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Addition Of Lactobacillus Sp. To Aid The Fermentation Of Alfalfa, Corn, Sorghum, And Wheat Forages, N J. Moon, L O. Ely Jun 2026

Addition Of Lactobacillus Sp. To Aid The Fermentation Of Alfalfa, Corn, Sorghum, And Wheat Forages, N J. Moon, L O. Ely

IGC Proceedings (1977-2023)

As preservation of forage by ensiling has increased, so has the use of additives to enhance acid fermentation. Many of the fermentation aids currently on the market contain microflora to insure a lactic acid fermentation. The objectives of this study were to characterize the basic patterns of fermentation in a variety of crops and to evaluate the effects of adding selected microflora to forages to enhance the fermentation. Four crops were ensiled in each of three seasons. Alfalfa was harvested at 20 %-40 % bloom, second cut; wheat was cut in the early dough stage; corn was cut in the …


Interrelationships Between Pattern Of Fermentation During Ensilage And Initial Crop Composition, J M. Wilkinson, P F. Chapman, R J. Wilkins, R F. Wilson Jun 2026

Interrelationships Between Pattern Of Fermentation During Ensilage And Initial Crop Composition, J M. Wilkinson, P F. Chapman, R J. Wilkins, R F. Wilson

IGC Proceedings (1977-2023)

Relationships between crop composition and silage composition were examined for 231 silages made at the Grassland Research Institute from 1968 to 1978 without additives. A test was made of the model of Weissbach et al. (1974) in which silage characteristics were related to the percentage of dry matter in the crop (OM) and the ratio of sugar (Z) to buffering capacity (PK). Although these factors accounted for significant variance, the percentage accounted for was low at 36 % for lactic acid (percentage of total acids), 26 % for Flieg's score, 22 % for ammonia N (percentage of total N), and …


Effect Of Delayed Sealing During Ensiling On Fermentation And Dry-Matter Loss, N Takano, Y Masaoka, T Manda Jun 2026

Effect Of Delayed Sealing During Ensiling On Fermentation And Dry-Matter Loss, N Takano, Y Masaoka, T Manda

IGC Proceedings (1977-2023)

Two experiments were carried out from 1976 to 1980 to ascertain the effect of delayed sealing of silo on fermentation, dry· matter (DM) loss, digestibility, and silage intake. The effect of delayed sealing (up to 72 hours) of grass and corn silage was tested in laboratory silos on fermentation quality with storage temperatures at 15°C and 30°C, moisture content from 49% to 85 % , water-soluble carbohydrate (WSC) content ranging from 11.1 % to 17.5%, and with and without an addition of 0.25% formic acid. In all cases, delayed sealing resulted in poor-quality silage with high pH values and low …


Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel Jun 2026

Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel

IGC Proceedings (1977-2023)

Experiments were conducted to determine the effect of hay ammoniation on hay consumption and weight gain by steers when the hay was fed unsupplemented and supplemented with energy and protein. Mature orchardgrass (Dacrylis glomerata L.) hay was baled in early June 1979 and treated with anhydrous ammonia at 30 g/kg of hay. Seven weeks after treatment the hay was uncovered and allowed to aerate for 3 days. It was then fed to weanling steer calves weighing approximately 225 kg each. Similar hay baled from the same field but not ammoniated was fed to separate groups of steers. Both the treated …


Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar Jun 2026

Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar

IGC Proceedings (1977-2023)

Large improvements in the feeding value of low-quality roughages have resulted from treatment of them with various chemicals. Chemical treatment of grains may also be a potentially useful practice. The research reported here was designed (1) to determine how Chelating Metal Caustic Swelling (CMCS), a nontoxic, alkaline, aqueous reagent, compares with sodium hydroxide (NaOH) in enhancing in-vitro cellulose digestion (IVCD) of cornstalks (CS) (Zea mays) and soybean residues (SBR) (G!),cine max.), and (2) to evaluate the effects of NaOH and CMCS treatments of fibrous grains using in-situ techniques. CMCS or 7.5% NaOH solutions were added to CS or SBR at …


Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg Jun 2026

Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg

IGC Proceedings (1977-2023)

