CAPES / O sucesso da produção agrícola na Integração Lavoura–Pecuária (ILP) está fundamentado no uso adequado de estratégias de manejo adotadas na fase pastagem, como o ajuste da intensidade de pastejo e a adubação nitrogenada. Diversos estudos comprovaram a influência da intensidade de pastejo e da adubação nitrogenada na dinâmica da qualidade física do solo, desempenho de máquinas agrícolas e produtividade de lavouras sucessoras. Entretanto, a maioria dos trabalhos estudam estes fatores de forma isolada e pouco se sabe sobre a interação entre eles no manejo de um sistema ILP. Nesse contexto, o objetivo deste trabalho foi avaliar as possíveis interações, envolvendo altura de pasto e época de adubação nitrogenada no sistema ILP, sobre as características físicas do solo, plantabilidade, os componentes de rendimento e produtividade da soja sucessora a uma pastagem. O experimento foi realizado em uma área de 14 ha, aonde desde 2012 vem sendo conduzido um experimento em longo prazo com ILP sob Plantio Direto, em Abelardo Luz – SC. O delineamento experimental foi blocos ao acaso com três repetições, distribuídos em um esquema fatorial (2x2). O primeiro fator foi a intensidade de pastejo (alta e baixa), caracterizado por duas alturas de manejo do pasto (10 e 25 cm), e o segundo fator foi a época de aplicação de N no sistema: N aplicado na pastagem (NP) e N aplicado na cultura de grãos (NG), na dose de 200 kg de N ha-1. A altura do pasto foi regulada por meio de pastejo com lotação contínua e taxa de lotação variável de bovinos de corte. A pastagem foi um consórcio de aveia preta ‘BRS 139’ + azevém ‘Barjumbo’. A cultivar de soja ‘Nidera 5909’ foi semeada em 28 de novembro de 2014, 18 dias após a retirada dos animais da área. A densidade do solo após a pastagem na camada 2,5 – 7,5 cm obteve uma média de 1,10 g cm-3 e depois do cultivo da soja 0,98 g cm-3. A variação espacial dos pontos no terreno alterou os valores de densidade e porosidade total devido à umidade se acumular em pontos de baixada durante o período de pastejo. A porosidade total aumentou após o cultivo da soja cujos os valores passaram de 0,58 para 0,62 m3 m-3. Já a resistência mecânica a penetração mostrou que a primeira camada do solo 0-10 cm apresentava mais compactada, porém com redução nos valores após o cultivo da soja. Os diferentes manejos não influenciaram a mobilização de solo, devido à ausência de diferença entre a densidade do solo, a quantidade de palhada não dificultar a operacionalidade da semeadora e a profundidade superficial de atuação da haste sulcadora. Os tratamentos avaliados não afetaram a demanda de força e potência exigida pelo trator para movimentar a semeadora. Não houve diferença significativa de produtividade entre os tratamentos com um valor médio obtido de 3820 kg ha-1. Isso é reflexo de que a área apresentava boas condições físicas e de fertilidade do solo, mostrando que é possível intensificar o sistema. / The success of agricultural production in Crop Livestock Systems (CLS) is based on the proper management of the pasture phase, such as grazing intensity and nitrogen fertilization. Several studies confirmed the influence of grazing and nitrogen in the soil physical traits, the performance of machines and the productivity of successive crops. However, most trials study these factors isolated and little is known about the interaction between them in the management of an CLS system. In this context, the aim of this work was to evaluate the soil physical characteristics and the soybean development and plantability, cropped in succession to winter pasture and managed according grazing intensities and nitrogen fertilization strategies. The experiment was carried out at the city of Abelardo Luz – SC – Brazil (26o31’30” S; 52o15’35”W; 850 m asl.), in a 14 ha area, where a long term no-till – CLS