Digital Commons Network^™

Pastures In Crop Rotations Enhance Earthworm Populations In Southern Australia, John C. Buckerfield

IGC Proceedings (1977-2023)

The effects of crop rotations on earthworm populations in seasonally dry arable lands was assessed on long-term field trials at 2 sites with an annual rainfall of 450-500 mm, In cropping and sheep-grazing areas of southern Australia. Earthworm densities were substantially higher in rotations of cereals with a volunteer-pasture phase than under continuous cropping with cereals and grain legumes. The degree and frequency of soil disturbance associated with cropping has been shown to influence earthworm numbers: trial plots In which crops were sown with minimal cultivation, in alternate years, supported earthworm populations 2-3 times higher than those conventionally cultivated and …

Costs And Benefits Of Controlling Grasshoppers On Rangeland, E W. Huddleston, R Sanderson, L A. Torell, J H. Davis, J G. Watts

IGC Proceedings (1977-2023)

Ultra low volume (ULV) aerial application of malathion at 0.58 I/ha is the common method of rangeland grasshopper control in the USA. Aircraft often are unavailable or too expensive for treating small infestations; therefore, air-assist ground equipment was adjusted 10 apply the ULV rate from a small truck. In winds of 2.2 m/sec or greater, control with the ground equipment was equivalent to that expected from aircraft. The low spray volume, low sprayer cost and use of a small truck have increased the benefit/cost ratio. Using results from this research and site-specific estimates of control costs and forage value, the …

The Rodent Pests Of Pasture And Their Control In China, Xixian Hou, Weihui Dong, Yanlin Zhou

IGC Proceedings (1977-2023)

Rodent damage is increasingly recognised as a major problem for grasslands of China rodents damage up to an estimated 33 million ha each year, There are two reasons for rodent damage in grassland: one is overgrazing, which causes degeneration of grassland and provides good habitats for rodents; another is the ecological characteristics of rodents. A rodent control programme has been followed for years in China, and includes: (1) studies on the ecology of major rodent pests in pasture, (2) prediction of population, (3) setting up control indexes paying attention to economic benefits, (4) tightening up grassland management and developing integrated …

Stylo Host Heterogeneity For Anthracnose Management, S Chakraborty, A N. Petitt, R M. Boland, S Low Choy, D F. Cameron, J A.G Irwin, R D. Davis

IGC Proceedings (1977-2023)

Small plots of 3 different mixtures of Stylosallllles. scabra genotypes were established within background paddocks of either pure cv. Seca, or a mixture of 6 S. scabra genotypes including Seca, to study anthracnose development in the three mixtures under exogenous inoculum pressures arising from the two backgrounds. There was no difference in disease severity between the background paddocks after the first year. In the small plots, severity of nearest neighbours significantly influenced anthracnose severity on the partially resistant accession 55860 in the first year; this effect disappeared as the disease became more widespread throughout the plot in later years. Replacing …

Increased Resistance To Sclerotinia Crown And Stem Rot Of Alfalfa Through Recurrent Selection Of Surviving Plants In Inoculated Field Plots, M Kanbe, F Fujimoto, S Inami

IGC Proceedings (1977-2023)

ABSTRACT Breeding alfalfa (Medicago saliva L.) for resistance to Sclerotinia crown and stem rot (SCR; causal agent Sclerotitivia trifoliorum Eriks.), which is a serious disease in Japan, was started in 1983. Increased resistance to this disease has been examined after repeated selected of surviving plants from artificially inoculated field plots to the 5th generation. The strains selected for SCR resistance showed higher resistance than Tachiwakaba, which was the main breeding material. The effectiveness of selection judged by the survival rate of progenies was low in the early selection generations but high in the later ones, It is considered that …

Biological Control Of Alfalfa Aphids In Japan Using Coccinella Septempunctata Brucki, Keiichi Takashi

IGC Proceedings (1977-2023)

The oviposition, predation, and survival abilities of Coccinella septempuncrara bmcki Mulsanl (lady beetle), a natural enemy of alfalfa aphids (Acyrtllosyphon kondoi Shinji), increased as temperatures rose in laboratory tests. The second-instar larvae were released into cages in alfalfa (Medicago saliva L.) fields in spring 1991. One month later, alfalfa plants in the control cages without larvae showed much lower yield; however, no damage was observed in cages in which larvae had been released. There is a strong probability that alfalfa aphids can be controlled by the timely release of lady beetle larvae in the field.