Treatment of crop residues with low levels of sodium hydroxide has been shown to improve organic-matter digestibility and animal performance. One objective of these experiments was to evaluate the effects of three treatments -water, sodium hydrox­ide, and chelating metal cellulose-swelling solution-on solubilization of cell-wall components in corn (Zea m£rys) stover. The two latter treatments were balanced for level of sodium hydroxide application, which was .3 .2 % of stover dry matter. The second objective was to determine the effects of these treatments on in-vitro and in-vivo digestibility as well as on consumption of corn stover. Twelve growing ram lambs were …


Factors Causing Greater In-Vitro Than In-Vivo Digestibility Of Sodium Hydroxide - Treated Roughages, L L. Berger, T J. Klopfenstein, R A. Britton Jun 2026

Factors Causing Greater In-Vitro Than In-Vivo Digestibility Of Sodium Hydroxide - Treated Roughages, L L. Berger, T J. Klopfenstein, R A. Britton

IGC Proceedings (1977-2023)

Research on sodium hydroxide (NaOH) treatment oflow-quality roughages generally indicates that in-vivo digestion is lower than in-vitro digestion. The purpose of this research was to identify factors that may cause less of the potentially digestible fiber to be digested in vivo than in vitro. Corn (Zea mays) cobs were raised to 60% moisture and treated to contain 0%, 2.5%, 5.0%, 7.5 % , and 10.0% NaOH. Lambs were fed diets containing 80% cobs and 20% supplement, giving a complete mixed diet con· taining 0%, 2.0%, 4.0%, 6.0%, and 8.0% NaOH. Five abomasally cannulated lambs were assigned to a 5 x …


Relationship Between Silage Quality And 15 N-Nitrate Reduction During Ensilage, K Ataku, M Horiguchi, T Matsumoto Jun 2026

Relationship Between Silage Quality And 15 N-Nitrate Reduction During Ensilage, K Ataku, M Horiguchi, T Matsumoto

IGC Proceedings (1977-2023)

Nitrate in forage has been proven to occasionally poison ruminants. Our recent studies, however, have shown that a high con­centration of nitrate inhibits butyric acid fermentation to the advantage of the silage quality. This work was undertaken to see the relationship between silage quality and the pattern of nitrate reduction during ensilage.


Ultracold Neutron Energy Spectrum And Storage Properties From Magnetically Induced Spin Depolarization, N. J. Ayres, G. Ban, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, D. Bowles, G. L. Caratsch, E. Chanel, W. Chen, P. J. Chiu, C. B. Crawford, V. Czamler, M. Daum, C. B. Doorenbos, M. Ferry, M. Fertl, A. Fratangelo, D. Galbinski, W. C. Griffith, Z. D. Grujic, K. Kirch, V. Kletzl, B. Lauss, T. Lefort, A. Lejuez, R. Li, K. Michielsen, J. Micko, P. Mullan, A. Mullins Jun 2026

Ultracold Neutron Energy Spectrum And Storage Properties From Magnetically Induced Spin Depolarization, N. J. Ayres, G. Ban, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, D. Bowles, G. L. Caratsch, E. Chanel, W. Chen, P. J. Chiu, C. B. Crawford, V. Czamler, M. Daum, C. B. Doorenbos, M. Ferry, M. Fertl, A. Fratangelo, D. Galbinski, W. C. Griffith, Z. D. Grujic, K. Kirch, V. Kletzl, B. Lauss, T. Lefort, A. Lejuez, R. Li, K. Michielsen, J. Micko, P. Mullan, A. Mullins

Physics and Astronomy Faculty Publications

We present a novel method for extracting the energy spectrum of ultracold neutrons from magnetically induced spin depolarization measurements using the n2EDM apparatus. This method is also used to exploit sensitivity to the storage properties of the materials used to trap ultracold neutrons, specifically, whether collisions are specular or diffuse. To do so, we utilize tomat simulation to map storage properties to correlation times of the ultracold neutrons to induced magnetic nonuniformities. We highlight the sensitivity of this new technique by comparing the two different storage chambers of the n2EDM experiment, which host different ultracold neutron energy spectra. This method …


Frontal Release Signs And Future Decline In Research Participants With Intact Cognition, Lauren G. Bojarski, Gregory A. Jicha, Elif Pinar Coskun, Frederick A. Schmitt, Linda Van Eldik, Erin L. Abner Jun 2026

Frontal Release Signs And Future Decline In Research Participants With Intact Cognition, Lauren G. Bojarski, Gregory A. Jicha, Elif Pinar Coskun, Frederick A. Schmitt, Linda Van Eldik, Erin L. Abner