experiment has been conducted since 2012. The experimental design was randomized blocks with three replications, arranged in a factorial scheme (2x2). First factor was composed by grazing intensities (high and low), stablished by two heights of pasture management (10 and 25 cm). The second factor was the N fertilization strategy, being the 200 kg of N ha-1 applied to the pasture (NP) or N applied in the grain crop (NG). The height of the pasture was regulated by grazing with put and take continuous with three animals testers. The pasture was a consortium of black oats 'BRS 139' + ryegrass 'Barjumbo'. The soybean cultivar ‘Nidera 5909’ was sown on November 28, 2014, 18 days after the animals were removed from the area. Soil density after grazing in de soil layer 2,5 – 7,5 cm averaged 1.10 g cm-3 and after cultivation of soybean 0.98 g cm-3. The spatial variation of the points in the terrain changed the values of density and the total porosity due to the moisture accumulating at points of discharge during the grazing period. Total porosity increased after soybean cultivation, whose values increased from 0.58 to 0.62 m3 m-3. Still, the mechanical resistance to penetration showed that the first layer of soil 0-10 cm was more compacted. The treatments did not influence the soil mobilization, as soon as no difference between soil density was observed. The amount of straw did not hinder the operability of the seed drill and the surface depth of the grooving rod. The treatments did not affected the demand of force and power required by the tractor to move the seeder. There was no significant difference in productivity between treatments with a mean value of 3,820 kg ha-1. This is a reflection of good physical conditions and good soil fertility of the area, showing that it is possible to intensify the use of this system.

Para avaliar a eficiência do uso de diferentes fontes nitrogenadas e associações de fertilizantes aplicadas no momento do diferimento de B. brizantha cv. Marandu sobre a produção de forragem e recuperação aparente do nitrogênio aplicado nos períodos de crescimento, pastejo e rebrota, além do valor nutritivo da forragem pastejada e das perdas por pastejo, foi realizada essa pesquisa, entre março e novembro de 2003. O delineamento foi em blocos completos ao acaso, com quatro repetições, sendo a dose de N aplicada de 50 kg.ha-1. Os seis tratamentos foram: testemunha (0 kg.N.ha-1), uréia, sulfato de amônio, uréia associada ao sulfato de amônio, uréia associada ao cloreto de potássio e uréia associada ao superfosfato simples. Durante o período de crescimento, entre março e julho, não houve diferenças entre tratamentos na produção de forragem aos 104 dias de vedação da planta indicando que estudos que objetivam a aplicação de associações de fertilizantes devem ter controle sobre a uniformidade da distribuição, por essa representar fonte de variação desconhecida. Os valores médios nesse momento foram de 6000, 2700 e 1100 kg.ha-1 de MS, MSV e LFV, respectivamente, sendo a taxa média de acúmulo de forragem de 26,1 kg MS.ha-1.dia-1. As máximas produções de MS, MSV e LFV ocorreram aos 77, 63 e 63 dias, aos 421, 328 e 429 GD e às 3855, 2709 e 3033 UF respectivamente, indicando que áreas diferidas adubadas devem ser utilizadas na primeira metade do período seco. O uso de GD e UF não apresentaram vantagens em relação à avaliação diária. A recuperação média do N aos 104 dias foi de 11,6%. No período de pastejo, entre julho e setembro, as reduções na MSV foram mais aceleradas que as de MS total. A altura da planta decresceu mais lentamente que a MS, principalmente devido à presença de hastes. Isso contribuiu para a definir a densidade volumétrica das folhas verdes como ferramenta indicada ao monitoramento da forragem diferida durante o pastejo. As perdas por pastejo situaram-se entre 