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

Agronomy and Crop Sciences Commons

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

Electronic Theses and Dissertations

Discipline
Institution
Keyword
Publication Year

Articles 61 - 90 of 180

Full-Text Articles in Agronomy and Crop Sciences

Phosphorus Use And Management Based On Fertilizer Placement, Rate Of Application, And Soil Biota In No-Till Situations, Brennan Alexander Bingham Lewis Jan 2022

Phosphorus Use And Management Based On Fertilizer Placement, Rate Of Application, And Soil Biota In No-Till Situations, Brennan Alexander Bingham Lewis

Electronic Theses and Dissertations

Phosphorus (P) pollution has become a concern among multiple scientific organizations as it leads to eutrophication, an algal bloom that depletes lacustrine and marine ecosystems of native species. Multiple strategies can be implemented to reduce phosphorus loss from agriculture fields, which is often implicated as a cause of eutrophication. Soil phosphorus chemistry results in phosphate fertilizers absorbing to clay minerals over time. Soil phosphorus is lost from agricultural fields primarily through wind and water erosion. No-till practices prevent soil erosion, which reduces the phosphorus from loading into waterways. Fertilizer placement affects phosphorus loss. Surface application of phosphorus fertilizers increases the …


Effect Of Essential Oils In The Control Of Fungal Diseases In Small Grains, Esneider Mahecha Bojaca Jan 2022

Effect Of Essential Oils In The Control Of Fungal Diseases In Small Grains, Esneider Mahecha Bojaca

Electronic Theses and Dissertations

Spring wheat (Triticum aestivum L.) and oats (Avena sativa L.) are important crops due to their high consumption in our daily diet worldwide. They are the main food of consumption per capita due to the high amino-acid content as well of vitamins. However, grain production is limited due to the negative impact of the diseases that cause significant yield loss. Diseases in oats, such as crown rust caused by Puccinia coronata f. sp. avenae (Pca), and in wheat such as Fusarium head blight (FHB) caused by the fungus Fusarium graminearum. Foliar diseases such as tan spot incited by the fungi …


Phomopsis Stem Canker Of Sunflower (Helianthus Annuus L.): Etiology And Epidemiological Conditions Affecting Endophytic Population Of Diaporthe Spp., And Fungicide Efficacy, Nabin Kumar Dangal Jan 2022

Phomopsis Stem Canker Of Sunflower (Helianthus Annuus L.): Etiology And Epidemiological Conditions Affecting Endophytic Population Of Diaporthe Spp., And Fungicide Efficacy, Nabin Kumar Dangal

Electronic Theses and Dissertations

Phomopsis stem canker (PSC), caused by species of Diaporthe, is a major disease of sunflower (Helianthus annuus L.) in the U.S., which can cause yield loss over 40%. The disease prevalence increased since 2010 in the major sunflower producing U.S. states of Nebraska, Minnesota, North Dakota, and South Dakota. Previous studies on the use of foliar fungicides in managing Phomopsis stem canker indicated mixed results on their efficacy in disease reduction and yield gain. Additionally, we do not have sufficient information on asymptomatic colonization by endophytic Diaporthe on sunflower tissue and how foliar fungicide and weather parameters affect the prevalence …


Study Of Root System Architectural Traits Of Oat And Response To Endophyte Inoculation And Drought Stress, Krishna Ghimire Jan 2022

Study Of Root System Architectural Traits Of Oat And Response To Endophyte Inoculation And Drought Stress, Krishna Ghimire

Electronic Theses and Dissertations

Oat is an important cereal crop grown worldwide. Oats have the potential to contribute to human health due to their unique nutritional attributes. Developing oat cultivars with efficient root systems able to extract heterogeneously distributed soil resources can help maintain yield under drought conditions and in nutrient poor soil. Various root traits determine the soil volume that is explored by the root system for resource acquisition. Knowledge about the genetic control of oat root traits and response to biotic and abiotic environmental factors is lacking. Identifying quantitative trait loci associated with root traits and understanding the response of roots to …


