Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Arkansas, Fayetteville (296)
- South Dakota State University (145)
- Utah State University (83)
- University of Kentucky (79)
- Universidad de La Salle (59)
-
- University of Tennessee, Knoxville (56)
- Louisiana State University (42)
- Brigham Young University (34)
- Purdue University (34)
- California Polytechnic State University, San Luis Obispo (29)
- Clemson University (22)
- Mississippi State University (19)
- The University of Maine (12)
- Eastern Illinois University (11)
- Missouri State University (10)
- Western University (7)
- Illinois State University (6)
- University of Vermont (6)
- Old Dominion University (4)
- Stephen F. Austin State University (4)
- West Virginia University (4)
- Claremont Colleges (3)
- University of New Mexico (3)
- Bard College (2)
- James Madison University (2)
- Murray State University (2)
- University of Northern Iowa (2)
- American University in Cairo (1)
- Bellarmine University (1)
- Cal Poly Humboldt (1)
- Keyword
-
- Biological sciences (102)
- Soybean (68)
- Rice (65)
- Nitrogen (35)
- Wheat (31)
-
- Corn (29)
- Cover crops (25)
- Cotton (24)
- Irrigation (24)
- Drought (22)
- Yield (19)
- Arkansas (17)
- Agriculture (16)
- Cover crop (16)
- Alfalfa (15)
- Bolivia (15)
- Fertilizer (15)
- Inheritance (15)
- Resistance (15)
- Herbicide (14)
- Soil (14)
- Maize (12)
- Palmer amaranth (12)
- Soybeans (12)
- Agronomy (11)
- GWAS (11)
- QTL (11)
- Soil health (11)
- Barnyardgrass (10)
- Implementación (10)
- Publication Year
- Publication
-
- Graduate Theses and Dissertations (281)
- Electronic Theses and Dissertations (164)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (81)
- Theses and Dissertations--Plant and Soil Sciences (63)
- Theses and Dissertations (60)
-
- Masters Theses (53)
- Ingeniería Agronómica (40)
- Open Access Theses (24)
- LSU Master's Theses (22)
- LSU Doctoral Dissertations (20)
- Master's Theses (20)
- Zootecnia (17)
- Doctoral Dissertations (13)
- All Theses (12)
- All Dissertations (10)
- MSU Graduate Theses (10)
- Open Access Dissertations (10)
- Crop, Soil and Environmental Sciences Undergraduate Honors Theses (8)
- Electronic Thesis and Dissertation Repository (7)
- University of Kentucky Doctoral Dissertations (7)
- University of Kentucky Master's Theses (7)
- Graduate College Dissertations and Theses (6)
- Agricultural Education and Communication (5)
- Biological Sciences Theses & Dissertations (4)
- Graduate Theses, Dissertations, and Problem Reports (4)
- Bard Center for Environmental Policy (2)
- BioResource and Agricultural Engineering (2)
- Biological and Agricultural Engineering Undergraduate Honors Theses (2)
- Biology ETDs (2)
- Biología (2)
Articles 1 - 30 of 1003
Full-Text Articles in Entire DC Network
Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe
Evaluation Of A Capsule Suspension Formulation Of S-Metolachlor For Use In Fenclorim-Treated Rice And Wheat, Samuel Charles Noe
Graduate Theses and Dissertations
The continued evolution of herbicide resistance is one of the primary concerns facing Arkansas growers today. Problematic weeds such as barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] have evolved resistance to some of the most used herbicides in rice (Oryza sativa L.) and wheat (Triticum aestivum L.). To counteract this resistance, alternative herbicide sites of action should be explored. S-metolachlor is a very-long-chain fatty acid (VLCFA)-inhibiting herbicide [Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 15] commonly used in U.S. row crops to control grasses and small-seeded broadleaf weeds. …
Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn
Use Of Herbicides Coated Onto Fertilizer And Applied Over-The-Top Of Cotton, Summer Linn
Graduate Theses and Dissertations
Cotton (Gossypium hirsutum L.) production faces numerous challenges, many related to weed management. A herbicide application method that focuses on combing resources that producers already have access to, such as herbicide-coated fertilizers, could be a practical approach for addressing late-season control of Palmer amaranth (Amaranthus palmeri S. Wats) and other problematic weed species. Two main factors would potentially impact the efficiency of utilizing this method: cotton tolerance to the application and weed control provided by the herbicide-coated fertilizers. Some considerations could affect the efficacy of these applications, such as when the treatments are applied and when they are activated by …
Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard
Evaluation Of A Diflufenican:Metribuzin:Flufenacet Premixture For Soybean Tolerance And Weed Control, Matthew Coleman Woolard
Graduate Theses and Dissertations
Palmer amaranth [Amaranthus palmeri (S.) Wats.] and waterhemp [Amaranthus tuberculatus (Moq.) Sauer] ranks among the most troublesome weeds of soybean [Glycine max (L.) Merr.], having evolved resistance to multiple herbicide sites of action. Bayer CropScience has announced its intentions to launch Convintro™ brand herbicides, one being a three-way premixture for use preplant until 3 d after planting in soybean. The premixture will include diflufenican (WSSA Group 12), metribuzin (WSSA Group 5), and flufenacet (WSSA Group 15) (DFF-containing premixture), adding a new site of action for use in soybean throughout the United States. In 2022 and 2023, field trials were conducted …
Bee Friendly Beef: Integrating Pollinator-Friendly Native Forbs Into Native Grass Pastures, Jessica Prigge
Bee Friendly Beef: Integrating Pollinator-Friendly Native Forbs Into Native Grass Pastures, Jessica Prigge
Doctoral Dissertations
Native pastures present an opportunity to diversify that can support an array of animals, including pollinators and livestock. A variety of insect pollinators, important for both crop production and wild fauna persistence, are in population decline and benefit from native floral resources to sustain across the landscape. The goals of our work were to document blooming and forage characteristics of a variety of native forbs and to determine their establishment, persistence, and forage characteristics under different grazing rest regimens. We also sought to measure animal productivity between grass and diversified pastures under continuous stocking. Forbs established and persisted differently based …
The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson
The Effects Of Cover Crop Adoption On Yield Distributions Under Extreme Drought, Emory Johnson
Graduate Theses and Dissertations
Increased frequency and severity of extreme weather events due to climate change negatively impact agriculture output. Of particular concern is the adverse impact of droughts on corn and soybean yields, as these crops represent a significant portion of cash crop receipts in the United States. Cover crops are one practice that has gained attention due to their agronomic benefits and their potential to reduce downside production risk for producers. This study focuses on the impact of cover crop adoption on corn and soybean yields during drought conditions. We use cover crop adoption data from the Operational Tillage Information System, RMA …
Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King
Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King
Graduate Theses and Dissertations
Palmer amaranth (Amaranthus palmeri S. Wats) is the most troublesome and problematic weed in most mid-southern U.S. row crop production systems. With the increased adoption of furrow-irrigated rice (Oryza sativa L.), there is a greater occurrence of Palmer amaranth due to sustained moist conditions allowing continual emergence of the weed throughout the growing season. Palmer amaranth has previously been shown to negatively affect crop yields when left unmanaged. Therefore, there is a high potential for rice yield loss due to the weed’s ability to emerge over an extended period and interfere with crop development. However, there is a lack of …
Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda
Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda
Graduate Theses and Dissertations
Climate smart agriculture (CSA) practiced has been promoted in Zambia since the 1980s to address the declining crop productivity due to increased occurrence of drought or dry spells caused by climate change. Despite considerable research indicating that CSA practices have many potential benefits such as increased yield and income, the adoption rate in southern Africa is still low especially where farmers have stable off farm income. This might be because most of the research and promotion has been directed to the main staple crop maize and other context specific impacts related to agroecological and socioeconomic heterogeneity. In this study we …