1500 e 2500 kg MS.ha-1. Os teores médios de NDT no pastejo simulado foram 52,9% e 50,7% na primeira e quarta quinzenas de pastejo, respectivamente. O teor de PB acompanhou a mesma tendência, apresentando valores médios tanto para planta toda quanto para pastejo simulado no início e final desse período de 4,2% e 3,1%, respectivamente. A DIVMS média da forragem colhida na simulação de pastejo foi superior a da forragem ofertada ao animal em pastejo, porém decrescente ao longo do período de pastejo. Os valores do pastejo simulado foram de 58% e 50,1% na segunda e oitava semanas de pastejo respectivamente. Não houve diferenças de produção de forragem entre os tratamentos durante a rebrota, porém a PB dos tratamentos adubados foi superior a da testemunha, o que resultou em recuperações do N crescentes ao longo das avaliações, atingindo 29% aos 47 dias de crescimento, e indicando que houve efeito residual da adubação nitrogenada no momento do diferimento, sem no entanto reverter em aumentos de produção de forragem. / The present research was conducted, from March through November 2003, to evaluate the efficiency of different nitrogen sources and fertilizers combinations on the deferment process of B. brizantha cv. Marandu upon forage production and applied nitrogen recovery along the growing, grazing and regrowth phases, besides the grazed forage nutritive value and the grazing losses. A four repetition, randomized complete block design was used, and the nitrogen amount applied was 50 kg.ha-1 (with exception for the control treatment). The six treatments imposed were: control, urea, ammonium sulfate, urea associated with ammonium sulfate, urea associated with potassium chloride and urea associated with single superphosphate. During growing phase, from March to July, there were no production differences among treatments after 104 days of growing period, indicating that fertilizer associations experiments should evaluate application uniformity, because it represents unknown variation source. The total dry matter production (DM), green dry matter production (GDM) and green leaves blades (GLB) obtained was 6000, 2700 and 1100 kg.ha-1, respectively. The maximum DM, GDM and GLB productions occurred at 77, 63 and 63 growing days; 421, 328 and 429 degree-days (DD); and 3855, 2709 and 3033 photothermal units (PU), respectively, indicating fertilized areas should be grazed at the end of autumn and beginning of winter. The DD and PU utilization weren’t better than the daily evaluation. The nitrogen average recovery at 104 days of growing was 11.6%. During grazing phase, from July trough September, GDM reductions occurred faster than DM. Plant height decreasing rhythm was slower than total DM, due to the stems. Therefore the green leaves volumetric density was chosen as the most appropriate monitoring tool of pasture during grazing. Losses values were located between 1500 and 2500 kg DM.ha-1. Simulated grazing TDN average fractions were 52.9% and 50.7% at second and eighth grazing weeks, respectively. CP fraction followed the same behavior, presenting simulated grazing and total offered forage average values of 4.2% and 3.1%, in the beginning and end of grazing phase, respectively. Average IVDMD of grazing simulation harvested forage was superior when compared with animal offered forage, however it was decreasing along the grazing phase. Simulated grazing digestibility values were 58% and 50.1% at second and eighth weeks, respectively. There were no forage production differences during regrowth phase; however fertilized treatments CP were higher than the control treatment, resulting in increased nitrogen recoveries along the period, reaching 29% with 47 growing days, and indicating there were residual fertilization effects. However, those effects weren’t reverted in forage production increases.

