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Slurry Injection Schemes on the Extent of Slurry Mixing and Availability during Chemical Mechanical PlanarizationBahr, Matthew, Sampurno, Yasa, Han, Ruochen, Philipossian, Ara 29 May 2017 (has links)
In this study, slurry availability and the extent of the slurry mixing (i.e., among fresh slurry, spent slurry, and residual rinse-water) were varied via three different injection schemes. An ultraviolet enhanced fluorescence technique was employed to qualitatively indicate slurry availability and its flow on the pad during polishing. This study investigated standard pad center area slurry application and a slurry injection system (SIS) that covered only the outer half of the wafer track. Results indicated that the radial position of slurry injection and the alteration of fluid mechanics by the SIS played important roles in slurry mixing characteristics and availability atop the pad. Removal rates were found to decrease with slurry availability, while a higher degree of slurry mixing decreased the fraction of fresh slurry and consequently lowered the removal rate. By using a hybrid system (i.e., a combination of slurry injection via SIS and standard pad center slurry application), the polishing process benefited from higher slurry availability and higher fraction of fresh slurry than the conventional pad center slurry application and the shorter SIS, individually. This work underscores the importance of optimum slurry injection geometry and flow for obtaining a more cost-effective and environmentally benign chemical mechanical planarization process.
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Simulation studies on chemical effects of additives in in-duct injection processesVenkataramakrishnan, Rajesh January 1994 (has links)
No description available.
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Control Of Slurry Flow, Temperature And Aggressive Diamonds In Chemical Mechanical PlanarizationWu, Changhong January 2015 (has links)
This dissertation presents a series of studies related to the study and control of slurry flow, process temperature, and aggressive diamonds in Chemical Mechanical Planarization (CMP). The purpose of these studies is to better understand the fundamentals of CMP and to explore solutions to some of CMP’s greatest challenges. Within-wafer removal rate non-uniformity (WIWRRNU) is a critical parameter to determine film thickness planarity on a wafer-scale level and it grossly impacts yield. Resolving this issue continues to be an area of intense focus in the industry. The first study in this dissertation shows the feasibility of adopting a new method to improve WIWRRNU during copper CMP that is solely based on intentional local temperature manipulation of the pad. A pad surface thermal management system is developed to locally change pad surface temperature. This system consists of one or more thermal transfer modules contacting the pad surface. In this study, the system is employed to adjust the "center-fast" copper removal rate profile to illustrate its effect during the process. Results shows that, when two thermal transfer modules are employed, local removal rates in the wafer center region decrease significantly while maintaining the removal rates near the wafer edge thereby significantly improving WIWRRNU. Another contribution of this dissertation is the investigation of the effect of pad groove design on slurry injection scheme during interlayer dielectric CMP. A novel slurry injector with multiple slurry outlets is designed, which provides optional slurry injection schemes (i.e. one injection point scheme and multi-injection point scheme). These schemes are compared with the standard slurry application method on a concentrically grooved pad and an xy-groove pad, respectively. On the concentrically grooved pad, the one injection point scheme generates significantly higher oxide removal rates (ranging from 22 to 35 percent) compared to the standard slurry application method at different slurry flow rates. On the xy-groove pad, the one injection point scheme still results in higher removal rates (ranging from 3 to 9 percent), however, its removal rate enhancement is not as high as that of the concentrically grooved pad. In order to further improve slurry availability on the xy-groove pad, the multi-injection point scheme is tested. Results show that the multi-injection point scheme results in significantly higher removal rates (ranging from 17 to 20 percent) compared to the standard slurry application method. This work underscores the importance of optimum slurry injection schemes for accommodating particular groove designs. The last contribution of this dissertation involves a study regarding aggressive diamond characterization and wear analysis during CMP. A 3M A3700 diamond disk is used to condition a Cabot Microelectronics Corporation (CMC) D100 pad for 30 hours. The top 20 aggressive diamonds for two perpendicular disk orientations are identified before the polishing, as well as after 15- and 30-hour polishing. The furrow surface area generated by these top 20 aggressive diamonds and their evolution are analyzed and compared. Results show that the original top 20 aggressive diamonds identified before polishing are subjected to wear after the first 15-hour polishing as the furrow surface area that they generate decreases dramatically (by 47%). As these original aggressive diamonds are worn, seven new aggressive diamonds are "born" and join the new top 20 list for both disk orientations. After the second 15-hour wafer polishing, the furrow surface area of these new top 20 aggressive diamonds do not change significantly. The furrow surface area created by all the active diamonds exhibits the same trend as the top 20 aggressive diamonds, confirming that most pad conditioning work is performed by these aggressive diamonds and that the disk loses its aggressiveness in the first 15 hours of polishing and then maintains its aggressiveness during the second 15 hours, albeit to a lesser extent.
