Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.

Submitted by FERNANDO VIEIRA COSTA GUIDORIZZI null (fernando_guidorizzi@hotmail.com) on 2016-05-02T19:07:11Z No. of bitstreams: 1 Fernando Guidorizzi - Dissertação Definitiva.pdf: 2781433 bytes, checksum: f56e6ea73314244bb7d600cdfc7a26d0 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-04T18:43:58Z (GMT) No. of bitstreams: 1 guidorizzi_fvc_me_bot.pdf: 2781433 bytes, checksum: f56e6ea73314244bb7d600cdfc7a26d0 (MD5) / Made available in DSpace on 2016-05-04T18:43:58Z (GMT). No. of bitstreams: 1 guidorizzi_fvc_me_bot.pdf: 2781433 bytes, checksum: f56e6ea73314244bb7d600cdfc7a26d0 (MD5) Previous issue date: 2016-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O cártamo é uma oleaginosa que vem despertando interesse na agricultura nacional, pois se apresenta como uma opção para o cultivo de segunda safra (outono-inverno). Entretanto, para expansão do cultivo de cártamo no Brasil faz-se necessário à realização de estudos abordando o seu crescimento e absorção de nutrientes nas suas fases de desenvolvimento, em diferentes condições de cultivo, pois o conhecimento sobre essas variáveis permitirá precisão na recomendação de adubação para a cultura. Assim, objetivou-se com este trabalho avaliar o acúmulo de matéria seca (MS) e de macronutrientes durante o ciclo, produtividade de grãos e exportação de macronutrientes por genótipos de cártamo em função da aplicação de nitrogênio (N) em cobertura, em sistemas plantio direto (SPD) com diferentes tempos de adoção. O experimento foi conduzido no município de Botucatu-SP, em um Nitossolo Vermelho distrófico. Foi adotado o delineamento em blocos casualizados no esquema de parcelas subdivididas, com quatro repetições. As parcelas foram compostas por oito tratamentos obtidos a partir da combinação de dois tempos adoção do SPD (SPDR - sistema plantio direto recém-implantado e SPDC - sistema plantio direto consolidado, com 28 anos desde a implantação), dois genótipos de cártamo (IMA 2234 e IMA 2237) e dois níveis de N em cobertura (0 e 100 kg ha-1). As subparcelas foram compostas por sete épocas de amostragens (de 22 dias após a emergência (DAE) até o final do ciclo da cultura). Ambos os genótipos de cártamo tiveram lento acúmulo de MS e macronutrientes durante o estádio de roseta (0 a 22 DAE). A partir desse estádio até o início do enchimento de grãos (entre 84 e 111 DAE) ocorreu o período de maior crescimento e acúmulo de macronutrientes pela cultura. O genótipo IMA 2234 apresentou maiores quantidades de MS, N, P, K e S acumuladas na parte aérea. A adubação nitrogenada de cobertura influenciou, principalmente, a absorção de N. Os componentes da produção, a produtividade de grãos e a exportação de macronutrientes não foram influenciados pelos genótipos, tempos de adoção do SPD ou adubação nitrogenada. A extração de macronutrientes, na média dos tratamentos, foi: K (168 kg ha-1) > N (149 kg ha-1) > Ca (125 kg ha-1) > S (15 kg ha-1) > Mg (14 kg ha-1) > P (13 kg ha-1). A exportação de macronutrientes pelos grãos seguiu a sequência, na média dos tratamentos: N (44 kg ha-1) > K (12 kg ha-1) > Ca (6 kg ha-1) > P (4 kg ha-1) > Mg (3 kg ha-1) > S (2 kg ha-1). / Safflower is an oilseed that has attracted national interest in agriculture, as is presented as an option for the second-crop cultivation (fall-winter). However, for expansion of safflower cultivation in Brazil is a need for studies addressing their growth and nutrient uptake in their stages of development in different growth conditions, as the knowledge of these variables will enable precision in fertilizer recommendation for the crop. Therefore, the aim was to evaluate the accumulation of dry matter (DM) and macronutrients over the cycle, grain yield, and macronutrient removal by safflower genotypes as affected by sidedressed nitrogen (N) fertilization in no-till system (NTS) with different adoption times. The experiment was conducted in Botucatu-SP, in a Typic Rhodudalf soil. It was adopted a randomized block design in a split-plot scheme with four replications. The plots were composed by eight treatments obtained from the combination of two adoption times of the NTS (NNTS - a newly implemented