Traditionally, local above- and below-ground plant and microbial communities, temperature and precipitation, topography and texture and composition of parent material have been thought to govern the soil processes that lead to soil organic matter accumulation over decades or centuries. Soil organic matter is a substantial global reservoir of carbon and disturbance of equilibrated soils often leads to efflux of significant quantities of CO2. Anthropogenic influences shift the inputs, disturb the structure and alter the biochemistry of soil, profoundly disrupting soil-forming processes. Urbanization leads to soil organic matter equilibria that are different from those in naturally forming soils. Measurement of soil organic matter in diverse cities suggests that they differ in their capacity to accumulate soil organic matter. Here I quantify soil organic matter and examine the limitations of its accumulation within cities by comparing differences in soil organic matter and natural and anthropogenic characteristics at the neighborhood, city and regional scales in Portland, Oregon to that in the Pacific Northwest. I found that each Portland neighborhood has distinct urban characteristics and tree and shrub community composition, but soil organic matter content is indistinguishable among them. Across Portland, neither vegetation structure nor urban factors appear to directly influence soil organic matter content. Rather, microbial biomass, bulk density and total nitrogen appear to be important factors controlling soil organic matter content in Portland. The amount of soil organic matter stored in Portland's soils is statistically indistinguishable from Pacific Northwest soils, in contrast to other temperate cities.

Biosolids have been used as soil conditioners and fertilizers in agriculture and mine land reclamation, but application of Exceptional Quality (EQ) biosolids to rehabilitate anthropogenic soils for urban agriculture is recent and requires greater study to ensure their appropriate use. The objectives were: 1) to quantify plant available nitrogen (PAN) of new EQ biosolids in a greenhouse bioassay; 2) to quantify PAN of EQ biosolids applied to an urban degraded subsoil via tall fescue N fertilizer equivalency, and compare field results to laboratory tests; 3) to investigate EQ biosolids and inorganic fertilizer effects on urban soil properties, vegetable yields, and potential N and phosphorus (P) loss. Biosolids evaluated were products of thermal hydrolysis plus anaerobic digestion (BLOOM), blending with woody mulch (BM) and sand/sawdust (BSS), composting (LBC), and heat-drying (OCB). Organic N mineralization of new blended biosolids products ranged between 20-25% in the greenhouse bioassay. Products BLOOM, BM, and OCB had the highest organic N mineralization as estimated by the 7-day anaerobic incubation, and this test and soil nitrate-N had the highest correlations with tall fescue N uptake (r=0.49 and r=0.505, respectively). We conducted a two-year field study with four growing seasons (fall 2016-2017 and summer 2017-2018) in an urban disturbed subsoil where EQ biosolids were applied seasonally at agronomic N rates, and yearly at reclamation rates (5x agronomic N). Cabbage yields were greater with reclamation rates (~3.0 kg m-2) and bell pepper yields were greater with BLOOM reclamation rate (~1.0 kg m-2) than with the inorganic fertilizer (1.0 kg m-2 and 0.2 kg m-2, respectively) during second year growing seasons. Soil carbon (C) accumulation (%C remaining in the soil) two years after biosolids additions ranged between 37 to 84%. Soil N availability and mineralization were limited most likely due to lack of residual soil C and N, and high clay content. Nitrogen leaching losses from reclamation rates were not greater than agronomic N rates. Leachate P was below detection during most of the experiment. Despite limiting soil conditions, biosolids amendment at reclamation rates showed greatest potential to increase vegetable yield and improve soil properties after two years of application, while not impairing water quality. / Doctor of Philosophy / Exceptional Quality (EQ) biosolids are by-products of wastewater treatment plants that have been processed to destroy pathogens, reduce attraction by disease-spreading organisms (e.g. flies, mosquitoes, rodents, etc.), and limit heavy metal concentrations. These characteristics make EQ biosolids safe for use by home gardeners for growing food crops. There is limited information on optimal recommended rates at which these products should be applied to urban gardens. The purpose of our research was to determine optimum application rates of EQ biosolids to urban gardens based on their essential plant nutrient (esp., nitrogen and phosphorus) availability. We learned that the EQ biosolids we studied are less concentrated in plant available nitrogen and phosphorus than biosolids applied to conventional agricultural fields. This is because we diluted our biosolids with sawdust, sand, and woody mulch to facilitate their storage, handling, and ease of application. We learned that high EQ biosolids application rates reduce soil compaction and increase essential plant nutrient availability and crop yields for agriculture practiced in urban soils. The high application rates of EQ biosolids accomplished such soil-improving and yield-increasing benefits without impairing local water quality.

