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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Reliability and Validity of a Pressure Algometer

Kinser, Ann M., Sands, William A., Stone, Michael H. 01 January 2009 (has links)
Algometers are devices that can be used to identify the pressure and/or force eliciting a pressure-pain threshold. It has been noted in pressure-pain threshold studies that the rate at which manual force is applied should be consistent to provide the greatest reliability. This study tested the reliability and construct validity of an algometer (1000-Hz sampling rate) by manually applying pressure on a force plate (500-Hz sampling rate): 10 sets of 5 applications to 80 N and 1 set of 5 applications to each force level: 20, 30, 40, 50, 60, 70, 80, 90, 100, and 110 N. The investigator had previously become familiar with and practiced with the algometer. The handheld algometer had a 1-cm2 round rubber application surface, and the maximum force reading was compared with maximum force readings by the force plate using SEM and t-tests. Force-time curves were analyzed for average slope representing rate of force application. Average Pearson (r) correlations between the maximum force reading of the algometer and force plate were excellent in both trials to 80 N (r = 0.990) and the incremental trials (r = 0.999). The application of force was reasonably constant, with slopes averaging 6.8 ± 0.932 N·s−1. The SEE was 0.323 N. In conclusion, with previous familiarization and practice, an investigator may have high reliability in the rate of force application. The device itself was also highly correlated with readings from a force plate and, therefore, may be considered valid.
2

Odour and greenhouse gas emissions from manure spreading

Agnew, Joy Melanie 28 June 2010
The Canadian livestock industry generates 150 million tonnes of manure annually and the majority of this manure is land applied. This practice allows the manure nutrients to be recycled to the soil crop system while improving soil fertility. However, land application of manure has the potential to negatively impact soil, water, and air quality if not managed properly. Microbial processes transform the manure nutrients into forms that are susceptible to leaching or volatilization. Balancing the nutrient loss dynamics from fertilized soil is very difficult because the nutrient transformations are affected by the soil environment such as air and water content, pH, and labile carbon content. All of these soil environmental factors can be influenced by manure application practices such as application rate, timing, and manure placement. Knowledge of how these management practices affect the soil environment can help producers make management decisions that reduce the likelihood of soil, water, and air contamination from manure application.<p> Very few data exist on how manure application practices affect odour emissions after spreading. Therefore, the efficiency of subsurface application in reducing odours from manure spreading for both solid and liquid manure was assessed. Flux chambers and dynamic dilution olfactometry were used to measure odour emissions from five livestock manure species applied at three application rates using surface and subsurface application methods. The results indicated that odour concentrations from injected plots were up to 66% (37% on average) lower than concentrations from broadcast applications. Injection seemed to have a larger impact on reducing odours from solid manure than liquid manure, mainly due to efficient manure coverage from solid manure injection. Odours measured immediately after solid manure applications were also 37% lower than from liquid manure applications. In general, odours from both manure types increased with higher application rates, but there was little difference in the odours among low, mid, and high application rates. The specific odour rate (odour emission rate per kg N applied) decreased with application rate due to the reduced surface area available for volatilization of compounds with higher application rates. Based on these results, injection of manure is an effective way to reduce the odour emissions immediately after spreading, particularly for solid manure. However, other factors associated with manure injection, such as the increased power requirement and soil disturbance must be considered when evaluating the overall impact of manure injection versus surface application.<p> The odour data collected in this study described how management practices affected odours immediately after spreading. Knowledge of how these practices affect the emission rate trend over time is required to apply dispersion models to optimize the minimum separation distances for manure spreading activities. The model parameters for an existing volatilization model were determined from field and literature data and the resulting model allowed the effects of application mode (surface vs. subsurface) and manure type (liquid vs. solid) on odour emissions for 48 hours after application to be simulated. The effects of injection depth and a coverage factor on emissions were also simulated. The modeled peak fluxes from liquid manure applications were higher than those for solid manure applications, but the extended duration of odour emissions from solid manure resulted in higher cumulative losses from solid manure applications. While the application rate had no effect on the initial odour flux, higher application rates resulted in higher peak fluxes, higher overall emissions, and longer odour durations for both manure types and application methods. Modest injection depths were shown to reduce odours from both liquid and solid manure applications compared to surface spreading. The percent reductions in cumulative odours due to injection were estimated assuming typical coverage factors. The general predictions of the model developed in this study agree reasonably well with odour emission rate trends reported in literature. Future work should focus on better estimation of the model parameters and the variation of effective diffusivity with time and soil conditions.<p> Greenhouse gas (GHG) emissions from agricultural activities such as land application of livestock manure cannot be ignored when assessing overall emissions from anthropogenic sources. Like odour emissions, the magnitude of the GHG emissions will be influenced by management practices such as manure placement during land application. The GHG fluxes resulting from the surface and subsurface application of liquid and solid manure were also compared within 24 hours of application using a static chamber and gas chromatography. The results showed that carbon dioxide equivalent (CO2-e) fluxes were approximately three times higher from the injected plots than the surface plots for both solid and liquid manure. The elevated CO2-e fluxes were mainly due to a pronounced increase in N2O fluxes which was likely caused by increased denitrification rates. The CO2-e fluxes from the liquid manure applications were also approximately three times higher than the CO2-e fluxes from the solid manure applications, probably due to higher levels of ammonium available for nitrification and subsequent denitrification. The CH4 fluxes were generally low and the treatments had no effect. The measured specific fluxes (total flux per kg N applied) remained relatively constant with application rate, indicating that, in this study, GHG emissions from manure applications were approximately proportional to the amount of land applied manure.<p> While the data from this study showed that manure type and placement influenced short-term nitrous oxide (N2O) emissions, manure management practices (particularly slurry injection or solid manure incorporation) have the potential to influence long-term emissions by changing the magnitude and pattern of the nitrogen cycle in the soil-plant system. Management practices also impact the magnitude of other nitrogen losses (ammonia volatilization, nitrate leaching) which affect indirect N2O emissions. A model that simulates the environmental conditions and nutrient transformations after manure application may allow a more reliable prediction of the effect of management practices on total GHG emissions. Numerous process-based models have been used to estimate N2O emissions as influenced by agricultural practices in Canada. However, these models do not account for enhanced denitrification that potentially exists after slurry injection or manure incorporation, resulting in an underestimation of N2O emissions. A simple mass balance of nitrogen after application to land showed that enhanced denitrification can increase total N2O-N emissions by a factor of 5. By accounting for the increased microbial activity, slower oxygen diffusion and higher water filled pore space that exists after manure injection, models may better estimate N2O emissions from manure application practices.
3