Detection Of Fungicide Resistance In Population Of Corynespora Cassiicola From Arkansas Soybean And Cotton Fields, Rafael Zaia
Detection Of Fungicide Resistance In Population Of Corynespora Cassiicola From Arkansas Soybean And Cotton Fields, Rafael Zaia
Graduate Theses and Dissertations
Target spot, caused by the fungus Corynespora cassiicola, has reemerged since 2016 as an economically important disease on soybean and cotton across the Southern U.S. The quinone outside inhibitors (QoI) and succinate dehydrogenase inhibitors (SDHI) are important fungicide classes used to control foliar diseases in soybean and cotton. The efficacy of these products is rapidly decreasing, impacting control, and causing significant yield losses. The overall objective of this study was to determine the risks associated with chemical control by screening fungicide sensitivity, evaluating target site alterations, and analysis of disease control efficacy and yield response of fungicides for soybean in …
Digital Agriculture Applications In Maize Nutrient Management And Soybean Crop Stands Assessment, Bhawana Acharya
Digital Agriculture Applications In Maize Nutrient Management And Soybean Crop Stands Assessment, Bhawana Acharya
LSU Master's Theses
High soil moisture from frequent excessive precipitation can reduce maize (Zea mays L.) yield and increase nitrogen (N) loss. Early-stage soybeans (Glycine max) are also susceptible to damage under these conditions. Traditional methods for assessing N status in maize and plant stands in soybean are labor-intensive and time-consuming. In this study, UAV remote sensing was used to assess maize N status under different N rates and excessive soil moisture. For soybeans, we compared a blob detection method with the YOLOv8 model to estimate plant density using ground images from a handheld camera. Additionally, YOLOv8 performance was evaluated …
Evaluating Past Progress And Assessing Prediction Breeding Strategies For Sustained Genetic Gains In The Louisiana Sugarcane Variety Development Program, Brayden A. Blanchard
Evaluating Past Progress And Assessing Prediction Breeding Strategies For Sustained Genetic Gains In The Louisiana Sugarcane Variety Development Program, Brayden A. Blanchard
LSU Doctoral Dissertations
The aim of this dissertation is to outline important considerations for the Louisiana Sugarcane Variety Development Program (LSVDP) as it pertains to historical progress, impact, goal setting, and new strategies for continued genetic gains. Industry progress was evaluated with robust regression models to quantify rates of productivity gains. Over the last 50 years, statistically significant productivity gains were identified in sucrose content (45%), cane yield (32.2%), and sugar yield (93%) while pairwise comparisons of decades showed that progress was incremental rather than rapid and sustained once achieved. The decade from 1990-1999 was identified as the only decade with a significant …
Identification Of Downy Mildew Resistance In Wild Arugula And Evaluation Of Downy Mildew Causing Pathogens And Management Practices, Reilly B. Blair
Identification Of Downy Mildew Resistance In Wild Arugula And Evaluation Of Downy Mildew Causing Pathogens And Management Practices, Reilly B. Blair
Master's Theses
Downy mildew has been a potentially devastating constraint to crop production within the Brassicaceae family worldwide (CABI, 2022) and on the Central Coast of California (Smukler, et al, 2008; Koike, et al. 2007). Downy mildew is a foliar disease, caused by the pathogens in the Hyaloperonospora genus on plants within the Brassicaceae family (Goker, et al, 2009). Downy mildew is a disease that is common in region of the world with Coastal climates that provide humidity and moderate temperatures (Sarahan, et al, 2017). Crops within the Brassicaceae family maintain a predominant role in agricultural systems worldwide (Cartea, et al, 2011) …
Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons
Assessing The Use Of Regenerative Agriculture In California Almonds As Climate Change Resilience, Skyler M. Seamons
Master's Projects and Capstones
