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Nitrogen Transfer From Cover Crops To The Subsequent Grain Crop And The Influence Of Variability In Winter Conditions, Spencer Heuchan Dec 2022

Nitrogen Transfer From Cover Crops To The Subsequent Grain Crop And The Influence Of Variability In Winter Conditions, Spencer Heuchan

Electronic Thesis and Dissertation Repository

Cover crops, which are used to provide ground cover after the harvest of the grain crop, can potentially improve the sustainability of agroecosystems by reducing nutrient losses. However, few data are available to document the extent to which cover crops improve both the retention of soil nitrogen (N) and the transfer of this N to the grain crop. The efficiency of this N transfer may be further influenced by variation in winter soil temperature; for example, reduced snow cover can increase the frequency and intensity of soil freezing, which can affect the survival of cover crops and the timing of …


An Evaluation On The Effects Of Additions And Deletions Of Specific Nutrient Management Strategies On Corn Yield At Different Plant Densities, James D. Dew Dec 2022

An Evaluation On The Effects Of Additions And Deletions Of Specific Nutrient Management Strategies On Corn Yield At Different Plant Densities, James D. Dew

Theses and Dissertations

Improved management strategies are needed to increase yield production and quality. The study aimed to determine suitable cultural practices for improved corn production. Experiments were set up at Verona and Stoneville, Mississippi, from 2020 to 2022. Treatments included row configurations (single and twin-row), plant populations (79,000 and 99,000 seeds ha-1), and six combinations of nutrients with or without fungicide. The nutrients evaluated were two nitrogen rates 235 and 314 kg N ha-1, phosphorus 45 kg P ha-1, potassium 112 kg K ha-1, sulfur 22 kg S ha-1, and zinc 11 kg Zn ha-1, and fungicide at 272 ml ha-1. In …


Songbird-Mediated Insect Pest Control In Low Intensity New England Agriculture, Samuel J. Mayne Mar 2022

Songbird-Mediated Insect Pest Control In Low Intensity New England Agriculture, Samuel J. Mayne

Masters Theses

Global agricultural intensification has caused large-scale wildlife declines, but agricultural lands that maintain natural habitats can support healthy wildlife populations and receive significant ecosystem services from these natural communities. However, how on-farm biodiversity results in beneficial ecosystem services is highly variable and is reported to differ among taxa and guilds. One group that has attracted attention for their potential beneficial role in reducing pest abundance are birds. Understanding the role of bird communities and individual species in pest control could be important for managing farms under a low intensity agroecological framework. In New England, farmers are increasingly applying low intensity …


Estimation Of Spatial Change In Cropland Area And Evaluation Of Irrigation Performance In Imperial Valley Using Remotely Sensed Data, Usha Poudel May 2021

Estimation Of Spatial Change In Cropland Area And Evaluation Of Irrigation Performance In Imperial Valley Using Remotely Sensed Data, Usha Poudel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Imperial Valley (IV) in the US is an extensively irrigated agricultural region, which includes multiple crops changing on an annual and semiannual basis. The valley is facing grave concerns about water management due to its semi-arid environment, water intensive crops, and limited water supply. A simple, inexpensive, and repeatable method to detect changes in cropping patterns may assist irrigation managers to understand crop diversification and associated consumptive use. In addition, a spatial assessment of existing water irrigation system performance and productivity is crucial to benchmark and improve current water management strategies. This thesis estimates the spatial pattern of change …


Effects Of Am Fungi From Conventional And No-Till Michigan Crop Fields On Plant And Soil Health, Derek Bennett May 2021

Effects Of Am Fungi From Conventional And No-Till Michigan Crop Fields On Plant And Soil Health, Derek Bennett

Masters Theses

Centuries of conventional till (CT) management in agriculture has depleted soil organic matter (SOM) by over 50%. While only comprising 5% in most soils, SOM provides soil with fertility and productivity. To compensate for SOM depletion, producers have been forced to increase their reliance on fertilizer and irrigation to maintain yields. In the coming decades, climate change is expected to challenge food production and threaten an already fragile system. With no remaining land left to cultivate, conservation management strategies such as no-till (NT) look to restore SOM and increase the resilience of food production for an ever growing, increasingly food …


Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela Morrison May 2021

Long-Term Changes In Soil Surface Properties As Affected By Management Practices In A Wheat-Soybean, Double-Crop System, Machaela Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Long-term agricultural sustainability and productivity are controlled by the integrative effects of different management practices on the soil. Many Arkansas producers use the double-crop system to grow soybeans [Glycine max (L.) Merr] and wheat (Triticum aestivum L.). Studying combinations of different, non-traditional, alternative agricultural techniques may help producers better understand the long-term implications of various management practice options on sustainability and productivity. The objective of this study was to evaluate the effects of agricultural management practices, including residue level, tillage, irrigation, and burning, and soil depth on the change in various soil properties from 2010 to 2020 in …


Increasing Groundwater Recharge Activity In The San Joaquin Valley Of California, Jacob Willhite, Jacob Willhite Jun 2020