Odour and greenhouse gas emissions from manure spreading

Agnew, Joy Melanie 28 June 2010 (has links)
The Canadian livestock industry generates 150 million tonnes of manure annually and the majority of this manure is land applied. This practice allows the manure nutrients to be recycled to the soil crop system while improving soil fertility. However, land application of manure has the potential to negatively impact soil, water, and air quality if not managed properly. Microbial processes transform the manure nutrients into forms that are susceptible to leaching or volatilization. Balancing the nutrient loss dynamics from fertilized soil is very difficult because the nutrient transformations are affected by the soil environment such as air and water content, pH, and labile carbon content. All of these soil environmental factors can be influenced by manure application practices such as application rate, timing, and manure placement. Knowledge of how these management practices affect the soil environment can help producers make management decisions that reduce the likelihood of soil, water, and air contamination from manure application.<p> Very few data exist on how manure application practices affect odour emissions after spreading. Therefore, the efficiency of subsurface application in reducing odours from manure spreading for both solid and liquid manure was assessed. Flux chambers and dynamic dilution olfactometry were used to measure odour emissions from five livestock manure species applied at three application rates using surface and subsurface application methods. The results indicated that odour concentrations from injected plots were up to 66% (37% on average) lower than concentrations from broadcast applications. Injection seemed to have a larger impact on reducing odours from solid manure than liquid manure, mainly due to efficient manure coverage from solid manure injection. Odours measured immediately after solid manure applications were also 37% lower than from liquid manure applications. In general, odours from both manure types increased with higher application rates, but there was little difference in the odours among low, mid, and high application rates. The specific odour rate (odour emission rate per kg N applied) decreased with application rate due to the reduced surface area available for volatilization of compounds with higher application rates. Based on these results, injection of manure is an effective way to reduce the odour emissions immediately after spreading, particularly for solid manure. However, other factors associated with manure injection, such as the increased power requirement and soil disturbance must be considered when evaluating the overall impact of manure injection versus surface application.<p> The odour data collected in this study described how management practices affected odours immediately after spreading. Knowledge of how these practices affect the emission rate trend over time is required to apply dispersion models to optimize the minimum separation distances for manure spreading activities. The model parameters for an existing volatilization model were determined from field and literature data and the resulting model allowed the effects of application mode (surface vs. subsurface) and manure type (liquid vs. solid) on odour emissions for 48 hours after application to be simulated. The effects of injection depth and a coverage factor on emissions were also simulated. The modeled peak fluxes from liquid manure applications were higher than those for solid manure applications, but the extended duration of odour emissions from solid manure resulted in higher cumulative losses from solid manure applications. While the application rate had no effect on the initial odour flux, higher application rates resulted in higher peak fluxes, higher overall emissions, and longer odour durations for both manure types and application methods. Modest injection depths were shown to reduce odours from both liquid and solid manure applications compared to surface spreading. The percent reductions in cumulative odours due to injection were estimated assuming typical coverage factors. The general predictions of the model developed in this study agree reasonably well with odour emission rate trends reported in literature. Future work should focus on better estimation of the model parameters and the variation of effective diffusivity with time and soil conditions.<p> Greenhouse gas (GHG) emissions from agricultural activities such as land application of livestock manure cannot be ignored when assessing overall emissions from anthropogenic sources. Like odour emissions, the magnitude of the GHG emissions will be influenced by management practices such as manure placement during land application. The GHG fluxes resulting from the surface and subsurface application of liquid and solid manure were also compared within 24 hours of application using a static chamber and gas chromatography. The results showed that carbon dioxide equivalent (CO2-e) fluxes were approximately three times higher from the injected plots than the surface plots for both solid and liquid manure. The elevated CO2-e fluxes were mainly due to a pronounced increase in N2O fluxes which was likely caused by increased denitrification rates. The CO2-e fluxes from the liquid manure applications were also approximately three times higher than the CO2-e fluxes from the solid manure applications, probably due to higher levels of ammonium available for nitrification and subsequent denitrification. The CH4 fluxes were generally low and the treatments had no effect. The measured specific fluxes (total flux per kg N applied) remained relatively constant with application rate, indicating that, in this study, GHG emissions from manure applications were approximately proportional to the amount of land applied manure.<p> While the data from this study showed that manure type and placement influenced short-term nitrous oxide (N2O) emissions, manure management practices (particularly slurry injection or solid manure incorporation) have the potential to influence long-term emissions by changing the magnitude and pattern of the nitrogen cycle in the soil-plant system. Management practices also impact the magnitude of other nitrogen losses (ammonia volatilization, nitrate leaching) which affect indirect N2O emissions. A model that simulates the environmental conditions and nutrient transformations after manure application may allow a more reliable prediction of the effect of management practices on total GHG emissions. Numerous process-based models have been used to estimate N2O emissions as influenced by agricultural practices in Canada. However, these models do not account for enhanced denitrification that potentially exists after slurry injection or manure incorporation, resulting in an underestimation of N2O emissions. A simple mass balance of nitrogen after application to land showed that enhanced denitrification can increase total N2O-N emissions by a factor of 5. By accounting for the increased microbial activity, slower oxygen diffusion and higher water filled pore space that exists after manure injection, models may better estimate N2O emissions from manure application practices.
4