The agriculture sector is responsible for 10% of the United States’ greenhouse gas emissions. In turn, anthropogenic climate change threatens crops. With its Mediterranean climate, California is the country’s largest agricultural-producing state. Many California crops are at risk due to increasing temperatures and changed precipitation patterns. This paper investigates regenerative farming techniques as a tool to protect California crops from a changing climate. Almonds are used as a case study to analyze the soil management practices, finances, and policies underlying regenerative agriculture in California. A literature review and comparative analysis are used to compare regenerative and conventional soil management practices …
Agroecology And Soil Stewardship: Values And Techniques Of Smallholder Farmers In Bernalillo County, Stephanie Olivas
Agroecology And Soil Stewardship: Values And Techniques Of Smallholder Farmers In Bernalillo County, Stephanie Olivas
Geography ETDs
Agrarian movements around the world use agroecology to build sovereignty and steward dynamic ecosystems. Research has shown that agroecological farmers steward more resilient crops, more resilient soil biomes, and greater biodiversity than conventional agriculture. GIS and remote sensing offer many tools to detect the impacts of these farmers on the environment, but it is less clear how such technologies fit into agroecological goals. This study asks: what values, experiences and knowledge do smallholder producers in Bernalillo County embody in their soil stewardship practices? Also, what experience or knowledge do smallholder producers in Bernalillo County have about remote sensing, and would …
Irrigation Strategies And Precipitation Scenario Effects On Wild Blueberries, Ali Bello
Irrigation Strategies And Precipitation Scenario Effects On Wild Blueberries, Ali Bello
Electronic Theses and Dissertations
Wild blueberries (Vaccinium angustifolium Ait. and V. myrtilloides Mitchx.) are now under increasing variations in climate conditions (Chen et al., 2022; Fernandez et al., 2020; Tasnim et al., 2021). High temperature and changes in rainfall patterns associated with climate change have direct effects on soil moisture regimes, and therefore wild blueberry crops. Over the last century, climate change in Maine (U.S.A) has been characterized by less frequent and more intense precipitation and warming temperatures. Extreme rainfall events are increasingly affecting the structure and functions of wild blueberries. Changes in precipitation patterns are influencing plant growth, physiology and edaphic conditions of …
Xyway Lfr@Fmc Fungicide: Improving Corn (Zea Mays L.) Water Use Efficiency And Productivity Under Water-Deficit Stress And Dryland Conditions, Isha Poudel
Doctoral Dissertations
Triazole fungicide has the ability to protect crops from varying water stresses. Xyway LFR@FMC is a triazole, at-plant fungicide and has been observed to improve plant performance under limited water conditions. A greenhouse study was conducted to assess the potential of Xyway LFR@FMC in altering the ability of corn plants to control transpiration rates under water deficit-stress (DS) conditions. Greenhouse grown plants were treated with Xyway LFR@FMC at 0.56, 0.77, 1.11,1.26 L ha-1. Plants treated with 1.11 L ha-1 reduced the amount of water loss in response to DS and had the highest fraction …
Yield And Nutritive Quality Of Fresh And Ensiled Reduced Lignin Alfalfa In Monoculture And Diculture With Novel Tall Fescue, Morgan Boss
All Theses
The objectives of this research were to: (1) evaluate the yield, nutritional value, and digestibility of fresh and ensiled reduced lignin alfalfa (RLA; Medicago sativa L.) in monoculture and when mixed with novel endophyte-infected tall fescue (F; Festuca arundinacea) in comparison to a conventional alfalfa (CA) cultivar; and (2) evaluate ensiled samples under varying DM concentrations; with or without inoculant. A trial was prepared as a randomized complete block design with 4 replicates per treatment. Treatments included reduced lignin alfalfa (RLA), conventional alfalfa (CA) and tall fescue (F) plots as well as RLA/F and CA/F plots. Plots were harvested on …