published_or_final_version / Geography / Master / Master of Philosophy

Made available in DSpace on 2015-03-26T13:53:37Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3074344 bytes, checksum: b64060ed53c4bf5c7220ac45eeca9468 (MD5) Previous issue date: 2006-06-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The fast urbanization of the underdeveloped countries and the exodus field-city increased the ability of the cities to attend this new demand to provide job and appropriate life conditions to growing population. The urban agriculture and around of urban areas shown as a viable activity for the improvement of the quality of life of the urban populations, mainly of the poorest layers. Rio Branco, the capital of the Acre state, is a typical city of the Brazilian Amazon, located inthe Acre river basin, whose formation was influenced to the growth of the extraction and commercialization of the latex. Rio Branco presented an accelerated urban and population growth in last decades, resulting in inefficient urban planning and inequalities in the form of occupation of the urban spaces. The main objective of this study was to elaborate a diagnosis of the use of the soils in the city of Rio Branco, with the approach of the public actions planning that increase or restrict use forms and maximize the family income in the soil conditions and atmosphere of the city in study. As hypothesis, was considered that different patterns from agricultural use of the urban soil in Rio Branco, shows relationship with the process of occupation of the area, with the cultural migrants variations that there fixed, and with the soils types. The soils of the Acre state, as well as of the Rio Branco, presents influenced genesis by sediments of the Andes Cordillera, and most possesses eutrophic characteristics and clay of high activity. Three study sites were selected, distributed in topographic sequence, along the urban area. Inside of each neighbourhood were selected five sampling points, also in topographic sequence. In the materials of soils were accomplished physical, chemical, mineralogical and heavy-metals analysis. After that was elaborated a land use cover and the soil types mapping, with subsequent geoprocessing operations, for example, crossing different maps, for the three studied neighbourhoods. The Plates neighbourhood is located in the highest part and has better soil drainage. This site presented most appropriate land use than the others neighbourhoods, Jardim Primavera and New City. That last neighbourhood presented the worst land use conditions, with few areas of arboreal vegetation and great impermeable areas and exposed soil. In general, all the soils along the topographic sequence have eutrophic characteristics and rich in nutrients, except in only one point located in the Jardim Primavera neighbourhood. All of the soil types are influenced by the freatic surface, for now in a more outstanding way, as in the gleic and fluvic soils, now minus, as in the plintita soils. In general, the soils did not present nutritional restrictions, and they were shown capable to the agricultural use. In many of the sample points, anthropogenic contributions was verified, with anomalous tenors of P, K, Ca, Mg and some micronutrients, as Fe, Zn and Cu, besides the presence of dumps and dejections. The largest restrictions to the agricultural use of the studied urban soils were: the height and variation of the freatic surface and the fragmentation and use of the urban lots. / A rápida urbanização dos países subdesenvolvidos e o êxodo campocidade aumentaram a necessidade das cidades de prover emprego e condições de vida adequadas à crescente população. A agricultura urbana e periurbana (AUP) mostra-se como uma atividade viável para a melhoria da qualidade de vida das populações urbanas, principalmente das camadas mais pobres. Rio Branco, capital do estado do Acre, é uma cidade típica da Amazônia brasileira, situada na bacia do rio Acre, cuja formação foi atrelada ao crescimento da extração e comercialização da borracha. Rio Branco apresentou crescimento urbano e populacional acelerado nas ultimas décadas, resultando em falta de planejamento urbano e desigualdades na forma de ocupação dos espaços urbanos. O principal objetivo deste estudo foi elaborar um diagnóstico do uso dos solos na cidade de Rio Branco, com vista ao planejamento de ações públicas que incrementem ou restrinjam formas de uso e maximizem a renda familiar nas condições de solo e ambiente da cidade em estudo. Como hipótese, considerou-se que padrões distintos de uso agrícola do solo urbano em Rio Branco mostram estreita relação com o processo de ocupação da região, com variações culturais dos migrantes que ali se instalaram, e com os tipos de solos. Os solos do estado do Acre, bem como de Rio Branco, apresentam gênese influenciada por sedimentos da Cordilheira dos Andes, e a maior parte possui caráter eutrófico e argila de atividade alta. Foram selecionados três bairros de estudo, distribuídos em toposequência, ao longo do sítio urbano. Dentro de cada bairro selecionaram-se cinco pontos de amostragem, também em toposequência. Nos materiais de solos foram realizadas análises físicas, químicas, mineralógicas e de elementos-traços. Realizou-se o mapeamento de uso e cobertura do solo e das classes de solo, com posterior cruzamento destes mapas, para os três bairros estudados. O bairro de Placas, localizado na parte mais alta e com melhor drenagem, apresentou um parcelamento e uso do solo mais adequados que os bairros Jardim Primavera e Cidade Nova. Esse último bairro apresentou as piores condições de parcelamento e uso do solo, com poucas áreas de vegetação arbórea e grandes áreas impermeabilizadas e em solo exposto. De forma geral, todos os solos ao longo da seqüência altimétrica mostram-se eutróficos e ricos em nutrientes, com exceção de um ponto no bairro Jardim Primavera. Todas as classes de solo são influenciadas pelo lençol freático, ora de forma mais marcante, como nos solos gleicos e flúvicos, ora menos, como nos solos com plintita. Em geral, os solos não apresentaram restrições nutricionais, e mostraram-se aptos ao cultivo agrícola. Em muitos dos pontos amostrados constatou-se aportes antropogênicos, com teores anômalos de P, K, Ca, Mg e alguns micronutrientes, como Fe, Zn e Cu, além da presença de entulhos e dejetos. As maiores restrições ao uso agrícola dos solos urbanos estudados foram: a altura e variação do lençol freático e a fragmentação e uso dos lotes urbanos.

