Physical Sciences and Mathematics Commons^™

Dynamic Soil Properties In The Lower Rio Grande Valley: Carbon And Nitrogen Responses To Different Tillage Practices, Luzyannet Ballesteros Gonzalez

Theses and Dissertations

There has been increased attention in utilizing agriculture for carbon sequestration. Soil carbon and nitrogen are two dynamic soil properties (DSPs) that are indicators of soil health and function and have overlapping cycles. These soil properties change frequently as a result of environmental conditions and agricultural management practices. This study focuses on the impact of tillage practices in unirrigated agricultural fields in Hidalgo and Willacy counties located in South Texas on Hidalgo Sandy Clay Loam; With a particular focus on Soil Total Carbon (TC), Soil Inorganic Carbon (SIC), Permanganate Oxidizable Carbon (POXC), Carbon and Nitrogen ratio (C:N), Soil Organic Matter …

An Assessment Of Physical And Microbial Dynamic Properties Sensitive To Tillage Practices In Hidalgo Sandy Clay Loam Soils, Rocio N. Hernandez

Theses and Dissertations

Mechanized tillage is known to impact the dynamic physical, biological and chemical properties of a given soil, and as a result, can cause systematic harm to the soil’s function (Alam et al., 2014). The aim of this study is to assess how a series of land management tillage practices will impact dynamic physical and biological soil health parameters such as aggregation, carbon, respiration, and enzymatic activity (β-glucosidase). According to Acir et al (2020), the aforementioned soil parameters are both co-influenced and dependent, indicating a response to tillage is likely. A total of 198 samples of Hidalgo series soils were collected …

Grapefruit Peel Biochar Applications For Immobilizing Copper And Lead In Soil, Michael Alfredo Navarro

Theses and Dissertations

This study investigated the efficacy of grapefruit peel (GP) derived biochar materials (two pyrolysis temperatures 450°C and 800°C) as a potential adsorbent to immobilize heavy metal (copper and lead) in a local sandy loam clay soil. A batch adsorption test with heavy metal concentrations at 50 mg L-1, and 100 mg L-1 revealed that soil itself had the highest immobilization percentage compared to the GP biochars. A soil column experiment was conducted to determine how much the GP biochar samples and the tested soil will exhibit adsorptive characteristics for heavy metals when 50 ml of 50 mg L-1 copper or …

Dynamic Soil Properties In The Lower Rio Grande Valley: Understanding Responses Of Infiltration Rate, Bulk Density, Aggregate Stability To Different Tillage Practices, Temiloluwa Faith Awotoye

Theses and Dissertations

Dynamic Soil Properties (DSPs) are soil properties that change in response to both natural and human-caused interruptions and pressures such as agro-based and wildland management. These soil properties can transform for months or even years in response to the farm use and management procedures. This research project investigates the relationship between different dynamic soil physical properties and tillage practices in the Texas Hidalgo sandy clay loam benchmark soil series. Data analyses was done to compare the effect of tillage to these soil physical properties and build a discussion about relationships between on-farm practices to other aspects of farm viability. We …

Determining The Effects Of Elevated Carbon Dioxide On Soil Acidification, Cation Depletion, And Soil Inorganic Carbon And Mapping Soil Carbons Using Artificial Intelligence, Jannatul Ferdush

Theses and Dissertations

Soil carbon is the largest sink and source of the global carbon cycle and is disturbed by several natural, anthropogenic, and environmental factors. The global increase of atmospheric CO₂ affects soil carbon cycling through varied biogeochemical processes. The first chapter is a compilation of current information on potential factors triggering soil acidification and weathering mechanisms under elevated CO₂ and their consequences on soil inorganic carbon (SIC) pool and quality. Soil water content and precipitation were critical factors influencing elevated CO₂ effects on the SIC pool. The second chapter examines a detailed column experiment in which six soils …

Assessment Of Nitrogen-Based Fertilizer Transport And Microbial Activities In Sandy Soil Profiles In South Texas, Gladys De La Rosa

