Earth Sciences Commons^™

Rice Biomass Response To Various Phosphorus Fertilizers In A Phosphorus-Deficient Soil Under Simulated Furrow-Irrigation, Jonathan B. Brye

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Wastewater-recovered phosphorus (P), in the form of the mineral struvite (MgNH4PO4⋅6H2O), may provide a sustainable alternative to rapidly decreasing rock phosphate reserves. Struvite can be generated via chemical and/or electrochemical precipitation methods, potentially reducing the amount of P runoff to aquatic ecosystems. The objective of this greenhouse tub study was to evaluate the effects of chemically- and electrochemically precipitated struvite (CPST and ECST, respectively) on above- and belowground plant response in a hybrid rice cultivar (Gemini 214, RiceTec) grown using furrow-irrigation compared to other common fertilizer-P sources [i.e., triple super phosphate (TSP) and diammonium phosphate (DAP)] in a P-deficient silt …

Building And Using A Hydrology Experiment For Place-Based Learning With Native American Students, Michaela Shallue

All Graduate Theses and Dissertations, Fall 2023 to Present

Geoscience has a known diversity problem, specifically a participation gap of ethnic minority representation, and it is especially severe regarding Native American representation. To address this participation gap, an identity gap needs to be addressed first. Native students need to visualize themselves as geoscientists before they can commit to geoscience programs and careers. This project uses a hands-on, place-based learning activity as an opportunity for Native students to better see themselves as geoscientists.

A portable rainfall simulator was constructed, calibrated, and refined for use in teaching concepts about rainfall, runoff, and erosion. It was employed in place-based learning exercises with …

Soil Nitrification Inhibition With Plantain (Plantago Lanceolata), M. E. Peterson, P. M. Fraser, C. R. Anderson, N. I. Joyce, H. G. Judson

IGC Proceedings (2001-2023)

One strategy to reduce nitrogen losses from intensively grazed forage systems is to slow the first stage of soil nitrification, specifically inhibiting the microbial oxidation of ammonium to nitrite. Plantain (Plantago lanceolata) leaves and roots are known to contain several bioactive compounds (e.g., aucubin, catalpol and verbascoside) that may contribute to this inhibition. Recent laboratory studies indicate that this inhibition occurs via consumption by grazing animals of precursor bioactive compounds in aboveground biomass and their subsequent excretion as secondary metabolites in urine and/or via active exudation from the roots. Different cultivars of plantain have been shown to impart …

Forage Genomics Accelerate The Germplasm Resource Innovation, Fan Wu, Qi Yan, Pan Xu, Zhen Duan, Jiyu Zhang

IGC Proceedings (2001-2023)

To achieve sustainability and food security we need expand the germplasm base and access novel genetic diversity to accelerate breeding. For developing new forage cultivars, the availability of a high-quality genome facilitates accurate characterization of new germplasm, and an understanding of the genetics underlying important traits. Here, we sequenced and assembled three high-quality chromosome-level forage genomes. The contig-level assembly of Cleistogenes songorica (2n = 4x = 40) comprised 540.12 Mb of the genome, with a contig N50 of 21.28 Mb. Complete assemblies of all telomeres, and of ten chromosomes were derived. The chromosome-scale genome size of elephant grass (2n = …

Theory And Application Of No-Till Reseeding Technology In Degraded Grasslands In China, Jingying Jing, Hongyan Ma, Yingjun Zhang

IGC Proceedings (2001-2023)

Grasslands occupy nearly 400 million hectares in China, accounting for about 40.7% of the total land area, provide multiple ecological and economic benefits. However, due to over-grazing and over-cultivation, more than 90% grasslands in China are threatened by degradation that has caused significant negative impact on biodiversity and ecosystem functioning, such as biodiversity losses, decreased productivity, increased soil erosion etc. Thus, restoration of degraded grassland is urgent for sustainable grassland management in China. No-till reseeding has been found to be an effective way for grassland vegetation regeneration with improved productivity and increased plant diversity via reseeding suitable species with minimum …

Rangeland-Centered Agroecosystems In Indian Central Himalayas: Operationalizing Ecological Sustainability In Mountain Agriculture, Vir Singh

IGC Proceedings (2001-2023)

Himalayan Mountains are home to unique agroecosystems harboring unique inter- and intra-species diversity in uncultivated and cultivated lands. The uncultivated lands are largely the rangelands which are ecologically more stable ecosystems than the cultivated lands which are ecologically prone areas. Rangelands, cultivated areas, and livestock in mountain agriculture are in organic linkages with each other, woven into a complex unitary whole, functionally oriented to produce foods and other life-supporting products – such as feed, fiber, fuel, fertilizers, etc. – and provide vital ecological functions. Rangelands in fragile Himalayan mountains serve as a key component of agriculture and the biodiversity conserved …

Mentoring Graduate Students For Academic Careers In Grassland Science, L. E. Sollenberger

IGC Proceedings (2001-2023)

