexander J. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study tested the performance of classification, regression, and ordination techniques to evaluate the spatiotemporal dynamics of threats to big sagebrush ecological sites. The research was focused on invasion by annual exotic grasses and encroachment by woodlands.

We sought to identify those areas that have had a persistent coverage of cheatgrass (Bromus tectorum) in big sagebrush ecological sites. We took advantage of the contrast in greenness between multi-temporal (within one year) remotely sensed vegetation indices captured in the spring and summer to find a distinct phenological signature that allowed mapping cheatgrass. We utilized support vector machines (SVM) to classify three …

Impact Of Student Motivation In Online Learning Activities, Amy Lathrop

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

With the prevalence of online learning in education for both distance and campus-based students, it is critical to determine how to design electronic learning materials that tailor to student motivation and facilitate learning.  Students were asked to complete an online plant breeding activity, motivation survey and an online learning quiz related to the activity.  The control group of students was those who elected not to complete the activity, while the experimental group of students chose to complete the activity.  Motivation scores were compared between control and experiment groups, courses, and gender using independent sample t-tests.  Pearson correlations were also used …

Relationships Of Exotic Plant Invasions With Biological Soil Crust, Desert Pavement, And Soil Carbon In The Eastern Mojave Desert, Adria Decorte

UNLV Theses, Dissertations, Professional Papers, and Capstones

In a matter of 50 years, exotic annual plants have become widespread in the Mojave Desert, contributing to drastic landscape changes such as those caused by recent fires. Invasions by exotics threaten native Mojave Desert plant communities by altering community functions (e.g. fire regimes) and by reducing plant diversity. Because it is not practical, or even possible, to eradicate these exotics, developing effective prevention techniques is the key to controlling these invasions.

This thesis used a greenhouse experiment, a field experiment, and a correlational field study to examine the affect soil surface types have on the establishment of three exotic …

Process-Based Management Of Downy Brome In Salt Desert Shrublands: Assessing Pre- And Post- Rehabilitation Soil And Vegetation Attributes, Merilynn Carol Hirsch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As an ecosystem driver, downy brome (Bromus tectorum L.) presents obstacles to land rehabilitation efforts, including restoring desirable species cover. Because damaged ecosystems may have crossed both abiotic and biotic thresholds, ecologically-based control strategies may assist with altering successional trajectories and restoring desirable plant species. My thesis research had three objectives: 1) assess soil and vegetation relationships in degraded salt desert ecosystems prior to implementing downy brome control treatments, 2) determine the effects of control treatments on soil properties and resident plant species, and 3) evaluate the relative importance of shrubland soil type, herbicide type, and herbicide rate on seedling …

Factors Affecting Greater Sage-Grouse (Centrocercus Urophasianus) Survival And Movement In South-Central Utah, Danny Caudill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse are the largest North American grouse species and are dependent on sagebrush for survival. Sage-grouse populations have declined throughout the west. Habitat fragmentation and degradation are likely the main causes of declining populations, and concern has lead to the petitioning for the sage-grouse to be listed under the Endangered Species Act. Survival of adult and juvenile sage-grouse is thought to be limiting population growth. However, survival of juvenile sage-grouse is poorly understood. I aimed to improve the knowledge gap regarding juvenile sage-grouse survival. With improved knowledge of juvenile survival, management actions can be employed to benefit sage-grouse populations. …

Creating An Environmental Placed Based Education At Norris Elementary, Ben Kittrell

Department of Environmental Studies: Undergraduate Student Theses

This study is focused on creating a place based education program. Place based education programs provide many benefits at the personal level with the students (PBEEC). The study was completed at Norris Elementary School where the students have access to the “Norris Forest” which is a planted forest with a walk way through the trees. Some of the trees are labeled for the students to identify and others are not. A graph of the unlabelled trees has been included for the students or the teachers to use.

This project incorporates activities that will engage the students in order to teach …

A Contribution To The Vascular Flora Of The Sequatchie Valley Within Sequatchie County, Tennessee, John Richard Evans

Masters Theses and Doctoral Dissertations

The vascular flora of the Sequatchie Valley within Sequatchie County, Tennessee was studied for three growing seasons from 2008 through 2010. The Sequatchie Valley is located within the southeastern portion of the Cumberland Plateau and is generally considered to be part of the Cumberland Plateau Physiographic Province. Nevertheless, a number of geological and ecological factors distinguish the Sequatchie Valley from the elevated Cumberland Plateau, suggesting that the floristic composition of the valley may be different from the surrounding region. Although several previous floristic studies have been conducted on the plateau surface, very little attention has been given to the Sequatchie …

