Orientador: Itamar Andrioli / Banca: Itamar Andrioli / Banca: Renato de Mello Prado / Banca: Adilson Pelá / Resumo: Os resíduos produzidos pelas culturas comerciais, geralmente, são insuficientes para proporcionarem uma adequada cobertura do solo. Portanto, é necessário introduzir ao sistema, plantas capazes de produzirem grandes quantidades de fitomassa com rápido desenvolvimento inicial e de ciclo curto. O objetivo deste trabalho foi avaliar a produção de matéria seca e o N acumulado pelas plantas de cobertura, a produção de matéria seca do milho, o fornecimento de N ao milho e o rendimento de grãos da cultura devido aos sistemas de sucessão de plantas de cobertura em pré-safra ao milho. O experimento foi conduzido na área experimental da FCAV - Unesp Jaboticabal SP, (21º15'27"S e 48º18'58"W; 595 m de altitude) nos anos agrícolas 2006/07 e 2007/08. O delineamento experimental adotado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições, em que os tratamentos principais foram constituídos por seis sistemas de sucessão (S1=crotalária/milho; S2=feijão-deporco/ milho; S3= lablabe/milho; S4=milheto/milho, S5=mucuna-preta/milho e S6=pousio/milho). Nas subparcelas foram aplicadas quatro doses de nitrogênio em forma de uréia em cobertura nas doses de 0, 60, 120 e 180 kg ha-1. Pode-se concluir que: as espécies de cobertura que produziram mais fitomassa foram milheto e crotalária (2007/08) e as que mais acumularam nitrogênio foram mucuna-preta (2006/07) e milheto e crotalária (2007/08). No ano agrícola 2007/08 a sucessão S1 apresentou os maiores teores de N no tecido foliar e maior MS do sabugo na ausência de adubação nitrogenada. Quando aplicado 60 kg ha-1 de N a sucessão S5 obteve maior teor de N foliar no milho. A maior produção de MS de grãos na ausência de adubação nitrogenada no ano 2007/08 ocorreu nas sucessões S1 e S3. O maior acúmulo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The residues produced by commercial crops usually are insufficient to produce a good soil cover. Therefore, it is necessary to introduce the system, plants capable of producing large quantities of biomass with rapid initial development and short cycle. The objective of this work was to evaluate the production of biomass and N accumulation by the plants cover, the dry biomass of corn, the N supply of corn and the grain yield of the crop due to the succession systems of plant cover in pre-safra to the corn. The experiment was conducted in the experimental area of FCAV - Unesp Jaboticabal SP, (21 º 15 'S and 48 º 18' W, 595 m altitude). The experimental design was randomized blocks, in split plots with four replications, where the main treatments were consisted of six succession systems (S1 = sunn hemp/corn; S2 = pig-bean/corn, S3 = lablab/corn; S4 = millet/corn, S5 = velvetbean /corn and S6 = fallow/maize). In the subplots were applied four rates of nitrogen as urea in coverage at doses of 0, 60, 120 and 180 kg ha-1. It can be concluded that the species of coverage that were produced more biomass were millet and sunn hemp (2007/08) and that accumulated more nitrogen was velvetbean (2006/07) and millet and sunn hemp (2007/08). In the year 2007/08 the succession S1 showed the highest levels of N in leaf tissue and increased MS of root in the absence of nitrogen fertilization. When applied 60 kg ha-1 of N the S5 succession was higher N level leaf and S1 succession higher of root MS. The highest production of MS grain in the absence of nitrogen fertilization in the year 2007/08 was in S1 and S3 successions. The highest accumulation of N in grain in the absence of nitrogen fertilization were found in S1, S3 and S5 successions. The S3 succession promoted the highest accumulation of N in biomass of corn in the year 2007/08. / Mestre

The mining of oil sands in the sub-humid region of Northern Alberta, Canada causes large-scale landscape disturbance, which subsequently requires extensive reclamation to re-establish the surface and subsurface hydrology. The reconstructed watersheds examined in this study are located at the Syncrude Canada Limited mine site, 40 km North of Fort McMurray, Alberta, Canada. The three experimental reconstructed watersheds, with nominal soil thicknesses of 1.0 m, 0.50 m and 0.35 m comprised a thin layer of peat (15-20 cm) over varying thicknesses of secondary (till) soil, have been constructed to cover saline sodic overburden and to provide sufficient moisture storage for vegetation while minimizing surface runoff and deep percolation to the underlying shale overburden. In order to replicate the hydrological behavior, assess the sustainability, and trace the evolution over time of the reclaimed watersheds, a suitable modeling tool is needed.</p> <p>In this research, a model is developed using the system dynamics approach to simulate the hydrological processes in the three experimental reconstructed watersheds and to assess their ability to provide the various watershed functions. The model simulates the vertical and lateral water movement, surface runoff and evapotranspiration within each watershed. Actual evapotranspiration, which plays an important role in the hydrology of the Canadian semi-arid regions, is simulated using an indexed soil moisture method. The movement of water within the various soil layers of the cover is based on parametric relationships in conjunction with conceptual infiltration models. The feedback relationships among the various dynamic hydrologic processes in the watershed are captured in the developed System Dynamic Watershed Model (SDWM). </p> <p>Most hydrological models