Effective mentorship enhances student productivity and career achievements, yet faculty generally do not receive mentorship training, nor does mentorship receive focused attention, evaluation, and recognition. The objectives of this paper are to 1) define mentorship and identify roles of a mentor, 2) highlight qualities and outcomes of effective mentoring, and 3) elaborate best mentoring practices, metrics for assessing mentoring, and challenges for mentoring the next generation of grassland scientists. Mentoring is a professional alliance where individuals work together to support the personal and professional growth, development, and success of the relational partners. Mentors should be altruistic discipline experts, have substantial …

National Forage Week, B. Stefancik, K. Mullenix

IGC Proceedings (2001-2023)

Social media can be a powerful tool for producers, researchers, and grassland professionals. Social media enables us to connect with a wide audience of producers, Extension personnel, colleagues, industry partners, and even the non-agriculture related community. This presentation in the thematic session on “Understanding the role of social media and digital resources in forage education and promotion” will focus on the impact of National Forage Week. National Forage Week is national campaign initiated by the American Forage and Grassland Council to promote forages and their contributions to society.

Maize-Alfalfa Intercropping Promote Ecosystem Services Than Fertilized Single Crops, D. X. Tao, Y. Z. Gao

IGC Proceedings (2001-2023)

Phosphorus is a non-renewable source of fertilization, which will challenge the future of food production and cropland sustainability worldwide. Crop diversity is known to promote food production, yet its capacity to alleviate the dependence of multiple ecosystem services on non-renewable fertilization remains virtually unknown. Here, we conducted a field experiment to quantify the contribution of maize-alfalfa intercropping to support multiple ecosystem services under contrasting levels of phosphorus fertilization. We showed that unfertilized intercropping systems can support larger levels of multiple ecosystem services such as soil microbial habitat, plant-soil mutualism, nutrient cycling, and soil carbon storage compared with phosphorus-fertilized single crops. …

Identification Of Hyperspectral Characteristics Of The Main Plants In Seriphidium Transiliense Desert Grassland, Wenhao Liu, Wanqiang Han, Guili Jin, Ying Li, Ke Gong, Jian Ma, Zhibiao Liu, Jiazin Li, Mengtian Chen

IGC Proceedings (2001-2023)

Ground hyperspectral images of sericite–Artemisia desert grassland in different seasons were obtained by a soc710 VP imaging spectrometer. Analysis of variance was used to extract the main species Seriphidium transiliense, Ceratocarpus arenarius, and Petrosimonia sibirica and the spectral characteristic parameters and vegetation indices of bare land in different seasons. On this basis, Fisher discriminant analysis was used to divide the samples into a training set and test set according to a ratio of 7:3. The spectral characteristic parameters and vegetation indices were used to identify the three main plants and bare land. Results showed that under Fisher discriminant analysis, …

A Transdisciplinary Approach To Landscape Transformation Towards Perennial, Diverse, Circular Systems: Why And How, V. Picasso, C. Williams

IGC Proceedings (2001-2023)

Prevailing agricultural systems in the U.S. are dominated by intensification through annual crop monocultures and high amounts of external inputs. Increased yields per unit of land have resulted but many undesirable environmental, ecological, and socioeconomic outcomes have co-occurred. Lack of resilience within intensified agricultural systems is a factor in these outcomes. Redesign of agricultural systems and changes in federal policy are needed to better support resilience in agriculture. Redesign for greater resilience must encourage adoption of agricultural systems that are diverse, perennial, circular, and include forages. We developed a transdisciplinary framework within a project orientation with a focus on crops …

Breeding Cool-Season Forage Grasses For A Warming Climate, D. P. Malinowski, J. Ford, A. Stewart, D. Woodfield, W. E. Pinchak

IGC Proceedings (2001-2023)

In many parts of the world, changing climatic conditions are resulting in increased temperatures and more variable precipitation, intensifying the duration and severity of drought, especially in summer. Warming climate is considered one reason for the increasing failure of traditional, summer-active cool-season perennial grasses at the margin of their zone of adaptation in naturally C4 grass-dominated ecosystems of the Southern Great Plains of the USA. Two cool-season perennial forage grasses orchardgrass (Dactylis glomerata L.) and tall fescue (Lolium arundinaceum (Schreb.) Darbysh.) are of major economic and ecological importance in these regions. In 2008, we initiated a breeding program …

Invasive Annual Grass Issues In Canadian Rangelands, V. Maloney

IGC Proceedings (2001-2023)

It has been understood for several years now that Canadian grasslands are among the world’s most endangered ecosystems. While the endangerment of the world’s coral reefs and rainforests may make the news more often, the increasingly fast decline of native Canadian grasslands is having a major impact on species diversity as well as global carbon supplies. In this paper, I will discuss the impact invasive annual grasses have had on two important rangeland ecosystems in Canada. Furthermore, strategies for protecting and restoring these invaluable lands will be discussed.

