Please read the abstract in the section 00front of this document / Dissertation (M Eng (Chemical Engineering))--University of Pretoria, 2007. / Chemical Engineering / unrestricted

This project recommends an appropriate land cover master plan for the lower portion of the west fork of Old Woman Creek. The project utilizes the various vegetative treatments, or measures available, to lessen storm water induced sediment concentration levels within the agricultural study site. The over riding design principle is that a return to a more native landscape through the addition of native-like plant species, en mass or as a hedgerow around agricultural fields, will improve the bio-filtering of sediment from runoff as it has in other locations. (Ingles 6/11/96) Suggestions for other erosion control alternatives such as `alternative crops' are also presented. The completion of the master plan is accomplished through identifying those areas in greatest need for erosion control enhancement, suggesting suitable amelioration responses for those areas and illustrating the landscape patterns which would result from the implementation of the project findings. / Department of Landscape Architecture

Orientador: Carolina Fernandes / Banca: José Eduardo Corá / Banca: Maria Helena Moraes Spinelli / Resumo: Sistemas de cultivo conservacionista, como o sistema de semeadura direta, seguem como princípios, a ausência de preparo do solo, a formação e a manutenção de cobertura vegetal e a rotação de culturas. Contudo, quando uma das premissas não é adequadamente adotada pode haver alterações na estrutura do solo e, consequentemente, nas relações solo-planta. Assim, objetivou-se avaliar os atributos físicos e o carbono orgânico do solo em área com preparo do solo e pousio (vegetação espontânea) na entressafra e em áreas sem preparo do solo, com pousio (vegetação espontânea) e com cultivo na entressafra. As áreas com sistemas de cultivo distintos localizaram-se próximas às coordenadas geodésicas 21°14'05'S, 48°17'05'W e altitude média de 550 metros, com clima tipo Aw. O solo das três áreas caracterizou-se como Latossolo Vermelho de textura argilosa (539 g kg-1 de argila na camada de 0,00-0,30 m). Há mais de dez anos, o milho é a principal cultura cultivada no período da safra nas três áreas: sistema de preparo convencional do solo (SPC), com pousio (vegetação espontânea) na entressafra, sistema semeadura direta (SSDE) com pousio (vegetação espontânea) na entressafra e sistema de semeadura direta (SSDM), com cultivo de milho na entressafra. Em cada área coletaram-se 20 amostras de solo em cada uma das camadas, 0,00-0,10 m, 0,10-0,20 m e 0,20-0,30 m de profundidade, em dezembro de 2016, cerca de quinze a vinte dias após a semeadura do milho. Os atributos do solo avaliados foram: diâmet... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Conservation cropping systems, such as the direct sowing system, follow as principles, the absence of soil preparation, the formation and maintenance of vegetation cover and the crop rotation. However, when one of the assumptions is not properly adopted there may be changes in soil structure and, consequently, in soil-plant relationships.. Thus, the objective was to evaluate the physical attributes and soil organic carbon in na area with soil preparation and fallow in the off season and in areas with no tillage, with fallow and with cultivation in the off season. The areas with distinct cultivation systems were located close to the geodesic coordinates 21°14'05'S, 48°17'05'W average altitude of 550 meters with Aw type climate. The soil of the three areas was characterized Red Latosol of clay texture (539 g kg-1 of clay in the layer of 0.00-0.30 m). For more than ten years, maize has been the main cultivated crop during the season in the three areas: conventional tillage system (CTS), fallow in the off season, direct sowing system (DSSS) with fallow (spontaneous vegetation) in the off season, and direct sowing system (DSSC) with corn crop in the off season. In each area 20 soil samples were collected in each of the layers, 0.00 - 0.10 m, 0.10 - 0.20 m and 0.20 - 0.30 m depth, in December 2016, about from fifteen to twenty days after sowing the corn. The soil attributes evaluated were: weighted average diameter of aggregates, aggregate classes, aggregate stability index, soil... (Complete abstract click electronic access below) / Mestre

The objective of this thesis is to provide a detailed investigation of phosphorus transformations in constructed wetlands. Five replicate Wetland Units were constructed adjacent the wastewater treatment plant in Richmond, Australia. Each wetland was supplied with secondary or tertiary sewage effluent and planted identically with species of schoenoplectus, Phragmites, and Triglochin. Detention times for each Unit were established at 5 or 15 days. Phosphorus concentrations were monitored routinely at the inlet and outlet of each Unit, with a number of specific studies conducted to investigate internal transformations. These studies, undertaken in 1994 and 1995, determined that plants were the dominant phosphorus store in the short term, during wetland establishment and that sediments were the dominant long-term phosphorus storage compartment. Laboratory investigations indicated that there was no significant role for bacteria or algae in the water column relating to phosphorus sequestering, although microorganisms appeared to have some role in the translocation of phosphorus to soil binding sites. After phosphorus contacted the soil surface, transpiration related entrainment of surface water and direct phosphorus uptake by plants were the dominant mechanisms for causing phosphorus to move deeper through the soil substrate. Removal of phosphorus from the interstitial water was by incorporation to biomass or direct sorption to soil binding sites / Doctor of Philosophy (PhD)

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 110 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references.