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 …


How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross Dec 2021

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …


The Effects Of Gibberellic Acid, Smoke Water, And Cold Stratification On The Germination Of Native Perennial Seed, Zyreasha Tippins Aug 2021

The Effects Of Gibberellic Acid, Smoke Water, And Cold Stratification On The Germination Of Native Perennial Seed, Zyreasha Tippins

Electronic Theses and Dissertations

In this study, I evaluated the germination rates of twenty native plant species and their response to cold stratification as well as four chemical solution treatments—water (control), gibberellic acid, smoke water, and gibberellic acid with smoke water. Seeds were evaluated and counted twice a week. Of the twenty evaluated species, sixteen had germination rates over 3% or 1 seed out of 30. Stratification increased germination by 54% when compared to the control. For chemical treatments, gibberellic acid and gibberellic acid with smoke water were significantly different from the control and increased germination by an average of 47% and 48%, respectively. …


Studying Morphological, Physiological, And Molecular Regulation Of Stomatal Conductance And Its Relationship To Water Use Efficiency In Alfalfa, Surbhi Gupta Jan 2021

Studying Morphological, Physiological, And Molecular Regulation Of Stomatal Conductance And Its Relationship To Water Use Efficiency In Alfalfa, Surbhi Gupta

Electronic Theses and Dissertations

Alfalfa (Medicago sativa), being a leguminous, highly fibrous, and proteinaceous plant has always been one of the top choices for the forage production but has high cost of irrigation in many dry and warm areas such as California and Arizona. Thus, a reduction of irrigation by using the higher water use efficiency (WUE) varieties can help the growers in reducing the cost and is critical for sustainable agriculture production. WUE is closely related to water loss through transpiring stomata. A study in our lab reported that Riverside (RS) an alfalfa genotype that has naturized in the national grassland in South …


A Biocontrol Pesticide Derived From Mycovirus-Infected Sclerotinia Sclerotiorum Can Induce Plant Resistance, Connor Pedersen Jan 2021

A Biocontrol Pesticide Derived From Mycovirus-Infected Sclerotinia Sclerotiorum Can Induce Plant Resistance, Connor Pedersen

Electronic Theses and Dissertations

Soybean leaf-associated gemycircularvirus-1 (SlaGemV-1) is a novel mycovirus discovered through the metagenomic sequencing of soybean leaves which is capable of inducing hypovirulence in the highly pathogenic fungus Sclerotinia sclerotiorum. RNASeq analysis techniques were used to determine the transcriptional changes caused by the infection of virus in S. sclerotiorum, as well as the transcriptional changes in Glycine max caused by the colonization of hypovirulent, SlaGemV-1-infected S. sclerotiorum. RNASeq results indicate that viral infection leading to hypovirulence may attenuate expression of genes relating to cell wall synthesis, microtubule formation, and metabolism of steroids and natural antibiotics. Cytochrome P450-related genes, kinesin domain genes, …


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 …


Evaluation Of Biotype 4 Aphis Glycines (Hemiptera: Aphididae) Induced Susceptibility On Soybean And Soja, Jakob David Hicks Jan 2021

Evaluation Of Biotype 4 Aphis Glycines (Hemiptera: Aphididae) Induced Susceptibility On Soybean And Soja, Jakob David Hicks

Electronic Theses and Dissertations

Soybean aphids have been a significant pest of soybeans in North America since 2000. Before 2000, soybeans did not face significant insect pest pressure from any arthropods with piercing-sucking mouthparts. It is estimated that economic damage from soybean aphids range from $1billion to $4.7 billion annually. Research efforts focused on the identification of host plant resistance genes in soybean and discovered many resistant to Aphis glycines genes (i.e., Rag genes) in soybean. However, the adoption of commercially released Rag soybean cultivars has been limited. The prospect of management with Rag genes was further complicated by the identification of three virulent …


