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Local Farmer Knowledge Of Adaptive Management On Diversified Vegetable And Berry Farms In The Northeastern Us, Alissa White

Graduate College Dissertations and Theses

Agricultural adaptation to climate change is notoriously context specific. Recently updated projections for the Northeastern US forecast increasingly severe and erratic precipitation events which pose significant risks to every sector of agricultural production in the region. Vegetable and berry farmers are among the most vulnerable to the risks of severe precipitation and drought due to the intensive soil and crop management strategies which characterize of this kind of production. To successfully adapt to a changing climate, these farmers need information which is tailored for the unique challenges of vegetable and berry production, framed at the level of climate impacts, and …

An Environmental Approach To Food Safety Assessment Using Artisan Cheese And Fresh Produce As Model Systems, Marie Limoges

Graduate College Dissertations and Theses

This dissertation examined recently issued regulatory standards using cheese and produce as model systems. FDA's 2015 Domestic and Imported Cheese and Cheese Products Compliance Program Guidelines (CPG) E. coli standards on cheese safety, and the extent to which these standards affect domestic and imported cheese commerce, was assessed. Results from FDA's Domestic and Imported Cheese Compliance Program for samples collected between January 1, 2004 and December 31, 2006 were analyzed. Of 3,007 cheese samples tested for non-toxigenic E. coli, 76% (2,300) of samples exceeded 10/g, FDA's target for regulatory activity. In cheese samples containing E. coli levels of 10/g and …

Modeling Agricultural Outcomes In A Warmer, Wetter Vermont, Rachel Mason

Graduate College Dissertations and Theses

This thesis aimed to model agricultural outcomes that are important to Vermont dairy farms and their surrounding communities -- runoff, erosion, nitrogen and phosphorus losses, crop yields, and timeliness of farm operations -- under a set of possible future climates. The Agricultural Policy/Environmental eXtender (APEX) model was used for this work, and the models were calibrated using data from a project that measured most of these outcomes on a set of local farms. The model setup and calibration methodology is thoroughly documented and may be a useful starting point for others who are new to agricultural modeling.

Applied to two …

Residual Soil Phosphorus In Tropical Oxisols: An Opportunity To Enhance Fertilizer Use Efficiency?, Lauren Bomeisl

Graduate College Dissertations and Theses

Phosphorus (P) is essential to life on Earth and often the limiting nutrient in agricultural systems. P fertilizer is thus an essential resource to maintain food security. In the last half century, agricultural intensification has led to an increase in P fertilizer consumption from 4.6 to 17.5 Tg of P/year to meet rising global food demand. Mineral P (i.e., phosphate rock) is a non-renewable resource in the context of the Anthropocene, and its price is vulnerable to global market fluctuations. Increased efficiency of P use on farms is considered the most effective strategy to conserve P. The soybean industry demands …

Mitigating Gaseous Nitrogen And Carbon Losses From Northeastern Agricultural Soils Via Alternative Soil Management Practices, Kyle Michael Dittmer

Graduate College Dissertations and Theses

Traditional agricultural practices often result in gaseous losses of nitrous oxide (N2O), ammonia (NH3), and carbon dioxide (CO2), representing a net loss of nutrients from agricultural soils, which negatively impacts crop yield and requires farmers to increase nutrient inputs. By adopting best management practices (BMPs; i.e., no-tillage, cover crops, sub-surface manure application, and proper manure application timing), there is great potential to reduce these losses. Because N2O and CO2 are also greenhouse gases (GHGs), climate change mitigation via BMP adoption and emissions reductions would be an important co-benefit. However, adopting a no-tillage and cover cropping system has had setbacks within …

Examination Of Bovine Rumen Fluid And Milk Fat Globule Membrane Proteome Dynamics, Mallory Cate Honan

Graduate College Dissertations and Theses

Proteomic technology has been increasingly incorporated into agricultural research, as characterization of proteomes can provide valuable information for potential biomarkers of health and physiological status of an animal. As dairy cattle are a dominant production animal in the USA, their biofluids such as milk, blood, urine, and rumen fluid have been examined by proteomic analysis. The research outlined herein was performed to further characterize the dynamics of specific proteomes and relate them to dairy cattle physiology.