are evaluated using runoff as the determining criterion for model calibration and validation, while accounting for the movement of moisture in the soil as a water loss. Since one of the primary objectives of a reconstructed watershed is to maintain the natural flora and fauna, it is important to recognize that soil moisture plays an important role in assessing the performance of the reconstructed watersheds. In turn, soil moisture becomes an influential factor for quantifying the health of the reconstructed watershed. The developed model has been calibrated and validated with data for two years (2001-2002), upholding the sensitive relationship between soil moisture and runoff. Accurate calibration of the model based on simulations of soil moisture in the various soil layers improves its overall performance. The model was subsequently used to simulate the three sub-watersheds for five years, with changing the calibrated model parameters to use them as indicators of watershed evolution. The simulated results were compared with the observed values. </p> <p>The results of the study illustrate that all three watersheds are still evolving. Failure to identify a unique parameter set for simulating the watershed response supports the hypothesis of watershed evolution. Soil moisture exchange between the till and peat layers changed with time in all of the watersheds. There was also a modest change in the water movement from the till to shale layers in each of the sub-watersheds. Vegetation is increasing in all of watersheds although there is an indication that one of the sub-watersheds may be sustaining deep rooted vegetation. The results demonstrate the successful application of the system dynamics approach and the developed model in simulating the hydrology of reconstructed watersheds and the potential for using this approach in assessing complex hydrologic systems.

The mining of oil sands in the sub-humid region of Northern Alberta, Canada causes large-scale landscape disturbance, which subsequently requires extensive reclamation to re-establish the surface and subsurface hydrology. The reconstructed watersheds examined in this study are located at the Syncrude Canada Limited mine site, 40 km North of Fort McMurray, Alberta, Canada. The three experimental reconstructed watersheds, with nominal soil thicknesses of 1.0 m, 0.50 m and 0.35 m comprised a thin layer of peat (15-20 cm) over varying thicknesses of secondary (till) soil, have been constructed to cover saline sodic overburden and to provide sufficient moisture storage for vegetation while minimizing surface runoff and deep percolation to the underlying shale overburden. In order to replicate the hydrological behavior, assess the sustainability, and trace the evolution over time of the reclaimed watersheds, a suitable modeling tool is needed.</p> <p>In this research, a model is developed using the system dynamics approach to simulate the hydrological processes in the three experimental reconstructed watersheds and to assess their ability to provide the various watershed functions. The model simulates the vertical and lateral water movement, surface runoff and evapotranspiration within each watershed. Actual evapotranspiration, which plays an important role in the hydrology of the Canadian semi-arid regions, is simulated using an indexed soil moisture method. The movement of water within the various soil layers of the cover is based on parametric relationships in conjunction with conceptual infiltration models. The feedback relationships among the various dynamic hydrologic processes in the watershed are captured in the developed System Dynamic Watershed Model (SDWM). </p> <p>Most hydrological models are evaluated using runoff as the determining criterion for model calibration and validation, while accounting for the movement of moisture in the soil as a water loss. Since one of the primary objectives of a reconstructed watershed is to maintain the natural flora and fauna, it is important to recognize that soil moisture plays an important role in assessing the performance of the reconstructed watersheds. In turn, soil moisture becomes an influential factor for quantifying the health of the reconstructed watershed. The developed model has been calibrated and validated with data for two years (2001-2002), upholding the sensitive relationship between soil moisture and runoff. Accurate calibration of the model based on simulations of soil moisture in the various soil layers improves its overall performance. The model was subsequently used to simulate the three sub-watersheds for five years, with changing the calibrated model parameters to use them as indicators of watershed evolution. The simulated results were compared with the observed values. </p> <p>The results of the study illustrate that all three watersheds are still evolving. Failure to identify a unique parameter set for simulating the watershed response supports the hypothesis of watershed evolution. Soil moisture exchange between the till and peat layers changed with time in all of the watersheds. There was also a modest change in the water movement from the till to shale layers in each of the sub-watersheds. Vegetation is increasing in all of watersheds although there is an indication that one of the sub-watersheds may be sustaining deep rooted vegetation. The results demonstrate the successful application of the system dynamics approach and the developed model in simulating the hydrology of reconstructed watersheds and the potential for using this approach in assessing complex hydrologic systems.

