Open Access. Powered by Scholars. Published by Universities.®

Agriculture Commons

Open Access. Powered by Scholars. Published by Universities.®

Electronic Theses and Dissertations

2021

Discipline
Institution
Keyword

Articles 1 - 23 of 23

Full-Text Articles in Agriculture

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado Dec 2021

Assessing Freezing Effect On Kiwifruit Cultivars And Mapping Suitable Areas For Growing The Crop In Eastern Texas, Lais De Oliveira Machado

Electronic Theses and Dissertations

Kiwifruit is a perennial vine originating from China where it has been grown for centuries. In the United States, green kiwifruit (Actinidia deliciosa) is primarily produced commercially in California. They are fuzzy, green fleshed and well known in the marketplace. Kiwifruit plants require low to moderate soil pH, adequate winter chilling and adequate precipitation to guarantee plant development and good fructification. Actinidia chinesis or golden kiwifruit are smooth skinned, feature golden flesh and are a more recent introduction into the global market. Kiwifruit crops have attributes that favor production in east Texas, including low pest problems, current long …


Adaptation Strategies For Wild Blueberry Growers In A Changing Climate: Mulching Effects On Crop Productivity And Fertility Effects On Blueberry Gall Midge, Rebecca Gumbrewicz Dec 2021

Adaptation Strategies For Wild Blueberry Growers In A Changing Climate: Mulching Effects On Crop Productivity And Fertility Effects On Blueberry Gall Midge, Rebecca Gumbrewicz

Electronic Theses and Dissertations

Wild blueberry (Vaccinium angustifolium Aiton.) cropping systems are considered resilient to environmental changes due to ecological and genetic diversity within each field. However, wild blueberries can be sensitive to weather fluctuations that cause extreme temperature or moisture regimes. Climate change in Maine is represented by increasing rates of warming temperatures, more intense precipitation events, and more frequent atmospheric “blocking” patterns. Warming temperatures result in the northward expansion of pest ranges and altered growing seasons. More extreme rainfall events lead to damaged plantings and soil erosion. Atmospheric blocking leads to an increased likelihood of heat waves and drought. Two experiments were …


To Know The Land With Hands And Minds: Negotiating Agricultural Knowledge In Late-Nineteenth-Century New England And Westphalia, Justus Hillebrand Aug 2021

To Know The Land With Hands And Minds: Negotiating Agricultural Knowledge In Late-Nineteenth-Century New England And Westphalia, Justus Hillebrand

Electronic Theses and Dissertations

Ever since the eighteenth century, experts have tried to tell farmers how to farm. The agricultural enlightenment in Europe marked the beginning of a long arc of new experts aiming to change agricultural knowledge and practice. This dissertation analyzes the pivotal period in the late nineteenth and early twentieth century in Germany and the United States when scientists, improvers, and market agents began to develop comprehensive ways to communicate agricultural innovation to farmers. In a functional approach to analyzing the negotiation of agricultural knowledge through its communication in things, words, and practices, this dissertation argues that the process of change …


Expanding Our Understanding On Feed Spoilage And Developing Novel Approaches For Its Mitigation, Marjorie A. Killerby Aug 2021

Expanding Our Understanding On Feed Spoilage And Developing Novel Approaches For Its Mitigation, Marjorie A. Killerby