Neurology Faculty Publications

Importance Frontal release signs (FRS) are primitive reflexes that regress with brain maturation and reappear in the setting of brain injury or neurodegeneration. Despite their association with dementia, the prognostic utility of this finding in the setting of early cognitive decline and preclinical disease is poorly understood. Objective To evaluate the association of FRS with future cognitive decline in research participants. Design, Setting, and Participants This cohort study examined the presence of FRS (from 2005-2024) among research cohort participants with intact cognition or mild impairment at study baseline. The study used single-center data collection of longitudinal research cohort data through …


The Polysubstance Assessment Tool, Amanda M. Bunting, Charles M. Cleland, S. Michaela Barratt, Brittany Griffin, Jaimee Williams, Carrie B. Oser, Joshua D. Lee, Jennifer Mcneely Jun 2026

The Polysubstance Assessment Tool, Amanda M. Bunting, Charles M. Cleland, S. Michaela Barratt, Brittany Griffin, Jaimee Williams, Carrie B. Oser, Joshua D. Lee, Jennifer Mcneely

Sociology Faculty Publications

Background and aims: There are currently no brief quantitative assessments that capture the drug patterns of people who engage in use of more than one drug on the same day or simultaneously. The current study examined the retest reliability, acceptability and feasibility of a new quantitative assessment to measure polysubstance use. Design: A tool for assessing simultaneous and same-day polysubstance behaviors, the polysubstance assessment tool (PAT) was developed in interviewer-administered and electronic self-administered formats. Participants were allocated 1:1 to receive either version of the PAT and returned one to three days later to repeat the assessment. Setting: New York City, …


The Aurora Survey, Ali Ahmad Khostovan, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Alex M. Garcia, Danielle A. Berg, Leonardo Clarke, Fergus Cullen, Richard S. Ellis, N. M.Förster Schreiber, Karl Glazebrook, Tucker Jones, Derek J. Mcleod, Anthony J. Pahl, Max Pettini, Paul Torrey Jun 2026

The Aurora Survey, Ali Ahmad Khostovan, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Alex M. Garcia, Danielle A. Berg, Leonardo Clarke, Fergus Cullen, Richard S. Ellis, N. M.Förster Schreiber, Karl Glazebrook, Tucker Jones, Derek J. Mcleod, Anthony J. Pahl, Max Pettini, Paul Torrey

Physics and Astronomy Faculty Publications

We present new constraints on the mass–metallicity (MZR) and fundamental metallicity relations (FMR) using a sample of 34 galaxies at 1.38 ≤ z ≤ 3.5 (median z = 2.28). These galaxies have direct Te measurements from [O iii]4363 Å and/or [O ii]7320,7331 Å auroral emission lines detected with JWST/NIRSpec as part of the AURORA survey. The detection of both oxygen auroral lines allows for dual-zone direct Te measurements and expands the dynamic range in (Formula presented) 12+log(O/H)  (7.68–8.65 dex), stellar mass (108–1010.4 M⊙), and star formation rate (1–100 M⊙ yr−1) …


Holographic Description Of 4d Maxwell Theories And Their Code-Based Ensembles, Ahmed Barbar, Anatoly Dymarsky, Alfred Shapere Jun 2026

Holographic Description Of 4d Maxwell Theories And Their Code-Based Ensembles, Ahmed Barbar, Anatoly Dymarsky, Alfred Shapere

Physics and Astronomy Faculty Publications

We formulate a precise holographic duality between an ensemble of 4d U(1)g Maxwell theories living on a spin four-manifold M4 and a topological Abelian BF-type 2-form theory of level N, summed over all five-manifolds with boundary M4. The elements of the boundary ensemble are Abelian gauge theories specified by self-dual symplectic codes over ℤN, that parameterize topological boundary conditions in the 5d TQFT. Similarly, the equivalence classes of topologies distinguished by the 5d theory are parameterized by orthogonal self-dual codes. Hence the holographic duality can be reformulated in the language of quantum stabilizer codes. …