The disturbed soil from a stream channelization project at Cooper Woods was used to evaluate the feasibility of establishing native grasses and forbs and their effectiveness in preventing soil erosion. Treatments included; 1- plots seeded, no application of herbicide, 2-plots seeded, herbicide applied, 3-unseeded and untreated control plots. The effect of variation in slope was assessed for each treatment. Cover and density were significantly different (Ps0.05) during the first and second year of sampling. No significant differences in mean total cover or mean density were attributed to slope variation. There was not a significant interaction between treatment variables in 1994 and 1995. Mean erosion was insignificant (Pz0.05) in 1994. Mean erosion was significantly different (Ps0.001) between slope categories in 1995. Bulk density was insignificant within vegetative treatments in 994, however in 1995, bulk density was significantly different(P=0.002). Plant cover and density were generally negatively associated with soil erosion and bulk density. However, there were a number of anomalies in the results. Four of the native species seeded in treatment plots became well established during the study period. Additional time is necessary to determine the establishment success of the remaining species and their effects on soil erosion. / Department of Biology

Orientador: Newton La Scala Junior / Coorientador: José Eduardo Corá / Coorientador: Daniel De Bortoli Teixeira / Banca: Zigomar Menezes de Souza / Banca: Diego Silva Siqueira / Resumo: A otimização de sistemas conservacionistas de produção, com objetivo de aumentar os estoques de carbono e diminuir a emissão de gases de efeito estufa, e em concomitância aumentar a produtividade agrícola, são considerados um dos maiores desafios da agricultura atual. Diante disto, objetivou-se avaliar a emissão de CO2 (FCO2) e sua relação com os atributos do solo em sistema de semeadura direta com diferentes sucessões de sequências de culturas de verão e de inverno. O estudo foi conduzido em área sob sistema de semeadura direta no município de Jaboticabal-SP, Brasil. Os tratamentos consistiram nas combinações de três sequências de culturas de verão com duas de inverno, sendo as de verão: monocultura do milho (MM), monocultura da soja (SS) e rotação soja e milho (SM). As culturas de inverno foram: crotalaria e milho O delineamento experimental foi em faixas com três blocos em parcelas subdivididas. Entre os meses de julho e agosto foram conduzidas 16 avaliações da emissão de CO2 (FCO2), temperatura (Ts) e umidade (Us) do solo ao longo de um período total de 51 dias. Após essas avaliações foram realizadas coletas de solo, na profundidade de 0-0,20 m para a determinação dos atributos físicos e químicos. Não foi observado interação (p > 0,05) das sequências das culturas verão com as culturas de inverno sobre os atributos do solo, FCO2, Us e Ts tanto na variação temporal quanto para a espacial, por este motivo as culturas de inverno foram comparadas isoladamente das sequências de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The optimization of conservationist production systems, with the aim of increasing carbon stocks, decreasing greenhouse gas emissions, and concom itantly increasing agricultural productivity, are considered one of the greatest challenges of the current agriculture. The objective of this study was to evaluate the CO 2 emission (FCO 2 ) and it is relation with the soil attributes in a direct seeding syst em with different successions of summer and winter crop sequences. The study was conducted in an area under direct seeding system in the municipality of Jaboticabal - SP, Brazil. The treatments consisted of the combinations of three sequences of summer and t wo winter cultures, being summer: maize monoculture (MM), soy monoculture (SS) and soybean and corn (SM) rotation. The winter crops were: crotalaria and corn the experimental design was in bands with three blocks in subdivided plots. Between July and Augus t, 16 evaluations of CO 2 emission (FCO 2 ), temperature (Ts) and soil humidity (Us) were conducted over a total period of 51 days. After these evaluations, soil samples were collected at a depth of 0 - 0.20 m for the determination of physical and chemical attr ibutes. There was no interaction (p > 0.05) of the sequences of summer crops with the winter crops on the attributes of the soil, FCO 2, Us and Ts in both temporal and spatial variation, for this reason the winter crops were compared Isolated from the summe r crop sequences. The Us was the attribute that most influenced the temporal variation of the FCO 2, w ith correlation of (r = 0.79, p < 0.0001) and (r = 0.70; p = 0.002) between MM and SS for the sequences of summer crops, to t he winter crops the correlatio n was (r = 0,78; p < 0,0001) for crotalaria residues (r = 0.66; p = 0. 005) for corn. FCO 2 sh... (Complete abstract click electronic access below) / Mestre

Thesis (M. Phil.)--University of Hong Kong, 1993.

Thesis (M.Phil.)--University of Hong Kong, 1993. / Also available in print.

published_or_final_version / abstract / toc / Applied Geosciences / Master / Master of Science