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Acúmulo de carbono no solo e potencial de aquecimento global influenciados pelo modo de aplicação de dejetos líquidos de suínos e inibidor de nitrificação / Soil carbon accumulation and global warming potential influenced by technique application pig slurri and use of nitrification inhibitorSantos, Daniela Batista dos 04 July 2016 (has links)
Studies about the effect of pig slurry (PS) injection in the soil and the use of nitrification inhibitors, such as dicyandiamide (DCD), have been focused on the dynamics of nitrogen in the soil-plant-atmosphere system. The aim of this work was to evaluate how the PS injection and the use of DCD can influence in total organic carbon accumulation in the soil (TOC) and the mitigation of global warming potential (GWP) due to the PS agricultural use as fertilizer in succession oats or wheat / corn under no-tillage. Two studies were conducted to field at the Federal University of Santa Maria, in experimental design of randomized blocks with four repetitions of the following treatments: PS applied on the soil surface (PSs), PSs + DCD, PS injected (PSi), PSi + DCD , mineral fertilizer (NPK) and control. The studies began in August and in December 2011 lasting 967 and 865 days on site 1 and 2, respectively. In the first place the PS application was manually, and the product Agrotain Plus®, which containing the DCD (81.0%), was applied at the rate of 10 kg ha-1. While in the second place exclusively PS injection was mechanized, whose grooves were spaced 0.35 m, in average depth 0.10 m and pure DCD was used in dose of 10 kg ha-1. In both places the DCD was mixed with PS at the moment of each application at cultures. Disturbed and undisturbed soil samples were collected at both sites in 2011 (initial condition) and in 2014, in the layers 0-0.05; 0.05-0.10; 0.10-0.20 and 0.20-0.30 m, and on site 2 the first layer was stratified into 0-0.025 and 0.025-0.05 m. We used the equivalent mass approach to determination of stocks TOC in the soil. During all the time from both experiments it was collected to greenhouse gas samples in order to quantify the cumulative emissions of nitrous oxide (N2O) and methane (CH4), and then convert them into CO2 equivalent and add them the rate of TOC accumulation in soil to estimate the net GWP (in area scale). To estimate the GWP in yield scale, it was divided the value of the net GWP by the average annual productivity of corn grain. The PS technique application and its combination with the DCD did not differ TOC accumulation in the soil neither the GWP. Regardless of the PS technique application and combination with DCD, the organic fertilization increases TOC accumulation in the soil and reduced the GWP compared to mineral fertilization. The PS injection associated with DCD increased the addition of C in the soil via biomass crops and COT accumulation in the soil in the layer from 0.00 to 0.30 m, compared to the absence of fertilization and NPK fertilization. Furthermore, when the PS are injected associated with the DCD it was observed at lower GWP in area scale than the mineral fertilizer, showing the environmental benefits of this first management. Negative values of the net GWP obtained in treatments with DCD indicate a positive potential effect of the nitrification inhibitor to mitigate emissions, this because the COT accumulation in the soil in these treatments was higher than the emissions of greenhouse gases. High GWP values in yield scale are observed in the control treatment, with no difference for this estimate, between organic and mineral fertilizers. It is noteworthy that there is a clear trend of associated injection to enable DCD environmental