The Aurora Survey, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Danielle A. Berg, Ali Ahmad Khostovan, Rychard J. Bouwens, Gabriel Brammer, Adam C. Carnall, Fergus Cullen, Romeel Davé, James S. Dunlop, Richard S. Ellis, N. M. Förster Schreiber, Steven R. Furlanetto, Karl Glazebrook, Garth D. Illingworth, Tucker Jones, Mariska Kriek, Derek J. Mcleod, Ross J. Mclure, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, Daniel Schaerer, Daniel P. Stark, Charles C. Steidel, Mengtao Tang, Leonardo Clarke, Callum T. Donnan, Emily Kehoe Jun 2026

The Aurora Survey, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Danielle A. Berg, Ali Ahmad Khostovan, Rychard J. Bouwens, Gabriel Brammer, Adam C. Carnall, Fergus Cullen, Romeel Davé, James S. Dunlop, Richard S. Ellis, N. M. Förster Schreiber, Steven R. Furlanetto, Karl Glazebrook, Garth D. Illingworth, Tucker Jones, Mariska Kriek, Derek J. Mcleod, Ross J. Mclure, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, Daniel Schaerer, Daniel P. Stark, Charles C. Steidel, Mengtao Tang, Leonardo Clarke, Callum T. Donnan, Emily Kehoe

Physics and Astronomy Faculty Publications

We present detections of auroral emission lines of [O iii], [O ii], [S iii], and [S ii] in deep JWST/NIRSpec spectroscopy for 41 star-forming galaxies at z = 1.4–7.2 from the AURORA survey. We combine these new observations with 98 star-forming galaxies at z = 1.3–10.6 with detected auroral lines drawn from the literature to form a sample of 139 high-redshift galaxies with robust electron temperature and direct-method oxygen abundance determinations. This sample notably covers a wider dynamic range in metallicity than previous work, spanning 0.02–0.9 Z⊙. We calibrate empirical relations between 19 emission-line ratios and oxygen abundance, …


The Relationships Among Neighborhood Disadvantage, Mental Health And Developmental Disabilities Diagnoses, And Race/Ethnicity In A U.S. Urban Location, Deborah Winders Davis, Kahir Jawad, Yana B. Feygin, Michelle Stevenson, Bethany Wattles, Veronnie Faye Jones, Jennifer Porter, W. David Lohr, Jennifer Le Jun 2026

The Relationships Among Neighborhood Disadvantage, Mental Health And Developmental Disabilities Diagnoses, And Race/Ethnicity In A U.S. Urban Location, Deborah Winders Davis, Kahir Jawad, Yana B. Feygin, Michelle Stevenson, Bethany Wattles, Veronnie Faye Jones, Jennifer Porter, W. David Lohr, Jennifer Le

Biostatistics Faculty Publications

Childhood health disparities by race have been found. Neighborhood disadvantage, which may result from racism, may impact outcomes. The aim of the study is to describe the distribution of mental health (MH) and developmental disabilities (DD) diagnosis across Child Opportunity Index (COI) levels by race/ethnicity. A cross-sectional study using 2022 outpatient visit data for children < 18 years living in the Louisville Metropolitan Area (n = 115,738) was conducted. Multivariable logistic regression analyses examined the association between diagnoses and COI levels, controlling for sex and age. Almost 18,000 children (15.5%) had a MH or DD (7,905 [6.8%]) diagnosis. In each COI level, the prevalence of MH diagnosis was lower for non-Hispanic (N–H) Black than for N–H White children. In adjusted analyses, there were no significant associations between diagnoses and COI for non-White children for MH or DD diagnoses. The odds of receiving a MH [OR: 1.74 (95% CI: 1.62, 1.87)] and DD [OR: 1.69 (95% CI: 1.51, 1.88)] diagnosis were higher among N–H White children living in Very Low compared to Very High COI areas. Current findings suggest that COI does not explain disparities in diagnosis for non-White children. More research is needed to identify potential multi-level drivers such as other forms of racism. Identifying programs, policies, and interventions to reduce childhood poverty and link children and families to affordable, family-centered, quality community mental and physical health resources is needed to ensure that families can build trusting relationships with the providers while minimizing stigma.