Impact Of Early-Season Postemergence Co-Applications Of Foliar And Residual Herbicides On Crop Injury, Growth, And Yield In 2,4-D- And Dicamba-Tolerant Cotton (Gossypium Hirsutum L.), Logan N. Vallee
LSU Master's Theses
Studies were conducted in 2021 through 2023 at the LSU AgCenter Dean Lee Research and Extension Center near Alexandria, LA to determine the sensitivity of 2,4-D- or dicamba- tolerant cotton (Gossypium hirsutum L.) to an early season application of a Group 15 and foliar-only herbicides. Both studies were randomized complete block designs with a two-factorial arrangement of treatments with four replications. In the dicamba-tolerant cotton study, Factor A consisted of no foliar-herbicide, dicamba alone, glyphosate alone, or dicamba plus glyphosate. Factor B consisted of either no Group 15 residual herbicide, acetochlor, or S-metolachlor. In the 2,4-D- tolerant cotton …
Enhanced Efficiency Nitrogen Fertilizer As Tool To Control Nitrogen Loss In Row Crop Production, Samuel Kudzo Okai
Enhanced Efficiency Nitrogen Fertilizer As Tool To Control Nitrogen Loss In Row Crop Production, Samuel Kudzo Okai
Masters Theses
The efficiency of urea-based fertilizers is substantially reduced through nitrogen (N) losses via ammonia volatilization. Soil pH, clay content, soil organic matter (SOM), and field capacity can affect ammonia loss. Incubation experiments were conducted on eight soils using a controlled environment system to study the effects of soil properties on ammonia volatilization from urea and urea ammonium nitrate (UAN) applied at 134.5 kg N/ha. Each experiment was set up as a randomized complete block design with four replicates. Ammonia loss was measured on 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, and 16 DAF (days after N application). …
Evaluation Of Late Season Potassium Applications To Arkansas Soybean, Carrie Ortel
Evaluation Of Late Season Potassium Applications To Arkansas Soybean, Carrie Ortel
Graduate Theses and Dissertations
Potassium (K) deficiency is one of the most important yield limiting factors in Arkansas soybean (Glycine max (L.) Merr.) production, although there are recently improved diagnostic and management opportunities available. However, several questions regarding the successful implementation of in-season K management in soybean production remain. Therefore, the research objectives were to (a) delineate the relationship between drought stress and K deficiency on soybean vigor, (b) identify the spatial dependencies of leaf-K concentrations at the production scale, (c) develop a leaf sampling protocol, (d) calibrate the fertilizer-K rate needed to correct varying levels of K deficiency at 15, 30, and 45 …
Effects Of Uv Filter Pollutants On The Growth Of Cucurbits And Possible Implications For Humans, Leia Staples
Effects Of Uv Filter Pollutants On The Growth Of Cucurbits And Possible Implications For Humans, Leia Staples
Undergraduate Theses
One main area of concern is the use of personal care products and pharmaceuticals in society and their long-term persistence when released into the environment (Chaturvedi et al. 2021). Cucurbits, however, are well-known for taking up pollutants (Namiki et al. 2013, Christou et al. 2019, Komives et al. 2009), so it essential to ensure that these pollutants do not negatively affect growth or productivity of plants. These plants are particularly useful in society because they have many health benefits and are consumed regularly by humans. While much research has been done on how much of the pollutant travels throughout the …
Machine Learning-Based Soybean Yield Prediction And Optimizing Lidar-Mounted Uav Efficiency, Leticia Santos
Machine Learning-Based Soybean Yield Prediction And Optimizing Lidar-Mounted Uav Efficiency, Leticia Santos
LSU Master's Theses
The first chapter of this thesis explores the predictive capabilities of random forests algorithm on datasets obtained from field plot experiments on crop management systems in soybean. Furthermore, the chapter presents a complementary analysis of model performance according to dataset sizes and two techniques on how to impute and deal with missing data. Random forests are being compared with standard statistical techniques such as linear regression on a well-structured, information-rich agronomic experiment. The key findings of this chapter includes the best hyperparameters adjustment and the identification of the dataset threshold for optimal algorithms performance. The second chapter has a research …