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 …


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 …


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 …


Evaluating Canola Genotypes For Growth And Yield Under Different Environmental Conditions In South Dakota, Unius Arinaitwe Jan 2021

Evaluating Canola Genotypes For Growth And Yield Under Different Environmental Conditions In South Dakota, Unius Arinaitwe

Electronic Theses and Dissertations

Canola (Brassica napus L) and carinata (Brassica carinata A. Braun) are potential oilseed crops for diversifying cropping systems and expanding into marginal lands impacted by saline and sodic soils in South Dakota (SD). However, genotypes that are high yielding, with high agronomic adaptability and stability over diverse environments, and salt tolerant have not been selected. One field experiment was conducted at two environments (Brookings - eastern SD and Pierre - western SD) from 2019 to 2020 to evaluate genotypes for growth and yield stability. Three greenhouse experiments were conducted to evaluate genotypes for salt tolerance in …


Auxin-Based Herbicide Program And Rhizobia Application For Weed Control And Nodulation Potential In Auxin Tolerant Soybean, Joy Amajioyi Jan 2021

Auxin-Based Herbicide Program And Rhizobia Application For Weed Control And Nodulation Potential In Auxin Tolerant Soybean, Joy Amajioyi

Electronic Theses and Dissertations

Foliar-applied Bradyrhizobia to V4 soybean has been reported to increase yield up to 5%. However, a stand-alone product application may not be practical. Applying with other treatments such as post-emergence herbicide application may be economical but herbicide and/or additives may be deleterious to rhizobial growth. A laboratory study investigated the impact of herbicides (glyphosate and dicamba), additives (an oil to improve absorption and spreading; and AMS used to overcome hard water impacts on glyphosate), and herbicide + additives on bacterial growth. Optical density (OD) measurements at the wavelength of 650 nm assessed solution turbidity, a surrogate measure of bacterial growth. …


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 …


The Role Of The Auxin Biosynthesis And Signaling In Soybean Root Nodule Development, Mucahid Bozkus Jan 2021

The Role Of The Auxin Biosynthesis And Signaling In Soybean Root Nodule Development, Mucahid Bozkus

Electronic Theses and Dissertations

Nitrogen(N) is one of the most important plant nutrients for plant growth and yield, however, its abundance in the soil is not sufficient for profitable crop production. The use of chemical fertilizers helps address soil N deficiency in agriculture. However, due to the environmental pollution resulting from excessive use of fertilizers, alternative forms of N for agriculture are a necessity. Leguminous plants such as soybean (Glycine max) form a symbiotic association with N-fixing rhizobia to meet their N demands. Legume-rhizobia symbiosis results in the formation of unique structures called nodules where rhizobia convert atmospheric nitrogen into plant usable forms, thus …


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, …


Determining The Effects Of Plant Extracts And Saltro Nematicide On Hatching, Mortality And Reproduction Of The Soybean Cyst Nematode (Heterodera Glycines), Bishnu Prasad Dhital Jan 2020

Determining The Effects Of Plant Extracts And Saltro Nematicide On Hatching, Mortality And Reproduction Of The Soybean Cyst Nematode (Heterodera Glycines), Bishnu Prasad Dhital

Electronic Theses and Dissertations

Soybean cyst nematode (SCN) is a microscopic worm that infects and feeds from the soybean roots, hence robbing the plant of nutrients, and entry wounds may facilitate other pathogens to infect the roots. Current SCN management practices include cultural, chemical, and biological methods. Cultural practices such as, crop rotation with non-host and different tillage practices are not efficient due to the persistent nature of SCN in the soil. Chemical nematicides, though effective, can be expensive, and some are not environmentally sound. SCN resistant soybean varieties are mainly derived from one source, PI 88788 and SCN population have already evolved to …