Use Of Function Diagrams In Physiology Education, Thad E. Wilson, Brian A. Jackson, B. Peter Sawaya Jun 2026

Use Of Function Diagrams In Physiology Education, Thad E. Wilson, Brian A. Jackson, B. Peter Sawaya

Physiology Faculty Publications

Function diagrams focus on physiological concepts rather than associated structures and can serve as elaboration tools and mnemonic aids. A function diagram prototype of the gastrointestinal system was recently described (Wilson TE, Barrett KE. Adv Physiol Educ 45: 264-268, 2021). In this article, a functional diagram of the glomerulus, nephron, urinary system, and bladder is proposed. Colloquially named "Nessie the Nephron" to loosely capture the looping structure and elusive understanding of renal blood flow, glomerular filtration, and epithelial transport for the student, not to mention the nearly mythical countercurrent multiplier. "Navigating the Lochs" references Nessie's possible habitat and more importantly …


Quantifying Landslide Strain Localization Phenomena Using Tensor Analysis Of Multi-Temporal Lidar Data, Sarah Johnson, Yichuan Zhu, Jason M. Dortch, William C. Haneberg Jun 2026

Quantifying Landslide Strain Localization Phenomena Using Tensor Analysis Of Multi-Temporal Lidar Data, Sarah Johnson, Yichuan Zhu, Jason M. Dortch, William C. Haneberg

Earth and Environmental Sciences Faculty Publications

A fundamental understanding of landslide evolution requires characterizing how deformation localizes within the sliding mass, as these non-homogeneous zones provide crucial insights into how destabilization initiates, failure surfaces develop, and the overall kinematic behavior evolves. While traditional analysis often assumes uniform movement, this study presents a methodology to quantify intricate patterns of surface deformation at a fine scale, allowing for the direct analysis of localization behavior. By applying strain tensor analysis to high-resolution displacement fields derived from multi-temporal Uncrewed Aerial Vehicle-Light Detection and Ranging (UAV-lidar) and Structure from Motion (SfM) surveys, we compute the divergence, gradient, and curl fields for …


School Renewal And School Well-Being, Jianping Shen, John Lane, Patricia Reeves, Siche Feng, Xin Ma Jun 2026

School Renewal And School Well-Being, Jianping Shen, John Lane, Patricia Reeves, Siche Feng, Xin Ma

Educational, School, and Counseling Psychology Faculty Publications

In this longitudinal case study, we examined school well-being during the change process. We operationalized the change process as the school renewal model and viewed school well-being from the perspective of the PERMA (positive emotion, engagement, relationships, meaning, and accomplishment) model. We found that all elements of the PERMA model were manifested in the school renewal process and that the school renewal process was not dominated solely by conflict and tension, as the literature typically suggests about the change process. The findings of the study suggest the possibility of reframing tension as productive rather than detrimental in the school renewal …


Weaning Stress Induced Alterations To The Hypothalamic-Pituitary-Thyroid And -Adrenal Axes In Swine, Isabel B. Walpole, Alyssa A. Smith, Kaylyn G. Rudy, Dayeon Jeon, J. Scott Radcliffe, J. Alex Pasternak Jun 2026

Weaning Stress Induced Alterations To The Hypothalamic-Pituitary-Thyroid And -Adrenal Axes In Swine, Isabel B. Walpole, Alyssa A. Smith, Kaylyn G. Rudy, Dayeon Jeon, J. Scott Radcliffe, J. Alex Pasternak

Animal and Food Sciences Faculty Publications

Combined modulation of the hypothalamic–pituitary–thyroid (HPT) and hypothalamic–pituitary–adrenal (HPA) axes is known to play a critical role in maintaining physiological stability in response to stress. In this study, stress induced modulation of these axes was examined using 20 pigs/treatment either weaned (WN), weaned with feed/water restriction 9 h (FR), transported 9 h (TRANS), or remaining with sow (SOS) and euthanized at 32 or 56 h post-weaning. Serum cortisol, thyroxine (T4), and triiodothyronine (T3) were measured before weaning and after 24, 32, and 56 h with no difference in cortisol concentrations among treatments at any timepoint. However, both T3 and T4 …


Building And Facility Asset Inventory Assessment And Maintenance, Catherine Keathley, Bethany Paris, Jon Wilcoxson Jun 2026

Building And Facility Asset Inventory Assessment And Maintenance, Catherine Keathley, Bethany Paris, Jon Wilcoxson

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) manages approximately 1,500 buildings statewide, including facilities such as office buildings, maintenance and equipment garages, and storage sheds. Because managing buildings and properties requires considerable effort, agency decision makers need reliable monitoring and management tools that generate and organize data which can be used to determine the best course of action for facility maintenance and replacement. In addition to assessing the Cabinet’s building inventory, this report advances recommendations to improve the collection, management, and reporting of facility-related data. Assessment of the inventory managed by KYTC included geolocation of all properties and the buildings therein. Once …