Prague and Brno belong to one of the most contaminated cities of Czech Republic. The main objective of this study was to compare PGE contents and concentrations of risk elements (Zn, Cd, Pb, Cu, As, Sb, Hg) in the soils of both cities's municipal parks. Soil samples were taken from depths of 0-10 cm, 10-20 cm and 20-30 cm. Besides soil samples, the sand samples from children sandpits were taken from depth 0-30 cm. In 52 samples of soil and sand Pd, Pt and Rh contents were determinated by ICP- MS after Ni-S fire assay procedure. Soil samples were additionally analysed on Pb isotopic composition. Higher PGE contents were determined in Prague; the highest contents were measured at location of Ortenovo náměstí (50,5 μg·kg-1 Pt, 33,9 μg·kg-1 Pd a 11,3 μg·kg-1 Rh). Elevated PGE concentrations were found in the upper layers of most soils in both cities. Elevated contents of risk elements were determined at locations with high traffic density. Most of samples showed that contents of risk elements decrease with depth. The highest concentrations reached Zn (394 mg·kg-1 ), Pb (290 mg·kg-1 ) and Cu (181 mg·kg-1 ). In Prague, the isotopic ratios 206 Pb/207 Pb vary from 1,136 to 1,181; in Brno from 1,161 to 1,192. Measured isotopic ratios suggest contamination both from gasoline and ore combustion. Key words:...