DepÃsito e perdas em aplicaÃÃes de defensivos na cultura do cajueiro com o uso de diferentes taxas e equipamentos de aplicaÃÃo / Deposit and losses on defensive cashew applications using different rates and application equipment.

Igor Martins Cordeiro 19 December 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A cajucultura, como atividade de importÃncia econÃmica para o Nordeste brasileiro, vem passando por um perÃodo de decrÃscimo de produtividade, muito por causa do regime extrativista empregado no seu cultivo e pela falta de um mÃnimo de tÃcnicas de manejo de produÃÃo, dentre eles o controle de pragas. Muitos sÃo os fatores que influenciam na eficiÃncia de uma aplicaÃÃo de defensivos, porem grande parte dos produtores dÃo mais importÃncia ao produto aplicado que a forma como ele à aplicado. Definir o volume adequado de calda a ser aplicado na copa de culturas arbÃreas à uma tarefa difÃcil, devido a variabilidade existente entre os cultivos. O conceito de TRV (Tree Row Volume) surgiu como uma forma de adequar a quantidade de calda a ser aplicada em funÃÃo do volume da copa da cultura. Objetivou-se com este trabalho avaliar a deposiÃÃo de calda e corante na folha do cajueiro e as perdas de corante e calda para o solo em aplicaÃÃes em oito taxas de aplicaÃÃo, sendo quatro dessas taxas aplicadas com um turboatomizador, trÃs com um equipamento costal motorizado e uma com equipamento costal manual. O experimento foi conduzindo em uma Ãrea de cajueiro anÃo precoce localizada no municÃpio de PacajÃs-CE. Para as aplicaÃÃes, as taxas dos equipamentos foram regulados, onde para o turboatomizador foram realizadas regulagens na orientaÃÃo do fluxo de ar, taxa de aplicaÃÃo e do perfil de distribuiÃÃo vertical da calda, para os equipamentos costal manual e costal motorizado foram feitas a regulagem das taxas de aplicaÃÃo. Os testes de deposiÃÃo de calda e corante na copa do cajueiro foram conduzidos no delineamento experimental de faixas, onde os tratamentos principais foram oito taxas de aplicaÃÃo, sendo quatro destas aplicadas com o turboatomizador (100%, 85%, 70% e 50% da taxa de aplicaÃÃo de referencia), trÃs pelo pulverizador costal motorizado (nÃvel 6, entre o nÃvel 3 e 4 e o nÃvel 1 do controlador de vazÃo) e uma com o pulverizador costal manual, os tratamentos secundÃrios foram os seis pontos de coletas na copa do cajueiro. Os testes de perdas de corante e de calda para o solo foram conduzidos no delineamento de blocos, onde os tratamentos foram as oito taxas de aplicaÃÃo utilizados nos testes de deposiÃÃo na copa. A deposiÃÃo de calda na copa da cultura se deu de forma crescente a medida que se aumentou a taxa de aplicaÃÃo, apresentando uma maior concentraÃÃo na parte lateral da copa da cultura. Maiores valores de deposito de corante foram encontrados nos tratamentos com o pulverizador costal motorizado com regulador de vazÃo no nÃvel 6 e entre os nÃveis 3 e 4, nas aplicaÃÃes com o turboatomizador uma maior deposiÃÃo de corante foi encontrada nos tratamentos com 70% e 55% da taxa de aplicaÃÃo de referÃncia. As aplicaÃÃes com o turboatomizador apresentaram maior uniformidade de distribuiÃÃo de corante nos pontos de coleta em relaÃÃo aos equipamentos costal motorizado e costal manual. Maiores perdas de calda foram encontradas a medida que se aumentou a taxa de aplicaÃÃo, com exceÃÃo da aplicaÃÃo com o equipamento costal manual. Maiores perdas da corante foram encontradas nas aplicaÃÃes com o equipamento costal manual, seguido das aplicaÃÃes com o turboatomizador e com o pulverizador costal motorizado. As aplicaÃÃes com equipamento costal motorizado com regulador de vazÃo no nÃvel 6 e entre os nÃveis 3 e 4 se mostraram mais eficiente em depositar calda na cultura do cajueiro, para as aplicaÃÃes com o turboatomizador a taxa da aplicaÃÃo com 55% da taxa da aplicaÃÃo de referÃncia se mostrou mais eficiente em depositar corante e com menores perdas. Pode-se concluir que a deposiÃÃo na folha e perda para o solo de calda à maior quanto maior a taxa, porÃm a deposiÃÃo de corante na folha à maior no equipamento costal motorizado e a maior perda de corante para o solo se dà na aplicaÃÃo com o equipamento costal manual. / The cashew cultivation as an activity of economic importance for the Brazilian Northeast, has been going for a period of decline in productivity, largely because of the extractive scheme employed in its cultivation and the lack of minimal technical management of production factors, among them pest control. There are many factors that influence the effectiveness of a pesticide application, however much the producers give more importance to the applied product that the form how it is applied. Set the appropriate water volume to be applied in the canopy of tree crops is a difficult task due to the variability between crops. The concept of TRV has emerged as a way to adjust the amount of syrup to be applied depending on the volume of the canopy. The objective of this study was to evaluate the deposition of dye and syrup in the cashew leaf and losses of dye and syrup for ground applications in eight application rates, with four of those rates applied air carrier sprayer with a three with a motorized knapsack equipment and a manual knapsack with equipment. The experiment was driving in an area of dwarf cashew localized in Pacajus - CE. The adjustment of application equipment used at