no-tillage system and ENTS - an established no-till system, with 28 years since the establishment), two safflower genotypes (IMA 2234 and IMA 2237) and two levels of sidedressed N fertilization in topdressing (0 and 100 kg ha-1). The subplots were composed of seven sampling dates (from 22 days after emergence (DAE) by the end of the cycle). Both safflower genotypes had slow accumulation of DM and macronutrients during the rosette stage (0-22 DAE). From this stage until the early grain filling (between 84 and 111 DAE) was the period of greatest growth and accumulation of macronutrients by crop. The genotype IMA 2234 have higher amounts of DM, N, P, K and S accumulated in the shoot. Sidedressed N fertilization influenced mainly N uptake. The yield components, grain yield, and nutrient removal were not influenced by genotype, adoption times of the NTS or sidedressed N fertilization. The uptake of macronutrient was, on average of treatments: K (168 kg ha-1) > N (149 kg ha-1) > Ca (125 kg ha-1) > S (15 kg ha-1) > Mg (14 kg ha-1) > P (13 kg ha-1). The removal of macronutrients by grains followed the sequence, on average of treatments: N (44 kg ha-1) > K (12 kg ha-1) > Ca (6 kg ha-1) > P (4 kg ha -1) > Mg (3 kg ha-1) > S (2 kg ha-1). / FAPESP: 2014/20301-8

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The pig slurry, pig deep-litter and cattle slurry applied in soils under no-tillage can serve as a source of nutrients for crops, increasing the production of dry matter of shoots and grain production. This is because, successive applications in the long term tend to change the soil chemical properties making it favorable for the development of agricultural crops, if handled properly. Moreover, these applications continued on the same area can promote the accumulation of nutrients in cultivated soils. Thus, there may be the transport of nutrients such as nitrogen (N) and phosphorus (P) to aquatic environments through runoff and or percolation, causing environmental imbalances. This aim of this study was to analyze the influence of continuous application of organic and mineral nutrient sources on grain yield and nutrient accumulation in crops and evaluate the changes in soil chemical properties and the transfer of nitrogen and phosphorus runoff and percolation under no-tillage. For this, two studies were developed: Study I aimed to evaluate, in the long term, the distribution of nutrients in the soil profile and the productivity of grain crops and ground cover plants when subjected to successive applications of organic and mineral sources nutrients. This study was conducted in a Typic Hapludalf with pig slurry applications (PS), cattle slurry (CS), pig deep-litter (PL) and mineral fertilizers (NPK) before the implementation of each of the succession culture: corn/oats in the years 2009/2010; 2010/2011 and 2011/2012 and in the year 2012/13 black oat /black beans. The study II aimed to evaluate transfers of forms of N and P by the drained solution and percolated in the same area subjected to successive applications of organic and mineral nutrient sources managed under no-tillage. In this experiment, samples were collected drained and leached solution and determined the total N, P-soluble P-particulate and P-total. The results obtained demonstrate that the CSS provided increment, both in the production of grain and dry matter accumulation and apparent recovery of N, P and K of cultures. The highest dry matter production of cultivated species and applications of different organic sources of nutrients promoted increase in levels of soil organic matter while allowing an increase in soil pH. Also provided the increase in important soil properties, such as the P, K, Ca and Mg available in the soil, in relation to the use of traditional mineral fertilization. The data showed that successive applications provide greater total-N transfer, surface runoff and percolation in the soil under the application of DLS and CSS. The largest transfers of P were observed in treatments with application of DLS, DLB and CSS in drained and leached solution. Therefore, it is essential to constantly monitor the quantities of organic and mineral sources added in crops, as well