Physical Sciences and Mathematics Commons^™

The Relationship Of Grazing Conditions To Annual Changes Of Sward Characteristics And Herbage Utilization By Lactating Dairy Cows In The Snowy, Cold Region In Japan, H Nakatsuji, I Nonaka, S Kondo, M Okubo

IGC Proceedings (1993-2023)

In order to determine the relationship of grazing conditions to annual changes of sward characteristics and herbage utilization in the snowy, cold region in Japan, the data for pasture utilization of dairy cows under a time-restricted grazing on Experimental Farm, Hokkaido University, from 1984 to 1992 were used for analyses. An annual herbage utilization did not always decrease though legume crown coverage declined gradually with advancing years after swardestablishment. The annual herbage utilization (tDM/ha, Y) increased with increasing the stocking rate (cow-hr/ha, X) (Y=0.00136X-0.685, r=0.752**).

Effect Of Grazing Pressure And Supplemental Level On Weight Gain In Dairy Heifers, J M. Mieres, Y M. Acosta

IGC Proceedings (1993-2023)

An experiment designed to assess the effect of two grazing pressures (GP, expressed as kg MS/100 kg LW) and four levels of supplement (0, 0.25, 0.50 and 0.75 expressed as kg/100 kg LW) fed to yearling heifers (212 kg) on live weight gain, was carried out at the Dairy Unit of INIA La Estanzuela (Uruguay). The experiment consisted of 8 treatments. Forty animals were used in the experiment, 5 per treatment, each animal being a replication of the treatment. The animals were blocked by weight in 5 blocks of 8 animals each, and then randomly assigned to the different treatments. …

Leaf Appearance Rate Of Native And Introduced Grasses Under Different Intensities Of Continuous Grazing (Argentina), M G. Agnusdei, A Mazzanti, J Cordero, M H. Wade

IGC Proceedings (1993-2023)

Results of two grazing experiments on the effect of maintaining contrasting sward states upon leaf appearance rate of individual tillers (LAR) and tiller density (D) are reported. The following species were evaluated: Cynodon dactylon(Cd), Leersia hexandra(Lh), y Paspalum dilatatum(Pd) in a natural grassland of the Flooding Pampa, and Festuca arundinacea in a sown pasture. Except for Pd, LAR decreased with the increment of sward surface height. The degree of this morphogenetic plasticity varied among species. Implications for the stability of grass populations under continuous grazing are suggested; the effect of sward state upon LAR may represent one alternative way …

Grazing Systems Research In The Falkland Islands, J A. Kerr

IGC Proceedings (1993-2023)

Conceptual models of both the metabolisable energy (ME) balance of sheep in relation to the environment and the effects heavy grazing on vegetation and soils will form the basis for the development of a sustainable grazing system for wool production in the Falkland Islands. Research which integrates plant community ecology, agricultural meteorology, sheep energetics, grazing systems and socio-economics is described.

Wool Production From Annual Pastures Intensively Grazed By Wethers In Southern Western Australia, M W. Hyder, A N. Thompson, P T. Doyle, M Grimm, P J. Michael

IGC Proceedings (1993-2023)

Intensively grazing annual pastures in southern Western Australia to target amounts of feed on offer increased the greasy wool production per hectare three-fold or more compared to production from a setstocked grazing regime. Feed on offer was maintained at 0.8, 1.1, 1.4, 2.0, 2.8 t DM/ha during spring and wool growth per hectare compared to that of sheep set-stocked at the district average of 8 sheep/ha. The role of intensive grazing as a tactic to increase production and profitability of wool producers in Mediterranean environments is discussed.

Utilized Metabolizable Energy And Its Impacts On The Management Of Grass Pastures In The Central Chaco Of Paraguay, D Stosiek, A Glatzle, R Schultze-Kraft

IGC Proceedings (1993-2023)

Animal production from sown pastures of Gatton Panic (Panicum maximum Jacq.) and Estrella (Cynodon nlemfuënsis Vand.) on a luvic Kastanozem in the Central Chaco of Paraguay (mean annual rainfall 850 mm) was measured over two years (Sep. 1992 to Nov. 1994). The pastures were grazed continuously by Brahman X Hereford steers at six stocking densities, ranging from 0.5 to 2.0 American Animal Units (1 AU = 454 kg) per hectare. Herbage availability, chemical composition (ME, XP, fibre) and cattle liveweight gains were measured at four weekly intervals. Building regression models for Utilized metabolizable energy (UME in GJ/ha) and …

