Agriculture Commons^™

Development Of The Core Lit Apparatus For Seaweed Hatcheries (Clash) Bioreactor Using A Germplasm Approach, Phillip O. Tahimic

Cal Poly Humboldt theses and projects

In comparison to the Asian aquaculture industry, the United States has minimal seaweed production. There are several drivers of the limited industry in the US, such as regulatory constraints and limited market demand, but the ability to scale is a considerable barrier to commercialization. One possible solution is the development of land-based systems that integrate bioreactors, which utilize fewer resources and do not wholly rely on an oceanic flow-through system. This study assessed the application of a modular bioreactor, known as Core Lit Apparatus for Seaweed Hatcheries (CLASH), as a nursery system and open-source project designed to expand land-based seaweed …

Soil Nutrient Sufficiency Versus Plant Nutrient Status In Compost-Amended Soils: Plant Tissue Analysis As A Diagnostic Tool, Chandralekha Joga Miss

Murray State Theses and Dissertations

This study evaluated whether Mehlich III soil nutrient sufficiency ratings reliably predict plant nutrient status and chlorophyll response across contrasting compost application histories. A greenhouse pot experiment was conducted with Chijimisai (Brassica rapa) planted in three treatment soils that had no compost (T1), moderate compost history (T2), and long-term hog manure compost application (T3). Plant performance was assessed through weekly shoot length and chlorophyll content (SPAD) measurements, leaf number at maturity, and leaf tissue nutrient analysis conducted at harvest. Soil test results indicated adequate to high nutrient levels across all three treatments. Leaf tissue analysis, however, revealed substantial …

An Analysis Of Systemic And Contact Herbicide Usage Trends In Illinois Corn Production Systems, Paige E. Mckittrick

Murray State Theses and Dissertations

Herbicide use is central to weed management in Illinois corn production; however, long-term changes in the balance between systemic and contact herbicides have not been well quantified at the statewide scale. This study analyzes herbicide trends in Illinois corn from 1982 to 2016 using secondary data from the USDA Agricultural Chemical Use Survey, paired with climate, regulatory, and herbicide resistance information. Herbicide active ingredients were classified into systemic and contact functional categories and grouped according to Weed Science Society of America (WSSA) mode-of-action (MOA) codes. For each survey year, total herbicide load (lb a.i./acre), functional proportions, MOA-specific contributions, and a …

Beef Cattle Producers’ Knowledge About And Preferences For Carbon Contracts, Zuyi Wang, Anastasia W. Thayer, Felipe De Figueiredo Silva, Michael Vassalos, Jordan M. Shockley, Nathan Smith

Agricultural Economics Faculty Publications

Carbon contracts have gained attention as a way to incentivize carbon-emissions reduction for the agricultural sector, particularly among beef-cattle producers.

Our study utilized data from a survey of 222 beef cattle producers in the southeastern United States to examine their knowledge, perceptions, and preferences regarding carbon contracts.

Survey respondents demonstrated a lack of accurate knowledge about carbon markets and contract specifications, with many overestimating the price of carbon.

Among the most common barriers to signing contracts were the cost of altering practices, the duration, and insufficient payments.

Further, our results indicated that producers require an additional $103.74/hectare ($42/acre) to accept …

Leveraging Research-Based Knowledge Translation Via Rural Libraries To Improve Maize Postharvest Practices In Uganda, Jackline Estomihi Kiwelu, Patrick Ngulube

Libraries

Background: Rural community libraries are increasingly recognised for providing localised knowledge, yet their potential to support agricultural extension services and improve access to postharvest knowledge in Uganda remains underexplored.
Objectives: This study examined the postharvest information needs of smallholder maize farmers and explored how community libraries can be leveraged to translate and repackage research-based knowledge to meet these needs.
Method: A mixed-methods parallel design was employed. Data were collected from a survey of 312 maize farmers, personal interviews and two focus group discussions (FGDs) with 22 extension workers and four librarians. Desk research was conducted to analyse relevant documents. Quantitative …

Soil Organic Carbon And Soil Health Property Responses To Land Management Across Topographic Positions, Mia D. Makovsky

All Graduate Theses, Dissertations, and Other Capstone Projects

uring the last ice age, ice sheets advanced and retreated across the upper Midwest, leaving behind a landscape characterized by poorly drained hummocky topography. Well-aerated soils have formed on uplands and lowlands are dominated by hydric soils. These wetlands and hydric soils have potential to store large quantities of carbon, particularly compared to the well-aerated uplands, but many have been drained and cultivated for decades. Conservation agriculture methods have emerged to protect and conserve soil health from negative effects due to cultivation.The purpose of this study is to determine how agricultural management practices and landscape properties (e.g, topographic position) affect …

Influence Of Microbial Communities And Dilute Heavy Metals In Green Manure On Growth In Lactuca Sativa, Robert Lemay