as the losses of N and P incurred pursuant to excess and / or in the same area, as these parameters are relevant when it aims to productivity and sustainability of agro-ecosystems. / Os dejetos líquidos de suínos e bovinos e a cama sobreposta de suínos aplicadas em solos sob plantio direto podem servir como fonte de nutrientes às culturas agrícolas, incrementando a produção de matéria seca da parte aérea e a produtividade de grãos. Isso ocorre, pois as aplicações sucessivas em longo prazo tendem a alterar os atributos químicos do solo, tornando-o favorável para o desenvolvimento das culturas agrícolas, se manejado adequadamente. Por outro lado, essas aplicações continuadas sobre uma mesma área pode promover o acúmulo excessivo de nutrientes nos solos cultivados. Dessa forma, pode ocorrer o transporte de nutrientes, como o nitrogênio (N) e fósforo (P), para ambientes aquáticos por meio do escoamento superficial e/ou percolação, causando desequilíbrios ambientais. O presente estudo objetivou analisar a influência da aplicação continuada de fontes orgânicas e mineral de nutrientes sobre a produtividade de grãos e acúmulo de nutrientes em culturas, avaliar as alterações nos atributos químicos do solo e a transferência de nitrogênio e fósforo por escoamento superficial e percolação em um Argissolo sob sistema plantio direto. Para isso, foram desenvolvidos dois estudos: O Estudo I objetivou avaliar, a distribuição de nutrientes no perfil do solo e a produtividade das culturas de grãos e plantas de cobertura, quando submetido a aplicações sucessivas de fontes orgânicas e mineral de nutrientes. Este estudo foi desenvolvido em um Argissolo Vermelho Distrófico arênico com aplicações de dejeto líquido de suínos (DLS), cama sobreposta de suínos (CSS), dejeto líquido de bovinos (DLB) e adubação mineral (NPK) antes da implantação de cada cultura da sucessão: milho/aveia preta, nos anos de 2009/2010; 2010/2011 e 2011/2012 e no ano de 2012/13 feijão preto/aveia preta. Para as culturas de milho e feijão foi avaliada a produtividade de grãos e, para todas as culturas, foi determinada a produção de matéria seca da parte aérea e o acumulo de N, P e K no tecido vegetal. Em setembro de 2012, quando completou 12 aplicações das fontes orgânicas, amostras de solo foram coletadas nas camadas 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 cm. Determinou-se o valor de pH em água (relação 1:1), os teores disponíveis de P, Cu e Zn, teores trocáveis de K, Al, Ca e Mg e os teores de matéria orgânica do solo. Calculou-se a CTCpH7,0, a saturação por Al, a saturação por bases e a acidez potencial (H+Al). O estudo II visou avaliar as transferências de formas de N e P pela solução escoada e percolada na mesma área submetida às aplicações sucessivas de fontes orgânica e mineral de nutrientes manejado sob sistema plantio direto. Nesse experimento foram coletadas amostras de solução escoada e percolada e determinado os teores de N-mineral, P-solúvel, P-particulado e P-total. Os resultados demostram que a CSS proporcionou incremento, tanto na produtividade de grãos quanto de matéria seca, acúmulo e recuperação aparente de N, P e K das culturas. As maiores produções de matéria seca das espécies cultivadas e as aplicações das diferentes fontes orgânicas de nutrientes promoveram incremento nos teores da matéria orgânica do solo ao mesmo tempo que permitiu um aumento no pH do solo. Além disso, proporcionou o incremento em atributos importantes do solo, tais como: nos teores P, K, Ca e Mg disponíveis no solo, em relação ao uso da adubação mineral tradicional. Os dados mostraram que as aplicações sucessivas proporcionam maior transferência de N-mineral, por escoamento superficial e percolação no solo submetido à aplicação de DLS e CSS. As maiores transferências de P foram observadas nos tratamentos com aplicação de DLS, DLB e CSS na solução escoada e percolada. Portanto, é imprescindível o monitoramento constante das quantidades de fontes orgânicas e mineral adicionadas nas lavouras, assim como, das perdas de N e P ocasionadas pela aplicação em excesso e/ou na mesma área, já que esses parâmetros são relevantes quando se almeja produtividade e sustentabilidade dos agroecossistemas.