work for the air carrier sprayer was made adjustments were made in the direction of air flow, application rate and the vertical distribution profile of the syrup to the knapsack and motorized knapsack equipment of the adjustment were made application rates. Tests of spray deposition and dye in cup cashew were conducted in experimental design tracks in a split plot design where the main treatments were eight application rates, four of which applied to the air carrier sprayer (100%, 85%, 70% and 50% of the application rate of reference), three by motorized knapsack sprayer (level 6, between level 3 and 4 and level 1 flow controller) and one with manual knapsack, secondary treatments were the six points collections in the cup cashew. Tests for loss of dye and syrup to soil were conducted in the experimental design of tracks, where treatments were eight application rates used in the tests deposition in the cup. The spray deposition on the cup occurred incrementally measure that increased the rate of application, with a higher concentration at the side of the cup. Higher values of deposit of dye were found in treatments with motorized knapsack sprayer with flow regulator at level 6 and between levels 3 and 4, the air carrier sprayer applications with greater deposition of dye was found in the treatments with 70 % and 55 % the rate of application of reference. The applications with the air carrier sprayer showed greater uniformity of dye at collection points in relation to motorized and manual equipment costal rib. Greater losses of the syrup as it increased the rate of application, with the exception of the application with knapsack equipment were found. Greater losses of dye were found in applications with manual knapsack equipment, followed by the air carrier sprayer applications and motorized knapsack sprayer. Applications with motorized knapsack equipment with flow regulator at level 6 and between levels 3 and 4 were more efficient in depositing the crop cashew dye, for applications with the air carrier sprayer application rate with 55 % of the rate of application of reference is more efficient in depositing dye and with smaller losses. It can be concluded that the deposition in the leaf and loss to the soil is greater the higher the rate, but the deposition of dye on the leaf is higher in motorized knapsack sprayer and more loss of dye to the ground occurs in the application equipment knapsack.tr
5

Effects of Compost on Soil Health and Greenhouse Gas Emissions: A Case Study in a Mediterranean Vineyard

Wong, Tsz Fai 01 June 2021 (has links) (PDF)
Compost is commonly used as an organic amendment in cropping systems such as vineyards, and has been shown to be beneficial to carbon (C) sequestration and soil health. As perennial crops, grapevines have a larger potential for C sequestration than most crops. Yet, there is a lack of understanding regarding the relationship between compost application rate, the magnitude of C sequestration, and its environmental tradeoff in the form of greenhouse gas (GHG) emissions. In the study, we investigated the effects of compost application rate on soil C sequestration, GHG emissions, crop growth, and overall soil health after two annual compost treatments at J. Lohr Vineyards and Wines, Paso Robles, CA. Compost was broadcasted to the entire plot area between harvest and the first precipitation in fall at the rate of 0 (control), 2, 4, and 6 tons/acre/year. Soil C sequestration, cumulative carbon dioxide (CO2) and nitrous oxide (N2O) emissions and soil physical properties were assessed at two functional locations (tractor row and vine row) and three depth increments (0-15, 15-30, and 30-60 cm). Cover crop biomass was determined in spring before mowing, while clusters per vine, cluster weight and yield were determined each year at harvest. Although compost application did not significantly affect total soil C stocks, significant increases in early indicators of C sequestration such as permanganate oxidizable carbon (POXC), aggregate distribution, and aggregate C content in large macroaggregates without increasing C mineralization suggests that C input from compost increased C stabilization in soil. Cumulative GHG emissions were not significantly affected by compost application. Both CO2 and N2O emissions were higher in the vine row than the tractor row in the dry season, but the trend for CO2 emissions was the opposite in the wet seasons. Seasonal patterns of GHG emissions were likely due to differences in plant activity and irrigation between functional locations. The lower bulk density in topsoil than subsoil, and the higher water holding capacity and aggregate stability in tractor row topsoil than in the vine row demonstrates how high C content improves soil physical properties. Cover crop growth and grape yield components were unaffected by compost application. Based on our results, early signs of C sequestration and improvements on overall soil health can be achieved in a coarse-texture vineyard in the Central Coast region after annually applying compost at a rate between 2 and 6 tons/acre for two years, without increasing GHG emissions or affecting grape yield. Further investigation is recommended to study the potential synergistic effects between compost application and cover cropping in vineyards if both practices are implemented at the same time.
6