Forage Data Hub – A Platform For Sharing Valuable Datasets For Resilience, Amanda J. Ashworth, L. Marshall, J. J. Volenec, M. Berti, E. Van Santen, C. Williams, V. Gopakumar, J. Foster, V. Picasso, J. Su

IGC Proceedings (2001-2023)

In accord with the necessity to enhance ecosystem services and productivity in food systems, is the increase of data availability at multiple scales and over time. To help meet this need, we discuss the development of a National Forage Data Hub which will act as a platform to curate, share, and analyze data pertaining to forage systems. This centralized hub will leverage existing datasets by bridging multiple sources including forage crop—soil, water, and nutrient availability—yield (animal and crop) potential (and gaps)— climate—management systems at high spatial and temporal resolution enabling system interaction assessments through next-generation analytics. This novel approach to …

Tennessee Master Beef Producer Program Promotes Sustainable Beef Production, K. M. Mason, G. E. Bates, J. D. Rhinehart

IGC Proceedings (2001-2023)

Tennessee is home to 1.75 million beef cattle as of January 2022 (USDA, 2022). The majority of cattle farms in Tennessee are cow-calf operations, with a few stocker-backgrounder operations across the state. Most of the cows in the state are maintained on tall fescue (Schedonorus arundinaceus (Schreb.) Dumort. pastures, with hay being fed in the winter months and sometimes during the summer. Maintenance of a strong cow herd and sufficient grazing land relies on utilization of sustainable production practices. With urban sprawl creating competition for land area, it is important to use production practices that are efficient and attainable …

Guidelines For Optimal Use Of Near Infrared Spectroscopy (Nirs) With Sample Preparation And Presentation Across Instrument Platforms, D. W. Mcintosh

IGC Proceedings (2001-2023)

Guidelines for optimal use of near infrared spectroscopy (NIRS) with sample preparation and presentation across instrument platforms will cover methods and resources specifically for NIRS analysis. Recommendations for sample preprocessing and scanning required to ensure compatibility across calibrations will be highlighted. Proper calibration determinations, monitoring, and performance will be demonstrated to create a baseline for correct use. Additional materials about the use and reporting of nutritive content predictions for publication will be discussed. Goals of this topic session are to develop an understanding of the basics of NIRS technology and provide the basics to what a laboratory is required to …

Challenges And Opportunities For Revegetation In Areas Dominated By Invasive Annual Grasses, B. A. Mealor, J. A. Crose

IGC Proceedings (2001-2023)

Invasive annual grasses (IAG) are a primary ecological threat to sustainability and ecological integrity of rangelands in the western U.S. While availability of effective tools to control IAG is increasing, ensuring compatibility of control practices with other management practices, such as seeding desirable species, is a critical information need. We summarize a series of studies investigating influences of timing, seeding depth, species selection, and planting timing with various herbicides in sites dominated by invasive annual grasses.

Transitioning To Multiple-Use Polyculture Grassland-Derived Bioenergy Feedstock Systems, J. P. Muir, J. L. Foster, A. Falk, S. Weiss, W. D. Pitman, W. Alsion, H. D. Naumann, J. R. Bow, C. Shadrock, E. Osei, O. Lasater

IGC Proceedings (2001-2023)

We argue that research and development of grassland-derived bioenergy feedstock (GBF) has focused unduly on dedicated monospecific biomass systems to the detriment of more stable multiple-use multispecies grasslands. This has retarded GBF adoption as a viable, sustainable contribution to renewable energy production in North America. We hypothesize that focusing on multiple-use GBFs will foster greater feedstock availability for nascent renewable energy generation while minimizing financial risk to grassland husbandry during market transitions from current grazing systems to more flexible business models. Our hypothesis is that source and demand are more likely to develop simultaneously under less risky multiple-use grassland management. …

Observing And Simulating Temperate Grasslands In Central Europe, C. Nendel

IGC Proceedings (2001-2023)

This presentation summarises recent activities to observe grassland features using remote sensing and uses this data to feed mechanistic simulation models for temperate grassland vegetation in Central Europe, in order to assess underlying processes that are difficult to observe. Public interest has recently focused on grassland ecosystem services, such as carbon stocks, nitrate retention and greenhouse gas emissions; variables that in principle can be simulated using models. However, current grassland models suffer from the fact that species dynamics in grasslands are very active, and may change in response to water supply and management. As different species come with different traits, …

The Effect Of Nitrogen Rates And Plant Density On Grain Yield Components And Persistence In Intermediate Wheatgrass (Thinopyrum Intermedium) And Mountain Rye (Secale Strictum), M. T. Newell, N. Munday, R. C. Hayes

IGC Proceedings (2001-2023)

Intermediate wheatgrass (IWG; Thinopyrum intermedium) and Mountain Rye (Mtn Rye; Secale strictum) have potential for release as dual-purpose (grazing and grain production) perennial grains in Australia due to their superior longevity compared to hybrid perennial wheats. Initially developed as perennial forage grasses, few management guidelines exist to inform agronomic practices to maximise grain yields and profitability in Australian environments. An experiment was established in 2020 to examine the effect of plant density and nitrogen rates on grain yield components. The experiment compared the two species (IWG, Mtn Rye) sown at three plant densities (50, 100 and 200 plants/m2) …