Electronic Theses and Dissertations

The main objective of this study is to improve the understanding and awareness of conserved feed spoilage and to develop novel technologies that can prevent it. In chapter 1, we conducted a meta-analysis to evaluate the effects of chemical (50 articles)and biological (21 articles)preservatives on hay spoilage during storage. Multi-level linear mixed-effects modelswere fit including moderators:Preservative Class (PC), forage type (FT); moisture class (MC), and application rate (AR). Dry matter (DM) loss was affected by PC×FT (P=0.045), PC×AR (P<0.001), and PC×MC (P=0.009),relative to the overall effect of preservatives (-0.37% units). DM loss in propionic acid (PropA)-treated hay was numerically reduced to a greater extent in grasses (-16.2), followed by mixed hay (-1.76), but it was actually increased (+2.2%)in legume hay.Increasing ARof PropA resulted in decrease in DM loss (β = -1.34).Application ofBuffered Organic Acids,Other Organic Acids, PropA,and Anhydrous Ammoniadecreased visual moldiness by -22.1, -29.4, -45.5 and -12.2% units, respectively (PC; P<0.001). Sugars increased in treated grass hay (+1.9) and decreased in treated legume hay -0.8% DM, respectively (P<0.001). Microbial inoculants had small effects on hay spoilage since the overall DM loss effect size was - 0.21%. Inoculated grass hay preserved moresugars (+1.47) than treated legume hay (+0.33) relative to untreated hay (x=4.63% DM; P<0.001). In conclusion, organic acid-based preservatives effectively prevent spoilage of hay as influenced by FT, MC and AR, but microbial inoculants had only small effects. In chapter 2, we evaluated the effects of chemical and biological preservatives and ensiling stage on spoilage, ruminal in vitro fermentation, and methane production of wet brewer’s grain (WBG) silage. Treatments (TRT) were sodium lignosulfonate at10 g/kg (NaL1) and 20 g/kg (NaL2; fresh WBG), propionic acid at 5 g/kg fresh WBG (PRP, 99%), a combination inoculant (INO; Lactococcus lactisand Lactobacillus buchneri each at 4.9 log cfu/fresh WBG g), and untreated (CON). Three stages (STG) were tested:treated WBG (Fresh) was ensiled for 60 d(Ensiled), after which they were opened and aerobically exposed for 10 d (AES). Data were analyzed as a RCBD (5 blocks) with a 5 TRT × 3 STG(Fresh, Ensiled and AES) factorial arrangement. Our results show that Ensiled PRP-treated WBG markedly preserved more sugars (250) and starch (190) than all other Ensiled TRT (x=136 ± 16.2sugarsg/kg DM and x=121 ± 6.15 starch g/kg DM, respectively; P<0.001). Due to its superior nutritive value, PRP-treated AES was less aerobically stable than CON (61.9 vs. 90.1 h; P = 0.03). Preservation was not improved by INO, NaL1 or NaL2, but the latter prevented the increase of neutral detergent fiber (NDF)across STG (x=384).In vitro ruminal fermentation of Fresh WBG resulted in higher methane concentration (0.94) and yield (0.27) than theother STG (x=0.84 ± 0.07mMand x=0.23 ± 0.03mmol/g fermented OM, respectively). In conclusion, PRP was the most effective at preserving WBG during ensiling but failed to improve aerobic stability. In chapter 3, we evaluated the effects of application rate (AR) of sodium lignosulfonate (NaL) and propionic acid(PRP)on high moisture alfalfa hay spoilage during storage and its nutritive value. Treatments (TRT; NaL and PRP) were applied at four AR: 0 (CON), 2.5, 5 and 10 g/kg (fresh basis) to alfalfa hay at 68.5% DM, packed into mini balesand stored for 33 d.Data were analyzed as a RCBD(5 blocks) with a 2 TRT x 4 AR factorial arrangement. At d 33, DM losses were decreased by PRP at 5 and 10 g/kg (0.9), vs.CON (6.92) andNaL (6.63 ± 1.13%). Visual moldiness (0-10) and mold counts were also decreased by PRP at 5 (2.4 and 5.30) and 10 g/kg (0 and 2.7) relative to CON (6.0 and 7.13) and NaL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). Both TRT increased apparent in vitroDM digestibility at all AR relative to CON (x=543 vs 501 ± 12.0g/kgof DM, respectively), but the acetate-to-propionate ratio was higher for NaL at 10 g/kg (3.02) vs. CON (2.89 ± 0.04). In conclusion, NaL failed to prevent spoilage of high moisture alfalfa hay while PRP was effective at doses >5 g/kg. Both TRT at 10 g/kg improved the rumen in vitro fermentation measures of high moisture alfalfa hay but PRP …