Water availability and arable lands are increasingly limiting resources in many parts of the U.S., particularly in semi-arid and arid regions. As a means of addressing food and fuel demands associated with burgeoning population growth, highly productive and water-use efficient crops need to be identified. One potential crop, Agave, merits consideration and evaluation due to its putative capability to provide sustenance and energy despite growing in water-limited regions and on marginal soils. However, little is known regarding the productivity these succulent plants will have under growing conditions of the Southwest, where high concentrated saline soils are abundant, and water is often limited. The objectives of these studies were to determine the effects of high levels of salinity and different volumetric water content levels (VWC) on plant growth, biomass accumulation, and nutrient uptake. I used a hydroponic study to compare the effects of four salinity treatments (0.5, 3, 6, and 9 dS m-1) on productivity of four Agave species (Agave parryi, Agave utahensis ssp. kaibabensis, Agave utahensis ssp. utahensis, and Agave weberi). In a second study, an automated irrigation system was established to examine four pre-determined VWC threshold set-points and simulated a gradient of well-watered to drought conditions, to evaluate how A. weberi would respond to varying levels of water availability. Salinity concentrations did not significantly affect root and plant dry weight accumulation in A. weberi, but all other agave plants experienced less biomass accumulation under high saline conditions (>6 dS m-1). Seedlings of A. utahensis were two times more likely to die in the two highest saline treatments (6 and 9 dS m-1) than the two lower treatments (0.5 dS m-1 and 3 dS m-1). Calcium, Mg, S, Mn levels decreased in both A. parryi and A. weberi at higher salinity levels. Agave weberi was able to tolerate salinity, but it also experienced lower biomass production ≤3 dS m-1. In the water-stress study, Agave weberi plants experienced a decrease of 2.11 g as compared to plants in the highest treatment. Plants in the intermediate VWC treatments had similar dry mass values as those in the highest treatment, which suggests that this species could have moderately high yields under limited water conditions, and consequently should be evaluated as a potential bioenergy crop for semi-arid regions, such as the U.S. Southwest. Agave shows considerable potential to be grown in arid and semi-arid regions that are moderately high in salinity and have limited water availability. Indeed, the cultivation of Agave as a crop appears to be a viable option for many areas of the Southwest. While some of the Agave species evaluated were quite productive under moderate salt and water stress, it is uncertain if growth will be significantly reduced if under these stress conditions for periods longer than 3 months.

Environmental contamination issues related to phosphorus (P) in surface waters substantiates the need to identify minimally-sufficient P fertilization amounts for production of containerized nursery crops and better understand the effect of routine amendments (i.e., dolomite [DL] and micronutrient fertilizer [MF]) added to pine bark substrates on chemical fate of P fertilizer. Four studies were conducted to accomplish two overarching objectives: 1) determine the minimum P fertilization amount and corresponding pore-water P concentration needed to achieve maximal growth of common containerized nursery crops and 2) determine the effect of DL and MF amendments in pine bark on P retention during irrigation and P fractions in substrate pore-water. In a fertigation, greenhouse study, calculated lowest P-fertilizer concentration that sustained maximal growth in Hydrangea paniculata ‘Limelight’ (panicle hydrangea) and Rhododendron ‘Karen’ (azalea) was 4.7 and 2.9 mg·L⁻¹ , respectively, and shoot growth Ilex crenata ‘Helleri’ (holly) was the same when fertilized with 0.5 to 6.0 mg·L⁻¹ P. Porewater P concentrations corresponding with treatments