benefits through the reduction of greenhouse gas emissions, COT accumulation increment in soil and maintenance of grain yield. / Estudos que tratem do efeito da injeção de dejetos líquidos de suínos (DLS) no solo e do uso de inibidores de nitrificação, como a dicianodiamida (DCD), têm sido voltados, principalmente, à dinâmica do nitrogênio no sistema solo-planta-atmosfera. O objetivo do presente trabalho foi avaliar como a injeção dos DLS no solo e o uso da DCD podem influenciar no acúmulo de carbono orgânico total (COT) no solo e na mitigação do potencial de aquecimento global (PAG) decorrente do uso agrícola de DLS como fertilizante na sucessão aveia ou trigo/milho em semeadura direta (SD). Dois estudos foram conduzidos a campo na Universidade Federal de Santa Maria, em delineamento experimental de blocos ao acaso, com quatro repetições dos seguintes tratamentos: DLS aplicados na superfície do solo (DLSs), DLSs + DCD, DLS injetados (DLSi), DLSi + DCD, testemunha (Teste) e adubação mineral (NPK). Os estudos iniciaram em agosto e em dezembro de 2011 com duração de 967 e 865 dias no local 1 e 2, respectivamente. No local 1, a aplicação dos DLS foi realizada de forma manual e o produto Agrotain Plus®, contendo a mistura de DCD (81,0%) foi aplicado na dose de 10 kg ha-1. No local 2, a injeção foi de realizada de forma mecanizada em sulcos espaçados de 0,35 m entre si, na profundidade média 0,10 m e a DCD pura foi utilizada, na dose de 10 kg ha-1. Em ambos os locais a DCD foi misturada aos DLS, no momento de cada aplicação destes antecedendo a implantação das culturas. Amostras deformadas e indeformadas de solo foram coletadas em ambos os locais no ano de 2011 (condição inicial) e em 2014, nas camadas de 0-0,05; 0,05-0,10; 0,10-0,20 e 0,20-0,30 m, sendo que no local 2 a primeira camada foi estratificada em 0-0,025 e 0,025-0,05 m. Utilizou-se a abordagem de massa equivalente para calcular os estoques de COT no solo. Durante todo o período de condução dos experimentos coletaram-se amostras de gases de efeito estufa com vistas à quantificar as emissões acumuladas de óxido nitroso (N2O) e metano (CH4), para então convertê-las em equivalente CO2 e somá-las à taxa real de acúmulo de COT no solo para estimativa do PAG líquido (em escala de área). Para estimativa do PAG em escala de rendimento, dividiu-se o valor do PAG líquido pela produtividade média anual de grãos de milho. Os modos de aplicação de DLS e sua combinação com a DCD não diferiram entre si quanto ao acúmulo de COT no solo e ao PAG. Independente do modo de aplicação e da combinação com DCD, a adubação orgânica com DLS aumenta o acúmulo de COT no solo e diminuiu o PAG quando com parada à adubação com NPK. A injeção de DLS associada à DCD aumentou a adição de C no solo via biomassa das culturas e o acúmulo de C no solo na camada 0,00 0,30 m, em comparação à testemunha e à adubação com NPK. Da mesma forma, quando os DLS são injetados no solo associados à DCD, observa-se PAG em escala de área menor do que na adubação NPK, evidenciando os benefícios ambientais desse primeiro manejo. Valores negativos do PAG líquido obtido nos tratamentos com DCD indicam um efeito potencial positivo do inibidor de nitrificação em mitigar as emissões, isso porque o acúmulo de COT no solo nesses tratamentos foi superior às emissões de gases de efeito estufa. Elevados valores de PAG em escala de rendimento de grãos de milho são observados no tratamento testemunha, sem que haja diferença, para essa estimativa, entre adubação orgânica e mineral. A injeção dos DLS em SPD, associada à DCD, proporciona benefícios ambientais, por meio da redução das emissões gasosas, incremento de acúmulo de COT no solo e manutenção da produtividade de grãos.