Development And Evaluation Of An Attachable Anti-Vibration Handle For Blueberry Hand Shaker, Jashwant Thota Jul 2021

Development And Evaluation Of An Attachable Anti-Vibration Handle For Blueberry Hand Shaker, Jashwant Thota

Electronic Theses and Dissertations

Blueberry production has skyrocketed in the past two decades due to an exponential increase in consumer demand around the world. The harvesting of fresh, high-quality blueberries requires extensive care. Large-scale automatic harvesters damage the fruit and make it unsuitable for storage and transportation, which requires more than two weeks to complete. Therefore, hand harvesters are used, avoiding damage to the fruit, and increasing harvesting efficiency multifold when compared with that of hand-picking. The downside of these hand harvesters is their high Hand Arm Vibration (HAV), which is very dangerous for the worker and can cause hand-arm vibration syndrome (HAVS). This …


Evaluating Methods For Research In Physical Weed Control And Farm Asset Tracking, Johnny J. Sanchez May 2021

Evaluating Methods For Research In Physical Weed Control And Farm Asset Tracking, Johnny J. Sanchez

Electronic Theses and Dissertations

Effective weed control has long been recognized as critical for agricultural production, yet weeds remain a major constraint to production and economic return in many agroecosystems. Moreover, improvements in physical weed control are necessary to address increasing problems of herbicide resistance in weeds of grain and fiber crops and the high cost of hand weeding in vegetables. From tractor-mounted cultivation tools to autonomous weeders, weeding implements are affected by weeds, crops, soil conditions, and actuator effectiveness. In order to address these complex and often interacting factors concerning weed control, new and innovative tools must be designed and evaluated. Chapter one …


Farmer Engagement Through Mental Modeling: Opportunities For Climate Change Outreach, Ruth S, Clements May 2021

Farmer Engagement Through Mental Modeling: Opportunities For Climate Change Outreach, Ruth S, Clements

Electronic Theses and Dissertations

Climate change poses a challenge to farming systems worldwide. Effective adaptation and mitigation may be facilitated by outreach that is locally tailored and framed in terms of farmers’ perceptions and values. However, existing research suggests that farmers and those providing outreach may have different climate change perspectives, and there is little understanding of how farmers consider and prioritize climate change in relation to other aspects of their farming system. Furthermore, the diverse agricultural, economic, social, and environmental challenges farmers face require agricultural research and engagement efforts that can identify and adapt to farmers’ dynamic priorities and perceptions. Mental modeling is …


Genome-Wide Association Analysis Permits Characterization Of Stagonospora Nodorum Blotch (Snb) Resistance In Hard Winter Wheat, Rami Altameemi Jan 2021

Genome-Wide Association Analysis Permits Characterization Of Stagonospora Nodorum Blotch (Snb) Resistance In Hard Winter Wheat, Rami Altameemi

Electronic Theses and Dissertations

Stagonospora nodorum blotch (SNB) is an economically important wheat disease caused by the necrotrophic fungus Parastagonospora nodorum. SNB resistance in wheat is controlled by several quantitative trait loci (QTLs). Thus, the identifying of novel resistance/susceptibility QTLs is crucial for continuous improvement of the SNB resistance. Here, the hard winter wheat association mapping panel (HWWAMP) comprising accessions from breeding programs in the Great Plains region of the US, was evaluated for SNB resistance and necrotrophic effectors (NEs) sensitivity at the seedling stage. A genome-wide association study (GWAS) was performed to identify singlenucleotide polymorphism (SNP) markers associated with SNB resistance and …


Characterization Of The Rumen Bacterial Communities Of Bison Heifers Fed A Grass-Based Diet Vs A Grain-Based Free-Choice Diet, Anlly Miley Fresno Rueda Jan 2021

Characterization Of The Rumen Bacterial Communities Of Bison Heifers Fed A Grass-Based Diet Vs A Grain-Based Free-Choice Diet, Anlly Miley Fresno Rueda