Milk Production From Ruzi Grass Alone, Ruzi Mixed With Leucaena And Ruzi Supplemented With Dolichos Lablab, S Tudsri, S Prasanpanich, S Swasdiphanich

IGC Proceedings (1993-2023)

Three groups of dairy cattle were compared under different grazing managements viz. strip-grazed on pure ruzi grass (Brachiaria ruziziensis), strip-grazed on mixed pasture between ruzi and leucaena (Luecaena luecocephala) and strip-grazed on pure ruzi and supplemented with lablab (Lablab purpureus). The results showed that the animals that received the legumes through supplementary or mixed with the grass produced higher in daily milk yield (13.63 and 13.26 kg/cow) and fat percentage (4.7 and 4.5) than that of the pure grass alone (12.00 kg/cow for milk yield and 4.2 % for fat). This advantage was due …

Zea Mays Grazing In Cattle Production Systems, V Mundy, B E. Anderson, T L. Gompert, T L. Mader, C A. Shapiro

IGC Proceedings (1993-2023)

Nebraska producers have used silage maize (Zea mays L.) hybrids as a grazed forage in dairy and beef production systems. In an onfarm case study, farmers and researchers collaborated to gather information on production practices, grazing management, and plant characteristics of grazing maize within three forage-based dairy and beef systems. Production practices were generally similar to conventional grain corn production, except that in one system maize was seeded directly into a suppressed grass sod. Milk production from grazing maize was 23 kg/day/animal, compared to 24 kg/day/ animal before using maize and 22 kg/day/animal after using maize. Average gain of …

Grazing Management Of Lotus In Eastern Australia: A Participatory Approach, M J. Blumenthal, J F. Ayers, Z Hochman

IGC Proceedings (1993-2023)

Both Lotus uliginosus Schkukr and L. corniculatus L. require lenient grazing management for persistent production. However, grazing systems, where Lotus is adapted in eastern Australia are based on intermittent set stocking. Conflict between plant ecophysiology and the adverse influences of traditional grazing systems that limit the adoption of new grazing management technology have been addressed by a participatory (co-learning) research and development process. The approach taken involved the use of a facilitator who ran an initial meeting to involve stakeholders and subsequently established “colearning” groups and “co-learning” experimental sites. These sites are monitored, progress is reviewed, and knowledge is …

Rhizobium Specificity In Leucaena, B F. Mullen, V E. Frank, R A. Date

IGC Proceedings (1993-2023)

Twenty-seven accessions of Leucaena, representing 20 species, were assessed for effective N-fixing symbioses in association with 13 strains of Rhizobium in N-free conditions in a glasshouse. Fifteen accessions formed effective symbioses with most strains of Rhizobium. Only 4 accessions required specific strains. Conversely, 9 of the strains of Rhizobium formed effective symbioses with most accessions of Leucaena. Only one strain was ineffective. Strains CB3060 and CB3126 were effective with 21 and 22 accessions of Leucaena, respectively.

Agronomic Performance Of 118 Leucaena Accessions In The Subtropical Environment Of Southeast Queensland, Australia, B F. Mullen, H M. Shelton

IGC Proceedings (1993-2023)

The DM productivity in contrasting environments of 118 Leucaena accessions was evaluated in sub-tropical Australia over a 2 year period. Harvests were timed to coincide with hot/wet and cool/dry seasons and data were analysed to compare growth in these environments. Eleven accession groups were identified by cluster analysis. Group 1, which contained F1 and F4 interspecific hybrids, were highly productive in all environments. Growth of L. leucocephala accessions was severely checked by psyllids in hot/ wet environments. Four groups comprising 60 accessions were unproductive in all environments. Identification of specific adaptation to cold temperature within groups in psyllid susceptible accessions …

The Effects Of Storage Period On The Germinability Of Rhodes Grass (Chloris Gayana), K C. Kawonga

IGC Proceedings (1993-2023)

An experiment was initiated to investigate the post harvest changes in the seed quality of Rhodes grass (Chloris gayana). The aim of the study was to find out the causes of poor germination of locally produced Rhodes grass seed. Random samples (72) were taken from a seed lot grown at Golden Valley Research Station. Seventy-two random samples were subdivided into groups of twelve and were stored at six locations. Half the samples were stored at room temperature and the other half were stored in the refrigerator for a period of one to six months. The germination test was …

Technology Development Of Pasture Seed Production For Small Scale Farmers In Uganda, P Lusembo, E N. Sabiiti, C Ebong