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Eficiência de uso do nitrogênio por gramíneas em função do modo de aplicação de dejetos suínos no solo e do uso de inibidor de nitrificação / Nitrogen use efficiency of grasses as affected by the pig slurry application mode and use of nitrification inhibitorGonzatto, Rogerio 01 April 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The effect of pig slurry (PS) injection into the soil and nitrification inhibitor use such as dicyandiamide (DCD) on gaseous N losses to the atmosphere is better documented than the effect of these practices on nitrogen use efficiency (NUE) and crop productivity. The aim of this work was to evaluate how the PS application method (shallow injection vs surface broadcasting) in no-till (NT) and DCD addition to PS affects the recovery of PS ammonium N (NH4-N) in the soil-plant system, NUE and productivity in a succession of grasses (corn/oat-wheat). Two studies were performed in the field at Universidade Federal de Santa Maria, in a Typic Paleudult. The experimental design was in randomized blocks with four repetitions of the following treatments: surface broadcast of pig slurry (PSs), PSs + DCD, injected PS (PSi), PSi + DCD, and control and surface application of mineral (NPK). Studies began in December 2011, with the first one finalized in June 2013 and the second in December 2015. In the first study, the PS ammonium fraction (NH4+-N) was 15N enriched to follow the fate of this fraction in the soil-plant system. Compared with the broadcast application, PS injection into the soil was more effective when followed by low soil moisture conditions, increasing in 22 kg N ha-1 the recovery of PS NH4+-N in corn. However, the DCD was more efficient in situations with higher soil moisture, increasing in 24 kg N ha-1 the recovery of NH4+-N in corn. In addition, PS injection efficiency was improved when combined with DCD, increasing in 21% NH4+-N retention in the plant-soil system. In the second study, PS injection also increased the apparent recovery of N (21%), agronomic efficiency of N (33%) and crop productivity (10%) compared to surface application. DCD use did not have significant effect on all crops, although, on the other hand, its use in wheat/2013 improved the evaluated attributes. The best performance of crops with PS injection as NUE is related mainly to the efficiency of this practice to reduce N losses by ammonia (NH3) volatilization, ensuring greater N availability for uptake by crops. The DCD, nevertheless, seems to be more effective when its application is followed by periods of high humidity, which favour N losses by denitrification or nitrate leaching (NO3-), and/or low temperatures that increase the longevity of the product in the soil. In conclusion, these results indicated that PS injection into the soil in NT is a promising alternative management for PS surface broadcasting, while the use of DCD requires further studies evaluating its effect on NUE by crops varying the soil and local weather conditions. / O efeito da injeção de dejetos líquidos de suínos (DLS) no solo e do uso de inibidores de nitrificação, como a dicianodiamida (DCD), sobre as perdas gasosas de N para atmosfera é melhor documentado do que o efeito destas práticas sobre a eficiência de uso do nitrogênio (EUN) e a produtividade das culturas. O objetivo do presente trabalho foi avaliar como o modo de aplicação (injeção subsuperficial vs aplicação superficial) de DLS no solo em sistema de plantio direto (SPD) e a adição de DCD aos DLS afetam a recuperação do N amoniacal (N-NH4+) dos DLS no sistema solo-planta, a EUN e a produtividade em uma sucessão de gramíneas (milho/aveia-trigo). Dois estudos foram conduzidos a campo na Universidade Federal de Santa Maria, em um Argissolo Vermelho Alumínico úmbrico, no delineamento experimental de blocos ao acaso com quatro repetições dos seguintes tratamentos: DLS aplicados na superfície do solo (DLSs), DLSs + DCD, DLS injetados (DLSi), DLSi + DCD, testemunha e adubação mineral (NPK) em superfície. Os estudos iniciaram em dezembro de 2011 com a aplicação dos tratamentos no milho, sendo o primeiro finalizado em junho de 2013 e o segundo em dezembro de 2015, ambos na cultura do trigo. A aplicação dos DLS foi realizada de forma manual com regadores, enquanto a injeção foi mecanizada em sulcos espaçados 35 cm entre si, na profundidade de 8-11 cm. A dose de DCD utilizada foi de 10 kg ha-1, misturada aos dejetos instantes antes da aplicação no solo. Para o primeiro estudo a fração amoniacal dos DLS foi enriquecida em 15N e aplicado em microparcelas (1,40 x 1,60 m) demarcadas dentro das parcelas principais do experimento (5,25 x 6,0 m) para avaliar o efeito do modo de aplicação e da adição de DCD sobre o destino dessa fração no sistema solo-planta. No segundo estudo foram colhidas plantas nas parcelas principais para determinar o efeito dos tratamentos sobre a EUN e a produtividade das culturas. Comparada à aplicação em superfície, a injeção dos DLS no solo mostrou-se mais eficiente quando seguida por condições de baixa umidade do solo, aumentando em 22 kg N ha-1 a recuperação