Increasing Groundwater Recharge Activity In The San Joaquin Valley Of California, Jacob Willhite, Jacob Willhite

Agricultural Education and Communication

Over the past several decades, groundwater has become a primary source of water used for agriculture in California. Surface water available for agricultural use has depleted due to declining rain totals and reallocation to environmental purposes. As a result, groundwater overdraft has become a severe challenge, especially in the San Joaquin Valley of California. This excessive overdraft causes a plethora of issues, one of the most serious being land subsidence (Faunt, Sneed, Traum, & Brandt, 2016). Studies suggest some areas of the San Joaquin Valley have experienced more than a 28-foot drop in the land level since the 1970’s (Alley …


Implementación De 1.300 M2 De Arveja (Pisum Sativum L), Como Alternativa Productiva Para El Municipio De Guavatá Santander, Sergio Sáenz Sicacha Jan 2020

Implementación De 1.300 M2 De Arveja (Pisum Sativum L), Como Alternativa Productiva Para El Municipio De Guavatá Santander, Sergio Sáenz Sicacha

Ingeniería Agronómica

La mayoría de la población colombiana se clasifica como pobres extremos, los cuales dependen de la agricultura y de las actividades conexas como parte significativa de sus ingresos (FAO, 2012). Con el proyecto productivo de arveja (Pisum Sativum), desde el campo agrónomico se buscó fortalecer los pequeños y medianos productores por medio de intercambio de conocimientos, lo que permitió mejorar el manejo de los cultivos de interés a través de la metodología "Aprender haciendo y enseñar demostrando" donde se desarrolló un aprendizaje teórico-práctico. Del mismo modo se buscó conocer alternativas de producción a través del establecimiento del proyecto productivo del …


Floral Trait Architecture In Crop Sunflower (Helianthus Annuus) Under Drought Conditions, Lauren Segarra Jan 2020

Floral Trait Architecture In Crop Sunflower (Helianthus Annuus) Under Drought Conditions, Lauren Segarra

All Master's Theses

Longer and more intense droughts are predicted to become more common in the coming century due to anthropogenic climate change. Drought can reduce crop yield and decrease food security. In order to mitigate the negative effects of drought on crop production, it is important to elucidate the underlying mechanisms that promote drought stress resistance in crop plants. Floral traits impact yield, especially in oilseed crops such as sunflower (Helianthus annuus), but their susceptibility to drought stress is understudied. The goal of this study was to describe the floral trait architecture of H. annuus crop lines under drought versus …


Testing The Potential Of Novel Grain Crop Cultivation In Rural Malawi During The Dry Season Through Irrigation And Soil Modification, Jessica Truman Apr 2018

Testing The Potential Of Novel Grain Crop Cultivation In Rural Malawi During The Dry Season Through Irrigation And Soil Modification, Jessica Truman

Undergraduate Honors Theses

This research project studied the germination and growth rates of oat and quinoa crops in Mtalimanja, Malawi. This project was part of a larger effort by General Mills and Brigham Young University researchers to increase the diversity and nutrient content of crops in impoverished countries worldwide. It was conducted from May to August 2017 during Malawi’s dry season. Tetraploid oats and quinoa, both modified to increase the protein content of harvested grains, were planted under three different soil conditions: unamended soil, soil mixed with composted chicken litter, and soil with surface-applied granular fertilizer. The research plots were watered daily except …


Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening Apr 2017

Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening

Theses and Dissertations

Nutrient pollution originating from agricultural regions in the Midwest is a serious issue, leading to pollution of drinking water sources as well as large hypoxic zones in the Gulf of Mexico. The source of much of this contamination has been shown to be runoff from agricultural fields in the Upper Mississippi River Basin. One method that has been shown to reduce this pollution from the Upper Mississippi River Basin is the planting of winter cover crops. Winter cover crops such as rye and tillage radish have been shown to significantly reduce nitrate exported from agricultural fields, even in tile-drained watersheds …


Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik Jan 2017

Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik

Honors Theses and Capstones

The expansion of local agriculture in the New England region is putting increased pressure on farmers to expand their arable land base. While clear-cutting is a traditional method of converting forested land to agriculture, it is known for having adverse ecological impacts. To minimize these impacts, farmers can create a silvopasture which incorporates a portion of the original forest canopy into pastures or crop fields. This study evaluates the impact of land-use changes for agriculture on soil nitrogen (N) retention. In particular, this study investigates the differences in soil N turnover, gaseous loss, and aqueous loss among an established forest, …


Soil Salinity Study In Northern Great Plains Sodium Affected Soil, Tulsi P. Kharel Jan 2016

Soil Salinity Study In Northern Great Plains Sodium Affected Soil, Tulsi P. Kharel

Electronic Theses and Dissertations

Climate and land-use changes when combined with the marine sediments that underlay portions of the Northern Great Plains have increased the salinization and sodification risks. The objectives of this dissertation were to compare three chemical amendments (calcium chloride, sulfuric acid and gypsum) remediation strategies on water permeability and sodium (Na) transport in undisturbed soil columns and to develop a remote sensing technique to characterize salinization in South Dakota soils. Fortyeight undisturbed soil columns (30 cm x 15 cm) collected from White Lake, Redfield, and Pierpont were used to assess the chemical remediation strategies. In this study the experimental design was …