Potencial de produção de grãos brasileiros via fertilização e impactos nas emissões de CO2eq

Roquetti Filho, David 07 February 2014 (has links)
Submitted by David Roquetti Filho (droquettifilho@uol.com.br) on 2014-04-02T18:46:11Z No. of bitstreams: 1 David_Roquetti_Filho_2014.pdf: 12362120 bytes, checksum: 079ed8901018620b54e278ce99ea81ef (MD5) / Rejected by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br), reason: Bom dia David, A dissertação não está de acordo com as Normas: 1 - agradecimento - justificar 2 - resumos (português e inglês) - após o agradecimento. 3 - numeração das páginas a partir da introdução Qualquer dúvida estou à disposição. Att. Suzi 11 3799-7876 on 2014-04-03T12:29:09Z (GMT) / Submitted by David Roquetti Filho (droquettifilho@uol.com.br) on 2014-04-03T17:48:25Z No. of bitstreams: 1 DISSERTAÇÃO_David_Roquetti_Filho_FGV_2012_2014_03.04.2014.pdf: 12367988 bytes, checksum: 62df142fa2a68311e1fc79115da12060 (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2014-04-03T18:34:17Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO_David_Roquetti_Filho_FGV_2012_2014_03.04.2014.pdf: 12367988 bytes, checksum: 62df142fa2a68311e1fc79115da12060 (MD5) / Made available in DSpace on 2014-04-03T18:37:04Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO_David_Roquetti_Filho_FGV_2012_2014_03.04.2014.pdf: 12367988 bytes, checksum: 62df142fa2a68311e1fc79115da12060 (MD5) Previous issue date: 2014-02-07 / For all Brazilian municipalities, data of planted area, quantity produced, types of soil and soil use, for Rice, Beans, Wheat, Corn and Soybeans, was collected. With the aid of a Geographic information System (GIS) maps were drawn, and by cross-checking them, crop yields per type of soil in anthropized areas were obtained. From the expected yield on the application rate of fertilizer per level of availability of primary major nutrients (Nitrogen, Phosphorus and Potassium) in the soil, recommended by Embrapa (WebAgritec), it was considered that each municipality, without area expansion as from its actual productivity value in 2011/12, would increase to the maximum xpected value related to the recommended application rate of fertilizers on the upper range of productivity. A period of ten years was considered for the rise of productivity level, which allowed a time horizon of the estimates from 2011/12 to 2061/62. The Fertilization Consumption, Application Rate and Efficiencies for the primary major nutrients, as well as the Balances of CO2eq, required for these new conditions, were projected. The horizon and the resulting volume of agricultural production were compared to the projections of MAPA (Ministério da Agricultura, Pecuária e Abastecimento and Outlook Fiesp 2023, whose horizon projections are 2021/22 and 20022/23 respectively. The potential volume of agricultural production via fertilization of these five cultures and the impact on the balance of CO2eq are then measured, thus culminating with the possibility of significant advances in this volume in terms of the number of harvests and the beneficial effect on the balance of CO2eq, allowing, due to the spared areas, significant postponement of emissions of CO2eq / Para todos os municípios Brasileiros foram coletados dados de área plantada, quantidade produzida, tipos de solos e uso do solo, para o Arroz, Feijão, Trigo, Milho e Soja. Com o auxílio de Sistema de Informações Geográficas (SIG), mapas foram elaborados, e a partir do cruzamento entre eles, produtividades por tipo de solo em áreas antropizadas foram obtidas. A partir das faixas de produtividades esperadas relativas às faixas de dosagem de adubação por nível de disponibilidade de macronutrientes primários (Nitrogênio, Fósforo e Potássio) no solo, recomendadas pela Embrapa (WebAgritec), considerou-se que cada município, sem nenhuma expansão de área, a partir de seu valor real de produtividade em 2011/12, aumentasse a mesma até o valor máximo esperado e correspondente à recomendação de dosagem de adubação relativa à faixa superior de produtividade. Considerou-se um período de dez anos para a subida de um patamar para outro de produtividade, o que permitiu um horizonte temporal das estimativas de 2011/12 até 2061/62. Projetaram-se os Consumos, Dosagens e Eficiências de Adubação, bem como os Balanços de CO2eq para os macronutrientes primários, necessários e resultantes destas novas condições. O horizonte e os volumes de produção agrícolas resultantes foram comparados com as projeções do MAPA 2021/22 e do Outlook Fiesp 2023. O potencial de volume de produção agrícola via fertilização destas cinco culturas e o impacto no balanço de CO2eq são então mensurados, culminando com a possibilidade de significativas antecipações deste volume em termos de número de safras e com o efeito benéfico no balanço de CO2eq, permitindo em virtude das áreas poupadas, postergação expressiva em termos de emissões de CO2eq
7