de N-NH4+ dos DLS no milho. A DCD, no entanto, foi mais eficiente em situações com maior umidade do solo, aumentado em 24 kg N ha-1 a recuperação de N-NH4+ no milho. Além disso, a eficiência da injeção foi maximizada quando combinada com DCD, aumentando em 21% a retenção de N-NH4+ no sistema solo-planta. No segundo estudo, a injeção também aumentou a recuperação aparente de N (21%), a eficiência agronômica do N (33%) aplicado com os DLS e a produtividade das culturas (10%) em comparação à aplicação superficial. O uso da DCD não teve efeito significativo em todos os cultivos, embora no trigo/2013 tenha melhorado os atributos avaliados. O melhor desempenho das culturas com a injeção de DLS, quanto a EUN foi relacionado, principalmente, à eficiência dessa prática em reduzir as perdas de N por volatilização de amônia (NH3), garantindo a maior disponibilidade de N às plantas. A DCD, no entanto, parece ser mais eficiente quando sua aplicação é seguida por períodos de umidade elevada, que favoreçam as perdas de N por desnitrificação ou lixiviação de nitrato (NO3-), e/ou com baixas temperaturas que aumentam a longevidade do produto no solo. Diante desses resultados, a injeção dos DLS no solo em SPD, constitui uma alternativa de manejo promissora, em relação à aplicação dos DLS na superfície do solo, enquanto o uso de DCD carece por mais estudos avaliando seus efeitos sobre a EUN pelas culturas, variando as condições de solo e clima.
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Reservoir screening criteria for deep slurry injectionNadeem, Muhammad January 2005 (has links)
Deep slurry injection is a process of solid waste disposal that involves grinding the solid waste to a relatively fine-grained consistency, mixing the ground waste with water and/or other liquids to form slurry, and disposing of the slurry by pumping it down a well at a high enough pressure that fractures are created within the target formation.
This thesis describes the site assessment criteria involved in selecting a suitable target reservoir for deep slurry injection. The main goals of this study are the follows: <ul> <li>Identify the geological parameters important for a prospective injection site</li> <li>Recognize the role of each parameter</li> <li>Determine the relationships among different parameters</li> <li>Design and develop a model which can assemble all the parameters into a semi-quantitative evaluation process that could allow site ranking and elimination of sites that are not suitable</li> <li>Evaluate the model against several real slurry injection cases and several prospective cases where slurry injection may take place in future</li> </ul> The quantitative and qualitative parameters that are recognized as important for making a decision regarding a target reservoir for deep slurry injection operations are permeability, porosity, depth, areal extent, thickness, mechanical strength, and compressibility of a reservoir; thickness and flow properties of the cap rock; geographical distance between an injection well and a waste source or collection centre; and, regional and detailed structural and tectonic setup of an area. Additional factors affecting the security level of a site include the details of the lithostratigraphic column overlying the target reservoir and the presence of overlying fracture blunting horizons. Each parameter is discussed in detail to determine its role in site assessment and also its relationship with other parameters. A geological assessment model is developed and is divided into two components; a decision tree and a numerical calculation system. The decision tree deals with the most critical parameters, those that render a site unsuitable or suitable, but of unspecified quality. The numerical calculation gives a score to a prospective injection site based on the rank numbers and weighting factors for the various parameters. The score for a particular site shows its favourability for the injection operation, and allows a direct comparison with other available sites. Three categories have been defined for this purpose, i. e. average, below average, and above average. A score range of 85 to 99 of 125 places a site in the ?average? category; a site will be unsuitable for injection if it belongs to the ?below average? category, i. e. if the total score is less than 85, and the best sites will generally have scores that are in the ?above average? category, with a score of 100 or higher. One may assume that for sites that fall in the ?average? category there will have to be more detailed tests and assessments. The geological assessment model is evaluated using original geological data from North America and Indonesia for sites that already have undergone deep slurry injection operations and also for some possible prospective sites. The results obtained from the model are satisfactory as they are in agreement with the empirical observations. Areas for future work consist of the writing of a computer program for the geological model, and further evaluation of the model using original data from more areas representing more diverse geology from around the world.