A principal limitação da Avaliação do Ciclo de Vida (ACV) é a necessidade da coleta de um elevado número de dados representativos para a região em estudo. Esta limitação pode ser contornada pela construção de bancos de dados regionais, ou seja, de inventários de elementos que são comuns aos ciclos de vida de inúmeros produtos. Entre esses elementos encontram-se os fertilizantes químicos. Nesse contexto este trabalho de doutorado apresenta uma contribuição ao banco de dados brasileiro para apoio aos estudos de ACV, qual seja: os inventários do ciclo de vida da uréia; do nitrato de amônio e do sulfato de amônio adequados às condições brasileiras. Para a elaboração dos inventários foi necessário obter o perfil detalhado do setor de fertilizantes nitrogenados no país. Em seguida, efetuou-se a identificação e quantificação das entradas de recursos naturais e das disposições de rejeitos associados ao ciclo de vida dos fertilizantes estudados. Por fim, fez-se uma discussão dos principais aspectos ambientais associados à produção dos três fertilizantes no Brasil. Os dados obtidos no inventário da uréia revelaram 45 aspectos ambientais. No que diz respeito às emissões atmosféricas, verificou-se que o dióxido de carbono foi responsável por 98,3% do total e em relação aos efluentes líquidos, os compostos nitrogenados corresponderam a 73,5% do total. Quanto ao inventário do nitrato de amônio, foram encontrados 42 aspectos ambientais. Verificou-se que o dióxido de carbono foi responsável por 79% do total de emissões atmosféricas e que em relação aos efluentes líquidos, os compostos nitrogenados corresponderam a 25,3% do total. O inventário do sulfato de amônio revelou a existência de 46 aspectos ambientais. Concluiu-se que o dióxido de carbono contribuiu por 99% do total de emissões e que os compostos nitrogenados e de enxofre foram responsáveis, respectivamente, por 5% e 41% do total de efluentes líquidos gerados. A partir dos resultados deste trabalho torna-se possível identificar oportunidades para a melhoria de desempenho ambiental dos processos industriais analisados. / The main limitation of Life Cycle Assessment (LCA) is the necessity for collection a large number of representative data for the region under study. This limitation can get rounded by the construction of regional databases, or inventories of elements that are common to the life cycle of many products. Among these elements are the chemical fertilizers. In this context is inserted this doctorate thesis which presents a contribution to the Brazilian database for support LCA studies which is: the life cycle inventories of urea, ammonium nitrate and ammonium sulfate for the Brazilian conditions. For the elaboration of inventories was necessary to get the detailed profile of nitrogen fertilizers industry in Brazil. Following, the quantified identification of the natural resources inputs and the waste dispositions associated to the fertilizers life cycle referred in this study is made. Finally, there was a discussion of main environmental aspects associated to production of the three fertilizers in Brazil. Data from urea inventory showed 45 environmental aspects. With regard to air emissions, it was found that carbon dioxide was responsible for 98.3% of the total and for the liquid effluents, the nitrogen compounds accounted for 73.5% of the total. As ammonium nitrate inventory, were found 42 environmental aspects. It was found that carbon dioxide was responsible for 79% of total emissions and in relation to liquid effluents, the nitrogen compounds accounted for 25.3% of the total. The ammonium sulfate inventory revealed the existence of 46 environmental aspects. It was concluded that carbon dioxide contributed by 99% of total emissions and the sulfur and nitrogen compounds were responsible, respectively, for 5% and 41% of all liquid effluents generated. From the results of this study becomes possible to identify opportunities for improving the environmental performance of industrial processes analyzed.

Orientador: José Maria Ferreira Jardim da Silveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Economia / Made available in DSpace on 2018-08-20T09:07:38Z (GMT). No. of bitstreams: 1 SilvaJunior_JaimJoseda_M.pdf: 2525719 bytes, checksum: d38aa205a46d664074614f1c0f151298 (MD5) Previous issue date: 2012 / Resumo: O objetivo geral deste estudo é discutir a inserção da biotecnologia moderna no sistema de produção agrícola, com foco na nutrição vegetal. Nas lavouras brasileiras de soja, a tecnologia da inoculação é capaz de suprir toda a demanda das plantas por nitrogênio através da fixação biológica do nutriente. Com isso, o uso dos inoculantes permite a substituição integral dos fertilizantes nitrogenados no cultivo da soja no Brasil e constitui um processo de destruição criativa. Com intuito de avaliar de forma empírica o impacto econômico deste processo é desenvolvido um modelo insumo produto a partir