We examined the physical and chemical soil characteristics in the cleared riparian areas at the Sooke Lake Reservoir, where the growing population has necessitated the expansion of the drinking water reservoir in Victoria, British Columbia. Additionally, hydrologic functioning was studied to establish the pathways riparian nutrients followed to the reservoir. In order to understand the potential release of nitrogen and phosphorous following inundation, both saturated riparian and upland areas were chosen as part of 17 transects encompassing the entire reservoir in four major soil types (Morainal, Colluvial, Fluvial and Organic). Various nutrient concentrations (TDP, TP. PO43- DOC, TC, IC, NO3-, NO2, NH4+, TN, TDN) were measured in relation to geomorphic features. Areal analyses confirm the hypotheses that nutrient concentrations differ with soil type, depth (0-10 cm, 10-30 cm, 30-60 cm) and hill slope. Hydrologic data established that seasonality and therefore transect connectivity is an important aspect for nutrient transport in the riparian areas via leaching and preferential flowpaths.

Two natural soils from Bahrain were used in this study to investigate the feasibility of using Arabian oil residue as a means to stabilize collapsible saline soils. Since the presence of oil residue in soils can pose an environmental threat, the high oil retention capability of the stabilized soils is critical to its application. / The behavior of the stabilized soils has been experimentally investigated in the laboratory. This study has concentrated on the evaluation of the mechanical properties of the stabilized soils, the oil retention characteristics and its bonding mechanisms, and the leaching and migration behaviors of oil residue from the stabilized soils. / The geotechnical investigation results indicated that the addition of 4% oil residue, by weight, was sufficient to significantly enhance the strength performance of the tested soils. The geochemical tests showed that the bonds formed between the oil and the soil surfaces were predominantly Van der Waal's attraction, weak hydrogen bonding, and cation and water bridging. These bonds were found to be relatively weak but stable and insensitive to leaching forces. The geo-environmental results revealed good oil retention in these samples, with less than 3% of the oil residue by weight leached from the stabilized soils after 40 days of leaching in distilled water. / The migration of oil from the stabilized soils has also been theoretically evaluated. The theoretical study utilizes the model developed by Yong et al. (1992) with a few modifications made to accommodate this particular situation. The model was solved using an explicit finite difference method, Powell's optimization technique, and experimental results. The predicted oil migration profiles were found to be slightly over-estimated as compared to the experimental profiles.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6119. Adviser: Robert G. Hoeft. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

We examined the physical and chemical soil characteristics in the cleared riparian areas at the Sooke Lake Reservoir, where the growing population has necessitated the expansion of the drinking water reservoir in Victoria, British Columbia. Additionally, hydrologic functioning was studied to establish the pathways riparian nutrients followed to the reservoir. In order to understand the potential release of nitrogen and phosphorous following inundation, both saturated riparian and upland areas were chosen as part of 17 transects encompassing the entire reservoir in four major soil types (Morainal, Colluvial, Fluvial and Organic). Various nutrient concentrations (TDP, TP. PO43- DOC, TC, IC, NO3-, NO2, NH4+, TN, TDN) were measured in relation to geomorphic features. Areal analyses confirm the hypotheses that nutrient concentrations differ with soil type, depth (0-10 cm, 10-30 cm, 30-60 cm) and hill slope. Hydrologic data established that seasonality and therefore transect connectivity is an important aspect for nutrient transport in the riparian areas via leaching and preferential flowpaths.

Untersucht wurde der Arsen- und Cadmiumtransfer vom Boden in die Pflanze. Die Boden- und Kornproben entstammten den Dauertestflächen aller Bodenregionen in Sachsen. Um die Pflanzenverfügbarkeit der beiden Elemente zu untersuchen, wurden sieben verschiedene Extraktionsmethoden verglichen. Der Aufschluss mit Königswasser oder Calcium-Ammonium-Lactat (CAL) zeigt dabei die höchsten Konzentrationen im Extrakt. Die Einhaltung des aktuellen Cadmium-Höchstgehalts für Brotweizen ist bis zu einem Cadmium-Gehalt des Bodens (Königswasser) von 1,0 mg/kg mit einer Wahrscheinlichkeit von 80 % gegeben. Auf der Grundlage der CAL-Extraktion beträgt dieser Schwellenwert 0,4 mg/kg. Die erwartete Absenkung des zulässigen Höchstgehalts auf 0,10 mg/kg Korn verschiebt die Schwellenwerte auf 0,40 mg CdKW/kg bzw. 0,22 mg CdCAL/kg. Die Untersuchungen im Freiland bestätigen die sortenspezifische Aufnahme von Cadmium aus Gefäßversuchen. Für die Transferuntersuchungen wird eine mehrfache Beprobung eines Schlages empfohlen, wobei jeweils von einem ca. 4 m² großen Teilstück eine Bodenmischprobe und eine Mischprobe des zugehörigen pflanzlichen Materials entnommen werden sollte.

