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Full-Text Articles in Physical Sciences and Mathematics
Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz
Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz
Graduate Theses and Dissertations
Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …
Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp
Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp
Electronic Theses, Projects, and Dissertations
Environmental impacts of mining at Calico, California, are poorly understood in comparison to the details of its history of silver production. Human health risks associated with arsenic from the lode rock, as well as mercury from the silver milling process, include central nervous system damage, organ failure, and death. To quantify the potential human health risk and manage remediation of this site, tailings from the Garfield Mill site were digitally mapped and chemically analyzed by portable x-ray fluorescence, which permitted volumetric estimates of total mill tailings and the arsenic and mercury budget, as well as identification of anomalies in the …
Lead Contamination Of Soils In An Abandoned Rifle Range, Augusta County, Virginia, Logan Mahoney
Lead Contamination Of Soils In An Abandoned Rifle Range, Augusta County, Virginia, Logan Mahoney
Senior Honors Projects, 2010-2019
Presence of high concentrations of Lead within the soil and water could lead to various health related impacts on humans and wildlife. Exposure to Lead short termly or long termly could lead to many detrimental impacts due to Lead poisoning. The overall concentration of Lead in a soil can be measured using an Inductively Coupled Plasma Mass Spectrometry (ICPMS) under laboratory conditions. The present study investigates the Lead concentration of contaminated abandoned riffle range located in Augusta County, Virginia. Soil samples were obtained using soil augurs from three locations randomly based on the severity of contamination. Location three, which was …
Landuse And Soil Property Effects On Infiltration And Soil Aggregate Stability In The Lower Mississippi River Valley, Rebecca Lynn Anderson
Landuse And Soil Property Effects On Infiltration And Soil Aggregate Stability In The Lower Mississippi River Valley, Rebecca Lynn Anderson
Graduate Theses and Dissertations
Following European settlement of the Lower Mississippi River Valley (LMRV), agricultural expansion and unsustainable, agriculturally related practices have caused groundwater depletion, soil erosion, and surface water contamination by eroded sediments and sediment-bound nutrients to become major environmental threats to the region. The objective of this study was to evaluate the effects of common landuses [i.e., native prairie, deciduous forest, coniferous forest, Conservation Reserve Program (CRP) grassland, and conventional-tillage (CT) and no-tillage (NT) agriculture] on surface water infiltration and aggregate-stability-related properties [i.e., water-stable macroaggregate (WSA) size distribution, total water-stable macroaggregate (TWSA) concentration, and mean weight diameter (MWD)]. The overall infiltration rate …
Root Biomass And Other Soil Properties Affecting The Co2 Flush From Laboratory Dried And Rewetted Soils, Audrey E. Laffely
Root Biomass And Other Soil Properties Affecting The Co2 Flush From Laboratory Dried And Rewetted Soils, Audrey E. Laffely
Electronic Theses and Dissertations
Soil that has been dried and rewetted has been observed to release a ‘burst’ or ‘flush’ of carbon dioxide (CO 2 ) upon rewetting. This CO 2 flush has been proposed as an indicator of soil health. This may be a valuable indicator of soil health, however the CO 2 flush has yet to be fully evaluated. Roots and root exudates influence the soil in a variety of ways that may impact the CO 2 flush, such as increasing aggregation, organic carbon (C), and microbial biomass. We conducted both field and greenhouse experiments to elucidate the relationship of root biomass …
Asian Jumping Worm (Megascolecidae) Impacts On Physical And Biological Characteristics Of Turfgrass Ecosystems, Ella L. Maddi
Asian Jumping Worm (Megascolecidae) Impacts On Physical And Biological Characteristics Of Turfgrass Ecosystems, Ella L. Maddi
Honors Theses
Asian Jumping worms (Megascolecid spp) were introduced to North America in the early 1900s and have been altering soils in forest ecosystems as they spread throughout the continent. The worms differ from other introduced earthworms in their ability to consume large densities of organic material and potentially alter nutrient cycling in the ecosystems that they invade (Greiner et al. 2012). This study examined if and how Asian jumping worms alter turfgrass systems by changing the biological or physical properties of soil. To do this we conducted a mesocosm experiment and observational field study. For the mesocosm study we inoculated boxes …
Ecosystem Function Along An Elevational Gradient In Vermont, Emily Page Piche
Ecosystem Function Along An Elevational Gradient In Vermont, Emily Page Piche
Graduate College Dissertations and Theses
Living (biotic) and non-living (abiotic) factors drive the function of ecosystems across a variety of scales from the root-soil interface to the watershed. Biotic and abiotic global change pressures such as increasing temperature and invasive species are shifting how ecosystems function. Thus, exploring and understanding how these factors shape function across the landscape is an important research area. For example, climate change both directly and indirectly affects soil microbial functions – such as carbon mineralization and nitrogen transformations – through increasing activity under warming and altering inputs to the soil through species composition changes. Mountains provide a useful tool for …
Seasonal Soil Carbon Fluxes In Transitioning Agricultural Soils In Central Washington State: Relations To Land-Use, Environmental Factors And Soil Carbon-Nitrogen Characteristics, Brandon Kautzman
All Master's Theses
Changing agricultural land-use practices to increase soil carbon sequestration contributes to climate change mitigation and improved food security by moving CO2 from the atmosphere into soil as soil organic carbon (SOC). In 2016, a farm in Thorp, Washington, Spoon Full Farm, began converting land historically farmed using conventional methods of tillage and synthetic fertilizers to conservation farming methods with direct seeding and organic soil amendments with a goal of sequestering carbon in the soil. This project evaluates relationships of soil CO2 respiration and net ecological exchange (NEE) with land-use types, seasonal environmental factors (air temperature, relative humidity, soil …