Estimating Methane Emissions From Orphaned Oil And Gas Wells In Kentucky: Results From The Initial Grant Program, T. Marty Parris, Deron W. Zierer, Stacy L. Woods, Steven E. Webb

Contract Reports--KGS

From February 2023 through August 2024, Kentucky Geological Survey (KGS) scientists measured methane emissions on 119 orphaned oil and gas wells distributed among 26 counties in eastern, south-central, and western Kentucky. Early measurements were done in partnership with the Well Done Foundation using a Ventbuster flowmeter (n = 41), whereas later measurements (n = 78) were done by KGS scientists using a SEMTECH High-Flow 2 sampler or a static chamber designed and fabricated at the University of Kentucky. The measurements were done in support of the Kentucky Division of Oil and Gas plugging program funded by the Bipartisan Infrastructure Law’s …

A Comparative Study Of Cave System Calcium Isotope Ratios: Implications For Quantitative Reconstruction Of Paleorainfall From Speleothems, Cameron B. De Wet, Elizabeth M. Griffith, Andrea Erhardt, Jessica L. Oster

Earth and Environmental Sciences Faculty Publications

Variations in speleothem calcium isotope ratios (δ44Ca) are thought to be uniquely controlled by prior carbonate precipitation (PCP) above a drip site and, when calibrated with modern data, show promise as a semi‐quantitative proxy for paleorainfall. However, few monitoring studies have focused on δ44Ca in modern cave systems. We present a multi‐year comparative study of δ44Ca, carbon isotopes (δ13C), and trace elemental ratios from cave drip waters, modern calcite, and host rocks from two cave systems in California—White Moon Cave (WMC) and Lake Shasta Caverns (LSC). Drip water and calcite δ44Ca from both caves indicate PCP‐ driven enrichment, and we …

Kentucky Geological Survey Landslide Inventory [2024], Matthew M. Crawford, Evelyn M. Bibbins, Hudson J. Koch

Research Data--KGS

The KGS landslide inventory provides the locations of known landslides and areas susceptible to debris flows. Various types of landslides are represented including slides, flows, rockfalls, and creep. The data are available as ArcGIS geodatabase feature classes. Landslide locations and associated attributes are compiled from Kentucky Geological Survey research, published maps, state and local government agencies, the public, and media reports. A confidence ranking system assigns a value to each feature. A description of the feature classes is here: https://kgs.uky.edu/kgsmap/helpfiles/landslide_help.shtm

The inventory viewed in a GIS with geology, soils, slope or other terrain-based data can serve as a basis for …

Analysis And Design Of Synchronous Machines With Reluctance Rotor And Pm Stator Combined Excitation, Oluwaseun A. Badewa, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper studies motors that are part of a general class of synchronous machines with stator-only excitation including those that may be referred to in recent literature as of the flux switching, variable flux reluctance, or hybrid excitation type. In the studied example machine, the active stator has circumferentially magnetized spoke-type PMs and concentrated toroidal coils for improved slot fill and shortened end turns. A systematic analysis of the mmf produced by the toroidal coils in the stator and open-circuit airgap flux is developed to define feasible polarities of this synchronous motor and to establish that the dominant pole pair …

Two-Level Design Optimization Of Ac Machines With Dc Stator Excitation And Minimal Torque Ripple Using Reluctance Rotor Profile Shaping, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Torque ripple mitigation in electric machines is important for a smooth and stable operation, minimize mechanical vibrations, and enhance the overall performance. In this paper, a novel two-level optimization method is proposed for the design of synchronous flux-switching and hybrid excitation machines with an innovative multi-point spline shaping method to minimize the torque ripple. This study uses models that are validated by experimental tests from a prototype with similar topology, and exemplifies the aforementioned optimization process on a 28 pole machine. The analysis results indicate that the torque ripple can be substantially reduced with improved electromagnetic torque of the electric …

Model Predictive Control Of 5l-Anpc Inverter Fed Coreless Afpm Motor With Mitigated Cmv In Electric Aircraft Propulsion, Farzad Y. Notash, Matin Vatani, Jiangbiao He, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper proposes a fast model predictive control (FMPC) method without weighting factors and mitigated common-mode voltage (CMV) for a five-level active neutral point clamped (5L-ANPC) inverter-fed electric aircraft propulsion system with a coreless axial flux permanent magnet (CAFPM) motor. This motor is specifically designed for electric aircraft propulsion through a combined electromagnetic and thermal evaluation, benefiting from a high specific power density, efficiency, and integrated thermal management system. The proposed method utilizes the deadbeat approach to calculate the reference voltage vector and compensate for the one-time interval delay between the predicted and applied switching commands. The angle and amplitude …