Monocot and dicot weed control with mixtures of quizalofop and florpyrauxifen-benzyl in the Provisia(TM) rice system

Sanders, Tameka LaShea 09 August 2019 (has links)
Quizalofop and florpyrauxifen-benzyl are both new herbicides for rice in the midsouthern U.S. Quizalofop is only effective for control of monocot weed species; therefore, mixtures of florpyrauxifen-benzyl with quizalofop could be beneficial in acetyl CoA carboxylase (ACCase)-resistant rice. Field experiments were conducted at the Delta Research and Extension Center in Stoneville, MS, in 2017 and 2018 to evaluate control of monocot and dicot weed species with sequential applications of quizalofop including auxinic herbicides in the first or second treatment. Other field experiments in 2017 and 2018 evaluated sequential applications of different rates of quizalofop with florpyrauxifen-benzyl included in treatments immediately prior to flooding. A final field experiment in 2017 and 2018 evaluated growth and yield of six ACCase-resistant rice cultivars and advanced lines following POST applications of florpyrauxifen-benzyl.
8

Floto-filtração como pós-tratamento de efluente de reator anaeróbio tratando esgoto sanitário / Floto-filtration as post-treatment of an anaerobic reactor effluent

Oliveira, André Luiz de 23 February 2007 (has links)
Este trabalho compreende o estudo do desempenho de sistema piloto de floto-filtração, aplicado ao pós-tratamento de efluente de reator anaeróbio, sob diferentes taxas de aplicação superficial, quantidade de ar fornecida ao processo e leitos filtrantes. O trabalho foi dividido em duas fases: ensaios preliminares (fase 1) e ensaios com o floto-filtro (fase 2), sem utilização de leito filtrante (etapa 1 da fase 2) e com utilização do leito filtrante (etapa 2 da fase 2). A fase 1, realizada com unidade de flotação por ar dissolvido em escala de bancada, apresentou resultados satisfatórios em termos de redução de turbidez, cor e Abs254nm para dosagens de cloreto férrico entre 40 a 80 mg/L na maior parte dos ensaios. Os dados desta fase serviram principalmente para a determinação e adoção dos melhores parâmetros operacionais a serem utilizados na fase seguinte. Na etapa 1 da fase 2, o sistema foi analisado sob a ótica da qualidade da água produzida em condições variáveis de dosagem de cloreto férrico, tempo e gradiente de floculação, taxa de recirculação e taxa de aplicação superficial. Para as amostras coletadas foram analisadas as variáveis turbidez, temperatura, condutividade, DQO, SST, pH, cor, Abs254nm, metais, OD, \'P-PO IND.4\'POT.3-\', NTK e \'N-NH IND.4\'POT.+\'. Foram obtidas eficiências globais de 88 a 97% de redução na turbidez (residual < 20 uT), 84 a 98% de SST (residual < 25 mg/L), 87 a 94% de \'DQO IND.B\' (residual < 60 mg/L), 78 a 92% de \'DQO IND.F\' (residual < 40 mg/L), 85 a 96% de \'P-PO IND.4\'POT.3-\' (residual < 2 mg/L) e menor que 30% para NTK e \'N-NH IND.4\'POT.-\'. Na etapa 2 da fase 2, além das análises supracitadas, foram analisadas as variáveis DBO, coliformes totais e fecais, sulfatos, dureza, alcalinidade, ácidos voláteis e turbidez ao longo do leito filtrante além da medida de perda de carga no decorrer da carreira de filtração. Foram monitorados a perda de carga ao longo do leito filtrante, carreira de filtração. Nesta fase, a instalação piloto de floto-filtração foi avaliada mediante a variação da taxa de aplicação superficial e do leito filtrante. Os resultados foram positivos com efluente final apresentando turbidez média abaixo de 2 uT e duração média da carreira filtração de 24 horas. Foram obtidas eficiências globais de 96 a 99% de redução na turbidez (residual < 7 uT), 96 a 99% de SST (residual < 6 mg/L) , 93 a 96% de \'DQO IND.B\' (residual < 40 mg/L), 89 a 97% de \'DQO IND.F\' (residual < 34 mg/L), 93 a 98% de \'P-PO IND.4\' POT.3-\' (residual < 0,3 mg/L), menor que 30% para NTK e \'N-NH IND.4\' POT.-\', 96 a 98% de cor (residual < 50 uC) e 80 a 82% de Abs254nm (residual < 0,198). Desta forma, em virtude dos bons resultados apresentados, pôde-se constatar que a floto-filtração é uma alternativa atraente no pós-tratamento de efluente de reator anaeróbio. / This works assesses the performance of a floto-filtration pilot system, applied to the post-treatment of an anaerobic reactor effluent, under different superficial application rates, amount of air supplied to the process and filter beds. The work was divided in two phases: preliminary essays (phase 1), essays with the floto-filter without using filter bed (step 1 of phase 2) and essays with the floto-filter using filter beds (step 2 of phase 2). Phase 1, carried out with bench scale dissolved air flotation unit, presented satisfactory results regarding turbidity removal, color and Abs254nm for ferric chloride dosages between 40 - 80 mg/L in most of the essays. The data acquired from this phase were mainly used to determine and adopt the best operational parameters to be employed in the following phase. In step 1 of phase 2, the system was analyzed concerning the quality of the water produced in favorable conditions for ferric chloride dosages, time and flocculation gradient, recirculation gradient and superficial application rate. The following variables were analyzed from the collected samples: turbidity, temperature, conductivity, COD, TSS, pH, color, Abs254nm, metais, OD, \'P-PO IND.4\'POT.3-\', NTK and \'N-NH IND.4\'POT.+\'. Global efficiencies of 88 to 97% for turbidity removal (residual < 20 uT), 84 to 98% for TSS (residual 25 mg/L), 87 to 94% for COD (residual < 60 mg/L), 78 to 92% for CODF (residual < 40 mg/L), 85 to 96% \'P-PO IND.4\'POT.3-\' (residual < 2 mg/L) and less than 30% for NTK and \'N-NH IND.4\'POT.+\' were obtained. In step 2 of phase 2, besides the aforementioned analyses, BOD, total and fecal coliforms, sulphates, hardness, alkalinity, volatile acids and turbidity throughout the filter in addition to the measure of headloss during the filter run. In this phase, the floto-filtration pilot plant was assessed varying the superficial application and filter bed rate. The results were positive with the final effluent presenting mean turbidity below 2 uT and mean filter run time of 24 hours. Global efficiencies of 96 to 99% for turbidity removal (residual < 7 uT), 96 to 99% for TSS (residual < 6 mg/L), 93 to 96% for \'COD IND.B\' (residual < 40 mg/L), 89 to 97% for \'COD IND.F\' (residual < 34 mg/L), 93 to 98% for \'P-PO IND.4\'POT.3-\' (residual < 0,3 mg/L), less than 30% for NTK and \'N-NH IND.4\'POT.-\', 96 to 98% for color (residual < 50 uC) and 80 to 82% for Abs254nm (resisual < 0,198). Thus, due to the good results that were presented, it can be said that floto-filtration is an attractive alternative for the post-treatment of an anaerobic reactor effluent.
9