da matriz insumo produto da economia brasileira do ano de 2006. A despeito da fixação biológica de nitrogênio, o uso dos inoculantes resulta também no enriquecimento da matéria orgânica do solo, em melhorias no padrão de germinação das sementes, em maior adsorção de nutrientes e no controle de estresses hídricos e térmicos do solo. Em conjunto, tais fatores possibilitam a prática de atividades agrícolas mais sustentáveis, sem comprometer o nível de produção. Porém, não são capazes de impulsionar a difusão dos inoculantes. A incorporação destes benefícios proporcionados pela inoculação ao sistema agrícola requer a construção de mecanismos de avaliação dos impactos dos inoculantes que extrapolem o âmbito dos mecanismos de mercado. Para isso, com base nas abordagens sistêmicas da inovação, este trabalho propõe ações que visam o fortalecimento da trajetória tecnológica dos inoculantes. Em linha com os objetivos deste estudo, a institucionalização de políticas de incentivo à difusão da inoculação constitui uma "porta de saída" para os esforços das organizações públicas de pesquisa e desenvolvimento agrícola e, aumentam as possibilidades de inovação em demais produtos biotecnológicos via o acúmulo de conhecimento nesta área / Abstract: The aim of this thesis is to discuss the insertion of modern biotechnology in the agriculture production system, in particular the plant nutrition. In the Brazilian soybean cultivation, the inoculation technology can supply all the nitrogen that plants need via the biological fixation of nutrients. Thus, the inoculation can replaces all the nitrogen fertilizers in soybean production representing a process of creative destruction. Seeking to empirically assess the economic impact of this process, an input-output model using the data from input-output matrix for the Brazil economy in 2006, is developed. In spite of nitrogen biological fixation, the inoculation also results in soil organic matter enrichment, better patterns of seed germination, great nutrients absorption and control of soil hydric and temperature stresses.Jointly, these factors contribute for more sustainable agricultures practices, without decreasing the production output. However, they cannot boost the diffusion of inoculation technology. To agriculture benefits from the adoption of inoculation technology it is necessary to build an evaluation mechanism that goes beyond the market mechanisms. Based on the systemic approaches innovation, this thesis recommends policies for strengthening the inoculation technology trajectory. In accordance with the proposal of this study, the institutionalization of policies that incentive the diffusion of inoculation technology represent a "way" to transform the efforts of public Research and Development centers in new products and process for agriculture. Additionally, it also increases the chance of innovation for other biotechnology products and processes via the learning by doing process / Mestrado / Ciências Economicas / Mestre em Ciências Econômicas

Please read the abstract in the section 00front of this document. / Dissertation (MSc (Plant Production))--University of Pretoria, 2004. / Plant Production and Soil Science / unrestricted

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A model (VTCROPS) was developed to simulate the long-term effects of nitrogen (N) leaching to groundwater in the Northern Neck region of Virginia, and ultimately to the Chesapeake Bay. VTCROPS simulates N fate and transport in a soil-plant-atmosphere continuum in a vertical slice between two crop rows, enabling consideration of nonuniform fertilizer placement and root growth patterns. VTCROPS models atmospheric, soil and crop subsystems. Atmospheric conditions (rainfall, temperature, solar radiation) may be directly input by the user or generated using a stochastic climatic generator. The soil subsystem simulates runoff, infiltration, drainage and soil-water redistribution, N immobilization, nitrification, mineralization, denitrification and advective N transport. The crop subsystem simulates plant N uptake, and vegetative and reproductive growth in response to soil and climatic factors, explicitly for maize or wheat. VTCROPS simulates soybean in a crop rotation empirically accounting for leaf area and root growth. The model is capable of simulating long-term cropping sequences under minimum and conventional tillage practices for continuous maize or for rotations involving maize, wheat, soybean and fallow. Critical internal model parameters were calibrated through comparison of output to field data. The sensitivity of output to input variables was determined. Model output is most sensitive to the climatic variables. Model predicted crop performance variables — grain and total dry matter yields and N content — and soil N content were compared with available field data from two sites over a three year period for maize. Data from six sites over a