No description available.

Historical gold mine tailings at several sites in Nova Scotia, Canada are publicly accessible and may pose a threat to human and ecosystem health because of high arsenic (As) concentrations in the tailings (max 25 wt.%) and associated pore waters (up to 100 mg/L). Two of these sites, Montague and Goldenville, are under consideration for remediation. Similar tailings sites have been cleaned up by covering the mine wastes with soil. However, the tailings at Montague and Goldenville have been weathering for at least 70 years, leading to a wide range of As-bearing secondary minerals which may dissolve under a soil cover, releasing As to local waters. The challenge of remediating these heterogeneous tailings lies in the different Eh-pH niches in which iron arsenates (oxidizing, acidic), calcium-iron-arsenates (oxidizing, alkaline), and sulfides (reducing) are stable. The main objectives of this study were to: 1) characterize pre-remediation geochemical controls on As mobility in subsurface tailings; 2) establish hydrogeological influences on As mobility; and 3) identify geochemical changes that result when a low organic soil cover is applied to the tailings. Pore water measurements were combined with bulk chemistry, scanning electron microscopy, and synchrotron micro-X-ray diffraction analyses, which were used to characterize the mineralogical composition of the tailings. Groundwater and surface water flow regimes throughout the tailings were defined through the use of piezometers and hydraulic conductivity measurements. Laboratory leaching experiments were used to assess the effects of a soil cover on the tailings. Variable weathering conditions over time have resulted in a continuum of saturation and redox environments and a range of As hosts in the tailings. In some areas, tailings pore waters are mixing with stream waters leading to As transport beyond the tailings. Applying a low organic soil cover does not induce reducing conditions in the tailings or cause dissolved As concentrations to increase compared to field pore water concentrations. This type of soil cover is effective in slowing sulfide mineral oxidation while maintaining stable conditions for secondary As-phases. The results of this research can be used to inform remediation decisions and guide ongoing environmental management of historical gold mine sites. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2014-06-04 10:22:43.838

Submitted by EDVANIA APARECIDA CORRÊA null (edvaniacorrea@ig.com.br) on 2016-02-25T00:45:45Z No. of bitstreams: 1 Tese_Edvania_Ap_Correa.pdf: 11022771 bytes, checksum: af5a3e14625bf39833f09a6da312c892 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-02-26T14:43:04Z (GMT) No. of bitstreams: 1 correa_ea_dr_rcla.pdf: 11022771 bytes, checksum: af5a3e14625bf39833f09a6da312c892 (MD5) / Made available in DSpace on 2016-02-26T14:43:04Z (GMT). No. of bitstreams: 1 correa_ea_dr_rcla.pdf: 11022771 bytes, checksum: af5a3e14625bf39833f09a6da312c892 (MD5) Previous issue date: 2016-01-22 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / No Brasil, poucos são os estudos sobre a estimativa de perdas de solo em cana-de-açúcar e sobre o levantamento do fator C da EUPS em cultivos alocados em paisagens com diferentes potenciais naturais à erosão. Também, no contexto mundial, poucos são os estudos que propõem metodologias alternativas para a determinação do fator C em climas tropicais. Assim, o objetivo desta pesquisa foi o de elaborar um procedimento metodológico para a determinação do fator C a partir da quantificação das perdas de solos e índices de vegetação em pastagens e cana-de-açúcar. Foram utilizados dados multissensores correlacionados aos valores do fator C estimados em 11 parcelas de monitoramento de erosão. As parcelas foram instaladas na bacia hidrográfica do córrego Monjolo Grande (Ipeúna/SP) e na bacia hidrográfica do ribeirão Jacutinga (Rio Claro/SP). Estas bacias apresentam semelhanças quanto às dimensões em área e uso da terra e variabilidade quanto às características pedológicas e de relevo. Em todas as parcelas com pastagens, as perdas de solo foram inferiores a 1,5 t ha-1 ano-1 e o fator C foi de 0,1. Mesmo