IGC Proceedings (1993-2023)

Pasture seed production by smallholder farmers in Uganda is hardly developed. The stages of development since the early 1960s are described as initial forage evaluation for adaptability and productivity of various species, seed production trials in relation to plant population, fertilizer requirements and the use of support systems for climbing forage legumes. Annual seed production by smallholder farmers, under an informal seed production system, is reported to have risen from 1,200kg in 1989 to over 35 metric tonnes of forage legume seed in 1995. This was attributed to the availability of appropriate seed production technology and the presence of a …

Flowering Cycle-Related Seed Quality Parameters On 15 New Guineagrass (Panicum Maximum Jacq.) Hybrids, R Usberti, A Usberti Jr, R S. Paterniani

IGC Proceedings (1993-2023)

Fifteen new guineagrass (Panicum maximum Jacq) hybrids, widely variable in flowering cycles, were tested for eleven seed quality parameters: seed viability (tetrazolium)-TZ; normal germination (with and without previous chemical scarification)-TG and NG; presence of viable seeds after the germination tests- RSTG and RSNG; seed dormancy-DTG and DNG; germination rate-TGR and NGR and seed vigor (after accelerated aging test) -AATG and AANG. The genetic materials used presented no significant differences for tetrazolium seed viability. Late- and intermediate-flowering genotypes showed the highest correlations between flowering cycle and seed quality for TG, NG, TGR and NGR (r= 0.468**; 0.731**; 0.422* and 0.683**, …

Effect Of Plant Density On Yield And Yield Components And Seed Chemical Composition Of Some Sunflower Varieties, N A. Noueldin, M E. El-Bially, B A. El-Ahmer, M G. El-Baz

IGC Proceedings (1993-2023)

The objective of this research is to study the effect of varieties (Mayak, Elorida 2000 and sigce 475), hill distance (20, 30 and 40 cm) and ridge width (50, 60 and 70 cm) on productivity of sunflower (Helianthus annus L.). The highest oil % was obtained by sowing sigco 475 at a 40 cm hills distince under 60 cm. ridge width and the highest oil yield feddan-1* as well as seed yield feddan-1 was obtained by sowing Mayak on 20cm hills under a 50cm ridge width.

Seed Banks In A Natural Pasture In Tasmania, Australia: Implications For Species Composition Change, D A. Friend, A S. Cameron, A J. Povey, P L. Dolan

IGC Proceedings (1993-2023)

Seed banks in a natural pasture in Tasmania were examined as part of a study of the effects of grazing on changes in species composition. The dominant native perennial grasses had relatively low seed banks, whereas annual grasses, sedges, rushes and a number of forbs had relatively high seed banks. The results confirm the vulnerability of the native grasses to local extinction in the event of loss of the established plants, e.g. through overgrazing.

Tropical Forage Seed Production In Southeast Asia: Current Status And Prospects, C Phaikaew, L Guodao, A Abdullah, M Tuhulele, E Magboo, B Bouahom, W Stur

IGC Proceedings (1993-2023)

The demand for forage seed in southeast Asia has increased in recent years. More than 1,200 tons of seed were produced in Thailand in 1995 with smaller quantities of seed having been produced in China, Lao PDR, Malaysia, Philippines and Indonesia. Large quantities have been produced of Brachiaria ruziziensis, Stylosanthes hamata, Stylosanthes guianensis and Panicum maximum. There are good prospects to increase forage seed production and to develop trade between countries in the southeast Asian region. There is a need to increase seed production of widely adapted species, and expand production of forages for other purposes such as turf …

Traditional Grassland And Fodder Management Systems In Tanzania And Potential For Improvement, R M. Otsyina, I Essai, D Asenga

IGC Proceedings (1993-2023)

The “Ngitiri” fodder conservation system was developed by the Sukuma agro-pastoralists as a strategy to alleviate acute dry season fodder constraints. This traditional agroforestry system provides the basis and opportunities for development of improved silvipastoral systems. Ngitiri is a major source of dry season fodder supply for livestock and thatch for roofing. The system is widespread in the Sukuma landuse system in central Tanzania. This paper presents the scope and importance of the Ngitiri system, management aspects, constraints, and farmers’ perceptions on improvement. Implications for agroforestry technology development in the Sukuma agropastoral system are also discussed.