Student Research Projects

This experiment investigated the effects of a green manure (Lemna minor, common duckweed) grown in varying levels of heavy metals and inoculated with local microbiomes on a crop (Lactuca sativa, volcana lettuce). The growth and health of the duckweeds were measured via root length and biomass, and the health of the lettuce crop was measured via head diameter and biomass.  Two levels of heavy metal concentrations were based on real-world stormwater runoff data to mimic an agricultural environment where accumulation of metals in local water bodies may be absorbed into green manure duckweeds. One microbial treatment and …

Limitations Of Reproductive Manipulation By Bacterial Endosymbionts In A Spider Host, Jordyn D. Proctor

Theses and Dissertations--Entomology

Maternally inherited bacterial endosymbionts are common in arthropods. Many of these bacteria manipulate host reproduction to favor the production of infected females, thereby increasing bacterial prevalence in the host population, even if cost is incurred to the host. However, there are also many factors that may inhibit symbionts’ ability to spread in host populations, including environmental constraints, symbiont-imposed costs on the host, interactions with co-infecting bacteria, or host biology. I explored two aspects of symbiont biology within a spider host, Mermessus fradeorum (Linyphiidae), which has varying combinations of up to five different bacterial endosymbionts in local populations: Rickettsiella, Tisiphia …

Impacts Of Livestock Dewormers On Dung Beetle Foraging Choices Across Spatial Scales, Madison L. Kluge

Theses and Dissertations--Entomology

Dung beetles provide ecosystem services in pasture systems but are vulnerable to chemical residues in livestock dung. Parasiticides containing macrocyclic lactones (MLs) are used to control parasites in livestock and are excreted unmetabolized in dung, exposing non-target organisms to these compounds. We used a multi-scale approach to examine whether ML residues alter dung beetle foraging ecology. At the field scale, we assessed dung beetle abundance and community composition using traps baited with dung from untreated cattle and cattle treated with ivermectin, moxidectin, or eprinomectin across eight farms and natural areas. At a smaller scale, we conducted behavioral assays to quantify …

Supplemental Bibliographic Details. From 2001 Mars Odyssey To Earth’S Climate Crisis: Integrating Gamma Spectroscopy, Martian Soil Simulants, And Plant Genomes For Agroecology, Anchored In Sri Lanka’S Mars-Context Serpentinites, Suniti Karunatillake, Maheshi Dassanayake, Carlos Gary Bicas

Planetary Science Lab

Bibliographic details follow to supplement hyperlinked citations in the multinational GANGOTRI-supporting project conceived by Karunatillake, Dassanayake, and Gary-Bicas

Midwestern Farmers' Willingness To Engage With Precision Agriculture Technologies And On-Farm Precision Experimentation, Reagen G. Tibbs, Nicholas J. Heller, David S. Bullock, Maria A. Boerngen

Faculty Publications - Agriculture

Precision agriculture technologies (PATs) have revolutionized the agriculture industry and provide many benefits to farmers. Among these benefits is the ability to conduct experiments in a process known as on-farm precision experimentation (OFPE). By conducting these experiments and through collaboration with researchers, crop consultants, and extension agents, farmers can learn site-specific management practices to better address challenges in their operations. However, adoption rates of these technologies have remained below 50% in the United States. Furthermore, very few studies have explored the factors that influence a farmer's decision to conduct experiments, or their willingness to collaborate with external stakeholders such as …

A Preliminary Study On Producing Volatile Fatty Acids From Winter Cover Crops, Tuba Yasmin Lubna, Robert L. Rhykerd, David E. Kopsell, Nicholas J. Heller, Md. Mahadi Hasan, Kathryn Stahl, Liangcheng Yang

Faculty Publications - Agriculture

Winter cover crops provide many ecological benefits, though their economic impacts have been shown to be mixed. While cover crop biomass is typically terminated or used as livestock feed, it can also serve as a feedstock for bioenergy production, offering opportunities for additional revenue. This study evaluated the potential of wild pennycress, CoverCress™, annual ryegrass, cereal rye, and field pea biomass for volatile fatty acids (VFAs) production through arrested anaerobic digestion (AAD). Specifically, the effects of harvest timing on cover crop biomass composition and VFAs yield were examined, given the need for effective utilization and storage of early-harvested biomass. The …

Eat With Understanding: A Um Student Guide To Food Systems, James Deacon, Cora Johnson, Lucas Dymit, Kaeli Rackham, Elsie Danyo

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The industrialized food system creates environmental harm, reduces food sovereignty, and contributes to growing food insecurity. These problems oftentimes are overlooked in higher education. To address this gap, our project examines how access to sustainable food education and campus-community partnerships can improve well-being and informed decision-making amongst University of Montana students. This collaborative project connects partners within UM Wellness, PEAS Farm, the Missoula Food Bank and Community Center, and the Big Sky Culinary Institute. Our research includes applied learning with these organizations by hosting a variety of speaker series presentations and coordinating a cooking workshop. We collected quantitative and qualitative …

Agricultural Productivity Under Energy Development: Insights From California, Wai Yan Siu, Sherzod B. Akhundjanov