that sustained maximal growth of panicle hydrangea, azalea and holly were as low as 0.6, 2.2 and 0.08 mg·L⁻¹ P, respectively. In a separate study, utilizing low-P controlled-release fertilizers (CRFs), shoot growth of Hydrangea macrophylla ‘P11HM-11’ (bigleaf hydrangea) produced in two ecoregions was maximal when fertilized with as little as 0.3 g CRF-P per 3.8-L container, a 50% P reduction from the industrystandard CRF. Holly required 0.2 or 0.4 g CRF-P depending on ecoregion. Mean pore-water P concentrations that corresponded with highest SDW were 0.8 and 1.2 mg·L⁻¹ for hydrangea and holly, respectively. When irrigating fallow pine bark columns containing CRF for 48 d, amending pine bark with DL and MF reduced orthophosphate-P (OP-P) leachate concentrations by ≈ 70%, most of which was retained within the substrate. In a greenhouse study, containerized Lagerstroemia ‘Natchez’ (crape myrtle) were grown for 91 d in pine bark containing CRF. In pine bark amended with DL and MF, pore-water OP-P and total P concentrations, measured approximately weekly, were reduced by, on average, 64% and 58%, respectively. Total dry weight values of plants grown with DL plus MF or MF-only were 40% higher than those grown with no amendments; however, tissue P amounts and relative P uptake efficiency were the same among plants in these three treatments. Therefore, sorption of OP-P by DL and MF reduced water-extractable OP-P but did not limit P uptake by plants. / Ph. D. / Phosphorus (P) pollution of surface waters is a global issue that has led to widespread fish kills, drinking water contamination and disruption of aquatic ecosystems. Nutrient runoff from agricultural sites is among the leading contributors to P loads in impaired waters. Optimizing P fertilization for containerized nursery crop production is particularly challenging since the primary soilless substrates used to grow containerized crops retain P poorly. Consequently, much of the applied P leaches from containers during irrigation. Reducing amounts of applied P fertilizer and amending substrates (e.g., pine bark) with P-sorbing materials are two methods previously shown to reduce P leaching and increase the proportion of applied P that is absorbed by containerized plants. Four studies were conducted to accomplish two overarching objectives: 1) determine the minimum P fertilization amount necessary for maximal growth of common containerized nursery crops and 2) determine the effect of dolomite (DL) and micronutrient fertilizer (MF) amendments in pine bark on P retention during irrigation. Our findings indicated that P fertilization requirements of woody ornamental crops is species-dependent. When using liquid fertilizer, Japanese holly and evergreen azalea achieved maximal growth when P fertilizer concentrations were reduced by 90% and 40%, respectively, compared to current recommendations. In contrast, the current minimum fertilizer recommendation of 5 ppm P was optimal for panicle hydrangea. In a subsequent study in which containerized woody ornamentals were grown using low-P controlled-release fertilizers (CRFs), bigleaf hydrangea reached maximal growth when given CRFs containing 50% less P than amounts in conventional CRFs. Considering hydrangea and azalea are among the top woody ornamental shrubs produced in the US, using fertilizers with minimally sufficient P amounts for these species could greatly reduce P runoff from nursery sites. Results of two studies conducted to achieve the second aforementioned objective indicated that amending CRF-fertilized pine bark with DL and MF can reduce water-extractable total P concentrations by > 50%. Despite lower levels of plant-available P in the substrate, P uptake by crape myrtle was unaffected by the amendments. The DL was primarily responsible for P retention in pine bark; however, the addition of MF was needed for maximal growth and P uptake of crape myrtle. According to this research, amending pine bark with DL and MF could be considered a best management practice for reducing P leaching from containerized crops.

