Physical Sciences and Mathematics Commons^™

Microwave Emission Model Parameter Tuning For Surface Soil Moisture Retrieval Using Uav-Mounted Dual Polarization L-Band Radiometer, Santiago Hoyos Echeverri

Open Access Theses & Dissertations

Surface soil moisture retrieval from L-band brightness temperature has been developed for the past decades due to multiple beneficial characteristics of 1-2 GHz frequency bands for remote sensing of the environment. Numerous microwave emission models have been proposed for tower and satellite-based operations with successful retrieval of surface soil moisture and vegetation water content. As a result of the development of cost-effective and low-mass microwave L-band radiometers such as the Portable L-band Radiometer (PoLRa), surface soil moisture surveying traditionally developed by satellite missions SMOS and SMAP can now be developed at local scales, bringing these operations to commercial small unmanned …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Land Use/ Land Cover Change Patterns And Trends In Two Dryland Regions, Omar Sulaiman Belhaj

Open Access Theses & Dissertations

Development and climate change affect the environment in numerous ways and to varyingdegrees. This effect appears prominent and more influential in arid regions. Therefore, land use/ land cover in these regions experience profound changes such as plant cover decrease and extinction of some plant species. Also, land use/ land cover in these regions has critical impacts on the environment and its components, such as shrublands shrinking and losing the habitat of animal species. The degree of changes and effects reaches severe levels that become urgent to figure out the impacts and find solutions to stop or mitigate the negative consequences. …

Addressing Challenges In Aggregating And Analyzing Agroecological Data, Sarah E. Mccord

Open Access Theses & Dissertations

Agroecosystems face multiple threats including land degradation and climate change, changing and competing land uses, invasive species and disease spread, and biodiversity loss. While scientists seek to understand rapidly changing ecosystems, land managers are struggling to maintain ecosystem services amid transitions to novel ecosystem states. Understanding agroecosystem drivers and ensuing responses requires quality information about ecosystems that span biomes, trophic scales, ecological processes, spatiotemporal scales, land use, and land ownership. Yet, using multi-scale agroecosystem information can be frustrating for both scientific researchers and land managers as it is difficult to locate data that are trustworthy, easily accessible, standardized, and connected …

Insights Into The Interaction Of Copper Oxide Nanopar-Ticles With Sweetpotato (Ipomoea Batatas (L.) Lam.): The Role Of Lignin On Copper Uptake And Translocation, Nestor Javier Bonilla Bird

Open Access Theses & Dissertations

Sweetpotato [Ipomoea batatas (L.) Lam.] is widely cultivated in many countries worldwide. The world production of sweetpotato is around 127 billion tons and it is ranked seventh in the world as a staple food. After harvesting, sweetpotato storage roots are treated with fungicides to prolong shelf life. Lignin plays an important role in the conservation of the storage roots. One of the practices to activate the lignification pathway is called “curing process.” The roots are placed under 80% relative humidity at a temperature of 29 ºC for a period of 7 to 15 days, followed by a cooling period at …

A Combined Field, Experimental And Modeling Approach To Understand The Impacts Of Flood Irrigation On Pedogenic Caco3 And Co2 Dynamics In Drylands, Anna Cristina Ortiz

Open Access Theses & Dissertations

Soil salinization is a global problem affecting 10% of agricultural soils, particularly in irrigated arid-lands. This study investigated salt loading through flood-irrigation, particularly of calcite (CaCO3) salt in the southwest of the United States. To evaluate the impact that flood-irrigation has on CaCO3 buildup and its effect on C-cycling, a natural soil and two agricultural soils were sampled: a pecan orchard and an alfalfa field in the El Paso, TX region. Agricultural soils in this study are flood irrigated by the Rio Grande river and by ground waters in its absence, both of which are oversaturated with calcite.

To trace …

Modulation Of The Physiological And Biochemical Effects Of Copper Nanoparticles In Kidney Beans (Phaseouls Vulgaris) Treated By Kinetin, Suzanne Annette Apodaca

Open Access Theses & Dissertations

It is imperative to not only understand the impact of engineered nanomaterials (ENMs) in edible plants, but also the interactions they have with various additives used in agriculture. In this study, kidney bean plants were grown in potting soil treated with nano copper (nCu), bulk copper (bCu), and copper chloride (CuCl2) at concentrations of 0, 50, and 100 mg/kg for 55 and 90 days. At 15 days of growth, 0, 10, and 100 μm of kinetin (KN) were applied to plants. Plant tissue samples were harvested at 55 days and seeds were reaped at 90 days. Physiological and biochemical parameters …

Effects Of Cerium Oxide Nanoparticles In Cereals: Insights Into The Toxicity Mechanisms And Macromolecular Modifications, Cyren Mendoza Rico

Open Access Theses & Dissertations

Despite the inundation of studies on the interaction of engineered nanomaterials (ENMs) with plants, investigations involving complete life cycle (i.e from seedling establishment to full maturity) are still lacking. Assessments on the nutritional value of plants cultivated to full maturity in ENMs-treated soil are also missing. Cerium oxide nanoparticles (nCeO2) have significant interactions with plants; however, there are no life cycle studies yet on their implications in cereals like rice (Oryza sativa L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.). These cereals are globally important crops that support the economic activity, and nutritional and health needs of billions …

Sensitivity Analysis Of Streambed Leakance Downstream Of Caballo Reservoir, Derrick Ohara

Open Access Theses & Dissertations

Modeling transient effects of streams near well fields is an important tool for understanding water balance within the Rio Grande Project (Project). The results are known as stream leakage. Stream leakage quantifies the amount of water seeping from a stream, canal and/or drain to/from a well field. Stream leakages near the Canutillo Well field, primary river losses for years 2005 through 2010 along with historical gain/losses and allocations of surface water with the associated agreements were evaluated.

The overall loss rates per mile in the Project for years 2005 to 2010 averaged -0.75 cubic feet per second (cfs). The historical …

Symbiotic Effects Of The Fungus Glomus Sp. On Chromium(Iii), Chromium(Vi), And Lead(Ii) Uptake By Mesquite (Prosopis Sp.): A Novel Method To Remediate Heavy Metals, Jack A. Arias

Open Access Theses & Dissertations

The indiscriminate disposal of lead (Pb) and chromium (Cr) containing wastes has resulted in a detrimental impact on environmental health. Lead and Cr are in the EPA priority list due to their degree of toxicity on humans, animals, plants, and other living organisms. The removal of toxic wastes involves technologies that are expensive, sometimes incomplete, and could represent health hazards. In addition, site restoration after contaminant removal encompasses time and technological resources. Phytoremediation, the use of plants alone or associated with microorganisms, represents a potentially cost-effective option in the long term management of contaminated sites. Various plants known as "hyperaccumulators" …