The Effects Of Manufactured Nanomaterial Transformations On Bioavailability, Toxicity And Transcriptomic Responses Of Caenorhabditis Elegans, Daniel L. Starnes Jan 2016

The Effects Of Manufactured Nanomaterial Transformations On Bioavailability, Toxicity And Transcriptomic Responses Of Caenorhabditis Elegans, Daniel L. Starnes

Theses and Dissertations--Plant and Soil Sciences

In recent decades, there has been a rapid expansion in the use of manufactured nanoparticles (MNPs). Experimental evidence and material flow models predict that MNPs enter wastewater treatment plants and partition to sewage sludge and majority of that sludge is land applied as biosolids. During wastewater treatment and after land application, MNPs undergo biogeochemical transformations (aging). The primary transformation process for silver MNPs (Ag-MNPs) is sulfidation, while zinc oxide MNPs (ZnO-MNPs) most likely undergo phosphatation and sulfidation. Our overall goal was to assess bioavailability and toxicogenomic impacts of both pristine, defined as-synthesized, and aged Ag- and ZnO-MNPs, as well as …


Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson Dec 2015

Long-Term Impacts Of Conservation Management Practices On Soil Carbon Storage, Stability, And Utilization Under Cotton Production In West Tennessee, Candace Brooke Wilson

Masters Theses

Biogeochemical cycling of soil carbon (C) is heavily influenced by conservation agricultural (CA) practices. This study examined SOC stability under three CA practices: reduced nitrogen (N) fertilizer application rate, cover cropping, and zero-tillage implemented for 31 years. Respiration rates measured from a 602-day incubation period were fitted to a double-pool first order exponential model of SOC decomposition. The active [respired] SOC pool showed distinct differences between applications of reduced (34N kg ha-1 [-1]) and high fertilization rates (101N kg ha-1) combined with tillage, and suggest that high fertilizer applications with conventional tillage allocated more C into a …


Farming: It's Not Just For Farmers Anymore, Jennifer Schmidt May 2014

Farming: It's Not Just For Farmers Anymore, Jennifer Schmidt

Pomona Senior Theses

Agricultural education, originally the province of land grant institutions, has recently entered the liberal arts curriculum. This represents a profound shift from the origins of agricultural education, when it was intended primarily as vocational training for future farmers, and has important implications for the future of the American food system. The first chapter of this thesis addresses the history of agricultural education: what was it originally like, and why did it come to be heavily criticized in the late twentieth century? Formal agricultural education changed significantly in response to these criticisms, making it more environmentally sustainable and bringing it into …


Native Grass And Forb Establishment In Post-Agricultural Soil, Courtney D. Hall Jan 2013

Native Grass And Forb Establishment In Post-Agricultural Soil, Courtney D. Hall

Electronic Theses and Dissertations

Restoration of degraded and abandoned agricultural land in arid and semiarid climates is a global problem. The erratic patterns of precipitation these lands experience makes restoration of a plant community difficult. Application of supplemental irrigation and inoculation with arbuscular mycorrhizal fungi (AMF) are two restoration techniques that have been suggested to overcome deficits in natural precipitation. The effects and the interactions of irrigation and seeding date on the ground cover of intended species and unintended exotic species were tested in a post-agricultural restoration experiment in south-central Colorado, USA. The greatest ground cover of intended species and lowest ground cover of …


Re-Integrating Crops And Livestock In Maine: An Economic Analysis Of The Potential For And Profitability Of Integrated Agricultural Production, Aaron K. Hoshide Aug 2005

Re-Integrating Crops And Livestock In Maine: An Economic Analysis Of The Potential For And Profitability Of Integrated Agricultural Production, Aaron K. Hoshide

Electronic Theses and Dissertations

This thesis examines the profitability of and sustainability indicators for potato and dairy farms in Maine integrating crops and livestock in two different ways. The first is inter-farm coupling, where two or more specialized producers are close enough to exchange manure applications for crops used as livestock feed. Land base is shared between farmers. The second is where farms are on-farm integrated. Here crops and livestock are raised on the same farm and manure is applied to cash crops and livestock feed crops. Face-to-face interviews with Maine producers were used to construct integrated and non-integrated representative budgets. Assuming …


A Study Of Puccinia Graminis And Cronartium Ribicola, Duane W. Hughes Aug 1963

A Study Of Puccinia Graminis And Cronartium Ribicola, Duane W. Hughes

Graduate Student Research Papers

It was the purpose of this study (1) to review the literary history of rusts in the United States and in the Northwest in particular, ( 2) to learn where rusts generally are found geographically, (3) to gain further information regarding the etiology of wheat rust (Puccinia graminis tritici), of white pine blister rust (Cronartium ribicola) and to become enlightened on other rusts, (4) to learn ways of controlling the two rusts, black stem rust of wheat and white pine blister rust, and to gain an appreciation of the economic importance of rust prevention.