Made available in DSpace on 2017-07-25T19:29:46Z (GMT). No. of bitstreams: 1 Helio Antonio Wood Joris.pdf: 1043981 bytes, checksum: 109199b60a4616b0e907e5a0a8e16d26 (MD5) Previous issue date: 2011-02-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The effects of soil acidity in a no-till system need to be further investigated under drought. The corn performance in response to surface application of lime, as affected by aluminum genotypic tolerance and soil moisture was evaluated in a sandy clay loam Typic Hapludox, in Ponta Grossa, Parana State, Brazil. The study was carried out in a field experiment and in undisturbed soil columns. In a field experiment, the changes in soil chemical attributes at 0-5, 5-10, 10-20, 20-40 and 40-60 cm depths, and the nutrition, export and nutrient uptake, above ground biomass and grain yield of corn in 2008-2009 were evaluated after surface application of lime at rates of 0, 4, 8 and 12 t ha-1 in 2004, in a randomized complete block with three replications. Undisturbed soil columns were removed from plots that received lime rates, and another experiment was carried out on them, testing two hybrids, one aluminum-sensitive and another moderately sensitive to aluminum, and two moisture levels, simulating the presence and absence of water stress. Surface liming ameliorated soil acidity in all depths studied, and improved root environment throughout profile. Corn root growth was influenced by lime application, mainly at 0-10 cm depth. Liming had a positive effect on nutrition, export and nutrient uptake, resulting in a significant increase in corn grain yield. In the undisturbed columns, soil amendment by surface liming benefited root growth, nutrient uptake and dry matter production of corn plants, mainly in a water stress condition. In general, there was no difference in the response of both sensitive hybrid and moderately sensitive hybrid to aluminum toxicity with liming. It is concluded that the corn crop performance is ameliorated by the reduction in soil acidity through surface liming under no-till, but the corn crop development is little influenced by soil acidity when water availability is adequate. However, in a water stress condition, the soil acidity severely compromises the corn crop development under no-till system. The effects of soil acidity in a no-till system need to be further investigated under drought. The corn performance in response to surface application of lime, as affected by aluminum genotypic tolerance and soil moisture was evaluated in a sandy clay loam Typic Hapludox, in Ponta Grossa, Parana State, Brazil. The study was carried out in a field experiment and in undisturbed soil columns. In a field experiment, the changes in soil chemical attributes at 0-5, 5-10, 10-20, 20-40 and 40-60 cm depths, and the nutrition, export and nutrient uptake, above ground biomass and grain yield of corn in 2008-2009 were evaluated after surface application of lime at rates of 0, 4, 8 and 12 t ha-1 in 2004, in a randomized complete block with three replications. Undisturbed soil columns were removed from plots that received lime rates, and another experiment was carried out on them, testing two hybrids, one aluminum-sensitive and another moderately sensitive to aluminum, and two moisture levels, simulating the presence and absence of water stress. Surface liming ameliorated soil acidity in all depths studied, and improved root environment throughout profile. Corn root growth was influenced by lime application, mainly at 0-10 cm depth. Liming had a positive effect on nutrition, export and nutrient uptake, resulting in a significant increase in corn grain yield. In the undisturbed columns, soil amendment by surface liming benefited root growth, nutrient uptake and dry matter production of corn plants, mainly in a water stress condition. In general, there was no difference in the response of both sensitive hybrid and moderately sensitive hybrid to aluminum toxicity with liming. It is concluded that the corn crop performance is ameliorated by the reduction in soil acidity through surface liming under no-till, but the corn crop development is little influenced by soil acidity when water availability is adequate. However, in a water stress condition, the soil acidity severely compromises the corn crop development under no-till system. / Os efeitos da acidez do solo em sistema plantio direto precisam ser mais investigados em situações de seca. O comportamento da cultura do milho em resposta à aplicação superficial de calcário, considerando a tolerância genotípica ao alumínio e a umidade do solo foi avaliado em um estudo realizado em Latossolo Vermelho distrófico textura média, em Ponta Grossa (PR). O trabalho foi realizado em área experimental no campo e em colunas indeformadas de solo, coletadas na mesma área experimental. No campo, após a aplicação superficial de calcário em 2004, nas doses 0, 4, 8 e 12 t ha-1, em um delineamento de blocos completos ao acaso com 3 repetições, avaliaram-se as alterações nos atributos químicos do solo nas profundidades de 0-5, 5-10, 10-20, 20-40 e 40-60 cm, o crescimento radicular, a nutrição e extração de nutrientes, a massa seca da parte aérea e a produção de grãos de milho, cultivado em 2008-2009. Nas parcelas que receberam as doses de calcário, foram retiradas colunas indeformadas de solo para a realização de outro experimento, o qual envolveu a utilização de dois híbridos, um sensível e outro moderadamente sensível ao alumínio, e dois níveis de umidade do solo, simulando ausência e presença de deficiência hídrica. A calagem superficial corrigiu a acidez do solo em todas as camadas estudadas e proporcionou melhoria no ambiente radicular em todo o perfil. O crescimento radicular do milho foi favorecido pela aplicação de calcário, principalmente na camada de 0-10 cm. A calagem exerceu efeito positivo sobre a nutrição e extração de nutrientes, refletindo em aumento da produção de grãos de milho. Nas colunas indeformadas de solo, a correção do solo pela calagem na superfície beneficiou o crescimento radicular, a extração de nutrientes e a produção de massa seca das plantas de milho, principalmente em situação de deficiência hídrica. Em geral, não houve diferença na resposta à calagem dos híbridos sensível e moderadamente sensível ao alumínio. Concluiu-se que a cultura do milho é beneficiada pela correção da acidez por meio da calagem na superfície em plantio direto, porém a acidez não exerce grande limitação no desenvolvimento da cultura quando há adequada disponibilidade hídrica. Em situação de restrição hídrica, entretanto, a acidez do solo prejudica severamente o desenvolvimento do sistema radicular e a produção da cultura do milho em sistema plantio direto.