em condições diversas de paisagem, as gramíneas presentes nas áreas de pastagens se comportaram de maneira similar frente aos processos erosivos. Por outro lado, verificou-se diferenças nas perdas de solos nas parcelas com cana-de-açúcar localizadas em ambas as áreas de estudo. Nos solos argilosos da bacia hidrográfica do ribeirão Jacutinga as perdas variaram de 0,8 a 2,76 t ha-1 ano-1. Já nos solos arenosos da bacia hidrográfica do córrego Monjolo Grande as perdas variaram de 49 a 84,8 t ha-1 ano-1. Assim, as diferenças nas perdas de solo em canaviais são derivadas das condições físicas de cada paisagem. Os valores do fator C nos canaviais variaram de 0,13 a 0,23 para a bacia hidrográfica do ribeirão Jacutinga e de 0,41 a 0,43 para a bacia hidrográfica do córrego Monjolo Grande. Assim, no contexto regional estudado, a expansão e o cultivo de cana-de-açúcar é realizado indistintamente, não considerando as condições de fragilidade natural de cada ambiente. Os dados de perdas de solo obtidos em campo correlacionados aos dados de sensoriamento remoto proporcionaram a criação de uma metodologia de determinação do Fator C. A utilização desta metodologia possibilitou a melhoria da modelagem da MEUPS em eventos individuais de chuva em ambas as áreas de estudo. / In Brazil, there are few studies on the estimation of soil losses in sugarcane and acquisition the factor C in the USLE in landscapes with different potential natural erosion. Also, in the global context, there are few studies that propose alternative methods for the extraction of Factor C in tropical climates. The objective of this research was to develop a preliminary methodological procedure to extract the factor C for pasture and sugarcane. Multisensor data correlated to the Factor C values estimated at plots were used. The plots were installed in the watershed of the stream Monjolo Grande (Ipeúna / SP) and Jacutinga (Rio Claro / SP). These basins have similarities as to the area and land use and variability as to the soil and relief. In all plots with pasture, soil losses were less than 1.5 t ha-1 yr -1 and C factor was 0.1. Even under various conditions of landscape, grasses present in pasture areas behaved in a similar way to the front erosion. On the other hand, there are differences in the losses of soil in the plots with sugarcane located in both study areas. In clay soils of the watershed of Jacutinga creek losses ranged from 0.8 to 2.76 t ha-1 yr-1 . In the sandy soils of the watershed stream Monjolo Grande losses ranged from 49 to 84.8 t ha-1 yr-1 . Thus, differences in soil loss in sugarcane fields are derived from the physical conditions of each landscape. The values of the C factor in the cane fields ranging from 0.13 to 0.23 for the watershed of the Jacutinga creek and 0.41 to 0.43 for the watershed stream Monjolo Grande. Thus, in the regional context studied, the expansion and sugarcane cultivation is done indiscriminately, without considering the fragility natural conditions of each environment. The data obtained in soil losses related to the field of remote sensing data led to the creation of a methodology for determining factor C. The use of this methodology improve the modeling of MEUPS in individual rainfall events in both study areas. / FAPESP: 2012/08527-5 / FAPESP: 2012/19935-7

Made available in DSpace on 2014-06-11T19:32:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-03-31Bitstream added on 2014-06-13T21:04:21Z : No. of bitstreams: 1 backes_c_dr_botfca.pdf: 1024890 bytes, checksum: 91a05475df40d34d77d94079924ecc73 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A disposição final de lodo de esgoto no solo representa não somente um sistema apropriado, mas também a oportunidade para o manejo dos mesmos com o mínimo de efeito sobre o ambiente podendo gerar benefícios químicos e físicos ao solo. O trabalho teve como objetivo avaliar doses de lodo de esgoto e o efeito residual na produção e qualidade de tapetes de grama esmeralda bem como as alterações químicas desse solo. Os experimentos foram instalados e conduzidos em uma propriedade de grama, localizada na cidade de Itapetininga - SP. A cultura utilizada foi a grama Zoysia japonica