Electronic Theses and Dissertations

A century ago, the North American grasslands and prairie ecosystems were dominated by bison. At least 30 million bison roamed the Great Plains when the first explorers arrived. By 1900, there were little over a thousand bison remained in the United States and Canada. Recovery efforts has been made since the 20th century to reestablish the herds and increase the bison population. Today, over 500,000 bison are distributed across North America, with more than 90% of the existing bison population under commercial production. Modern conservation strategies are made via the collaborative efforts of conservationist, producers, and researchers, resulting in increased …


Interrogating The Socio-Ethical Dilemmas Of Precision Agriculture Technologies, Ayorinde Ogunyiola Jan 2021

Interrogating The Socio-Ethical Dilemmas Of Precision Agriculture Technologies, Ayorinde Ogunyiola

Electronic Theses and Dissertations

Farming has moved into a digital age where data and information are available to farmers to make informed agronomic and financial on-farm decisions. The development of precision agriculture (PA), such as big data technologies and machine learning algorithms is transforming the agricultural food production system in diverse ways, economically, environmentally, and socially. Despite benefits afforded by PA to agricultural productivity and environmental sustainability, these technologies can raise unintended societal challenges that can also limit their adoption among farmers. PA is changing how farming is done, reconstructing farmers’ social identities, and influencing relationships between farmers, agronomists, and technology developers. This dissertation …


Exploring The Determinants Of Aspects Of Rotational Grazing In The U.S. Great Plains, Iftekhar Uddin Ahmed Chowdhury Jan 2021

Exploring The Determinants Of Aspects Of Rotational Grazing In The U.S. Great Plains, Iftekhar Uddin Ahmed Chowdhury

Electronic Theses and Dissertations

Pasture and rangeland make up about 45 percent of the agricultural land in the U.S. Great Plains and one of the most common form of mismanagement of this pasture is overgrazing. Which results in many detrimental effects on environment. Many practitioners endorsed Rotational grazing (RG) as an improved grazing management practice over season-long continuous grazing. The overall goal of the current study is to assess the certain aspects of using RG in the U.S. Great Plains. Using mail survey data of the of 874 beef cattle producers of North Dakota, South Dakota, and Texas, the study found that neighborhood practice, …


Management And Dietary Strategies To Mitigate Environmental Stressors In Northern Plains Cattle Feeding Systems, Warren Carl Rusche Jan 2021

Management And Dietary Strategies To Mitigate Environmental Stressors In Northern Plains Cattle Feeding Systems, Warren Carl Rusche

Electronic Theses and Dissertations

Three studies were undertaken to examine strategies to mitigate environmental stress faced by Northern Plains cattle feeders. In the first study, 46 feedlot managers from SD (n = 21), MN (n = 6), and NE (n = 19) were surveyed on use and perceptions of heat stress (HS) mitigation strategies. All respondents avoided cattle handling during heat stress events and incorporated some method of HS mitigation. Buildings or shades were perceived as the most successful strategy (60.9%) and were most commonly named as strategies managers would like to employ (63% for shades and 17.4% for buildings). Increasing dietary corn silage …


Influence Of Cover Crops On Water And Nutrient Cycles In South Dakota, Sam Ireland Jan 2021

Influence Of Cover Crops On Water And Nutrient Cycles In South Dakota, Sam Ireland

Electronic Theses and Dissertations

A major concern of farmers implementing cover crops into a crop rotation is a potential reduction in soil moisture and nutrients available for the following cash crop. If soil moisture or nutrients are limited, the following cash crop yield suffers. One option to conserve soil moisture is to terminate cover crops with herbicides prior to a killing freeze. The purpose of this study is to develop a better understanding of the impact of cover crops and termination timing to the water and nutrient cycles and furthermore, the agronomic impact to the following cash crop (corn). Field experiments were conducted in …


Assessing Dairy Farm Employees Health, Leyby Stephany Guifarro Rodriguez Jan 2021