Floto-filtração como pós-tratamento de efluente de reator anaeróbio tratando esgoto sanitário / Floto-filtration as post-treatment of an anaerobic reactor effluent

André Luiz de Oliveira 23 February 2007 (has links)
Este trabalho compreende o estudo do desempenho de sistema piloto de floto-filtração, aplicado ao pós-tratamento de efluente de reator anaeróbio, sob diferentes taxas de aplicação superficial, quantidade de ar fornecida ao processo e leitos filtrantes. O trabalho foi dividido em duas fases: ensaios preliminares (fase 1) e ensaios com o floto-filtro (fase 2), sem utilização de leito filtrante (etapa 1 da fase 2) e com utilização do leito filtrante (etapa 2 da fase 2). A fase 1, realizada com unidade de flotação por ar dissolvido em escala de bancada, apresentou resultados satisfatórios em termos de redução de turbidez, cor e Abs254nm para dosagens de cloreto férrico entre 40 a 80 mg/L na maior parte dos ensaios. Os dados desta fase serviram principalmente para a determinação e adoção dos melhores parâmetros operacionais a serem utilizados na fase seguinte. Na etapa 1 da fase 2, o sistema foi analisado sob a ótica da qualidade da água produzida em condições variáveis de dosagem de cloreto férrico, tempo e gradiente de floculação, taxa de recirculação e taxa de aplicação superficial. Para as amostras coletadas foram analisadas as variáveis turbidez, temperatura, condutividade, DQO, SST, pH, cor, Abs254nm, metais, OD, \'P-PO IND.4\'POT.3-\', NTK e \'N-NH IND.4\'POT.+\'. Foram obtidas eficiências globais de 88 a 97% de redução na turbidez (residual < 20 uT), 84 a 98% de SST (residual < 25 mg/L), 87 a 94% de \'DQO IND.B\' (residual < 60 mg/L), 78 a 92% de \'DQO IND.F\' (residual < 40 mg/L), 85 a 96% de \'P-PO IND.4\'POT.3-\' (residual < 2 mg/L) e menor que 30% para NTK e \'N-NH IND.4\'POT.-\'. Na etapa 2 da fase 2, além das análises supracitadas, foram analisadas as variáveis DBO, coliformes totais e fecais, sulfatos, dureza, alcalinidade, ácidos voláteis e turbidez ao longo do leito filtrante além da medida de perda de carga no decorrer da carreira de filtração. Foram monitorados a perda de carga ao longo do leito filtrante, carreira de filtração. Nesta fase, a instalação piloto de floto-filtração foi avaliada mediante a variação da taxa de aplicação superficial e do leito filtrante. Os resultados foram positivos com efluente final apresentando turbidez média abaixo de 2 uT e duração média da carreira filtração de 24 horas. Foram obtidas eficiências globais de 96 a 99% de redução na turbidez (residual < 7 uT), 96 a 99% de SST (residual < 6 mg/L) , 93 a 96% de \'DQO IND.B\' (residual < 40 mg/L), 89 a 97% de \'DQO IND.F\' (residual < 34 mg/L), 93 a 98% de \'P-PO IND.4\' POT.3-\' (residual < 0,3 mg/L), menor que 30% para NTK e \'N-NH IND.4\' POT.-\', 96 a 98% de cor (residual < 50 uC) e 80 a 82% de Abs254nm (residual < 0,198). Desta forma, em virtude dos bons resultados apresentados, pôde-se constatar que a floto-filtração é uma alternativa atraente no pós-tratamento de efluente de reator anaeróbio. / This works assesses the performance of a floto-filtration pilot system, applied to the post-treatment of an anaerobic reactor effluent, under different superficial application rates, amount of air supplied to the process and filter beds. The work was divided in two phases: preliminary essays (phase 1), essays with the floto-filter without using filter bed (step 1 of phase 2) and essays with the floto-filter using filter beds (step 2 of phase 2). Phase 1, carried out with bench scale dissolved air flotation unit, presented satisfactory results regarding turbidity removal, color and Abs254nm for ferric chloride dosages between 40 - 80 mg/L in most of the essays. The data acquired from this phase were mainly used to determine and adopt the best operational parameters to be employed in the following phase. In step 1 of phase 2, the system was analyzed concerning the quality of the water produced in favorable conditions for ferric chloride dosages, time and flocculation gradient, recirculation gradient and superficial application rate. The following variables were analyzed from the collected samples: turbidity, temperature, conductivity, COD, TSS, pH, color, Abs254nm, metais, OD, \'P-PO IND.4\'POT.3-\', NTK and \'N-NH IND.4\'POT.