Steud. conhecida como grama esmeralda. O delineamento experimental utilizado foi o de blocos ao acaso em parcelas subdivididas, com quatro repetições, sendo as parcelas principais constituídas por dois sistemas de manejo (com e sem o uso de um escarificador superficial “estrelinha”, utilizado para romper uma camada superficial compactada). e as subparcelas de cinco doses de lodo (0, 10, 20, 30 e 40 Mg ha-1, base seca), mais um tratamento com adubação química, de acordo com as necessidades da cultura. Utilizou-se o lodo da Estação de Tratamento de Esgoto de Jundiaí. As doses de lodo aplicadas correspondem às doses de 100, 200, 300 e 400 kg ha-1 de nitrogênio. Após a colheita dos tapetes, avaliou-se o efeito residual das doses de lodo e dos sistemas de manejo utilizados. Pode-se concluir que aos 165 dias após a aplicação do lodo de esgoto, a dose de 31 Mg ha-1 permitiu a formação completa do tapete de grama (100% da taxa de cobertura do solo). O mesmo resultado foi encontrado quando utilizou-se a adubação química. A testemunha e as parcelas que receberam 10 Mg ha-1 de lodo não formaram tapete. Verificou-se redução na massa dos tapetes de grama com o aumento das doses de lodo aplicadas. Com a utilização do escarificador... / The final disposal of municipal waste in the ground is not only an appropriate system, but also the opportunity for management of those with the least possible effect on the environment and can generate chemical and physical benefits to the soil. The present study aimed to evaluate the sewage sludge doses and its residual effects in the zoysiagrass sod production system and also the chemical changes in the soil. The experiment was carried out in a grass grower property, located in the city of Itapetininga-SP. The turfgrass used was Zoysia japonica Steud. known as esmeralda. The experimental design adopted was randomized blocks with split plot design, with four replications, the main plots consisting of two management systems (with and without chisel use, to break a compacted surface layer) and subplots consisting of five doses of sludge (0, 10, 20, 30 and 40 Mg ha-1, a dry basis), another treatment with chemical fertilization, according to the requirement of the culture. The sludge used came from “Estação de Tratamento de Esgoto de Jundiaí”. The doses of sludge applied correspond to the doses of 100, 200, 300 and 400 kg ha-1 of nitrogen. After sod harvesting it was evaluated the residual effect of the sludge doses and evaluated the management system used. It can be concluded that 165 days after application of sewage sludge the dose of 31 Mg ha-1 allowed the complete closing of the zoysiagrass sod (100% of soil cover rate). The same results were found when used chemical fertilization. The control and the plots that received 10 Mg ha-1 of sludge did not formed sod. There was a reduction in weight of zoysiagrass sod with increasing doses of sludge applied. With the use of surface chisel, there was a decrease in the strength of zoysiagrass sod. There were residual effect of sludge application and also of chemical fertilization in...(Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:23:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-17Bitstream added on 2014-06-13T19:29:19Z : No. of bitstreams: 1 romero_ncs_me_jabo.pdf: 222375 bytes, checksum: d476616a717c38931554bc9504c6794f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As reduções das perdas de matéria orgânica e nutrientes por erosão hídrica do solo tornam-se fundamentais, no contexto atual de sistemas de produção sustentáveis, para o aumento do seqüestro de carbono no solo e, consequentemente, diminuir as emissões de gases que contribuem para o efeito estufa como o CO2. Deste modo, o objetivo do presente trabalho foi o de quantificar as concentrações de matéria orgânica (MO) e nutrientes (P, K, Ca e Mg) e, calcular, a taxa de enriquecimento desses elementos no sedimento erodido, em área cultivada com a cultura de cana-de-açúcar, em níveis de cobertura do solo de 0% (CS0), 50% (CS50) e 100% (CS100).As parcelas experimentais foram submetidas à ação de uma chuva simulada com intensidade de 60 mm h-1, durante 65 minutos. Foram feitas análises do sedimento