Communities That Heal Intervention And Mortality Including Polysubstance Overdose Deaths: A Randomized Clinical Trial, Bridget Freisthler, Rouba A. Chahine, Jennifer Villani, Redonna Chandler, Daniel J. Feaster, Svetla Slavova, Jolene Defiore-Hyrmer, Alexander Y. Walley, Sarah Kosakowski, Arnie Aldridge, Carolina Barbosa, Sabana Bhatta, Candace Brancato, Carly Bridden, Mia Christopher, Tom Clarke, James David, Lauren D'Costa, Irene Ewing, Soledad Fernandez, Erin Gibson, Louisa Gilbert, Megan E. Hall, Sarah Hargrove, Timothy Hunt, Elizabeth N. Kinnard, Lauren Larochelle, Aaron Macoubray, Shawn R. Nigam, Edward V. Nunes, Carrie B. Oser, Sharon Pagnano, Peter J. Rock, Pamela Salsberry, Aimee Shadwick, Thomas J. Stopka, Sylvia Tan, Jessica L. Taylor, Philip M. Westgate, Elwin Wu, Gary A. Zarkin, Sharon L. Walsh, Nabila El-Bassel, T. John Winhusen, Jeffrey H. Samet, Emmanuel A. Oga

Biostatistics Faculty Publications

IMPORTANCE: The HEALing Communities Study (HCS) evaluated the effectiveness of the Communities That HEAL (CTH) intervention in preventing fatal overdoses amidst the US opioid epidemic.

OBJECTIVE: To evaluate the impact of the CTH intervention on total drug overdose deaths and overdose deaths involving combinations of opioids with psychostimulants or benzodiazepines.

DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was a parallel-arm, multisite, community-randomized, open, and waitlisted controlled comparison trial of communities in 4 US states between 2020 and 2023. Eligible communities were those reporting high opioid overdose fatality rates in Kentucky, Massachusetts, New York, and Ohio. Covariate constrained randomization stratified …

2024 Kentucky Water Resources Annual Symposium, Kentucky Water Research Institute

Kentucky Water Resources Annual Symposium

The program and proceedings contains details of the 2024 Kentucky Water Resources Symposium, including presentations, award winners, and poster presentations.

This symposium was planned and conducted as a part of the state water resources research institute annual program that is supported by Grant/Cooperative Agreement Number G21AP10631-02 from the United States Geological Survey (USGS). The contents of this proceedings document and the views and conclusions presented at the symposium are solely the responsibility of the individual authors and presenters and do not represent the official views of the USGS or of the symposium organizers and sponsors. This publication is produced with …

2024 Kentucky Water Resources Annual Symposium, Kentucky Water Research Institute

Kentucky Water Resources Annual Symposium

No abstract provided.

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1977-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …

The Ecology Of Grazing Management, R K. Heitschmidt

IGC Proceedings (1977-2023)

The broad objective of this paper is to review the fundamental principles of grazing management as a means of assessing the inherent value of intensive and extensive grazing systems. Conceptual analyses of intensive and extensive grazing systems reveal that the fundamental differences between intensive and extensive grazing systems are related to differences in non-grazing rather than grazing tactics. Intensive grazing systems employ a wide array of non-grazing tactics in an attempt to overcome the inherent ecological constraints that limit secondary (i.e., livestock) productivity in extensively grazed systems. Moreover, analyses of the ecological or true efficiency of various agricultural production systems …

An Analysis Of The Dry Matter Intake And Rate Of Live-Weight Gain Of Growing Cattle Fed Forage Diets, J G. Buchanan-Smith

IGC Proceedings (1977-2023)

The intake and rate of live-weight gain of 500 growing steer calves fed experimental forage diets in 7 trials were compared with corresponding values predicted using the Na1ional Research Council (NRC) model (1984). The cattle were predominantly weaned calves and most of the experimental diets were alfalfa-grass silage, either unsupplemented or supplemented with various protein sources, but some diets were based on maize silage or maize grain. The feeding period evaluated in this study ranged between the first 84 and 147 days when protein accretion rate in the cattle would be relatively high. Dry matter intakes were overpredicted by the …

Management Of Extensive Pastures For Dairy Youngstock, G.E J. Fisher, D J. Roberts

IGC Proceedings (1977-2023)

The effects of low input systems on the ground cover of species and yield and chemical composition of herbage cul from extensive lowland swards was studied over 3 years. The live-weight gain of dairy heifer replacements offered grazed or conserved forage from these pastures was also assessed, The swards were sown with a mixture of grasses, wildflowers and herbs and received no inorganic fertilizers, Applications of slurry in January and February increased herbage yield by 43%, but reduced the cover of flowers and herbs. Using a 2- cut conservation system improved yield of metabolisable energy/ha in herbage by 33%, and …

Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis

IGC Proceedings (1977-2023)

In the temperate region of North America, high temperature and moisture deficit cause low forage growth during the summer of most years, making it difficult to grow beef (Bos taurus), calves through summer grazing. Alfalfa (Medicago sativa), offers some potential to provide high dry matter production during summer if an effective system of grazing can be developed. The objective of this study was to test a system of intensive grazing of beef steers on alfalfa to maximise live-weight gains/ha and maintain plant population. Alfalfa was no-till seeded into a 6.5 ha field in autumn 1988 after …

Variance Across Years In Growth Of Cattle On Annual Pastures In A Mediterranean Climate, K D. Greathead, J Zorrilla Rios

IGC Proceedings (1977-2023)

Annual pastures were continuously grazed by new drafts of yearling cattle each year for 4 years at 2 sites. The variability of weight gained across years at any date was not different between sites. The level of rainfall in April, but strongly influenced weight gained by the cattle in any year. Variances in weight change were small up to April, they increased rapidly from April to late July and were not different after July (P<0.05).

Modification Of The Botanical Composition Of Perennial And Annual Temperate Pastures By Strategic Grazing Practices, D R. Kemp, P M. Dowling

IGC Proceedings (1977-2023)

Where livestock production depends upon pastures, management is more difficult in environments where rainfall varies considerably from season to season and year to year. Flexible grazing practices are needed to optimise species composition and pasture productivity. Results presented in this paper show that pasture composition can be improved within climatic constraints, by grazing practices within seasons, In temperate annual pastures, long rests in winter (similar to a long rotation during that season) increased annual legume content in early spring from 20 to 50%. Annual grass content was unchanged. In perennial (phalaris) pastures, the dominant legume can change over years from …

Development Of Grass-Clover Pasture Systems For Autumn-Calving Beef Cows. I. Forage Production, G D. Mooso, D G. Morrison, J I. Feazel, D R. Morris

IGC Proceedings (1977-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sodseeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg Nnm, 2) annual ryegrass (Lolium multiflorum Lam)+clover +81 kg N/ha, 3) ryegrass+clover+l39 kg N/ ha, and 4) ryegrass+139 kg N/ha. Monthly forage accumulation was estimated for 3 years by clipping samples from 2 exclosures/pasture. Environmental conditions had a significant effect on total annual forage dry matter (DM) production. Systems 3 and 4 produced more (P<0.05) forage DM than Systems 1 and 2 (11.0 v. 10,3 Mg/ha). System I produced more (P<0.l) forage DM than 2 (10.6 ll, 9.8 Mg/ha). Systems 3 and 4 were similar, producing I 1.0 Mg/ha. Monthly forage accumulation was lowest in winter (December to February) and highest in spring and summer (March to August). The results of this study demonstrate that at a low N level, there was no benefii from including ryegrass in the system and al a moderate N level, there was no benefit from including clover.

Development Of Grass-Clover Grazing Systems For Autumn-Calving Beef Cows. Ii. Cow-Calf Production And Economic Analysis, D G. Morrison, J I. Feazel, G D. Mooso

IGC Proceedings (1977-2023)

Four 8-ha areas of bermudagrass-based (Cynodon dactylon (L.) Pers.) grazing systems were sod seeded and received annual N fertiliser as follows: I) clover (Trifolium sp.)+81 kg/ha, 2) annual rye grass (Lolium multiflorum Lsm.)+clover +81 kg/ha, 3) ryegrass+clover+139 kg/ha, and 4) ryegrass+l39 kg/ha. Each system was stocked year-round with 20 (2,5/lla) cows each with crossbred suckling calf. Cow and calf performance data for 3 of 4 years are included. Year affected (P<0.01) cow and calf live weight, Cows in System 2 were 25-50 kg lower in live weight in autumn and winter than cows in other systems. From February to July, cow daily live-weight gains were 0.11 kg higher (P<0.01) for Systems 2 and 3, Cow live weight in July was affected by N level (Systems 1,2<3,4; P<0,01), Year by system interactions (P<0.05) occurred for cow live weight in February, April and July because of live weight increasing over years in Systems 3 and 4 but not in Systems 1 and 2. Calf daily live-weight gain February to weaning (July) was higher (P<0.01) for System 2 v. 1 (0.06 kg), Syuem 3 v. 4 (0.07 kg), and Systems 3, 4 v. 1, 2 (0.07 kg), Estimated net returns favoured Systems 3 and 4 over Systems 1 and 2.