Theses and Dissertations

Conventional farming is a common practice in Lower Rio Grande Valley (LRGV) and the application of nitrogen fertilizer is essential for plant growth and support. However, managing the rate of nitrogen that is applied can benefit farmers financially and reduce nitrate leaching that can have an adverse effect on the local environment and aquatic systems, e.g., rivers and estuaries. Sandy soils are more vulnerable to water infiltration due to the large proportion of macropores. This study aims to (i) assess how nitrate from a variety of fertilizers (i.e., synthetic and organic) distributes on the top 60 cm layer of a …

The Effects Of Cover Crops In An Integrated Livestock/Continuous Corn Cropping System In East-Central Mississippi, Ken Randolph Waddell

Theses and Dissertations

There is growing interest within the agricultural industry on how cover crop systems affect soil health and economic productivity in integrated crop-livestock systems. This study investigated the combined effects of cover crop species; no-till and conventional till; and grazed (G) and un-grazed (UG) in a continuous corn (Zea mays) production system in east-central Mississippi. Cover crops were established in the fall of 2019 and 2020 in two separate field studies. Corn yield was not affected by grazing or tillage but was affected by cover crop species. We then compared the difference in cover crop species treatments with their respective corn …

Soil Chemistry Modification By Guinea Grass In Semi-Arid Soils: A Litter Mediated Positive Feedback, Vanessa Elizabeth Thomas

Theses and Dissertations

Nutrients are a key component of healthy soils. Their composition plays an important role in plant growth through nutrient cycling and directly influences the functioning of plant communities in both agricultural and natural ecosystems. Shifts in macronutrients such as phosphorus and nitrogen may be initiated by invasive growth as a driver for competition with native plants. The goal of this study is to explore the plant soil feedback in an exotic invasive plant, Guinea grass (Pancium maximum), an invasive bunch grass originally from Africa, across different habitat types in the Lower Rio Grande Valley (LRGV). To determine a positive plant …

Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang

Theses and Dissertations

Chapter 1: In this chapter, we have provided a review on the components of rhizosphere engineering and the potential use of PGPR and its challenges to serve as an efficient component for sustainable agriculture.

Chapter 2: In this chapter, we isolated 35 different strains of a PGPR, Pseudmonas fluorescens and characterized various plant growth promoting traits such as production of ammonia, protease, Indole acitic acid (IAA), 1-aminocyclopropane-1-carboxylate deaminase (ACC) deaminase, ammonia, hydrogen cyanide (HCN), and souliblization of zinc and phosphate.

Chapter 3: In this chapter, we tested the influence of plant beneficial soil microbe, P. fluorescens, on the growth and …

Snow-Albedo Feedback In Northern Alaska: How Vegetation Influences Snowmelt, Lucas C. Reckhaus

Theses and Dissertations

This paper investigates how the snow-albedo feedback mechanism of the arctic is changing in response to rising climate temperatures. Specifically, the interplay of vegetation and snowmelt, and how these two variables can be correlated. This has the potential to refine climate modelling of the spring transition season. Research was conducted at the ecoregion scale in northern Alaska from 2000 to 2020. Each ecoregion is defined by distinct topographic and ecological conditions, allowing for meaningful contrast between the patterns of spring albedo transition across surface conditions and vegetation types. The five most northerly ecoregions of Alaska are chosen as they encompass …

Predicting Patterns Of Heavy Metal Contamination In Rio Grande Valley Agricultural Soils, Joy Z. Youwakim

Theses and Dissertations

The Rio Grande Valley of Texas is the statewide leader in the production of produce and grains and is irrigated by the Rio Grande River, in which heavy metal contaminants have been documented by both the International Boundary Water Commission and the United States Geological Survey. This work attempts to observe and document patterns of heavy metal pooling in order to mitigate the increased risk of contamination due to urbanization. We hypothesize that relationships exist between heavy metal content and proximity to roads, land use, and soil type. This research tests these relationships through soil sampling and atomic absorption spectrometry …

Perceptions Of A Small Midwestern Food Cooperative: A Case Study, Rebecca Forsythe

Theses and Dissertations

The purpose of this research is to illuminate how individuals form perceptions of cooperatives, specifically of Green Top Grocery, a cooperative located in Bloomington Illinois, using the Bourdieu-sian habitus and notions of capital as a frame. Green Top Grocery suffers from fiscal instability since they opened in 2017. They also struggle to gain support of lower income individuals, a key demographic they sought to help since their inception based on their stated values. By conducting qualitative interviews of three sample groups: Green Top Grocery board members and leadership, local food access experts, and West Bloomington residents, and non-participant observations, this …