erodido e determinouse, as taxas de enriquecimento do mesmo em MO e nutrientes, valores estes que tiveram as seguintes variações: MO (2,9 a 0,5), P (1,5 a 0,2), K (2,4 a 0,8), Ca (3,5 a 0,5), Mg (3,3 a 0,3) sendo cobertura do solo 0% a 100% respectivamente, mostrando que a cobertura do solo de 100% é eficiente, apresentando todos os valores da taxa de enriquecimento (ER) abaixo de 0,9 e com diferença significativa para com as outras coberturas, 0% e 50%, com exceção do potássio. A cobertura do solo de 100%, em relação a 0%, reduziu a concentração de MO, no sedimento erodido, em 81,9%, a concentração de fósforo em 84,2%, a de potássio em 66,7%, a de cálcio em 84,5%, e reduziu em 89,8% a de magnésio / Reductions in losses of organic matter and nutrients by water erosion become crucial in the current context of sustainable production systems to increase carbon sequestration in soil and thus reduce greenhouse gas emissions that contribute to the greenhouse gases like CO2. Thus the present work had a goal to quantify the concentration of organic material (MO) and nutrients (P,K,Ca, and Mg) into a erosive sediments and also make an calculate according to increasing and enrichment soil’s rates, if there are enrichment of MO and nutrients in a cultivated area of sugar-cane plantation provided with mechanical crop the next levels of soil’s coverage, 0% (CS0), 50% (CS50) and 100% (CS100). The experimental pieces were submited into a simulated raining with intensity of 60 mm h-1, during 65 minutes. After that, the analysis of the sediments, determinated the following variation: MO (2.9 to 0.5), P (1.5 to 0.2), K (2.4 to 0.8), Ca (3.5 to 0.5), Mg (3.3 to 0.3), being the soil’s coverage 0% (CS0) to 100% (CS100), showing that the soil’s coverage of 100% was efficient, presenting all values of enrichment rates (ER) below 0.9 with significant difference comparing to the others coverage, 0% (CS0) and 50% (CS50), except for potassium. The soil’s coverage of 100%, on soil’s coverage of 0%, have reduced the concentration of MO, in the erosive sediments, in 81.9%, the concentration of phosphorus in 84.2%, the concentration of potassium in 66.7%, the concentration of calcium in 84.5%, And reduced in 89.8% the magnesium concentration

Made available in DSpace on 2014-06-11T19:23:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-29Bitstream added on 2014-06-13T18:09:31Z : No. of bitstreams: 1 moda_lr_me_jabo.pdf: 236202 bytes, checksum: 2f221f2f0788cdea5a4f1b5ae5f8e67b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os resíduos produzidos pelas culturas comerciais, geralmente, são insuficientes para proporcionarem uma adequada cobertura do solo. Portanto, é necessário introduzir ao sistema, plantas capazes de produzirem grandes quantidades de fitomassa com rápido desenvolvimento inicial e de ciclo curto. O objetivo deste trabalho foi avaliar a produção de matéria seca e o N acumulado pelas plantas de cobertura, a produção de matéria seca do milho, o fornecimento de N ao milho e o rendimento de grãos da cultura devido aos sistemas de sucessão de plantas de cobertura em pré-safra ao milho. O experimento foi conduzido na área experimental da FCAV – Unesp Jaboticabal SP, (21º15’27”S e 48º18’58”W; 595 m de altitude) nos anos agrícolas 2006/07 e 2007/08. O delineamento experimental adotado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições, em que os tratamentos principais foram constituídos por seis sistemas de sucessão (S1=crotalária/milho; S2=feijão-deporco/ milho; S3= lablabe/milho; S4=milheto/milho, S5=mucuna-preta/milho e S6=pousio/milho). Nas subparcelas foram aplicadas quatro doses de nitrogênio em forma de uréia em cobertura nas doses de 0, 60, 120 e 180 kg ha-1. Pode-se concluir que: as espécies de cobertura que produziram mais fitomassa foram milheto e crotalária (2007/08) e as que mais acumularam nitrogênio foram mucuna-preta (2006/07) e milheto e crotalária (2007/08). No ano agrícola 2007/08 a sucessão S1 apresentou os maiores teores de N no tecido foliar e maior MS do sabugo na ausência de adubação nitrogenada. Quando aplicado 60 kg ha-1 de N a sucessão S5 obteve maior teor de N foliar no milho. A maior produção de MS de grãos na ausência