Research And Assessment Of Needs For Sign And Signal Maintenance, Megan White, Eric Green Jun 2026

Research And Assessment Of Needs For Sign And Signal Maintenance, Megan White, Eric Green

Kentucky Transportation Center Research Report

Kentucky Transportation Cabinet (KYTC) sign and signal crews have expressed multiple concerns related to compensation, expertise, and having the financial and personnel resources needed to help the agency comply with Manual on Uniform Traffic Control Devices (MUTCD) guidelines while continuing to perform routine job duties. Internal reorganizations and personnel changes have reduced staffing and budgets available to underwrite the activities of sign and signal crews even as workloads have remained steady or increased. To document the challenges facing sign and signal crews and associated engineering staff, Kentucky Transportation Center (KTC) researchers administered a statewide survey. Respondents gave their perspectives on …


Fate Of Nitrogen Applied To Grassland In Animal Wastes, M Sherwood May 2026

Fate Of Nitrogen Applied To Grassland In Animal Wastes, M Sherwood

IGC Proceedings (1977-2023)

The experiment was designed to determine the effects of land spreading of animal manures on the nutrient content of surface runoff water and infiltrating soil water. This report deals only with nitrogen (N) and attempts to quantify the losses through runoff, leaching, and volatilization of ammonia (NH3) as well as N uptake in the grass over a 3-year period. Experimental plots sited on grassland, on two soil types (a moderately drained loam and an impermeable gley), were equipped to collect surface runoff water. Ceramic probes were installed in each plot at 15-, 30-, 60-, and 100-cm depths to extract in­filtrating …


Annual Losses Of Ammonia From A Grazed Pasture Fertilized With Urea, V R. Catchpoole, L A. Harper, R J.K Keyers May 2026

Annual Losses Of Ammonia From A Grazed Pasture Fertilized With Urea, V R. Catchpoole, L A. Harper, R J.K Keyers

IGC Proceedings (1977-2023)

Nitrogen-balance studies have shown losses of applied nitrogen (N) from grazed pastures in southeastern Queensland. Losses as high as 80% have been observed from urea N broadcast at 376 kg N/ha/yr over 8 years on a Setaria sp1uu:elata cv. Nandi pasture. Management techniques aimed at reducing this loss and thereby increasing the efficiency of use of N by pastures cannot be devised until the pathways of loss are known. The objective of this research was to estimate the annual ammonia (NH3) loss by convective transport from a urea-fertilized pasture at Samford Pasture Research Station in southeastern Queensland. Urea was broadcast …


Nitrogen Losses From Urine-Affected Areas Of A New Zealand Pasture, Under Contrasting Seasonal Conditions, P R. Ball, D R. Keeney May 2026

Nitrogen Losses From Urine-Affected Areas Of A New Zealand Pasture, Under Contrasting Seasonal Conditions, P R. Ball, D R. Keeney

IGC Proceedings (1977-2023)

Grazing ruminants aggregate large quantities of forage nitrogen (N) into urine patches. Pasture plots treated with urine N were studied to assess its fate under contrasting seasonal conditions: cool-moist (representing winter-spring); warm-moist (late spring-early summer), and warm-dry (late summer-autumn). A permanent ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) sward on free-draining alluvial soil was studied. 'freatments were replicated in randomized blocks. Urine N was applied at 30 or 60 g N/m2• Relevant measurements were then continued until treatment differences disappeared. Apparent N balances for urine treatments were compiled. Fixation by white clover was always greatly reduced in …


Effects Of Grazing Management On Seasonal Variation In Nitrogen Fixation, J L. Brock, J H. Hoglund, R H. Fletcher May 2026

Effects Of Grazing Management On Seasonal Variation In Nitrogen Fixation, J L. Brock, J H. Hoglund, R H. Fletcher

IGC Proceedings (1977-2023)

Using the acetylene reduction assay, field studies in recent years have investigated the variation in N fixation in grazed systems, and some of the principles involved in the interaction with available soil N have been described. This experiment ex­tends this work to include the effect of grazing management on the factors influencing N fixation. Two self-contained sheep-grazed units, one a 10-paddock rotationally grazed system and the other set stocked, were estab­lished on a high-fertility ryegrass-white clover pasture, with a basic stocking rate of 22 sheep/ha. Over the 1975-1978 period, both units were monitored for pasture growth, N fixation, and associated …