Improved Grazing Systems For Lamb Production On Appalachian Hill Farms, R L. Reid, J R. Puoli, G A. Jung, D P. Belesky

IGC Proceedings (1977-2023)

Improved grazing methods were tested to increase lamb outputs per ha from Appalachian hill farms. Components of a grazing system were cool-season grass [tall fescue (Festuca arundinacea Schreb.), Grasslands Matua prairie grass (Brom us willdenowii Kunth)J or grass­legume [Kentucky bluegrass (Poa pratensis L.)•red clover (Trifolium pralense L.)] pastures in spring and early autumn, warm-season grass [switchgrass (Panicum virgatum L.)] in summer, and brassicas in late autumn and early winter. Matua was highly productive in cool weather but was subject to fungal infection and grazing ewes had low Mg status in spring. Rotationally grazed switchgrass maintained high numbers …

Use Of Brassica Forage Crops To Extend The Grazing Season In The North-East Usa, G A. Jung, H W. Harpster, M G. Lambert, K T. Leath, R A. Byers

IGC Proceedings (1977-2023)

Forage turnip (Brassica rapa L,) can be made available for animal utilisation in late summer or In late autumn-early winter, when cool­season grass pastures have a low animal carrying capacity. field trials were conducted to identify and quantify factors that influence turnip yield in December or January and to determine whether these factors affect turnip cultivars similarly. Different levels of production in late autumn-winter were attributed to summer drought, foliar diseases, freezing temperatures and rate of leaf senescence. In all instances, the effects of these factors varied with turnip cultivar. However, cultivar ranking generally was the same whether mean …

Interactions Of Rotational And Continuous Grazing With Stocking Rate On Warm And Cool-Season Pastures, David I. Bransby

IGC Proceedings (1977-2023)

With more intense commercialisation of electric fencing many production and economic advantages have been claimed for rotational grazing compared with continuous grazing. However, very little research data are available from the south-eastern USA to verify these claims, Therefore, the objective of this study was to evaluate animal performance under conditions of continuous and IO-paddock rotational grazing on cool- and warm-season pastures commonly used in this region. Three 2-year grazing experiments were conducted, one each on a mixed rye-annual ryegrass (Secale cereale-Lolium multiflorum) pasture, Coastal bermudagrass ( Cynodon hybrid) and Pensacola bahiagrass (Paspalum notatum). In each experiment continuous …

Integrating Pasture Technology Research With Farm Management, R T. Cowan, T M. Davison, K F. Lowe, G K. Reason, G D. Chopping

IGC Proceedings (1977-2023)

An applied research programme which involved farmers in a continuum of trials measuring pasture, soil and milk responses to the application of nitrogen fertiliser to tropical grasses is described. Pasture responses were consistent across farms, grass species and, within limits, rainfall zones and soil types. Soil pH declined by 0.03 lo 0.2 units each year. Additional milk production ranged from 4 to 14 I/kg nitrogen, the response being greater at lower levels of application. Results from farm and research station experiments were consistent. The high adoption rate, reaching 68% in 6 years, was ' attributed to the integration of farm …

Hay Supplementation And Stocking Rate Effects On Live Weight Gain Of Steers Grazing Rye And Ryegrass, Susan E. Sladden, David I. Bransby

IGC Proceedings (1977-2023)

The objective of this study was to evaluate continuous ad lib. supplementation of hay as a means of compensating for the uneven growth distribution of rye (Secale cereale) and ryegrass pastures (Lolium multiflorum) grazed by steers in the south-eastern USA. Pastures were continuously grazed by 230 to 270 kg steers at stocking rates of 2.5, 3.1, 4.1 and 4.9 head/ha with and without hay supplementation for 2 grazing seasons. On average, average daily live-weight gain (ADO) at the highest stocking rate (4.9 steers/ha) was 0.47 kg higher (P<0.01) when hay supplement was provided. Although not significant, in both years ADO tended to be higher for h_ay supplementation even at low stocking rates .

Improved Pasture Species, Fertilizer And Pasture Use To Increase The Productivity Of Wool Sheep In South-Western Victoria, G R. Saul, D Jowett, T Morgan, P Noble, D Borg

IGC Proceedings (1977-2023)

Pastures were upgraded by sowing perennial grasses and subterranean clover (Trifolium subterranum) and applying fertiliser to paddocks on S farms in the wool sheep region of south-western Victoria. Upgraded pastures were stocked at higher rates to ensure utilisation of feed grown. In the third year after sowing, wool production was increased by 56% (35 v. SS kg/ha), and ewe live weights by 4% (49.4 v. 51.4 kg) from upgraded pastures compared with untreated pastures. The results demonstrate the considerable potential to increase output from sheep farms in the region by upgrading pastures. Poor persistence of sown perennial grasses may …