This study aims to determine the concentration of 16 Polycyclic Aromatic Hydrocarbons (PAHs) in urban soils from West Yorkshire in order to determine what the factors are controlling their distribution and abundances. Although PAHs have been reported before from soils and sediments, the majority of these studies have come from China, sometimes with contrasting results, which emphasises the need to obtain equivalent data from other areas. Therefore this work provides the first measurements of their type from the area studied. Soil samples were collected from one hundred sites across an area from Bradford to Leeds on two occasions, one in autumn and one in the following summer. The soil samples were analyzed by X-ray diffraction and all found to have similar mineralogical composition, which was mainly silica and calcite. Trials using iodine as a marker for PAHs showed there were notable interactions between the minerals and PAHs, with calcium carbonate absorbing PAHs much more than silica. There is a negative correlation between the soil organic content (determined by loss on ignition) and PAHs, which confirms the PAH-mineral interaction. Gas chromatography with mass spectrometry (GC-MS) using targeted selected ion monitoring was used to determine and quantify PAHs in the one hundred soil samples with the aid of PAH external standards. The results showed highest concentrations of total PAHs in the same sample from Leeds from the autumn (1,525 ng/g) and in the summer (1,768 ng/g). In Bradford there was only moderate pollution of PAHs, the maximum being 122 ng/g. However the majority of data from Bradford showed lower levels of pollution in both summer and autumn. On the basis of prior published information, the ratio of these compounds has been used to help in identifying sources. In the samples collected from Bradford in both seasons and Leeds in autumn the PAH pollution originated from pyrogenic, biomass and petroleum combustion, however in the summer the source appeared more to be from a petrogenic source. These ratios in the samples which were collected from the area between Bradford and Leeds implied pyrogenic, biomass source of pollution in the autumn, but in the summer another source of organic compounds was indicated namely petroleum combustion. When the locations were resampled nine months later, after taking into account within-site variability, there was a strong indication that the PAH concentrations were higher. This might have been due to a seasonal effect, but when a further (third) subsample was taken at a later date it showed a further increase in PAH level which suggests the effect is accumulative rather than seasonal. The results were analysed using Principal Component Analysis (PCA) to determine whether the type of road had an effect on the concentration of the 16 PAHs compounds, but it was concluded that there was no such effect. However, the distance from the soil sample to the nearest road did have an effect on the concentration of the 16 PAH compounds, especially in soil samples having the shortest distance to the road. Traffic volume was also tested and found to influence the PAH concentrations. It is notable that, comparing the groupings from autumn with those from summer by cluster analyses, they largely had the same compounds grouping together in both cases; only two compounds differed at all in where they occurred in the clusters, with consistent patterns of grouping found for the other compounds. These analyses indicate that PAH compounds behave in a consistent way amongst groups of PAH compounds. The grouping of PAHs appears linked to their sources rather than number of rings or molecular weight. / Libyan Government and Embassy

Les grands réaménagements urbains génèrent d’importants volumes de terres excavées, dont la valorisation est désormais possible si elles sont compatibles avec le fond pédo-géochimique du site receveur. Afin de faciliter cette valorisation, cette thèse s’intéresse à des méthodologies de traitement de données acquises à d'autres fins que la détermination du fond pédo-géochimique, afin de fournir un référentiel de qualité géochimique des sols urbains à l'échelle d'un quartier ou d'une ville. Les premiers tests montrent les limites des calculs statistiques, usuellement utilisés avec des données dédiées au fond pédo-géochimique du fait de leur sensibilité à la limite de quantification, à la loi de distribution ou encore au pourcentage d'anomalie. Le découpage du territoire en entités géographiques cohérentes à partir de la nature des sols et sous-sols et des pressions anthropiques (actuelles ou passées) permet la constitution de différents niveaux de fond suivant la qualité géochimique des sols, mais une des difficultés concerne le renseignement de l'ensemble des entités. La classification statistique des échantillons, même spatialisée, n'apporte, actuellement pas de résultats exploitables pour la gestion des terres excavées. Enfin, le filtrage géostatistique via un modèle linéaire de corégionalisation présente une alternative solide pour le filtrage des anomalies et l'estimation du fond à l'échelle d'un quartier. / Large urban redevelopments generate large volumes of excavated soils whose reusability is now possible if they are compatible with the pedo-geochemical background of the receiving site. In order to facilitate this valorization, this thesis focuses on processing methodologies on data acquired for other purposes than the determination of the pedo-geochemical background, in order to provide a geochemical quality reference system for urban soils at the scale of one neighborhood or city. The first tests show the limits of the statistical stresholds, usually used with data dedicated to the pedo-geochemical background because of their sensitivity to the limit of quantification, to the distribution law or to the percentage of anomaly. The segmentation of the territory into coherent geographical entities based on the nature of the soil and subsoil and the anthropogenic pressures (current or past) allows the constitution of different geochemical background levels according to the geochemical quality of the soils, but one of the difficulties concerns the information of all entities. The statistical classification of the samples, even if spatialized, does not currently provide usable results for the management of the excavated earth. Lastly, geostatistical filtering via a linear model of coregionalisation provides a solid alternative for anomaly filtering and background estimation at a neighborhood scale.

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