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Regenerative agriculture, a soil health focused alternative to conventional agriculture, has been increasingly popular among producers and consumers for its ability to produce nourishing food while also prioritizing the health of the environment. The practices used within this style of farming and ranching also have benefits that make operations more resilient to various agricultural hazards. Few studies have addressed the role of resiliency in the transition process to regenerative agriculture. The purpose of this study was to explore the role of disaster resilience in the decision-making process farmers and ranchers use as they transition to regenerative agricultural practices. Drawing from qualitative, semi-structured interviews with Texas ranchers that use regenerative methods, four major themes were found. First, climate related hazards are a recurring issue because agricultural operations are continually threatened by the same hazards. Next, the food system is in dire need of change, as producers recognize a major problem in the food system, and it is leading to a food insecure future. Also prevalent, disaster resilience is a built-in benefit because regenerative practices result in the creation of systems that build resilience. Finally, learning opportunities are expanding as an increased interest in regenerative agriculture is providing more opportunities for both producer and consumer. The implications of this study highlight new opportunities to bridge the gap between emergency management and agriculture, specifically focusing on the resilience capabilities of using regenerative methods.

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Doctor of Philosophy / Department of Agronomy / Gary M. Pierzynski / The bioavailability of Pb and Zn is linked to the solubility of solid phases and other soil chemical characteristics, which is associated with their environmental risk, suggesting that in situ stabilization of these elements can be accomplished by influencing their chemistry. However, more research is needed to investigate the effectiveness of different soil amendments on reducing Pb and Zn bioavailability. A lab study was conducted to evaluate the effects of five different P amendments and time on Pb/Zn speciation in a contaminated soil using synchrotron-based techniques, while a field investigation studied the effects of composted beef manure on plant biomass production and the influence on microbial function, size, and community shifts. In the lab study, the Pb-phosphate mineral plumbogummite was found as an intermediate phase of pyromorphite formation, which has not been documented until now. Additionally, all fluid and granular P sources were able to induce Pb-phosphate formation, but fluid phosphoric acid (PA) was the most effective with time and distance from the treatment. However, acidity from PA increased the prescence of soluble Zn species, which can have negative environmental consequences. Granular phosphate rock (PR) and triple super phosphate (TSP) reacted to generate both Pb- and Zn-phosphates, with TSP being more effective at greater distances than PR. In the field study, compost additions of 269 Mg ha[superscript]1 significantly decreased bioavailable Zn, while increasing estimated available water, plant nutrients, and plant biomass as compared to a contaminated control and low addition of compost (45 Mg ha[superscript]1) over three years. Additionally, compost additions of 269 Mg ha[superscript]1 significantly increased microbial enzyme activities, nitrification, and microbial biomass over the contaminated control through the duration of the study. Increases in microbial activity and biomass are related to increases in total C, available water, and extractable P, while negative relationships were found with electrical conductivity and with bioavailable Zn. The addition of lime or lime plus bentonite with compost did not further reduce metal availability, increase plant biomass, or improve the size or function of microbial communities. High compost additions caused a slight shift in microbial community structure according to phospholipids fatty acid analysis. Increases in the mole percents of both Gram-positive (Gm[superscript]+) and Gram negative (Gm[superscript]-) bacteria were found depending on site. Microbial biomass of Gm[superscript]+, Gm[superscript]-, and fungi were also increased by high compost additions. Results indicate that large additions of compost are needed to increase microbial biomass, improve microbial activity, and re-establish a healthy vegetative community. This study proposes that organic matter and P amendments can be used to stabilize and reduce the bioavailability of heavy metals in soils and mine waste materials, but must be managed carefully and intelligently.