one year period were tested for wheat. Predictions for maize and total N content were fairly accurate, with a tendency to greater error in dry years. Predictions for wheat were somewhat less accurate, but incomplete field data precluded determining the source of discrepancies. Long-term model predictions, for two year crop rotations with minimum and conventional tillage, were evaluated by comparing performance variables with literature values. Appropriate responses were obtained for N transformation processes. Mass conservation for soil-water and N were good. Maize performance variables were within the range of literature values, and were higher under minimum till. Wheat yields and N contents were somewhat higher than values reported in the literature. Nitrogen load is correlated to drainage and water use over the short run, and to rainfall and drainage over longer periods. Minimum tillage did not increase N load to groundwater. Over a year nitrogen load was strongly periodic, with most leaching taking place from January through April. More than 50% of the N load over a rotation was lost during an extended fallow period that followed soybeans. Nitrogen load increased with fertilizer rates, however, N leaching fraction was optimal around rates of 150 — 200 kg/ha. The model was applied to the Virginia counties of Richmond, Westmoreland, Lancaster, King George and Northumberland to assess the potential for long term N leaching to groundwater. Soil surveys indicated that 34 soil map units occurred within 123,000 hectares of cultivated land. In order to reduce the number of simulations, principal component analysis and cluster analysis were employed to subdivide the cultivated area into 10 land units based on different soil properties. Historical climatic data from the area was used to calibrate the stochastic climatic generator. Analyses were performed to determine long-term crop performance and N loads to ground and surface waters in the study area over a 26 year period (13 rotations). Two management systems were applied to the land units. The first management system consisted of a rotation of minimum tilled maize, conventionally tilled wheat, minimum tilled soybeans and a fallow period. The second management system had a similar cropping sequence, but all crops were conventionally tilled. In both cases, fertilizer was applied at a rate of 150 kg-N/ha/crop. With the exception of two land units, mean yield, water use and N uptake over the simulation was fairly uniform among the land units. Runoff and drainage were highly variable between land units and over time within units. Mineralization, denitrification and N load were highly variable both between land units and over time. Nitrogen load ranged from 66 to 131 kg/ha/rotation between land units. Long-term average N loads and N concentrations from the cultivated area and from the total area of the study region were estimated. For this analysis it was assumed that 80% of the cultivated area was under minimum till and 20% under conventional tillage. An area-weighted average of 5.4 million kg-N/ha/year or 29% of total N applied is discharged to groundwater with an average drainage concentration of 9.9 mg/L. The average N concentration from the study area (including uncultivated areas) to groundwater is estimated at 5.1 mg/L. Average N concentration to the Chesapeake Bay from all sources, after dilution with runoff is 4.5 mg/L which is lower than the drinking water standard for nitrate N of 10 mg/L. The possibility of using sewage sludge as a replacement for, or in consort with N fertilizer was investigated for a typical land unit, under a conventionally tilled maize-wheat- soybean-fallow rotation. Simulations were conducted with 100%, 50% and 0% sludge (C—N ratio of 12). With fertilizer N augmenting the sludge, the total N input (250 kg/ha) was the same for each treatment. Mean yields were similar for 50% and zero sludge, but lowered by 10% and 16%, respectively, for maize and wheat with 100% sludge. Discrepancies in yields were attributed to the fact that mineralization rates of sludge are not high enough to supply the crop N requirement during periods of peak uptake. Nitrate leaching was reduced by 41 and 25% with 100 and 50% sludge applications, respectively. / Ph. D.

The movement of nitrogen from the surface, where it is applied as fertilizer, to groundwater is of importance due to the health concerns associated with nitrate and potential eutrophication of groundwater impacted surface water. The computer model, PRZM (Pesticide Root Zone Model) was used to simulate the transportation of nitrogen through the soil column, past the crop root zone to groundwater. Then MOC (Method of Characterization), a groundwater model, was used to transport the nitrogen that had reached the water table offsite. Results were compared to existing field data in an attempt to verify the validity of the simulation. / Master of Science