de adubação nitrogenada no ano 2007/08 ocorreu nas sucessões S1 e S3. O maior acúmulo... / The residues produced by commercial crops usually are insufficient to produce a good soil cover. Therefore, it is necessary to introduce the system, plants capable of producing large quantities of biomass with rapid initial development and short cycle. The objective of this work was to evaluate the production of biomass and N accumulation by the plants cover, the dry biomass of corn, the N supply of corn and the grain yield of the crop due to the succession systems of plant cover in pre-safra to the corn. The experiment was conducted in the experimental area of FCAV - Unesp Jaboticabal SP, (21 º 15 'S and 48 º 18' W, 595 m altitude). The experimental design was randomized blocks, in split plots with four replications, where the main treatments were consisted of six succession systems (S1 = sunn hemp/corn; S2 = pig-bean/corn, S3 = lablab/corn; S4 = millet/corn, S5 = velvetbean /corn and S6 = fallow/maize). In the subplots were applied four rates of nitrogen as urea in coverage at doses of 0, 60, 120 and 180 kg ha-1. It can be concluded that the species of coverage that were produced more biomass were millet and sunn hemp (2007/08) and that accumulated more nitrogen was velvetbean (2006/07) and millet and sunn hemp (2007/08). In the year 2007/08 the succession S1 showed the highest levels of N in leaf tissue and increased MS of root in the absence of nitrogen fertilization. When applied 60 kg ha-1 of N the S5 succession was higher N level leaf and S1 succession higher of root MS. The highest production of MS grain in the absence of nitrogen fertilization in the year 2007/08 was in S1 and S3 successions. The highest accumulation of N in grain in the absence of nitrogen fertilization were found in S1, S3 and S5 successions. The S3 succession promoted the highest accumulation of N in biomass of corn in the year 2007/08.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Several factors can modify the qualitative features of water resources in watershed areas. Such changes are due to natural processes and from human activities such as agriculture, livestock and removal of riparian vegetation which interfere in the original conditions of use and soil cover. Because of these practices in springs areas the water quality may be degraded. In such context, this study aimed to evaluate the influence of different uses and soil covers on the physical, chemical and biological features in the water of springs located in the Arroio Manoel Alves watershed, Itaara town, RS. Therefore, six springs (N1, N2, N3, N4, N5 and N6) as its pipeline (CC), were monitored under different land uses and covers (agriculture, buildings, eucalyptus, grass, native forest, water resource and access roads). The study was developed between January 2015 and January 2016, with a bi-weekly water sampling and analysis of the following qualitative parameters: temperature, turbidity, pH, EC, OD, BOD5,20, total coliforms, Escherichia coli, TS, DS, SS, PO4-, NO2-, NO3-, SO42- and Cl-. There were installed two rain gauges to quantify the rainfall in the watershed, which corresponded to the annual total of 2267,2 mm. The flow rates were hourly monitored reaching maximum values of 5,67 L.s-1, the N1, N2, N3, N4 and N6, 14,17 L.s-1 to N5 and 255,5 L.s-1 to CC. The retention curves and the resolution of the framework classes 357/2005 CONAMA revealed that the N5 and the CC overcame class 4 for variable turbidity. For BOD5,20, all areas exceeded the limits of class 4 for the major part of the period. For E. coli, N6 remained in class 4 at most of the time. For the DS parameter, the N1, N2, N3, N4 and N6 did not fit in classes 1, 2 and 3 in the analyzed period. WQI got "average" standards in the springs N3, N4 and N6, and "good" standards for N1, N2, N5 and CC. FA formed three components in N1, designated as climate, weathering and diffuse pollution factors. The N2 showed three components, explained by weathering, climate and pollution diffuse factors. The N3 was explained by the superficial, environment and microbiological factors. The N4 obtained the three components, characterized by