+\'. Global efficiencies of 88 to 97% for turbidity removal (residual < 20 uT), 84 to 98% for TSS (residual 25 mg/L), 87 to 94% for COD (residual < 60 mg/L), 78 to 92% for CODF (residual < 40 mg/L), 85 to 96% \'P-PO IND.4\'POT.3-\' (residual < 2 mg/L) and less than 30% for NTK and \'N-NH IND.4\'POT.+\' were obtained. In step 2 of phase 2, besides the aforementioned analyses, BOD, total and fecal coliforms, sulphates, hardness, alkalinity, volatile acids and turbidity throughout the filter in addition to the measure of headloss during the filter run. In this phase, the floto-filtration pilot plant was assessed varying the superficial application and filter bed rate. The results were positive with the final effluent presenting mean turbidity below 2 uT and mean filter run time of 24 hours. Global efficiencies of 96 to 99% for turbidity removal (residual < 7 uT), 96 to 99% for TSS (residual < 6 mg/L), 93 to 96% for \'COD IND.B\' (residual < 40 mg/L), 89 to 97% for \'COD IND.F\' (residual < 34 mg/L), 93 to 98% for \'P-PO IND.4\'POT.3-\' (residual < 0,3 mg/L), less than 30% for NTK and \'N-NH IND.4\'POT.-\', 96 to 98% for color (residual < 50 uC) and 80 to 82% for Abs254nm (resisual < 0,198). Thus, due to the good results that were presented, it can be said that floto-filtration is an attractive alternative for the post-treatment of an anaerobic reactor effluent.
10

Measured Soil Hydraulic Properties as RZWQM2 Input to Simulate Soil Water Dynamics and Crop Evapotranspiration

Shahadha, Saadi Sattar 01 January 2018 (has links)
Agricultural system models integrate many different processes that cannot all be measured in field experiments and help quantify soil water dynamics, crop evapotranspiration, and crop growth with high temporal resolution. Understanding soil water dynamics and crop evapotranspiration is essential to improve agricultural management of field crops. For example, the interaction between nitrogen application rate and water dynamics is not sufficiently understood. In most cases, model simulations deviate from field measurements, especially when model input parameters are indirectly and unspecifically derived. The extent to which measured soil hydraulic property inputs decrease the discrepancy between measured and simulated soil water status is not well understood. Consequently, this study: (i) investigated thr use of measured soil hydraulic properties as Root Zone Water Quality Model (RZWQM2) inputs compared to indirectly derived inputs; (ii) explored the capability of calibrating measured soil hydraulic property input parameters for one crop and using them for other crops without further calibration; (iii) studied the effect of the nitrogen application rate on the behavior of soil water dynamics and crop evapotranspiration using RZWQM2 under different rainfall amounts. To evaluate the model in different field management conditions, a field experiment with soybean, corn, wheat, and fallow soil was conducted from 2015 – 2017 to collect field data to calibrate and validate the RZWQM2 model. The model presented a satisfactory response to using measured soil hydraulic property inputs and a satisfactory capability to quantify the effect of nitrogen rates on daily crop evapotranspiration, soil water dynamics, and crop growth. With sufficient measurements of soil hydraulic parameters, it was possible to build a RZWQM2 model that produced reasonable results even without calibration.

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