Evaluation Of Winter Cereal Cover Crops Across Nitrogen Management Strategies In No-Till Corn Production, Robert Nalley
Evaluation Of Winter Cereal Cover Crops Across Nitrogen Management Strategies In No-Till Corn Production, Robert Nalley
Theses and Dissertations--Plant and Soil Sciences
Rye (Secale cereale L.) is the most popular winter cereal cover crop utilized before corn, but wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) may provide a comparable value due to their similar fibrous root systems. Despite the benefits associated with winter cereal cover crops, drawbacks are possible for the subsequent corn crop. A field study was conducted with three site-years in Kentucky to measure the impact of the three winter cereals across nitrogen (N) management strategies. Wheat produced the most biomass compared with barley or rye cover crops. Wheat and rye needed approximately 100 more …
Nitrogen Application Timing And Cereal Rye (Secale Cereale L.) Cover Crop Influence Greenhouse Gas Emissions, Graig Reicks
Nitrogen Application Timing And Cereal Rye (Secale Cereale L.) Cover Crop Influence Greenhouse Gas Emissions, Graig Reicks
Electronic Theses and Dissertations
Dryland contributions to greenhouse gas (GHG) emissions are increased by N fertilizer applications and high soil water contents. Fertilizer timing and spring growth of cover crops prior to cash crop planting were investigated in separate studies to examine impacts on overall GHG emissions using a near continuous measurement system. There was a significant interaction between N fertilizer rate (0 vs. 224 kg N ha-1 surface-applied as urea) and application date (p= 0.01) for CO2 emissions. This interaction occurred because N fertilizer increased CO2 emissions by 35% for the 21 d interval following early spring application. When application was delayed until …
Integrating Early Season Clover Cover Crops As A Living Mulch In Broccoli And Transitional Organic Winter Squash Production In Eastern South Dakota, Alexis Rose Barnes
Integrating Early Season Clover Cover Crops As A Living Mulch In Broccoli And Transitional Organic Winter Squash Production In Eastern South Dakota, Alexis Rose Barnes
Electronic Theses and Dissertations
Managing weeds, improving soil health, and reducing the use of plastic mulch continue to be priorities for South Dakota vegetable farmers. Farmers have expressed an interest in integrating cover crops into their farm systems. Clover cover crops used as a living mulch within and along cash crop rows may aid in weed suppression, nitrogen fixation, and prevent soil erosion. However, prior research has shown challenges of incorporating living mulch due to yield decreases. Research conducted in 2022 and 2023 in eastern South Dakota investigated the effects of four clover and four in-row soil management treatments on broccoli and organic winter …
The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson
The Hutton Project: Long-Term Agricultural Impacts On Soil Loss And Carbon Dynamics In Eastern South Dakota, Eli Halverson
Electronic Theses and Dissertations
Long-term and intensified agricultural land management has resulted in increased rates of soil erosion and has altered much of the carbon cycle at regional and global scales. Anthropogenic degradation of soil resources is a barrier to sustainable production, soil functioning, and ecosystem services. It is difficult to quantify the scope of pedogenic changes due to the lack of legacy data and short temporal scales. This study utilized decades to century-old soil information to quantify historical soil erosion losses and changes in soil carbon pools of eastern South Dakota soils. The results show that soils in the region have been significantly …
Utilizing Soil Sensors To Assess Soil Health And Investigating Cover Crops Impact On Methane Emission, Shailesh Pandit
Utilizing Soil Sensors To Assess Soil Health And Investigating Cover Crops Impact On Methane Emission, Shailesh Pandit
Electronic Theses and Dissertations