Symbiotic Nitrogen Fixation Of Alfalfa, Birdsfoot Trefoil, And Red Clover, G H. Heichel, C P. Vance, D K. Barnes May 2026

Symbiotic Nitrogen Fixation Of Alfalfa, Birdsfoot Trefoil, And Red Clover, G H. Heichel, C P. Vance, D K. Barnes

IGC Proceedings (1977-2023)

Forage legumes such as alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus comiculatus L.), and red clover (Trifolium pratense L.), grown in crop rotations, can provide an inexpensive source of nitrogen (N) to succeeding crops. Few quantitative measurements of seasonal patterns of N fixation in managed communities of perennial forage legumes have been undertaken, chiefly because of the lack of satisfactory methods. Therefore, there is little knowledge of how N fixation varies with crop development, yielding ability, and weather patterns. Quantitative measurements of N fixation are important in choosing the appropriate legume for use in a crop rotation and for …


Photosynthate Supply And Nitrogen Fixation In Forage Legumes, P M. Murphy May 2026

Photosynthate Supply And Nitrogen Fixation In Forage Legumes, P M. Murphy

IGC Proceedings (1977-2023)

Photosynthate supply is known to limit nitrogen fixation in legumes, and the resulting shortfall in energy supply necessary for maximum crop production may be aggravated by the energy-wasteful process of hydrogen (H2) evolution by the legume N2 fixing system. There is less information available on these aspects of the nitrogen-fixing process in forage legumes, such as white clover (Trifolium repens). The objectives of the present work were to determine how N2(C2H2) fixation and H2 production are in­fluenced by carbohydrate supply in forage legumes.

Plants were grown under controlled environmental conditions, and nodule energy supply was varied by adjusting …


Selection Of Rhizobium Strains For Enhanced Dinitrogen Fixation In Forage Legume Production, C Hagedorn, W E. Knight May 2026

Selection Of Rhizobium Strains For Enhanced Dinitrogen Fixation In Forage Legume Production, C Hagedorn, W E. Knight

IGC Proceedings (1977-2023)

A set of procedures for the selection of Rhizobium strains for enhanced dinitrogen fixation in forage legumes is presented. Although forage legumes are among the most efficient members of the Leguminosae regarding biological nitrogen fixation (BNF), they are generally neither productive nor persistent without effective nodulation by appropriate rhizobia. The following methods define a selection and evaluation process to obtain appropriate Rhizobium strains. These include (1) regional survey of the production area, (2) strain collection and soil analyses, (3) strain characterization, (4) strain selection and manipulation, and (5) field evaluation of strains. The initial procedure is to survey the region …


Interactions Between Grasses And Rhizosphere Nitrogen-Fixing Bacteria, M H. Gaskins, D H. Hubbell, S L. Albrecht May 2026

Interactions Between Grasses And Rhizosphere Nitrogen-Fixing Bacteria, M H. Gaskins, D H. Hubbell, S L. Albrecht

IGC Proceedings (1977-2023)

Sorghum and Digitaria cultivars grown in soil or nutrient solutions were inoculated with a strain of Azospirillum in short-term greenhouse experiments. Carbon compounds lost by roots in solution culture experiments were determined in order to estimate the quantity of energy substrates that might be obtained by rhizosphere organisms from growing plants. Other plants were treated with plant growth hormones, and responses were compared to those of plants treated with killed Azospirillum cells. The similarity of the responses suggests that growth-hormone production by the inoculant organism, rather than nitrogen (N) fixa­tion, is responsible for part or all of the increase in …


Simple Computer Simulation Models For Forage-Management Applications, G W. Fick, D Onstad May 2026

Simple Computer Simulation Models For Forage-Management Applications, G W. Fick, D Onstad

IGC Proceedings (1977-2023)

Dynamic computer simulation models of forage growth can be useful in interpreting physical and biological limitations on production and in designing management systems for testing in the field. The explanatory detail of such models makes them both more reliable and more expensive to use than simple empirical formulations. Simple simulation models reduce the expense. They can also serve as reference points for designing, evaluating, or selecting more complex versions and thus provide a more ra­tional basis for using models in grassland research and management. Our objectives were to develop and to test a simple dynamic simulation model of alfalfa (Medicago …