Assessing Dairy Farm Employees Health, Leyby Stephany Guifarro Rodriguez

Electronic Theses and Dissertations

This Master thesis evaluates the impact of general health care and eating habits (Study 1), vision care (Study 2), and mental health status (Study 3) on Latino dairy farmworkers lifestyle and work performance in South Dakota. We hypothesized that the health status of dairy workers has a negative impact on the workers’ job performance. In study 1, data from a total of 70 participants were collected, using a face-to-face survey in Spanish, which allowed us to assess various topics and details related to employees’ daily routine tasks, eating habits, and general health status. Furthermore, recommendations to improve general health care …


Implications Of Broadleaf, Grass, And A Blend Of Broadleaf And Grass Cover Crops On Soil Health And Corn Production In South Dakota, Hunter Bielenberg Jan 2021

Implications Of Broadleaf, Grass, And A Blend Of Broadleaf And Grass Cover Crops On Soil Health And Corn Production In South Dakota, Hunter Bielenberg

Electronic Theses and Dissertations

Cover crops have recently gained attention in the U.S. Midwest because of their potential to increase soil organic matter and protect overall soil health. This study was conducted to determine the effects of different cover crop mixtures on soil health measurements and corn grain yield at increasing nitrogen (N) rates. Cover crops were planted in the fall after small grains harvest as a dominantly grass mixture, dominantly broadleaf mixture, or a 50/50 grass and broadleaf mixture with a no cover crop control. Soil and cover crop biomass samples were collected in the fall before winter cold termination and in the …


Soil Organic Carbon, Hydro-Physical Properties, Pore Structure And Greenhouse Gas Fluxes Under Integrated Crop-Livestock System, Jashanjeet Kaur Dhaliwal Jan 2021

Soil Organic Carbon, Hydro-Physical Properties, Pore Structure And Greenhouse Gas Fluxes Under Integrated Crop-Livestock System, Jashanjeet Kaur Dhaliwal

Electronic Theses and Dissertations

Integrated crop-livestock system (ICLS) can improve soil organic carbon (SOC), enhance soil hydro-physical properties, and mitigate greenhouse gas (GHG) emissions. The objectives of this study were to: (i) investigate the influence of grazing, cover crop (CC), and a combination of grazing and CC on labile soil carbon (C) and nitrogen (N) fractions and soil enzyme activity, (ii) assess the impacts of short-term (3-4 years) and long-term (>30 years) ICLS on SOC, bulk density, structural quality and water infiltration, (iii) evaluate soil pore structural properties such as porosity, number of pores, pore size, pore shape, fractal dimension, anisotropy and tortuosity …


Genome Wide Association Study On Kernel Size In Avena Sativa (Oats), Koryne Ann Carlson Jan 2021

Genome Wide Association Study On Kernel Size In Avena Sativa (Oats), Koryne Ann Carlson

Electronic Theses and Dissertations

Kernel size is a vital milling characteristic for Avena sativa L. (oats), with larger kernel size being desirable for milling facilities. This project evaluated the effect of genotype, environment, and their genotype by environment interaction (G by E) on kernel width, length, and area for a set of 27 oat cultivars grown at multiple locations in South Dakota over three years. Findings indicated significant differences among oat varieties, and that environment had a substantial effect on kernel size. However, we did not see a strong influence of genotype by environment interaction on kernel size. The lack of impact for genotype …


Intellectual Property Rights In The Seed Industry: Barriers To Sustainable Agriculture, Elena A. Filatova Jan 2021

Intellectual Property Rights In The Seed Industry: Barriers To Sustainable Agriculture, Elena A. Filatova

Electronic Theses and Dissertations

The dynamics of the dominant industrial agriculture system restrict the seed industry’s innovative landscape, leading to significant negative consequences including an exacerbation of environmental risks which threaten global food security. This thesis explores how exclusionary intellectual property rights (IPRs) in the context of the seed industry constrict innovation, evolutionary pathways, and opportunities for the implementation of sustainable agriculture methods. To overcome these barriers, the application of an open source framework to seed innovation, specifically through the platform of the Open Source Seed Initiative, is evaluated as a tool for enhancing innovative capacities in seed development while broadening the accessibility and …