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The potato (Solanum tuberosum L.) has great importance in human nutrition where it occupies the fourth place among the most consumed foods in the world. It is a highly demanding culture technology especially in the nutritional point of view. Despite the titanium (Ti) is not considered a nutrient, studies have shown beneficial effects of this element when applied to plants. The application of Ti leaf can be an alternative for this element is slightly movable in the soil and is generally present in insoluble forms. Thus, the objective was to evaluate the influence of application rates of Ti foliar in the potato crop. We conducted an experiment in the period from August to November 2014, installed at the experimental station Udi Pesquisa e Development in Uberlândia-MG, with kind Ágata. Variables related to metabolism were evaluated: SPAD chlorophyll content, nitrate reductase activity (NRA), lipid peroxidation (LP), urease, proline, catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD). Nutritional factors such as levels of nutrients nitrogen (N), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) present in leaves and tubers were measured stages of growth, tuber and tuber filling. At the end of the crop cycle was quantified the average mass, diameter, commercial classification and productivity of tubers. The design was a randomized block design with four replications and six treatments. The supply of the Ti compound fertilizer was through for 5% of magnesium oxide, 10% sulfur trioxide and 0,85% titanium complex and the treatments was: T1 - without the application of Ti, T2 -10.2; T3 - 15.3; T4 - 20.4; T5 - 22.9 and T6 - 25.5 g Ti ha-1 divided into three equal applications during the growth phase, tuber and tuber filling. It was concluded that in the growth phase the foliar application of Ti reduces the Mn content in the leaves and there is increased activity of POD and ANR and reduced urease activity. In the tuberization phase the Fe absorption, SOD activity and POD response to increasing Ti dose. In tubers filling stage foliar application of Ti increases chlorophyll levels (Spad value). The application of Ti in the leaf growth stages, tuber and tuber filler results in a lower Zn content in the tubers. The average tuber weight, the average diameter of tubers and the total productivity of tubers are affected by foliar application of Ti. The dose Ti foliar applied for further tuber yield is 5.74 g Ti ha-1. / A batata (Solanum tuberosum L.) tem grande importância na alimentação humana onde ocupa o quarto lugar entre os alimentos mais consumido no mundo. É uma cultura altamente exigente em tecnologias especialmente sob o ponto de vista nutricional. Apesar do titânio (Ti) não ser considerado um nutriente, trabalhos demonstram efeitos benéficos deste elemento quando aplicado às plantas. A aplicação de Ti foliar pode ser uma alternativa pois este elemento é pouco móvel no solo e geralmente está presente em formas insolúveis. Desta forma, objetivou-se avaliar a influência da aplicação de doses de Ti via foliar na cultura da batata. Realizou-se um experimento no período de agosto a novembro de 2014, instalado na estação experimental Udi Pesquisa e Desenvolvimento em Uberlândia-MG, com utilização da cultivar Ágata. As variáveis relacionadas ao metabolismo avaliadas foram: teor clorofila SPAD, atividade da nitrato redutase (ANR), peroxidação lipídica (PL), urease, prolina, catalase (CAT), superóxido desmutase (SOD) e peroxidase (POD). Aspectos nutricionais como os teores dos nutrientes nitrogênio (N), cobre (Cu), ferro (Fe), manganês (Mn) e zinco (Zn) presentes em folhas e tubérculos foram mensurados fases de crescimento, tuberização e enchimento de tubérculos. Ao final do ciclo