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Reservoir screening criteria for deep slurry injectionNadeem, Muhammad January 2005 (has links)
Deep slurry injection is a process of solid waste disposal that involves grinding the solid waste to a relatively fine-grained consistency, mixing the ground waste with water and/or other liquids to form slurry, and disposing of the slurry by pumping it down a well at a high enough pressure that fractures are created within the target formation.
This thesis describes the site assessment criteria involved in selecting a suitable target reservoir for deep slurry injection. The main goals of this study are the follows: <ul> <li>Identify the geological parameters important for a prospective injection site</li> <li>Recognize the role of each parameter</li> <li>Determine the relationships among different parameters</li> <li>Design and develop a model which can assemble all the parameters into a semi-quantitative evaluation process that could allow site ranking and elimination of sites that are not suitable</li> <li>Evaluate the model against several real slurry injection cases and several prospective cases where slurry injection may take place in future</li> </ul> The quantitative and qualitative parameters that are recognized as important for making a decision regarding a target reservoir for deep slurry injection operations are permeability, porosity, depth, areal extent, thickness, mechanical strength, and compressibility of a reservoir; thickness and flow properties of the cap rock; geographical distance between an injection well and a waste source or collection centre; and, regional and detailed structural and tectonic setup of an area. Additional factors affecting the security level of a site include the details of the lithostratigraphic column overlying the target reservoir and the presence of overlying fracture blunting horizons. Each parameter is discussed in detail to determine its role in site assessment and also its relationship with other parameters. A geological assessment model is developed and is divided into two components; a decision tree and a numerical calculation system. The decision tree deals with the most critical parameters, those that render a site unsuitable or suitable, but of unspecified quality. The numerical calculation gives a score to a prospective injection site based on the rank numbers and weighting factors for the various parameters. The score for a particular site shows its favourability for the injection operation, and allows a direct comparison with other available sites. Three categories have been defined for this purpose, i. e. average, below average, and above average. A score range of 85 to 99 of 125 places a site in the ?average? category; a site will be unsuitable for injection if it belongs to the ?below average? category, i. e. if the total score is less than 85, and the best sites will generally have scores that are in the ?above average? category, with a score of 100 or higher. One may assume that for sites that fall in the ?average? category there will have to be more detailed tests and assessments. The geological assessment model is evaluated using original geological data from North America and Indonesia for sites that already have undergone deep slurry injection operations and also for some possible prospective sites. The results obtained from the model are satisfactory as they are in agreement with the empirical observations. Areas for future work consist of the writing of a computer program for the geological model, and further evaluation of the model using original data from more areas representing more diverse geology from around the world.
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Emissões de amônia e óxido nitroso após aplicação de dejetos de bovinos na semeadura e ureia em cobertura na sucessão trigo/milho em plantio direto / Ammonia and nitrous oxide emissions after dairy slurry application in no-till wheat/maize sowing and urea sidedressedTonetto, Felipe 25 November 2016 (has links)