Crop Rotations, Tillage And Cover Crops Influences On Soil Health, Greenhouse Gas Emissions And Farm Profitability, Jasdeep Singh Jan 2020

Crop Rotations, Tillage And Cover Crops Influences On Soil Health, Greenhouse Gas Emissions And Farm Profitability, Jasdeep Singh

Electronic Theses and Dissertations

This study assessed the effects of three levels of crop rotation: [2-yr; corn (Zea mays L.)- soybean (Glycine max L.), 3-yr; corn-soybean-oat (Avena sativa L.) or 4-yr; cornsoybean- oat-winter wheat (Triticum aestivum L.)], two tillage [conventional-till (CT) and no-till (NT)], and two winter cover cropping systems [cover crop (CC) or fallow control (NC)] on soil biochemical and physical properties, greenhouse gas emissions (GHG), microbial community composition, crop yield and farm profitability under silty clay loam soil of south eastern South Dakota. Experimental design was a randomized complete block design in a split-split plot treatment arrangement with four replications. Rotations, tillage …


Development Of A Near Infrared Reflectance Spectroscopy (Nirs) Platform For Rapid Wheat Quality Analysis, Lily Schimke Jan 2020

Development Of A Near Infrared Reflectance Spectroscopy (Nirs) Platform For Rapid Wheat Quality Analysis, Lily Schimke

Electronic Theses and Dissertations

Wheat is a valuable cereal grain in terms of its growability, versatility, and multifunctional nutritional components. Research into the genetic characteristics and growing conditions of the grain is advantageous to wheat breeders, farmers, food scientists, food processors, and consumers. Optimizing the quality of the wheat grain is important to yielding a crop with the most desirable traits. Analytically obtaining data on the quality attributes of wheat is a lengthy and resource intensive process. Near infrared reflectance spectroscopy (NIRS) technology is rapid, cost-effective, and a powerful analytical tool that can be harnessed to create predictive calibrations for estimations of wheat parameters. …


Plant Microbial Interactions In Wheat: Fusarium Head Blight And Arbuscular Mycorrhizal Fungi, Yaqoob Rashid Thurston Jan 2020

Plant Microbial Interactions In Wheat: Fusarium Head Blight And Arbuscular Mycorrhizal Fungi, Yaqoob Rashid Thurston

Electronic Theses and Dissertations

Plant microbial interactions consist of the many relationships between plants and microbes which involve studies that observe the biology and molecular genetics of pathological, symbiotic, and associative interactions. Worldwide studies involving these interactions are scarcely available in wheat (Triticum aestivum L.). In South Dakota (SD), wheat research is a major platform used to understand the nature and consequences of these interactions. Specifically, our research efforts here at South Dakota State University (SDSU) concentrate on two different, but valuable, interactions in wheat: the fungal pathogen that causes fusarium head blight (FHB) and the symbiotic interaction of arbuscular mycorrhizae fungi (AMF) with …


Predicting Farinograph Stability Of Wheat Flour With Mixograph And Glutomatic Tests, Brooke Shumate Jan 2020

Predicting Farinograph Stability Of Wheat Flour With Mixograph And Glutomatic Tests, Brooke Shumate

Electronic Theses and Dissertations

Hard red spring wheat (Triticum aestivum L.; HRSW) flour is typically used to produce wheat-based foods where dough strength is a key quality component. Maintaining acceptable levels of dough strength is an important goal in the development of new HRSW cultivars. In a commercial setting, dough strength is often measured as Farinograph stability, though due to various resource constraints, stability is often predicted in breeding programs via other methods like the Mixograph. The objective of this research was to combine Glutomatic with Mixograph data to determine whether Farinograph stability predictions might be improved over the use of Mixograph data …


Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil Jan 2020

Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil

Electronic Theses and Dissertations

Glyceollin is a secondary metabolite produced under stress conditions by soybean to act as a plant defender to pathogen attack. The antimicrobial nature of glyceollin makes it a promising natural alternative to antibiotics if incorporated into livestock feed. However, production of glyceollin is highly variable, dependent on soybean variety, and fungal elicitor used as inoculum. Our study compares two fungal spore elicitors, Trichoderma reesei and Aspergillus sojae on soybeans of diverse maturity level, and fungal susceptibility to determine highest glyceollin titer. Spore inoculation with T. reesei elicited highest glyceollin titers of 2.42±0.20 mg/g at 120 h, while A. sojae elicited …


Crop Rotations And Cover Crops Influences On Soil Biochemical Properties, Root Characteristics And Economic Performance, Hanxiao Feng Jan 2020

Crop Rotations And Cover Crops Influences On Soil Biochemical Properties, Root Characteristics And Economic Performance, Hanxiao Feng

Electronic Theses and Dissertations

Introducing cover crops (CC) and increasing crop diversity in agricultural systems are beneficial in improving the soil health and crop production. However, limited research has been conducted that focuses the influence of CC and crop rotation on soil ecosystem, root growth and development, crop production, and economic returns. The objectives of this study were to (i) assess the impacts of CC management on soil enzyme activities and soil microbial community structure changes, (ii) evaluate the crop rotation management on crop root growth and development, nutrient storage in crop grain and biomass, and crop yield, and (iii) investigate the crop rotation …


Soil Physical And Hydrological Properties, And Greenhouse Gas Emissions Under Integrated Crop-Livestock Agroecosystems, Navdeep Singh Jan 2020

Soil Physical And Hydrological Properties, And Greenhouse Gas Emissions Under Integrated Crop-Livestock Agroecosystems, Navdeep Singh

Electronic Theses and Dissertations

Cover crops (CCs) and grazing play a critical role in successful implementation of the integrated crop-livestock system (ICLS) because they can have a direct impact on soils and greenhouse gas emissions. The objectives of this study were to (i) evaluate the short-term impacts of CCs [grass dominated cover crops (GdC) and legume dominated cover crops (LdC)] and grazed CCs and corn (Zea mays L.) residue under oat (Avena sativa L.)–CC–corn rotation on soil physical and hydrological properties; (ii) quantify the architecture of soil pores using X-ray computed tomography (CT) for soils managed under long-term ICLS, native grazed pasture and corn-soybean …


Cover Crop Nutrient Cycling On Western South Dakota Croplands, Justin Brown Jan 2020

Cover Crop Nutrient Cycling On Western South Dakota Croplands, Justin Brown

Electronic Theses and Dissertations

Cover crops (CC) are widely gaining attention and implementation by producers. Much of this is due to the positive influence that CCs can have. Increases in crop yield, biological diversity, water infiltration, and nutrient cycling have been observed as well as reductions in wind and water erosion. The semiarid climate of western South Dakota presents a challenge in the use of CCs with the limited rainfall received. Little research has been done in this area on the effects of CCs on cropland. Three studies were performed to evaluate CCs on nutrient cycling, forage production and crop yield. First, is an …


Utilizing Rhizospheric And Bacterial Endophytes For Use As Potential Bio-Fertilizers For Sustainable Agricultural Production, Vincent Peta Jan 2020

Utilizing Rhizospheric And Bacterial Endophytes For Use As Potential Bio-Fertilizers For Sustainable Agricultural Production, Vincent Peta

Electronic Theses and Dissertations

Brassica carinata crop production offers an exciting alternative approach to the energy crisis when looking at novel ways to power our motor vehicles. Bacterial endophytes, while residing in host-plant tissues, offer a wide array of plant growth promotion benefits such as nitrogen fixation to impart nitrogen (N) nutrition, phosphate (P) solubilization to make soil-bound phosphate more mobile in soil for plant uptake, can suppress pathogenic microbes such as fungus and produce plant growth hormones to offset stress incurred by the plant. Previous literature has shown that there is large interest in studying endophytes from economically important crops such as wheat, …