Developing Whey Protein Encapsulated Probiotics And Evaluating Environmental Listeria Using Whole-Genome Sequencing, Shayanti Minj Jan 2021

Developing Whey Protein Encapsulated Probiotics And Evaluating Environmental Listeria Using Whole-Genome Sequencing, Shayanti Minj

Electronic Theses and Dissertations

In this study, a novel value-added dairy-based health formulation was developed using whey protein hydrolysate and probiotic organisms. In the first part of the study, different forms of whey proteins, concentrate WPC80, isolate WPI90, and hydrolysates WPH10, WPH15 and WPH20 were screened for bioactivities (antimicrobial, antioxidant, and antihypertensive activity). Hydrolysate WPH10, exhibiting the highest bioactivities was conjugated with maltodextrin. A batch of 2L conjugated solution was spray dried in a Niro drier with an inlet and outlet temperature of 200⁰C and 90⁰C, and alternatively, freeze dried at −80 °C under 50 mTorr vacuum. The bioactivities of the conjugated samples were …


School Gardening In America And A Survey Of South Dakota Schools, Aminah Hassoun Jan 2021

School Gardening In America And A Survey Of South Dakota Schools, Aminah Hassoun

Electronic Theses and Dissertations

School gardening has a longstanding history in American education, dating as far back as the mid-1800s. Despite fluctuations in popularity throughout the twentieth century, school gardens have grown into an established method for hands-on teaching. This paper builds upon a historical framework of school gardening in American public education with particular focus on the connections between school gardens and agricultural education. This study offers a descriptive portrait of contemporary K-12 school gardens in South Dakota. Schools across the state were surveyed about their gardens to gain a better understanding of garden-based teaching in practice both in general education and agricultural …


Studies On Genetic Characterization Of Agronomic Traits And Disease Resistance In Bread Wheat, Jyotirmoy Halder Jan 2021

Studies On Genetic Characterization Of Agronomic Traits And Disease Resistance In Bread Wheat, Jyotirmoy Halder

Electronic Theses and Dissertations

A steady increase in wheat yield is vital to feed the continuously rising world population. Systematic exploitation of wheat germplasm and a better understanding of the underlying genetic control could be pivotal in accelerating the genetic gain for yield and disease management. Various modern techniques such as genome-wide association study (GWAS), genomic selection (GS), fine mapping, and cloning can expedite wheat improvement and broaden our understanding of the complex wheat genome. In the first objective of this study, we evaluated the Watkins core set of 121 landrace cultivars (LCs) to identify novel sources of resistance against the tan spot, Stagonospora …


Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai Jan 2021

Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai

Electronic Theses and Dissertations

Integrated crop-livestock systems (ICLs), if managed properly, have the potential for enhancing crop production and economics. Cover crops in ICL can be grazed to provide feed for livestock and improve nutrient recycling. This dissertation focused on assessing the impacts of ICL on crop yield and economics using field and modeling studies. Specific objectives of this dissertation are: (i) evaluating the impacts of the ICL on crop yield, and economic performance in a 3-yr oat (Avena sativa L.) – maize (Zea mays L.) – soybean (Glycine max (L.) Merr.) rotation, (ii) assessing the impacts of the ICL on maize biomass accumulation, …


Genetically Modified Corn Diffusion And Biofuel Usage: Impacts On Corn Belt Cropping Systems Changes, Kenneth Annan Jan 2021

Genetically Modified Corn Diffusion And Biofuel Usage: Impacts On Corn Belt Cropping Systems Changes, Kenneth Annan

Electronic Theses and Dissertations

The adoption of genetically modified (GM) crops, the rise of ethanol production that produced an additional derived demand for corn, and the increasingly prominent position of corn and soybeans in crop rotations embody major changes in U.S. agriculture during the past decades. This study investigates the linkages among these developments in two ways. First, we look at how biotechnology and biofuels have influenced cropping system changes in the Corn Belt region of the United States, using state-level data from 2000 to 2019. Second, we investigate the determinants of corn acreage intensification levels and heterogeneity at the state level using data …