Forage Seed Production In Egypt For Domestic Marker And For Export, M A. El-Nahrawy, A Rammah, O Niemelainen

IGC Proceedings (1993-2023)

In Egypt, no major effort is made to provide local and export markets with seeds of correctly identified and pure cultivars of forage crops in spite of the existence of all the essential factors for a successful seed industry. A wide genetic base of indigenous forage crops such as berseem clover and alfalfa, proper irrigation, a harvest and seed maturation period free from rain, sunshine and clear sky all year and highly fertile soils in isolated areas are available. Moreover, uncertified, uncontrolled and unidentified local seeds of berseem clover and alfalfa are highly demanded by foreign markets due to their …

Numerical Simulations Suggest Asteroids (101955) Bennu And (162173) Ryugu Are Likely Second Or Later Generation Rubble Piles., K J Walsh, R-L Ballouz, W F Bottke, C Avdellidou, Harold Connolly Jr., M Delbo, D N Dellagiustina, E R Jawin, T Mccoy, P Michel, T Morota, M C Nolan, S R Schwartz, S Sugita, D S Lauretta

School of Earth & Environment Departmental Research

Rubble pile asteroids are widely understood to be composed of reaccumulated debris following a catastrophic collision between asteroids in the main asteroid belt, where each disruption can make a family of new asteroids. Near-Earth asteroids Ryugu and Bennu have been linked to collisional families in the main asteroid belt, but surface age analyses of each asteroid suggest these bodies are substantially younger than their putative families. Here we show, through a coupled collisional and dynamical evolution of members of these families, that neither asteroid was likely to have been created at the same time as the original family breakups, but …

Mid- To Late-Miocene Hypogene Speleogenesis Tied To The Tectonic History Of The Central Basin And Range Province, Usa, Louise D. Hose, Victor Polyak, Harvey R. Duchene, J. Douglas Powell, Leslie A. Melim, Gretchen M. Baker, Donald G. Davis, Yemane Asmerom

International Journal of Speleology

Twenty-five caves displaying evidence of hypogene speleogenesis in White Pine County, Nevada, were studied between May 2022 and October 2023. Results demonstrate that the central Basin and Range Province is a major hypogenic cave region with speleogenesis dating back to the Middle Miocene. The U-Pb radiometric dates of cave mammillaries obtained so far cover a wide span of time, ranging between 14 Ma to 2 Ma. Tectonic shearing along the Snake Range Décollement up to about 22 Ma probably brackets the maximum age of speleogenesis. Thus, speleogenesis began between 22-14 Ma, which predates most of the Basin and Range extensional …

Valorization Of Seafood Waste For Food Packaging Development, Zhijing Zhan, Yiming Feng, Jikai Zhao, Mingyu Qiao, Qing Jin

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Packaging plays a crucial role in protecting food by providing excellent mechanical properties as well as effectively blocking water vapor, oxygen, oil, and other contaminants. The low degradation of widely used petroleum-based plastics leads to environmental pollution and poses health risks. This has drawn interest in renewable biopolymers as sustainable alternatives. The seafood industry generates significant waste that is rich in bioactive substances like chitin, chitosan, gelatins, and alginate, which can replace synthetic polymers in food packaging. Although biopolymers offer biodegradability, biocompatibility, and non-toxicity, their films often lack mechanical and barrier properties compared with synthetic polymer films. This comprehensive review …

The Fishing Cat: New Insights On Distribution In The Northern Sector Of Chitwan National Park, Nepal, Rupesh Maharjan, Rama Mishra, Jhamak Bahadur Karki

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Fishing cat Prionailurus viverrinus (Bennett, 1833) is an elusive and medium-sized feline species with distinguished marking patterns on their head and body separating them from other feline species. Despite being distributed widely among diverse geographic locations, their abundance has declined due to significant habitat loss and human disturbances. There exists a substantial research gap regarding their abundance and distribution in Nepal. In this article, we presented the updated documentation of the fishing cat distribution in the northern sector of Chitwan National Park through our species-focused camera trapping survey. The study was carried out between April and May 2021 with a …

Multi-Case Study Of Left-Flank Boundaries Within Supercells, Peyton B. Stevenson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study investigates the prevalence and significance of forward-flank convergence boundaries (FFCBs) and left-flank convergence boundaries (LFCBs) in shaping the structure and intensity of supercells, using observational data from various field projects. Unlike previous research focusing on individual cases, this study examines a diverse range of cases to provide comprehensive insights into the relationship between these boundaries and supercell characteristics such as intensity, longevity, and tornadogenesis. By analyzing high-resolution surface data, the research addresses the frequency, location, and intensity of these boundaries, and their impact on pseudo vertical vorticity, pseudo convergence, and density gradients. A total of 228 boundary identifications …

Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Esthonyx is an early Eocene tillodont found in North America, Europe, and India. The genus was named by Edward Drinker (E. D.) Cope in 1874 based on specimens from the San Jose Formation in New Mexico. Since then, several species of Esthonyx have been described from North America alone. The best record of Esthonyx comes from the central Bighorn Basin (BHB) in Wyoming, where it appears in 220 localities in a 640 m-thick stratigraphic succession. Since the last summary of Esthonyx in the BHB, several hundred new specimens have been collected and curated at the Denver Museum of Nature and …

Phylogeny And Disparity Of Ammonoid Family Acanthoceratidae Over Ocean Anoxic Event 2, Lindsey Howard

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

The widespread use of genera as proxies for species in paleobiological studies might affect the results of these studies. Although most attention has been given to taxonomic diversity studies, this could also be true of disparity and phylogenetic studies. In particular, the assumption that particular character states truly diagnose all members of a genus might distort results. This study examines the disparity of Acanthoceratid ammonoids at both the generic and species level. 149 species from 42 genera were examined with 52 characters measured. Following the measurements, an inverse modeling simulation was run 100 times to generate a simulated phylogeny with …

Design And Evaluation Of An Esa-Based Method Of Ensemble Subsetting For A Wofs (Warn On Forecast-Like System), Daniel J. Butler

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Forecasting severe thunderstorm environments in the southeastern United States can be challenging due to mesoscale heterogeneities such as shortwave troughs, pre-existing airmass boundaries, cold fronts aloft, low-level jets, dry air intrusions, and mesoscale lows. To combat these challenges, ensemble sensitivity analysis (ESA) may be applied to a Warn-on-Forecast (WOF)-like ensemble to improve forecasts of severe convection through ensemble weighting and subsetting. Ensemble-based weighting and subsetting uses ensemble members that most accurately represent the thunderstorm environment in areas of mesoscale heterogeneity. This study creates and evaluates the ensemble-based weighting and subsetting in four cases of severe thunderstorm occurrence. The open parameter …

Assessing Soil Properties For Optimized Irrigation Development In Sudan, Northern Africa, Suhib Hamid, Derek M. Heeren, Aaron R. Mittelstet, Saleh Taghvaeian, Randall S. Ritzema

Department of Biological Systems Engineering: Conference Presentations and White Papers

Sustainable irrigation methods maximize agricultural productivity in Northern African countries like Sudan. This project evaluates soil properties to develop optimized irrigation strategies for Sudan's arid and semi-arid climate. Assessing soil characteristics such as texture, infiltration rates, and nutrient content informs the selection of modern irrigation systems. Data from 3,192 locations, collected using GPS and ring infiltrometers for infiltration rates, alongside laboratory analyses for soil properties, were employed. A ranking system determined suitable irrigation systems for specific soil classes, considering factors like slope, wind, crop tolerance, available water capacity (AWC), drainage, germination, capital cost, labor cost, maintenance, and evapotranspiration (ET). The …

Population Demography, Occupancy, And Connectivity Of Invasive Bigheaded Carp In The Platte River, Nebraska And Its Tributaries, Blake W. Logan

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis, collectively referred to as bigheaded carp, are invasive species in the United States of America that have expanded their range throughout the Missouri River basin in the last three decades. It may be desirable to develop management plans directed at the monitoring, control, or removal of bigheaded carp within the Missouri River basin. However, a knowledge gap exists regarding bigheaded carp ecology in Missouri River tributaries, which may be important for the development of management plans. As such, this study characterized bigheaded carp population demographics, occupancy, and connectivity in …

Exploring Producers' Willingness To Pay For Ecosystem Services: Three Essays On Soil Health, Location Preferences, And Cover Crop Adoption, Kaouter Essakkat

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

This dissertation comprises three essays: one assessing Midwest producers' willingness-to-pay (WTP) for soil health-enhancing ecosystem services (ES), another examining the impact of policy implementation locations on WTP, and a third identifying factors influencing producers' adoption of cover crops (CC).

The first essay pioneers the understanding of agricultural producers’ valuation of soil health-associated ES amid growing concerns of soil degradation due to agricultural intensification. Using a discrete choice experiment, this study assesses producers’ WTP for a policy that incentivizes ES provision, specifically improved water quality, carbon sequestration, and enhanced crop yield. Surveying producers across Iowa, Kansas, and Nebraska, our results show …