Exploring The Potential Of Agave As A Biofuel Crop On Arid Land, Rhea Conlu, Diana Ha, Jeffery Shen

Festival of Communities: UG Symposium (Posters)

Worldwide awareness of global warming and depleting fossil fuel sources has made research into alternative resources, such as plant fuels imperative. Since groundwater irrigation is unsustainable, especially in desert climates, plants that are drought resistant or can utilize otherwise unusable water are more viable sources of future biofuel production. Agave nevadensis, a species belonging to the family Agavaceae are succulent plants native to Las Vegas. This experiment aims to expose A. nevadensis to both wastewater and drought conditions and observe its response. The results can help define Agave as a water-resourceful biofuel both tolerant of drought and capable of utilizing …

Screening Synteny Blocks In Pairwise Genome Comparisons Through Integer Programming, Haibao Tang, Eric Lyons, Brent S. Pedersen, James C. Schnable, Andrew H. Paterson, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Background:

It is difficult to accurately interpret chromosomal correspondences such as true orthology and paralogy due to significant divergence of genomes from a common ancestor. Analyses are particularly problematic among lineages that have repeatedly experienced whole genome duplication (WGD) events. To compare multiple “subgenomes” derived from genome duplications, we need to relax the traditional requirements of “one-to-one” syntenic matchings of genomic regions in order to reflect “one-to-many” or more generally “many-to-many” matchings. However this relaxation may result in the identification of synteny blocks that are derived from ancient shared WGDs that are not of interest. For many downstream analyses, we …

Impact Of Climate Change And Climate Variability On Productivity Of Grain Crops, P. V. Vara Prasad

INTSORMIL Presentations

1. Climate change and climate variability (past and future). 2. Temperature and carbon dioxide: response of grain sorghum and dry bean. 3. Climate change and variability in El Salvador (climate models). 4. Impact of temperature increaseongrainyieldofsorghum,maizeanddrybeaninElSalvador(cropsimulationmodels). 5.Concludingremarks.

Review Of The Tallgrass Prairie Center Guide To Prairie Restoration In The Upper Midwest. By Daryl Smith, Dave Williams, Greg Houseal, And Kirk Henderson., Gerry Steinauer

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Tallgrass prairie restoration in the Upper Midwest is the focus of this guide. Its geographic area of coverage includes the eastern fifth of South Dakota and Nebraska and northeast Kansas, a region some ascribe to the eastern Great Plains. Two types of prairie restoration are dealt with: prairie reconstruction, which the authors define as creating prairie from scratch on sites where prairie plants no longer exist; and prairie remnant restoration, defined as upgrading degraded existing prairies. The book comprises five sections: "Reconstruction Planning," "Implementing Reconstruction," "Prairie Restoration and Management," "Special Cases," and "Native Seed Production." There are 16 chapters, each …

Characteristics Of Kentucky’S Nursery And Greenhouse Industries, Dewayne L. Ingram, Winston Dunwell, Alan Hodges

Agriculture and Natural Resources Publications

The nursery and greenhouse industry, distributed throughout Kentucky, is diverse and contributes significantly to the local and state economy. This industry represents the largest segment of Kentucky’s sales of horticultural products and is comprised almost completely of farm families. Nursery and greenhouse crops are produced and marketed in containers or grown in the field and dug and sold as balled and burlapped or bare root plants. Most of Kentucky’s nursery and greenhouse crops are marketed in Kentucky and surrounding states.

Vegetation Classification And Mapping Of Homestead National Monument Of America, Project Report, Kelly Kindscher, Hayley Kilroy, Jennifer Delisle, Quinn Long, Hillary Loring, Kevin Dobbs, Jim Drake

United States National Park Service: Publications

Executive Summary

Homestead National Monument (HOME) was created at the to celebrate the significance of the Homestead Act of 1862 which granted 160 acres of free land to claimants and was one of the most significant and enduring events in the westward expansion of the United States. The National Monument encompasses 184 acres in Gage County, west of Beatrice, Nebraska. This unique site also hosts the oldest prairie restoration in the National Park system, and the second-oldest tallgrass prairie restoration known. This park unit also has a small remnant of native tallgrass prairie and remnants of bur-oak forest.

A three-year …

Mojave Applied Ecology Notes Spring 2011, Scott R. Abella, Ross Guida, S. D. Smith, Christopher L. Roberts, Haroon Stephen, William J. Smith, Zhongwei Liu, James S. Holland, Aurore Giguet

Mojave Applied Ecology Notes

Red brome distribution in the eastern Mojave Desert, A look at the UNLV xeric gardens and Marjorie Barrick museum, Summary of recent science synthesis efforts