The first experiment evaluated the diurnal dynamicity of the rumen metaproteome in Holstein dairy cattle. Rumen fluid was collected from three mid to late …

Organic Dairy Profitability In Vermont: Measuring The Impacts Of Management And Market Forces On Farm Financial Performance, Jonathan Patrick Walsh

Graduate College Dissertations and Theses

The total number of operating dairy farms in the US has decreased by 74.1% over the past 25 years, dropping from 155,339 in 1992 to just 40,219 in 2017. As milk prices have fallen and become more volatile, profit margins have tightened, causing farmers to leave the business due to low profitability. Some Vermont farmers are currently looking for new economic strategies. One approach has been to transition from conventional to organic production in order to take advantage of better prices and new market opportunities. In order to make production decisions, farmers need accurate financial information on the costs and …

Repelling Contarinia Nasturtii (Diptera: Cecidomyiidae), A Brassica Specialist, Using Non-Host Essential Oils, Chase Stratton

Graduate College Dissertations and Theses

Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), is an invasive pest causing marketable losses on Brassica crops in the Northeastern United States and throughout southern Canada. Heading brassicas, like cauliflower and broccoli, are particularly susceptible because larvae feed concealed inside meristematic tissues of the plant, where head formation occurs. Our work details the development of a sustainable, affordable pest management tactic for swede midge – plant derived repellents.

First, it was necessary to establish both a damage and marketability threshold for swede midge, so we developed a technique to manipulate larval density of swede midge on cauliflower, We asked: (1) …

Comprehensive Farm-To-School: A Mixed-Methods Case Study Of The Classroom, Cafeteria, And Community, Suzanna Elkin

Graduate College Dissertations and Theses

Farm-to-school (FTS) programs are supported at federal, state, and local levels as a cross-sectoral intervention to curb rising levels of obesity, strengthen local food systems, and improve school climate and academic outcomes. Comprehensive FTS programming, according to the “3-C” approach embraced by leaders in the FTS movement, includes interventions in three domains: the cafeteria, classroom, and community. FTS programming in these domains may include procurement of local food; school gardens; and education related to food, agriculture, and nutrition. Existing research supports the comprehensive FTS approach, illustrating that multi-component programs with strategies that are integrated across these environments improve outcomes for …

Evaluation Of Candidate Pheromone Blends For Mating Disruption Of The Invasive Swede Midge (Contarinia Nasturtii), Elisabeth Ann Hodgdon

Graduate College Dissertations and Theses

Swede midge (Contarinia nasturtii, Diptera: Cecidomyiidae) is a small invasive fly that is currently threatening Brassica vegetable and oilseed production in the Northeastern U.S. and Canada. Larvae feed on plant meristems, resulting in deformed leaves, stems, and heads. Extremely low damage thresholds for heading Brassica vegetables, multiple overlapping generations, and lack of effective organic insecticide options present serious challenges for managing this pest. Pheromone mating disruption (PMD), which involves confusing male insects with unnaturally large doses of sex pheromones, is particularly promising for swede midge management because it prevents mating and subsequent oviposition. One major challenge to PMD for swede …

Governing Water Quality Limits In Agricultural Watersheds, Courtney Ryder Hammond Wagner

Graduate College Dissertations and Theses

The diffuse runoff of agricultural nutrients, also called agricultural nonpoint source pollution (NPS), is a widespread threat to freshwater resources. Despite decades of research into the processes of eutrophication and agricultural nutrient management, social, economic, and political barriers have slowed progress towards improving water quality. A critical challenge to managing agricultural NPS pollution is motivating landowners to act against their individual farm production incentives in response to distant ecological impacts. The complexity of governing the social-ecological system requires improved understanding of how policy shapes farmer behavior to improve the state of water quality. This dissertation contributes both theoretically and empirically …

Consumer Support For Renewable Energy Systems: A Case Study Of Community Biodigesters In Vermont, Katelynn Maria Conedera

Graduate College Dissertations and Theses

From the steady rise in dairy farm closures to concerns over algae blooms in Lake Champlain, Vermont’s dairy industry is facing a multitude of challenges. While many potential solutions have been proposed, this study focuses specifically on community anaerobic digester systems (CADS) to aid in manure management, help to mitigate runoff, produce renew energy, and even provide an alternative revenue source to participating farms. CADS technology converts the gas emissions from manure and other organic substances into biogas through a process called anaerobic digestion. Unlike traditional on-farm biodigesters, which are often only financially viable for the largest dairy farms, CADS …

On The Application Of Computational Modeling To Complex Food Systems Issues, Serge William Wiltshire

Graduate College Dissertations and Theses

Transdisciplinary food systems research aims to merge insights from multiple fields, often revealing confounding, complex interactions. Computational modeling offers a means to discover patterns and formulate novel solutions to such systems-level problems. The best models serve as hubs—or boundary objects—which ground and unify a collaborative, iterative, and transdisciplinary process of stakeholder engagement. This dissertation demonstrates the application of agent-based modeling, network analytics, and evolutionary computational optimization to the pressing food systems problem areas of livestock epidemiology and global food security. It is comprised of a methodological introduction, an executive summary, three journal-article formatted chapters, and an overarching discussion section.

Chapter …