The application of dairy slurry (DS) to the soil surface in no-till can result in the ammonia (NH3) and nitrous oxide (N2O) emission to atmosphere, with negative repercussions both agronomical and environmentally. The magnitude of these emissions may reduce the expected benefits from the agricultural use of dairy slurry as a nitrogen (N) source to crops. The objective of this work was to evaluate the N2O and NH3 emission according to the method of DS application in soil (surface broadacast vs. shallow injection), with and without the use of the nitrification inhibitor dicyandiamide (DCD) at sowing, associated with the application of urea sidedress. The work was developed in the experimental area of the Department of Soils of the Federal University of Santa Maria (UFSM), in a Hapludalf. The experiment was established in a randomized complete block design with four replications and plots with dimensions of 33 m2 (5,5 m x 6 m). The treatments were: T1- Control; T2- Surface application of mineral fertilization in sowing and urea sidedress (NPK + U); T3- DS broadcast and urea (DSs + U); T4- DSs broadcast with DCD and urea (DSs + DCD + U); T5- DS injected and urea (DSi + U) and T6- DS injected with DCD and urea (DLBi + DCD + U). The N2O evaluations were performed using static chambers and the ammonia was evaluated in the wheat through semi-open static chambers and in the corn through semi-open collectors. Dairy slurry injection in sowing increase N2O emission in 2,198 g ha-1 (56%) in relation to the traditional way of urea use, applying 1/3 of the N at sowing and 2/3 in sidedress. The DCD addition to dairy slurry did not affect the annual N2O emission when the dairy manure was applied on the soil surface in sowing of wheat and corn, compare with exclusive use of urea. The results showed that the lower N2O emission occurred with the use combined of DCD with dairy slurry before its injection into the soil, in sowing of the cultures. NH3 cumulative emissions did not differ between the application of dairy manure in pre-sowing associated with sidedress urea from the traditional mode of exclusive use of urea. The results suggest that N2O and NH3 emissions factors preconized by IPCC are overestimated for dairy manure for Southern Brazil. / A distribuição dos dejetos líquidos de bovinos (DLB) na superfície do solo em plantio direto pode resultar na emissão para a atmosfera de amônia (NH3) e óxido nitroso (N2O), com reflexos negativos tanto do ponto de vista agronômico quanto ambiental. A magnitude destas emissões pode reduzir os benefícios esperados com o uso agrícola dos dejetos como fonte de nitrogênio (N) às culturas. O objetivo do trabalho foi avaliar a emissão de N2O e NH3 em função do modo de aplicação dos DLB no solo, em superfície ou injetado, com e sem o uso do inibidor de nitrificação dicianodiamida (DCD) na semeadura, associado com a aplicação de ureia em cobertura. O trabalho foi desenvolvido na área experimental do Departamento de Solos da Universidade Federal de Santa Maria (UFSM), em um Argissolo Vermelho Distrófico arênico. O delineamento experimental foi blocos ao acaso com 4 repetições. Os tratamentos foram os seguintes: T1- Testemunha, sem aplicação de fertilizantes; T2- Adubação mineral (NPK) aplicada na superfície do solo + ureia em cobertura (NPK + U); T3- DLB na superfície do solo + ureia em cobertura (DLBs + U); T4- DLB com DCD na superfície do solo + ureia em cobertura (DLBs + DCD + U); T5- DLB injetado no solo + ureia em cobertura (DLBi + U) e T6- DLB com DCD injetado no solo + ureia em cobertura (DLBi + DCD + U). Os tratamentos foram aplicados no trigo e reaplicados no milho. A emissão de N2O foi avaliada usando câmaras estáticas, desde a aplicação dos tratamentos no trigo até 22 dias após a colheita do milho, totalizando 364 dias de avaliação. A amônia foi avaliada no trigo através de câmaras semi-abertas estáticas e no milho através de coletores semi-abertos. A injeção dos DLB em pré-semeadura no trigo e no milho, com aplicação de ureia em cobertura, aumentou a emissão anual de N-N2O em 2.198 g ha-1 (56%), em relação ao modo tradicional de uso da ureia nas culturas, aplicando-se 1/3 do N na semeadura e 2/3 em cobertura. A adição de DCD aos DLB não afetou a emissão anual de N2O quando os DLB foram aplicados na superfície do solo em pré-semeadura do trigo e do milho, porém reduziu a emissão anual em 39% quando os DLB foram injetados, não diferindo do tratamento com uso exclusivo de ureia. Os resultados do estudo indicam que a menor emissão de N2O ocorreu com o uso combinado de DCD aos DLB antes da sua injeção no solo, na pré-semeadura das culturas. A volatilização acumulada de NH3 nos tratamentos em que os dejetos de bovinos foram aplicados em pré-semeadura associados à aplicação de ureia em cobertura não diferiu do modo tradicional de uso exclusivo de ureia nas culturas. Os resultados indicam que o fator de emissão de N2O e NH3 preconizado pelo IPCC está superestimado para a aplicação de dejetos de bovinos e ureia no trigo e no milho no Rio Grande do Sul.
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