Soil-Grapevine Interactions: Insight From Verdicchio In The Marche Wine Region, Italy, Megan Luna Barlow

Theses and Dissertations

Verdicchio is a white grape varietal notably grown in the Marche wine region of east-central Italy within two Denominazione Origine Controllata (DOCs); Castelli di Jesi and Matelica, located less than 50 km apart. Jesi lies in the Apennine foothills near the coast of the Adriatic Sea and produces a smooth wine noted with apple-pear undertones and crisp, clean acidity. Conversely, Matelica is located in a synclinal valley of a fold-and-thrust belt and produces stronger wine with penetrating floral aromas and bold acidity. While macro-climatic variations do exist between DOCs, this research focuses on geological variations, specifically variations in soil composition, …

Short-Term Effects Of Nutrients On A Barrier Island Grassland Community, Ashley Moulton

Theses and Dissertations

Increased nutrient availability globally has the potential to affect community functional composition of plants in nutrient limited environments, such as coastal grassland systems. Stability of these systems are threatened worldwide by urbanization, as well as effects of sea level rise and increased frequency and intensity of storms, and atmospheric N deposition, associated with climate change. Annual net primary productivity (ANPP), species composition, and functional traits (community weighted specific leaf area (CWSLA), leaf area index (LAI), growth form and photosynthetic pathway) were measured across four treatments to assess multiple resource limitation of nitrogen (N) and phosphorus (P) and functional community response …

Improving The Efficiency Of Fall Applied N With Cover Crops, Corey Lacey

Theses and Dissertations

Nitrate loss studies in Midwestern tile-drained fields have found that fall applied nitrogen (N) resulted in elevated nitrate concentrations in tile water during both the corn and soybean year of a 2 year rotation. The effectiveness of cover crops to reduce nitrate leaching when N is spring applied has been well demonstrated, however there is a dearth of knowledge on the ability of cover crops to reduce nitrate leaching in a system where N is fall applied. Thus, the objectives of this research were to (i) investigate the efficacy of winter cover crops to reduce nitrate leaching from fall applied …

Efficiency Of The Inorganic Fertilization In The Cultivation Of Alfalfa (Medicated Sativa L) And Whitewashing For The Correction Of The Ph Of The Soil, Alex Gonzalo Bravo Morocho

Theses and Dissertations

In our country the necessity to offer new alternatives for the agricultural sector is high-priority especially for the lucern cultivation that every day is surface cultivated especially in the Chimborazo province increases; for what is of our interest to establish the answer from the cultivation to the inorganic fertilization and liming for the flora pH correction, for this way to obtain better yields and for consequence to improve the economic conditions of the farmers. With the result that the titled investigation: Efficiency of the Inorganic Fertilization in the Alfalfa Cultivation (Medicago sativa L) and Liming for the Correction of the …

Certain Edaphic And Biotic Factors Affecting Vegetation In The Shadscale Community Of The Kaiparowits Area, Vane Orlan Campbell

Theses and Dissertations

A study area on the southern extensions of the Great Basin cold desert (Kaiparowits Basin, Utah) was selected which has had varying amounts of disturbance. Areas with similar slope and exposure in the Shadscale community were sampled. At each site, soil samples were collected and percent sand, percent clay, percent silt, soluble salts, and hydrogen ion concentrations were measured. Cluster analysis based on percent frequency of the perennial species showed that eight groups or sub-communities were definable within the area sampled. Patterns within the vegetation were shown to be independent with the use of cluster analysis. Discriminant analysis on soil …

The Effect Of Recreational Uses On Vegetation And Soil In The Buffalo Campground, Targhee National Forest, Island Park, Idaho, Susan Daines Foster

Theses and Dissertations

The effect of trampling on vegetation and soil, as a result of recreational pressure, was studied in the Buffalo campground of the Targhee National Forest, Idaho. Site deterioration was most evident in the forty-two year old site. The tree stand had matured, but there were few young trees and tree reproduction had been reduced to ten seedlings per acre for Pinus contorta. Only two shrub species were sampled with a combined population of eight individuals per acre. Most of the grass species had been seeded; forbs provided 20% of the ground cover, 13% was bare ground and 71% litter. The …