ODU Articles

This paper examines how agricultural productivity patterns in Kern County, California, a leading region for both agricultural production and oil and gas development, co-vary with the spatial and temporal expansion of hydraulic fracturing and associated energy infrastructure. Using parcel- and county-level analyses, we characterize how agricultural productivity differs across proximity to energy development and across spatial scales. The results reveal spatially heterogeneous and scale-dependent patterns: parcel-level evidence indicates lower Enhanced Vegetation Index-based vegetation productivity within the 20-mile proximity zone around fracking wells, while county-level results show heterogeneous crop-specific yield changes during the post-expansion period. Together, these findings highlight the importance …

Cover Crop Effects On Soil Porewater Nutrients And Hydrothermal Properties, Md Mahadi Hasan

Theses and Dissertations

Adoption of winter cover crops in the U.S. Midwest may reduce nitrogen (N) and phosphorus (P) leaching from soils, potentially shrinking the hypoxic zone by limiting nutrient runoff into the Gulf of Mexico. To evaluate the impact of selected winter cover crops on soil porewater N and P concentration, a field study was conducted at the Illinois State University Research Farm (ISURF) and the Western Illinois University Research Farm (WIURF). The experimental design was a block experiment with four replications.  Cover crop treatments included a winter fallow, wild pennycress (WPC), golden pennycress (GPC), cereal rye (CR), annual ryegrass (AR), and …

Effects Of Compost Incorporated Versus Surface Applied On Soybean Yield And Soil Health, Maheshwari Kuchanapally

Theses and Dissertations

Compost application is increasingly recognized as a sustainable soil management practice that enhances soil health and crop production. However, the method of application, incorporated versus surface applied, may influence its effectiveness in improving soil properties and crop productivity. This study evaluated the effects of compost application method on soybean (Glycine max L. Merr.) yield and soil health at Illinois State University Research Farm in Lexington, Illinois, across two growing seasons, 2024 and 2025. The 2024 experiment used a Completely Randomized Design comparing incorporated versus surface-applied compost (n = 4; 8 plots). The 2025 experiment used a Randomized Complete Block Design …

Seasonal Population Dynamics And Interspecific Interactions Of Drosophila Suzukii, Eleanor Mccabe

Theses and Dissertations--Entomology

Invasive species are a growing problem, and it is important to investigate how invasives interact with novel ecosystems, which are characterized by distinct abiotic and biotic factors. In this dissertation, I investigate abiotic and biotic factors affecting two invasive pests in central Kentucky, Drosophila suzukii and Zaprionus indianus. In Kentucky, seasonality, and landscape features on population dynamics and fitness are unknown. I found that D. suzukii overwinters in Kentucky and that wild berry species improve winter survival. I used local weather data to identify meteorological variables that best predict D. suzukii populations. I tested the extent to which D. suzukii …

Fusarium Head Blight Of Hemp: A Destructive Disease Emerges On A New Host, Henry Smith

Theses and Dissertations--Plant Pathology

Hemp was reintroduced as a commercial crop in 2018 after a near 50-year production ban under the Controlled Substances Act. Since reintroduction, Kentucky has consistently ranked among the top five hemp producing states in the US. Surveys have shown that hemp is susceptible to a multitude of diseases that impact production. Among the most concerning diseases in Kentucky is Fusarium head blight (FHB). FHB is a major disease of cereals that is caused by various Fusarium species, predominately F. graminearum. FHB of hemp caused by F. graminearum was first reported in Kentucky in 2020. A survey of 25 different …

Between The Rails: Experiential Education And Its Impact On Compliance And Consistency In Racetrack Surface Management, Heather Mackenzie

Theses and Dissertations--Community & Leadership Development

Recent regulatory requirements within the Thoroughbred racing industry have increased expectations for consistent collection and reporting of racetrack surface data. Despite clear standards, implementation in daily operations remains inconsistent, highlighting a gap between regulation, knowledge, and practice. This study examined the impact of an experiential education curriculum on racetrack personnel’s self-efficacy and reporting consistency.

Using a quantitative design, data were collected through pre- and post-surveys measuring self-efficacy and records of the number of days surface data were entered. Descriptive statistics, paired-samples t-tests, and effect size analyses were used. Results showed a statistically significant increase in self-efficacy (p < .001) with large effect sizes, indicating meaningful gains in confidence and comfortability. Reporting consistency did not show a statistically significant change (p = .885).

Overall, experiential education …

Growing South Dakota (Winter 2026), College Of Agriculture, Food And Environmental Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

[Page] 2 International Year of Rangelands and Pastoralists: South Dakota rangelands take center stage
[Page] 4 The professor and the soil
[Page] 8 Range ready: Helping students bridge the gap between conservation and agriculture
[Page] 9 Resilient rangelands: Native Plant Initiative’s role in reviving South Dakota’s prairies
[Page] 10 Jackrabbits lead the charge in bison research and education
[Page] 12 Agricultural and biosystems engineering celebrates century of education
[Page] 16 SDSU Quarter Scale Tractor Club: An impact beyond awards
[Page] 18 Building a legacy of opportunity: Karen D. Stuck Endowment strengthens agricultural communication program at South Dakota State University
[Page] …