leaching, diffuse pollution and decay factors. For N5 three components formed were described by decomposition, weathering and microbiological factors. In N6, the components were classified by superficial, environment and microbiological factors. For CC, formed three components, explained by diffuse pollution, weathering and climate factors. In general, the methodologies used for evaluation and analysis of the influence by use and soil covers on water quality of monitored areas shown to be satisfactory, where the N3 had livestock activity interference, the N6 of rural household s effluents and, N1 and N2, indicated results of forest protection on water quality. The N5 expressed influence of external factors on water quality, the N4, characterized by low concentrations of pH and DO, and the pipeline, demonstrated influence by the flow rates, the tributaries and by the land use and soil covers of the watershed. / Diversos fatores podem alterar as características qualitativas dos recursos hídricos em áreas de bacias hidrográficas. Tais alterações são decorrentes de processos naturais, assim como de atividades antrópicas (agricultura, pecuária, retirada da mata ciliar), as quais interferem nas condições originais de uso e cobertura do solo. Em áreas de nascentes, devido a essas práticas, a qualidade das águas pode ser degradada. Nesse contexto, o presente estudo teve como objetivo avaliar a influência dos diferentes usos e coberturas do solo nas características físicas, químicas e biológicas das águas de nascentes localizadas na microbacia hidrográfica do Arroio Manoel Alves, no município de Itaara, RS. Para tanto, monitoraram-se seis nascentes (N1, N2, N3, N4, N5 e N6) e o respectivo exutório (CC), sob diferentes usos e coberturas do solo (área agrícola, edificações, eucalipto, gramínea, mata nativa, recurso hídrico e vias de acesso). O estudo desenvolveu-se entre janeiro de 2015 e janeiro de 2016, com coletas de água quinzenais e análise dos parâmetros qualitativos temperatura, turbidez, pH, CE, OD, DBO5,20, coliformes totais, Escherichia coli, ST, SD, SS, PO4-, NO2-, NO3-, SO42-, Cl-. Instalaram-se dois pluviômetros para a quantificação da precipitação pluviométrica na microbacia, a qual correspondeu ao total anual de 2267,2 mm. As vazões foram monitoradas em frequências horárias alcançando valores máximos de 5,67 L.s-1, para a N1, N2, N3, N4 e N6, de 14,17 L.s-1 para a N5 e de 255,5 L.s-1 para a CC. As curvas de permanência e as classes de enquadramento da Resolução 357/2005 do CONAMA, revelaram que a N5 e a CC superaram a classe 4 para a variável turbidez. Para a DBO5,20, todas as áreas excederam os limites da classe 4. Em relação a E. coli, a N6 permaneceu como classe 4 em maior parte do tempo. Para os SD, a N1, N2, N3, N4 e N6 classificaram-se nas classes 1, 2 e 3 em todo o período analisado. O IQA obteve padrões médio nas nascentes N3, N4 e N6, e bom , para N1, N2, N5 e CC. A AF formou três componentes para a N1, designados como fator clima, intemperismo e poluição difusa. A N2 resultou em três componentes, explicados pelos fatores intemperismo, clima e poluição difusa. A N3 foi explicada pelos fatores superficial, ambiente e microbiológico. A N4 obteve três componentes, caracterizados pelos fatores lixiviação, poluição difusa e decomposição. Para a N5 os três componentes formados foram descritos pelos fatores decomposição, intemperismo e microbiológico. Na N6, os componentes classificaram-se pelos fatores superficial, ambiente e microbiológico. Para a CC, formaram-se três componentes, explicados pelos fatores poluição difusa, intemperismo e clima. De modo geral, as metodologias utilizadas para avaliação e análise da influência dos usos e coberturas do solo na qualidade das águas das áreas monitoradas demonstraram-se satisfatórias, onde a N3 teve interferência da atividade pecuária, a N6 de efluentes de residências rurais e, a N1 e N2, indicaram resultados da proteção florestal na qualidade das águas. A N5 expressou influência de fatores externos na qualidade das águas, a N4, caracterizou-se pelas baixas concentrações de pH e OD e, o exutório, demonstrou influência das vazões, dos afluentes e dos usos e coberturas do solo da microbacia.