Soil health is influenced by climate change, cultural practices, topography, crop rotations, cover crops, soil parent materials, and soil biota. Interactions between these factors can improve or reduce soil health. This thesis investigates two topics, using soil sensors to provide a rapid assessment of soil health, and the impact of cover crops on soil biological activity and greenhouse gas emissions. Chapter 1 explores the use of two types of sensors to measure apparent electrical conductivity (ECa) and provides examples on the use of these sensors. Even though both sensors measure ECa using different processes, they provide useful information about temporal …
The Relationship Between Soil Test Phosphorus And Soil Biology - A Natural Management Of Soil Phosphorus Through Conservation Practices, Clarence Frederick Winter
The Relationship Between Soil Test Phosphorus And Soil Biology - A Natural Management Of Soil Phosphorus Through Conservation Practices, Clarence Frederick Winter
Electronic Theses and Dissertations
Phosphorus (P) management is an ongoing challenge in modern agriculture. Due to the importance of P in agriculture, P fertilizer additions are made throughout the U.S. to avoid nutrient-depleted soil. However, the application of P is problematic, as an excess of P in an agricultural system elevates the risk of environmental degradation, and current synthetic P sources are a fleeting resource. Additionally, a majority of P found in agricultural soils are insoluble, in the form of secondary and primary P minerals, making this large pool of P unavailable to plants. Fortunately, soil fungi organisms, such as arbuscular mycorrhizal fungi (AMF) …
Plant Pathways Associated With Competition For Soybean Root Colonization By Bradyrhizobium Strains, Athira Sethu Madhavan
Plant Pathways Associated With Competition For Soybean Root Colonization By Bradyrhizobium Strains, Athira Sethu Madhavan
Electronic Theses and Dissertations
Nitrogen is a crucial nutrient for the growth and development of plants. Legume crops like soybeans develop symbiotic associations with soil bacteria from the genus, Bradyrhizobium to obtain fixed nitrogen. In this mutualistic association, rhizobia are released into root nodules that provide a compatible environment for rhizobia to grow and fix nitrogen (Symbiotic Nitrogen Fixation (SNF)). A caveat in such beneficial associations is the competition between different rhizobium strains in soil for infection and nodule occupancy. The elite inoculant strains encounter competition by indigenous rhizobial population in the soil to infect and nodulate a susceptible legume host, because of which …
Ecophysiology Of Bradyrhizobium Diazoefficiens Usda 110, Armaan Kaur Sandhu
Ecophysiology Of Bradyrhizobium Diazoefficiens Usda 110, Armaan Kaur Sandhu
Electronic Theses and Dissertations
With increasing demand for soybean, maximizing plant yield is important yiel is dependent on nitrogen availability, but nitrogen fertilizers can meet the plant's needs but have severe environmental impacts. An economically and environmentally sustainable approach is to enhance nitrogen availability through Biological Nitrogen Fixation by symbiotic rhizobia, Bradyrhizobium, an efficient nitrogen fixer for soybean. This symbiosis begins with attachment of rhizobia to legume roots. Root and rhizobia surface properties play a significant role in this attachment. Another major factor affecting root colonization is bacterial competition ability. There is a lack of knowledge on the role of bacterial surface properties, competition …
Surveys, Field Studies, And Laboratory Incubation Experiments To Improve Alfalfa Production In The Mid-South, William Fleming
Surveys, Field Studies, And Laboratory Incubation Experiments To Improve Alfalfa Production In The Mid-South, William Fleming
Theses and Dissertations--Plant and Soil Sciences
The objective of the alfalfa survey was to determine the role of soil fertility in the alfalfa yield plateau. Soil samples at depths of 10, 15, and 30 cm and tissue samples were collected from 114 alfalfa stands across Kentucky and surrounding states. Results indicate that soil fertility is likely contributing but not driving the alfalfa yield plateau. The main objective of the polyhalite incubation study is to determine if POLY4 was soluble enough to support potassium (K) and sulfur (S) for plant growth. The design of the study included four fertilizer treatments, three soil types, and four incubation times. …