da cultura foi quantificada a massa média, diâmetro médio, classificação comercial e a produtividade dos tubérculos. O delineamento foi o de blocos casualizados, com quatro repetições e seis tratamentos. O fornecimento do Ti foi através de fertilizante composto por 5% de óxido de magnésio, 10% de trioxido enxofre e 0,85% de complexo de titânio com os seguintes tratamentos: T1 sem aplicação de Ti, T2 -10,2; T3 -15,3; T4 - 20,4; T5 - 22,9 e T6 - 25,5 g de Ti ha-1 divididos em três aplicações iguais durante a fase de crescimento, tuberização e enchimento de tubérculos. Concluiu-se que os teores de Cu não são influenciados pelas doses de Ti nas fases avaliadas. Na fase de crescimento a aplicação foliar de Ti reduz o teor de Mn nas folhas e há aumento da atividade da POD e ANR e redução da atividade da urease. Na fase de tuberização a absorção de Fe e atividade de enzimas SOD e POD tem resposta ao aumento da dose de Ti. Na fase de enchimento de tubérculos a aplicação foliar de Ti incrementa os teores de clorofila (valor Spad). A aplicação de Ti foliar nas fases de crescimento, tuberização e enchimento de tubérculos resulta em menor teor de Zn nos tubérculos. A massa média de tubérculos, o diâmetro médio de tubérculos e a produtividade total de tubérculos são influenciados pela aplicação foliar de Ti. A dose de Ti aplicada via foliar para maior produtividade de tubérculos é de 5,74 g de Ti ha-1. / Mestre em Agronomia

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An experimental study was carried out to evaluate the performance of pilot scale constructed wetlands for the treatment of domestic wastewater in Addis Ababa, Ethiopia. Three parallel sets of constructed wetlands; consisting of one Horizontal Flow (HF), one Vertical Flow (VF) and one hybrid of HF and VFconstructed in series were built in Addis Ababa. The wetland systems had identical wetland fill media and macrophytes but with different wastewater flow types. The total surface area of the wetland systems was 72 m2 /24 m2 for each/ and designed to treat 3.15 m3 of domestic wastewater per day. Triplicate grab samples were taken from the influent and effluents every 15 days for one year and analyzed within 24 hours. Temperature, pH, DO and EC were measured onsite and the nutrient content of macrophytes was determined twice during the monitoring period. During the first 12 months monitoring period, the average removal efficiencies of the HFCW, VFCW and hybrid CW were: BOD (89.1%, 92.2% and 93.4%), COD (80.6%, 82.1% and 84.0%), TSS (89.1, 83.8% and 84.7%), NH4 + (58.6%, 66.2% and 65.4%), NO3 - (64.0%, 71.5% and 73.5%), TN (49.1%, 54.9% and 58.7%), PO4 3- (45.4%, 50.3% and 48.4%), TP (58.0%, 51.7% and 54.4%) and FC (98.6%, 96.6% and 96.5%), respectively. The hybrid system showed relatively higher removal efficiencies for most pollutants. Again, the wetland systems showed relatively higher percent reduction during the dry seasons /from Dec - May/. The areal removal rate constants of BOD5, TN, PO4 3- and TP were higher than the literature values while the values of COD and TSS were lower compared to the literature values. Concerning the nutrient content of the wetland plant, the average TN contents of the below-ground and above-ground plant part were 1.56% and 2.27% for the HFCW, 1.75% and 2.74% for the VFCW and 1.80% and 2.63% for the hybrid system, respectively. Meanwhile, the average TP contents of the belowground and above-ground plant part were 0.139% and 0.064% for the HFCW, 0.167% and 0.067% for the VFCW and 0.115% and 0.065% for the hybrid systems, respectively. In general, the results showed that properly designed constructed wetland systems could be used as effective wastewater treatment method in Ethiopia. / Environmental Sciences / Ph. D. (Environmental Sciences)